View FT234XD-R_9034032.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

copyright ? 201 5 future technology devices international limited 1 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 future technology devices international ltd . ft234xd ( usb to basic uart ic ) the ft234xd is a usb to serial uart interface with op timised packaging (3mm x 3mm 12 pin dfn) for smaller pcb designs and the following advanced features: ? single chip usb to asynchronous serial data transfer interface. ? entire usb protocol handled on the chip . no usb specific firmware programming required. ? f ully integrated 2048 byte m ulti - time - programmable (mtp) memory, storing device descriptors and cbus i/o configuration. ? fully integrated clock generation with no external crystal required plus optional clock output selection enabling a glue - less interface t o external mcu or fpga. ? data transfer rates from 300 baud to 3 mbaud (rs422 , rs485 , and rs232) at ttl levels . ? 512 byte receive buffer and 512 byte transmit buffer utilising buffer smoothing technology to allow for high data throughput. ? ftdis royalty - free virtual com port (vcp) and direct ( d2xx ) drivers eliminate the requirement for usb driver development in most cases. ? configurable cbus i/o pi n . ? transmit and receive led drive signals. ? uart interface support for 7 or 8 data bits, 1 or 2 stop bits and odd / even / mark / space / no parity ? synchronous and asynchronous bit bang interface options with rd# and wr# strobes . ? usb battery charg ing detection. allows for usb peripheral devices to detect the presence of a higher power source to enable improved charging . ? device supplied pre - programmed with unique usb serial number. ? usb power configurations; s upports bus - powered, self - powered and bus - powered with power switching ? integrated + 3.3v level converter for usb i/o . ? true 3.3v cmos drive output and ttl input ; operates down to 1v8 with external p ull ups . tolerant of 5v input. ? configurable i /o pin output drive strength ; 4 ma ( min) and 16 ma ( max) . ? integrated power - on - reset circuit. ? fully integrated avcc supply filtering - no external filter ing required. ? ua rt signal inversion option. ? + 5v single supply operation. ? internal 3 .3 v/1 .8 v ldo regulators ? low operating and usb suspend current ; 8ma (active - typ) and 70ua (suspend - typ) . ? uhci/ohci/ehci host controller compati ble . ? usb 2.0 full speed compatible. ? e xtended operating temperature range ; - 40 to 85 ? c . ? available in compact pb - free 12 p in dfn package (3mm x 3mm) rohs compliant. neither the whole nor any part of the information contained in, or the product described in this manual, may be adapted or re produced in any material or electronic form with out the prior written consent of the copyright holder. this product and its documentation are supplied on an as - is basis and no warranty as to their suitability for any particular purpose is either made or implied. future technology devices international l td will not accept any claim for damages howsoever arising as a result of use or failure of this product. your statutory rights are not affected. this product or any variant of it is not intended for use in any med ical appliance, device or system in which the failure of the product might reasonably be expected to result in personal injury. this document provides preliminary information that ma y be subject to change without notice. no freedom to use patents or other intellectual property rights is implied by the publication of this document. future technology devices international ltd, unit 1, 2 seaward place, centurion business park, glasgow g41 1hh united kingdom. scotland registered company number: sc136640
copyright ? 201 5 future technology devices international limited 2 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 1 typical applications ? usb to rs232/rs422/rs485 co nverters ? upgrading legacy peripherals to usb ? utilising usb to add system modularity ? incorporate usb interface to enable pc transfers for development system communication ? cellular and cordless phone usb data transfer cables and interfaces ? interfacing mcu/p ld/fpga based designs to add usb connectivity ? usb audio and low bandwidth video data transfer ? usb smart card readers ? usb instrumentation ? usb industrial control ? usb flash card reader and writers ? set top box pc - usb interface ? usb wireless modems ? usb bar co de readers ? usb dongle implementations for software / hardware encryption and wireless modules ? detection of dedicated charging port for battery charging at higher supply currents. 1.1 driver support royalty free virtual com port (vcp) drivers for... ? windows 10 32,64 - bit ? windows 8/8.1 32,64 - bit ? windows 7 32,64 - bit ? windows vista and vista 64 - bit ? windows xp and xp 64 - bit ? windows 98, 98s e, me, 2000, server 2003, xp, server 2008 and server 2012 r2 ? windows xp embedded ? windows ce 4.2, 5.0 and 6.0 ? mac os 8/9, os - x ? li nux 2.4 and greater royalty free d2xx dir ect drivers (usb drivers + dll s/w interface) ? windows 10 32,64 - bit ? windows 8/8.1 32,64 - bit ? windows 7 32,64 - bit ? windows vista and vista 64 - bit ? windows xp and xp 64 - bit ? windows 98, 98s e, me, 2000, server 2003, xp, server 2008 and server 2012 r2 ? windows xp embedded ? windows ce 4.2, 5.0 and 6.0 ? linux 2.4 and greater ? android(j2xx) the drivers listed above are all available to download for free from ftdi website ( www.ftdichip.com ) . various 3rd party drivers are also available for other operating systems - see ftdi website ( www.ftdichip.com ) for details. for driver ins tallation, please refer to http://www.ftdichip.com/documents/installguides.htm 1.2 part numbers part number package ft234xd - x 12 pin d fn note: packing codes for x is: - r: taped and reel - 5 ,000pcs per reel. - t : tray packing - 490pcs per tray .
copyright ? 201 5 future technology devices international limited 3 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 1.3 usb compliant the ft234xd is fully compliant with the usb 2.0 specification and has been given the usb - if test - id (tid) 40001465 (rev d).
copyright ? 201 5 future technology devices international limited 4 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 2 ft234xd block diagram figur e 2 . 1 ft234xd block diagram for a description of each function please refer to section 4. 3 . 3 v o l t l d o r e g u l a t o r 1 . 8 v o l t l d o r e g u l a t o r u s b t r a n s c e i v e r w i t h i n t e g r a t e d 1 . 5 k p u l l u p s a n d b a t t e r y c h a r g e d e t e c t i o n u s b d p l l i n t e r n a l 1 2 m h z o s c i l l a t o r x 4 c l o c k m u l t i p l i e r s e r i a l i n t e r f a c e e n g i n e ( s i e ) u s b p r o t o c o l e n g i n e u a r t f i f o c o n t r o l l e r u a r t c o n t r o l l e r w i t h p r o g r a m m a b l e s i g n a l i n v e r s i o n b a u d r a t e g e n e r a t o r r e s e t g e n e r a t o r f i f o t x b u f f e r ( 5 1 2 b y t e s ) f i f o r x b u f f e r ( 5 1 2 b y t e s ) i n t e r n a l m t p m e m o r y 4 8 m h z g n d r e s e t # t o u s b t r a n s c e i v e r c e l l 3 v 3 o u t 4 8 m h z 3 v 3 o u t v c c u s b d p u s b d m 1 v 8 i n t e r n a l c o r e s u p p l y t x d r x d r t s # c t s # c b u s 0
copyright ? 201 5 future technology devices international limited 5 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 table of contents 1 typical applications ................................ ................................ ...... 2 1.1 driver support ................................ ................................ .................... 2 1.2 part numbers ................................ ................................ ...................... 2 1.3 usb compliant ................................ ................................ .................... 3 2 ft234xd block diagram ................................ ............................... 4 3 device pin out and signal description ................................ .......... 7 3.1 12 - pin dfn package ................................ ................................ .......... 7 3.1.1 dfn package pinout d escription ................................ ................................ .................... 7 3.2 cbus signal options ................................ ................................ ........... 9 4 function description ................................ ................................ ... 11 4.1 key features ................................ ................................ ..................... 11 4.2 functional block descriptions ................................ ........................... 11 5 devices characteristics and ratings ................................ ........... 14 5.1 absolute maximum ratings ................................ ............................... 14 5.2 dc characteristics ................................ ................................ ............. 15 5.3 mtp memory reliability characteristics ................................ ............ 19 5.4 internal clock characteristics ................................ ........................... 19 6 usb power configurations ................................ .......................... 20 6.1 usb bus powered con figuration ................................ ...................... 20 6.2 self powered configuration ................................ .............................. 21 6.3 usb bus powered with power switching configuration .................... 22 7 application examples ................................ ................................ . 23 7.1 usb to rs232 converter ................................ ................................ ... 23 7.2 usb to rs485 coverter ................................ ................................ ..... 24 7.3 usb to rs422 converter ................................ ................................ ... 25 7.4 usb battery charging detection ................................ ....................... 26 7.5 led interfac e ................................ ................................ .................... 27 8 internal mtp memory configuration ................................ ........... 28 8.1 default values ................................ ................................ .................. 28 8.2 methods of programming the mtp memory ................................ ....... 29 8.2.1 prog ramming the mtp memory over usb ................................ ................................ ...... 29 8.3 memory map ................................ ................................ ..................... 30 9 package parameters ................................ ................................ ... 31 9.1 dfn - 12 package mechanical dimensions ................................ .......... 31 9.2 dfn - 12 package markings ................................ ................................ 32
copyright ? 201 5 future technology devices international limited 6 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 9.3 solder reflow profile ................................ ................................ ........ 33 10 contact information ................................ ................................ ... 34 appendix a C references ................................ ................................ ........... 35 appendix b - list of figure s and tables ................................ ..................... 36 appendix c - revision history ................................ ................................ .... 37
copyright ? 201 5 future technology devices international limited 7 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 3 device pin out and signal description 3.1 12 - pin dfn package figure 3 . 1 dfn schematic symbol 3.1.1 dfn package pinout description note : # denotes an active low signal. pin no. name type description 4 ** vcc power input 5 v (or 3 .3v ) supply to ic 9 vccio power inpu t 1 .8 v C 3 .3 v supply for the io cells 3 ** 3 .3 vout power output 3 .3 v output at 50ma. may be used to power vccio . when vcc is 3 .3 v; pin 3 is an input pin and should be connected to pin 4 . 5 , 13 gnd power input 0v ground input. table 3 . 1 power and ground * pin 13 is the centre pad under the ic. connect to gnd. * * if vcc is 3 .3 v then 3 .3 vout must also be driven with 3 .3 v input v c c i o 9 g n d 5 r t s # 8 c t s # 1 1 u s b d p 1 2 u s b d m 1 3 v 3 o u t 3 r e s e t # 2 v c c 4 c b u s 0 6 1 3 t x d 7 r x d 1 0 g n d
copyright ? 201 5 future technology devices international limited 8 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 pin no. name type description 1 usb dm input /output usb data signal minus. 12 usb dp input /output usb data signal plus. 2 reset# input reset input (active low). table 3 . 2 common function pins pin no. name type description 7 txd output transmit asynchronous data output. 10 rxd input re ceiving asynchronous data input. 8 rts# output request to send control output / handshake signal. 11 cts# input clear to send control input / handshake signal. 6 cbus0 i/o configurable cbus i/o pin. function of this pin is configured in the device mtp m emory . t he default configuration is txden . see cbus signal options, table 3 . 4 . table 3 . 3 uart interface and cbus group (see note 1 ) notes: 1 . when used in input mod e, the input pins are pulled to vccio via internal 75 k ( approx. ) resistors. these pins can be programmed to gently pull low during usb suspend (pwren# = 1) by se tting an option in the mtp memory .
copyright ? 201 5 future technology devices international limited 9 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 3.2 cbus signal options the following options can be configured on the cbus0 i/o pin . these options can be configured in the internal mtp memory using the software utility ft_p rog which can be downloaded from the ftd i utilities ( www.ftdichip.com ) . the default configuration is described in s ection 8 . cbus signal option cbus pin description tri - state cbus0 io pad is tri - stated drive 1 cbus0 output a constant 1 drive 0 cbus0 output a constant 0 txden cbus0 enable transmit data for rs485 pwren# cbus0 output is low after the device has been configured by usb, then high during usb suspend mode. this output can be used to control power to external logic p - channel logic level mosfet switch. enable the interface pull - down option when using the pwren# in this way. txled# cbus0 transmit data led drive C pulses low when transmitting data via usb. see section 7.5 for more details. rxled# cbus0 receive data led drive C pulses low when receiving data via usb. see section 7.5 for more details. tx&rxled# cbus0 led drive C pulses low when transmitting or rec eiving data via usb. see section 7.5 for more details. sleep# cbus0 goes low during usb suspend mode. typically used to power down an external ttl to rs232 level converter ic in usb to rs232 converter designs. clk24 mhz cbus0 24 mhz clock output.* clk12 mhz cbus0 12 mhz clock output.* clk6 mhz cbus0 6 mhz clock output.* gpi o cbus0 cbus bit bang mode option. allows the cbus pin to be used as general purpose i/o. configured in the internal mtp memory . a separate application note, an232r - 01 , available from ftdi website ( www.ftdichip.com ) describes in more detail how to use cbus bit bang mode. bcd charger cbus0 battery c harg ing detect ion indicates when the device is connected to a dedicated battery charger host. active high output. bcd charger # cbus0 inverse of bcd charger bitbang_wr# cbus 0 synchronous and asynchronous bit bang mode wr# strobe output. bitbang_rd# cbus0 synchronous and asynchronous bit bang mode rd# strobe output. vbus sense cbus0 input to detect when vbus is present. time stamp cbus0 toggle signal which changes state eac h time a usb
copyright ? 201 5 future technology devices international limited 10 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 cbus signal option cbus pin description sof is received keep_awake# cbus0 prevents the device from entering suspend state when unplugged. table 3 . 4 cbus configuration control *when in usb suspend mode the outputs clocks are also susp ended.
copyright ? 201 5 future technology devices international limited 11 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 4 function description the ft234xd is a compact usb to a basic serial uart interface device which simplifies usb implementations in a small optimised package . the device reduces external component count by fully integrating an mtp memory , and an integ rated clock circuit which requires no external crystal. it has been designed to operate efficiently with usb host controller s by using as little bandwidth as possible when compared to the total usb bandwidth available . 4.1 key features functional integration . fully integrated mtp memory , clock generation, avcc filtering, power - on - reset ( por ) and ldo regulator s . configurable cbus i/o pin options. the fully integrated mtp memory allows configuration of the control bus (cbus) functionality and drive strength sel ection. there is one cbus i/o pin cbus0 . the configurable options of cbus0 are detailed in section 3. 2 the cbus line can be configured with any one of these output options by setting bits in the internal mtp memory . the device is s hipped with the most comm only used pin definitions pre - programmed - see section 8 for details. asynchronous bit bang mode with rd# and wr# strobes. the ft234xd supports ftdis previous chip generation bit - bang mode. in bit - bang mode, th e four uart lines can be switched from the regular interface mode to a 4 - bit general purpose i/o port. data packets can be sent to the device and they will be sequentially sent to the interface at a rate controlled by an internal timer (equivalent to the b aud rate pre - scalar ). either t he internal rd# or the internal wr# strobe signal can mapped to the cbu s0 pin (only one cbus pin available) which can be used to allow external logic to be clocked by access to the bit - bang i/o bus. this option will be describ ed more fully in a separate application note available from ftdi website ( www.ftdichip.com ) . synchronous bit bang mode. the ft234xd supports synchronous bit bang mode. this mod e differs from asynchronous bit bang mode in that the interface pins are only read when the device is written to. this makes it easier for the controlling program to measure the response to an output stimulus as the data returned is synchronous to the outp ut data. an application note, an232r - 01 , available from ftdi website ( www.ftdichip.com ) describes this feature. source power and power consumption . the ft234xd is capable of operating at a voltage supply between + 3.3 v and +5 .25 v with a nominal operational mode current of 8 ma and a nominal usb suspend mode current of 125 a. this allows greater margin for peripheral designs to meet the usb suspend mode current limit of 2.5ma . an integrated level converter within the uart interface allows the ft234xd to interface to uart logic running at +1.8v to +3.3v (5v tol erant ). 4.2 functional block descriptions the following paragraphs detail each function within the ft234xd . please refer to the block diagram shown in figure 2.1 internal mtp memory . the internal mtp memory in the ft234xd is used to store usb vendor id (vid), product id (pid), device serial numbe r, product description string and various other usb configuration descriptors. the internal mtp memory is also used to configure the cbus pin functions. the ft234xd is supplied with the internal mtp memory pre - programmed as described in section 8 . a user area of the internal mtp memory is available to system designers to allow storing additional data from the user application over usb . the internal mtp memory descriptors can be programmed in circuit, over usb wi thout any additional voltage requirement. the descriptors can be programmed using th e ftdi utility software called ft_ prog, which can be downloaded from ftdi utilities on the ftdi website ( www.ftdichip.com ) . +3.3v ldo regulator. the +3.3v ldo regulator generates the +3.3v reference voltage for driving the usb transceiver cell output buffers. it requires an external deco upling capacitor to be attached to the 3v3out regulator output pin. it also provides +3.3v power to the 1.5k internal pull up resistor on usbdp. the main function of the ldo is to power the usb transceiver and the reset generator cells rather than to powe r external logic. however, it can be used to supply external circuitry requiring a +3.3v nominal supply with a maximum current of 50ma. +1.8 v ldo regulator. the + 1.8 v ldo regulator generates the + 1.8 v reference voltage for internal use driving the ic core functions of the serial interface engine and usb protocol engine.
copyright ? 201 5 future technology devices international limited 12 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 usb transceiver. the usb transceiver cell provides the usb 1.1 / usb 2.0 full - speed physical interface to the usb cable. the output drivers provide +3.3v level slew rate control signalling, whilst a differential input receiver and two single ended input receiv ers provide usb data in, single - ended - 0 (se0) and usb reset detection conditions respectfully. this function also incorporates a 1.5k pull up resistor on usbdp. the block also detects when connected to a usb power supply which will not enumerate the devic e but still supply power and may be used for battery charging . usb dpll. the usb dpll cell locks on to the incoming nrzi usb data and generates recovered clock and data signals for the serial interface engine (sie) block. internal 12mhz oscillator - the in ternal 12mhz oscillator cell generates a 12mhz reference clock. this provides an input to the x4 clock multiplier function. the 12mhz oscillator is also used as the reference clock for the sie, usb protocol engine and uart fifo controller blocks. clock mul tiplier / divider. the clock multiplier / divider takes the 12mhz input from the internal oscillator function and generates the 48mhz, 24mhz, 12mhz and 6mhz reference clock signals. the 48mz clock reference is used by the usb dpll and the baud rate generat or blocks. serial interface engine (sie). the serial interface engine (sie) block performs the parallel to serial and serial to parallel conversion of the usb data. in accordance with the usb 2.0 specification, it performs bit stuffing/un - stuffing and crc5 /crc16 generation. it also verifies the crc on the usb data stream. usb protocol engine. the usb protocol engine manages the data stream from the device usb control endpoint. it handles the low level usb protocol requests generated by the usb host controll er and the commands for controlling the functional parameters of the uart in accordance with the usb 2.0 specification chapter 9. fifo r x buffer (512 bytes). data sent from the usb host controller to the uart via the usb data out endpoint is stored in the fifo rx (receive) buffer. data is removed from the buffer to the uart transmit register under control of the uart fifo controller. (rx relative to the usb interface). fifo t x buffer (512 bytes). data from the uart receive register is stored in the t x buffe r . the usb host controller removes data from the fifo tx buffer by sending a usb request for data from the device data in endpoint. (tx relative to the usb interface). uart fifo controller. the uart fifo controller handles the transfer of data between the fifo rx and tx buffers and the uart transmit and receive registers. uart controller with programmable signal inversion and high drive. together with the uart fifo controller the uart controller handles the transfer of data between the fifo rx and fifo tx b uffers and the uart transmit and receive registers. it performs asynchronous 7 or 8 bit parallel to serial and serial to parallel conversion of the data on the rs232 (or rs422 or rs485) interface. control signals supported by uart mode include rts, cts. t he uart controller also provides a transmitter enable control signal pin option ( txden ) to assist with interfacing to rs485 transceivers. rts/cts and x on / x off handshaking options are also supported. handshaking is handled in hardware to ensure fast respo nse times. the uart interface also supports the rs232 break setting and detection conditions. additionally, the uart signals can each be individually inverted and have a configurable high drive strength capability (using ft_prog) . both these features are configurable in the mtp memory . baud rate generator - the baud rate generator provides a 16x clock input to the uart controller from the 48mhz reference clock. it consists of a 14 bit pre - scalar and 3 register bits which provide fine tuning of the baud ra te (used to divide by a number plus a fraction or sub - integer). this determines the baud rate of the uart, which is programmable from 183 baud to 3 mbaud. the ft234xd supports all standard baud rates and non - standard baud rates from 183 baud up to 3 mbau d. achievable non - standard baud rates are calculated as follows - baud rate = 3000000 / (n + x ) where n can be any integer between 2 and 16,384 ( = 2 14 ) and x can be a sub - integer of the value 0, 0.125, 0.25, 0.375, 0.5, 0.625, 0.75, or 0.875. wh en n = 1, x = 0, i.e. baud rate divisors with values between 1 and 2 are not possible. this gives achievable baud rates in the range 183.1 baud to 3,000,000 baud. when a non - standard baud rate is required simply pass the required baud rate value to the dri ver as normal, and the ftdi driver will calculate the required divisor, and set the baud rate. see ftdi application note an232b - 05 on the ftdi website ( www.ftdichip.com ) for more details.
copyright ? 201 5 future technology devices international limited 13 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 reset generator - the integrated reset generator cell provides a reliable power - on reset to the device internal circuitry at power up. the reset# input pin allows an external device to reset the ft234xd . reset# can be tied to vcc or left unconnected if not being used.
copyright ? 201 5 future technology devices international limited 14 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 5 devices characteristics and ratings 5.1 absolute maximum ratings the absolute maximum ratings for the ft234xd devices are as follows. these are in accord ance with the absolute maximum rating system (iec 60134). exceeding these may cause permanent damage to the device. parameter value unit conditions storage temperature - 65c to 150c degrees c floor life (out of bag) at factory ambient (30c / 60% rela tive humidity) 168 hours (ipc/jedec j - std - 033a msl level 3 compliant)* hours ambient operating temperature (power applied) - 40c to 85c degrees c mttf ft234xd tbd hours vcc supply voltage - 0.3 to +5 . 5 v vccio io voltage - 0.3 to +4.0 v dc input voltage C usbdp and usbdm - 0.5 to +3.63 v dc input voltage C high impedance bi - directional (powered from vccio) - 0.3 to +5.8 v dc output current C outputs 22 ma table 5 . 1 absolute maximum r atings * if devices are stored out of the packaging beyond this time limit the devices should be baked before use. the devices should be ramped up to a temperature of + 125 c and baked for up to 17 hours .
copyright ? 201 5 future technology devices international limited 15 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 5.2 dc characteristics dc characteristics (ambient tem perature = - 40c to + 85c ) parameter description minimum typical maximum units conditions vcc vcc operating supply voltage 2.97 5 5.5 v normal operation vcc 2 vccio operating supply voltage 1.62 --- 3.63 v icc1 operating supply current 6. 5 8 8.3 ma norm al operation icc2 operating supply current 125 a table 5 . 2 o perating voltage and current
copyright ? 201 5 future technology devices international limited 16 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 parameter description minimum typical maximum units conditions voh output voltage high 2.97 vccio vccio v ioh = +/ - 2ma i/o drive strength* = 4ma 2.97 vccio vccio v i/o drive strength* = 8ma 2.97 vccio vccio v i/o drive strength* = 12ma 2.97 vccio vccio v i/o drive strength* = 16ma vol output voltage low 0 0.4 v iol = +/ - 2ma i/o drive strength* = 4ma 0 0.4 v i/o drive strength* = 8ma 0 0.4 v i/o drive strength* = 12ma 0 0.4 v i/o drive strength* = 16ma vil input low switching threshold 0.8 v lvttl vih input high switching threshold 2.0 v lvttl vt switching threshold 1. 49 v lvttl vt - schmitt trigger negative going threshold voltage 1.1 5 v vt+ schmitt trigger positive going threshold voltage 1.6 4 v rpu input pull - up resistance 40 75 190 k? vin = 0 rpd input pull - down resistance 40 75 190 k? vin =vccio iin input leakage current - 10 +/ - 1 10 a vin = 0 ioz tri - state output leakage current - 10 +/ - 1 10 a vin = 5.5v or 0 table 5 . 3 i/o pin char acteristics vccio = +3.3v (except usb phy pins) * the i/o drive strength and slow slew - rate are configurable in the mtp memory .
copyright ? 201 5 future technology devices international limited 17 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 parameter description minimum typical maximum units conditions voh output voltage high 2.25 vccio vccio v ioh = +/ - 2ma i/o drive strength* = 4ma 2.25 vccio vccio v i/o drive strength* = 8ma 2.25 vccio vccio v i/o drive strength* = 12ma 2.25 vccio vccio v i/o drive strength* = 16ma vol output voltage low 0 0.4 v iol = +/ - 2ma i/o drive strength* = 4ma 0 0.4 v i/o drive strength* = 8ma 0 0.4 v i/o drive strength* = 12ma 0 0.4 v i/o drive strength* = 16ma vil input low switching threshold 0.8 v lvttl vih input high switching threshold 0.8 v lvttl vt switching threshold 1.1 v lvttl vt - schmitt trigge r negative going threshold voltage 0.8 v vt+ schmitt trigger positive going threshold voltage 1. 2 v rpu input pull - up resistance 40 75 190 k? vin = 0 rpd input pull - down resistance 40 75 190 k? vin =vccio iin input leakage current - 10 +/ - 1 10 a vin = 0 ioz tri - state output leakage current - 10 +/ - 1 10 a vin = 5.5v or 0 table 5 . 4 i/o pin char acteristics vccio = +2.5 v (except usb phy pins) * the i/o drive strength and slow slew - rate are configurable in the mtp memory .
copyright ? 201 5 future technology devices international limited 18 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 parameter description minimum typical maximum units conditions voh output voltage high 1.62 vccio vccio v ioh = +/ - 2ma i/o d rive strength* = 4ma 1.62 vccio vccio v i/o drive strength* = 8ma 1.62 vccio vccio v i/o drive strength* = 12ma 1.62 vccio vccio v i/o drive strength* = 16ma vol output voltage low 0 0.4 v iol = +/ - 2ma i/o drive strength* = 4ma 0 0.4 v i/o d rive strength* = 8ma 0 0.4 v i/o drive strength* = 12ma 0 0.4 v i/o drive strength* = 16ma vil input low switching threshold 0.77 v lvttl vih input high switching threshold 1.6 v lvttl vt switching threshold 0.77 v lvttl vt - schmitt trigg er negative going threshold voltage 0.557 v vt+ schmitt trigger positive going threshold voltage 0.893 v rpu input pull - up resistance 40 75 190 k? vin = 0 rpd input pull - down resistance 40 75 190 k? vin =vccio iin input leakage current - 10 +/ - 1 10 a vin = 0 ioz tri - state output leakage current - 10 +/ - 1 10 a vin = 5.5v or 0 table 5 . 5 i/o pin char acteristics vccio = +1.8 v (except usb phy pins) * the i/o drive strength and slow slew - rate are configurable in the mtp memory .
copyright ? 201 5 future technology devices international limited 19 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 parameter description minimum typical maximum units conditions voh output voltage high vcc - 0.2 v vol output voltage low 0.2 v vil input low switching threshold - 0.8 v vih input high switching threshold 2.0 - v table 5 . 6 usb i/o pin (usbdp, usbdm) characteristics 5.3 mtp memory reliability characteristics the interna l 2048 b yte mtp memory has the following reliability characteristics: parameter value unit data retention 1 0 years write cycle 2 ,000 cycles read cycle unlimited cycles table 5 . 7 mtp memory characteristics 5.4 internal clock characteristics the internal clock oscillator has the following characteristics: parameter value unit minimum typical maximum frequency of operation (see note 1) 11.98 12.00 12.02 mhz clock period 83.19 83.33 83.47 ns duty cycle 45 50 55 % table 5 . 8 internal clock characteristics note 1: equivalent to +/ - 1667ppm
copyright ? 201 5 future technology devices international limited 20 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 6 usb power configurations the following sections illustrate possible usb power configurations for the ft234xd . the illustration s have omitted pin numbers for ease of understanding since the pins differ between the ft234xd s and ft234xd q package options. all usb power configurations illustrated apply to both package options for the ft234xd device. please refer to section 9 for the package option pin - out and signal descriptions. 6.1 usb bus powered configuration figure 6 . 1 bus powered configuration figure 6 . 1 illustrates the ft234xd in a typical usb bus powered design configuration. a usb bus powered device gets its power from the usb bus. basic rules for usb bus power devices are as follows C i) on plug - in to usb, the device sho uld draw no more current than 100ma. ii) in usb suspend mode the device should draw no more than 2.5ma . iii) a bus powered high power usb device (one that dr aws more than 100ma) should use the cbus pin configured as pwren# and use it to keep the current below 100ma on plug - in and 2.5ma on usb suspend. iv) a device that consumes more than 100ma cannot be plugged into a usb bus powered hub. v) no device can draw more than 500ma from the usb bus. the power descriptors in the internal mtp memory of the ft234xd should be progra mmed to match the current drawn by the device. a ferrite bead is connected in series with the usb power supply to reduce emi noise from the ft234xd and associated circuitry being radiated down the usb cable to the usb host. the value of the ferrite bead de pends on the total current drawn by the application. a suitable range of ferrite beads is available from laird technologies ( http://www.lairdtech.com ) for example laird technologies part # mi0805k 601 r - 10. f t 2 3 4 x d 1 2 3 4 5 s h i e l d f e r r i t e b e a d g n d g n d v c c g n d v c c 3 v 3 o u t u s b d m u s b d p v c c i o v c c a g n d g n d r e s e t # 1 0 0 n f 1 0 0 n f 1 0 n f 4 . 7 u f + 2 7 r 2 7 r g n d 4 7 p f 4 7 p f
copyright ? 201 5 future technology devices international limited 21 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 6.2 self powered configuration figure 6 . 2 self powered configuration figure 6 . 2 illustrates the ft234xd in a typical usb self powered configurati on. a usb self powered device gets its power from its own power supply, vcc, and does not draw current from the usb bus. the basic rules for usb self powered devices are as follows C i) a self powered device should not force current down the usb bus when the usb host or hub controller is powered down. ii) a self powered device can use as much current as it needs during normal operation and usb suspend as it has its own power supply. iii) a self powered device can be used with any usb host, a bus powered usb hub or a se lf powered usb hub. the power descriptor in the internal mtp memory of the ft234xd should be programmed to a value of zero (self powered). in order to comply with the first requirement above, the usb bus power (pin 1) is used to control the vbus_sense pin of the ft2234 x d device. when the usb host or hub is powered up an internal 1.5k resistor on usbdp is pulled up to +3.3v, thus identifying the device as a full speed device to the usb host or hub. when the usb host or hub is powered off, vbus_sen se pin wil l be low and the ft234 x d is held in a suspend state. in this state the internal 1.5k resistor is not pulled up to any power supply (hub or host is powered down), so no current flows down usbdp via the 1.5k pull - up resistor. failure to do this may cause s ome usb host or hub controllers to power up erratically. figure 6 . 2 illustrates a self powered design which has a + 3.3 v to +5 .25 v supply. note: 1. when the ft234xd is in reset, the uart interface i/o pins are tri - st ated. input pins have internal 75 k pull - up resistors to vccio, so they will gently pull high unless driven by some external logic. f t 2 3 4 x d 1 2 3 4 5 s h i e l d g n d g n d v c c g n d v c c 3 v 3 o u t u s b d m u s b d p v c c i o v c c ( 3 . 3 - 5 . 2 5 v ) a g n d g n d r e s e t # 1 0 0 n f 1 0 0 n f 1 0 0 n f 4 . 7 u f + g n d 4 k 7 1 0 k 2 7 r 2 7 r g n d 4 7 p f 4 7 p f v b u s _ s e n s e
copyright ? 201 5 future technology devices international limited 22 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 6.3 usb bus powered with power switching configuration figure 6 . 3 bus powered with power switching configuration a requirement of usb bus powered applications, is when in usb suspend mode, the application draws a total current of less than 2.5ma . this requirement includes external logic. some ext ernal logic has the ability to power itself down into a low current state by monitoring the pwren# signal. for external logic that cannot power itself down in this way, the ft234xd provides a simple but effective method of turning off power during the usb suspend mode. figure 6 . 3 shows an example of using a discrete p - channel mosfet to control the power to external logic. a suitable device to do this is an international rectifier (www.irf.com) irlml6402, or equivale nt. it is recommended that a soft start circuit consisting of a 1k series resistor and a 0.1f capacitor is used to limit the current surge when the mosfet turns on. without the soft start circuit it is possible that the transient power surge, caused wh en the mosfet switches on, will reset the ft234xd or the usb host/hub controller. the soft start circuit example shown in figure 6 . 3 powers up with a slew rate of approximaely12.5v/ms. thus supply voltage to extern al logic transitions from gnd to +5v in approximately 400 microseconds. as an alternative to the mosfet, a dedicated power switch ic with inbuilt soft - start can be used. a suitable power switch ic for such an application is the micrel ( www.micrel.com ) mic2025 - 2bm or equivalent. with power switching controlled designs the following should be noted: i) the external logic to which the power is b eing switched should have its own reset circuitry to automatically reset the logic when power is re - applied when moving out of suspend mode. ii) set the pull - down on suspend option in the internal ft234xd mtp memory . iii) the cbus 0 pin should be configured as pwre n# in the internal ft234xd mtp memory , and used to switch the power supply to the external circuitry. iv) for usb high - power bus powered applications (one that consumes greater than 100ma, and up to 500ma of current from the usb bus), the power consumption of the application must be set in the max power field in the internal ft234xd mtp memory . a high - power bus powered application uses the descriptor in the internal ft234xd mtp memory to inform the system of its power requirements. v) pwren# gets its vcc from vcci o. for designs using 3v3 logic, ensure vccio is not powered down using the external logic. in this case use the +3v3out. f t 2 3 4 x d 1 2 3 4 5 s h i e l d f e r r i t e b e a d g n d g n d v c c g n d v c c 3 v 3 o u t u s b d m u s b d p v c c i o a g n d g n d r e s e t # 1 0 0 n f 1 0 0 n f 1 0 n f 4 . 7 u f + c b u s 0 p w r e n # 1 0 0 k 1 k s w i t c h e d 5 v p o w e r t o e x t e r n a l l o g i c 0 . 1 u f 0 . 1 u f p c h a n n e l p o w e r m o s f e t 2 7 r 2 7 r g n d 4 7 p f 4 7 p f
copyright ? 201 5 future technology devices international limited 23 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 7 application examples the following sections illustrate possible applications of the ft234xd . 7.1 usb to rs232 converter figure 7 . 1 application example showing usb to rs232 converter an example of using the ft234xd as a usb to rs232 converter is illustrated in figure 7.1. in this application, a 3v3 ttl to rs232 leve l converter ic is used on the serial uart interface of the ft234xd to convert the 3v3 levels of the ft234xd to rs232 levels. this level shift can be done using line drivers from a variety of vendors e.g. zywyn. a useful feature on some of these devices is the shdn# pin which can be used to power down the device to a low quiescent current during usb suspend mode. a suitable level shifting device is the zywyn zt32 22 f which is capable of rs232 communication at up to 1000k baud. gnd r5 10k gnd vbus c4 10nf c3 0.1uf c1 4.7uf gnd gnd fb1 600r/0.5a vbus 1 d- 2 d+ 3 gnd 4 cn1 usb c5 47pf c6 47pf gnd gnd c2 0.1uf rxd 10 g n d 5 usbdp 12 usbdm 1 3v3out 3 reset# 2 v c c 4 cbus0 6 txd 7 v c c i o 9 g n d 1 3 cts# 11 rts# 8 u1 ft234xd r1 10k c7 10nf gnd gnd txd rxd rts# cts# sleep# r3 27r r2 27r 16 12 13 9 15 10 17 8 c1+ 2 c2+ 5 gnd 18 c1- 4 vcc 19 c2- 6 v- 7 v+ 3 en 1 shdn 20 nc 11 nc 14 u2 zt3222f c10 0.1uf c9 0.1uf c11 0.1uf c12 0.1uf c8 0.1uf gnd txd_rs232 rxd_rs232 rts_rs232 cts_rs232
copyright ? 201 5 future technology devices international limited 24 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 7.2 usb to rs485 covert er figure 7 . 2 application example showing usb to rs485 converter an example of using the ft234xd as a usb to rs485 converter is shown in figure 7.2. in this application, a 3v3 - tt l to rs485 level converter ic is used on the serial uart interface of the ft234xd to convert the ttl levels of the ft234xd to rs485 levels. this example uses the zywyn zt 485een device. equivalent devices are available from maxim and analogue devices. the z t485een is a rs485 device in a compact 8 pin sop package. it has separate enables on both the transmitter and receiver. with rs485, the transmitter is only enabled when a character is being transmitted from the uart the txden signal cbus pin option on the ft234xd is provided for exactly this purpose and so the transmitter enable is wir ed to cbus which has been configured as txden. note that the txden is activated 1 bit period before the start bit. txden is deactivated at the same time as the stop bit. this is not configurable. rs485 is a multi - drop network; so many devices can communicate with each other over a two wire cable interface. the rs485 cable requires to be terminated at each end of the cable. a link (which provides the 120? termination) allows t he cable to be terminated if the zt3485 is physically positioned at either end of the cable. txd rxd c8 0.1uf gnd re 2 de 3 di 4 vcc 8 ro 1 6 7 gnd 5 d r u2 zt485een gnd data + data - txden gnd vbus c4 10nf c3 0.1uf c1 4.7uf gnd gnd fb1 600r/0.5a vbus 1 d- 2 d+ 3 gnd 4 cn1 usb c5 47pf c6 47pf gnd gnd c2 0.1uf rxd 10 g n d 5 usbdp 12 usbdm 1 3v3out 3 reset# 2 v c c 4 cbus0 6 txd 7 v c c i o 9 g n d 1 3 cts# 11 rts# 8 u1 ft234xd r1 10k c7 10nf gnd gnd r3 27r r2 27r
copyright ? 201 5 future technology devices international limited 25 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 7.3 usb to rs422 converter figure 7 . 3 usb to rs422 converter configuration a n example of using the ft234xd as a usb to rs422 converter is shown in figure 7.3. in this application, two ttl to rs422 level converter ics are used on the serial uart interface of the ft234xd to convert the ttl levels of the ft234xd to rs422 levels. ther e are many suitable level converter devices available. this example uses zywyn zt 490e devices . p - channel mosfet connected in the vcc line of zt490e ensures that usb standby current of 2.5ma is not exceeded. the zt490e is specified to transmit and receive d ata at a rate of up to 1 0 mbaud. in this example the maximum data rate is limited to 3 mbaud by the ft234xd . gnd y 5 z 6 di 3 vcc 1 ro 2 a 8 b 7 gnd 4 d r u2 zt490e q1 irlml6402 r4 2k c9 0.1uf y 5 z 6 di 3 vcc 1 ro 2 a 8 b 7 gnd 4 d r u3 zt490e gnd c8 0.1uf r6 120r r7 120r r5 10k txd+ txd- rxd+ rxd- rts- rts+ cts+ cts- gnd vbus c4 10nf c3 0.1uf c1 4.7uf gnd gnd fb1 600r/0.5a vbus 1 d- 2 d+ 3 gnd 4 cn1 usb c5 47pf c6 47pf gnd gnd c2 0.1uf rxd 10 g n d 5 usbdp 12 usbdm 1 3v3out 3 reset# 2 v c c 4 cbus0 6 txd 7 v c c i o 9 g n d 1 3 cts# 11 rts# 8 u1 ft234xd r1 10k c7 10nf gnd gnd txd rxd rts# cts# pwren# r3 27r r2 27r
copyright ? 201 5 future technology devices international limited 2 6 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 7.4 usb battery charging detection a recent addition to the usb specification ( http://www.usb.org/developers/docs/devclass_docs/bcv1.2_070312.zip ) is to allow for additional charging profiles to be used for charging batteries in portable devices. these charging profiles do not enumerate the usb port of the periphera l. the ft234xd device will detect that a usb compliant dedicated charging port (dcp) is connected. once detected while in suspend mode, a battery charge detection signal is provided to allow external logic to switch to charging mode as opposed to operati on mode . figure 7 . 4 usb battery charging detection to use the ft234xd with battery charging detection the cbus0 pin must be reprogrammed to allow for the bcd charger output to s witch the external cha rger circuitry on. the cbus0 pin is configured in the internal mtp memory with the free utility ft _ prog. if the charging circuitry requires an active low signal to enable it, the cbus 0 pin can be programmed to bcd charger# as an alter native. x - c h i p p i n f u n c t i o n e e p r o m s e t t i n g c b u s 0 b c d b a t t e r y o p t i o n s b a t t e r y c h a r g e r e n a b l e f o r c e p o w e r e n a b l e d e - a c t i c a t e s l e e p x g n d g n d 0 . 1 u f 0 . 1 u f g n d g n d 6 0 0 r / 2 a 1 0 n f v b u s 3 v 3 o u t 0 . 1 u f 0 r g n d s l d g n d 2 7 r 2 7 r v b u s 1 d - 2 d + 3 g n d 5 i d 4 c n u s b v c c 2 f a u l t 3 t i m e r 4 g n d 5 n t c 6 p r o g 7 s h d n 8 b a t 9 a c p r 1 0 c h r g 1 g n d 1 1 l t c 4 0 5 3 e d d g n d 3 v 3 o u t 3 v 3 o u t 4 . 7 u f 0 . 1 u f g n d v b u s v b u s g n d v b a t t g n d g n d 1 k 5 g n d 1 t b 3 . 5 m m v b u s v b u s n t c 0 . 1 u f g n d v b u s 1 u f 1 r g n d v b u s b c d 2 k 2 g n d j p 1 1 - 2 2 - 3 n c t e n a b l e d n c t a v a i l a b l e j p 1 s i p - 3 n t c g n d n c t d i s a b l e d ( d e f a u l t ) j u m p e r - 2 m m 4 k 3 2 1 % g n d d p d m 3 v 3 o u t r e s e t # v c c g n d c b u s 0 v c c i o f t 2 3 4 x d b c d 1 a w h e n c o n n e c t e d t o a d e d i c a t e d c h a r g e r p o r t 0 a w h e n e n u m e r a t e d 0 a w h e n i n s l e e p 0 a w h e n n o t e n u m e r a t e d a n d n o t i n s l e e p + - n c t n . f .
copyright ? 201 5 future technology devices international limited 27 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 when connected to a usb compliant dedicated charging port (dcp, as opposed to a standard usb host) the device usb signals will be shorted together and the device suspended. the bcd charger signal will bring the ltc4053 out of suspend and allow battery charging to start. the charge current in the example above is 1a as defined by the resistance on the prog pin. to calculate the equivalent resistance on the prog pin select a charge current, then res = 1500v/i chg for more configuration options of the ltc4053 refer to: an_175_battery charging over usb note: if the ft2 34 xd is connected to a standard host port such that the device is enumerated the battery charge detection signal is inactive as the device will not be in suspend. 7.5 led interface the cbus 0 i/o pin can be configured to drive an led. the ft234xd has 3 configuration options for driving leds from the cbus. these are txled#, rxled#, and tx&rxled#. refer to section 3.2 for configuration options. figure 7 . 5 single led configuration an example of using the ft234xd to drive an led is shown in figure 7 . 5 7 . in this example the cbus 0 pi n is used to indicate when data is being transmitted or received by the device (tx&rxled). in this configuration the ft2 34 xd will drive only a single led. f t 2 3 4 x d c b u s 0 v c c i o 2 7 0 r t x & r x l e d #
copyright ? 201 5 future technology devices international limited 28 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 8 internal mtp memory configuration the ft234xd includes an internal mtp memory which holds the usb con figuration descriptors, other configuration data for the chip and also user data areas. following a power - on reset or a usb reset the ft234xd will scan its internal mtp memory and read the usb configuration descriptors stored there. in many cases, the defa ult values programmed into the mtp memory will be suitable and no re - programming will be necessary. the defaults can be found in section 8.1 . the mtp memory in the ft234xd can be programmed over usb if the value s need to be changed for a particular application. further details of this are provided from section 8.2 onwards. users who do not have their own usb vendor id but who would like to use a unique product id in th eir design can apply to ftdi for a free block of unique pids. see tn_100 C usb vendor id/product id guidelines for more details . 8.1 default values the default factory programmed values of the internal mtp memory are shown in table 8 . 1 . parameter value notes usb vendor id (vid) 0403h ftdi default vid (hex) usb product ud (pid) 60 1 5 h ftdi default pid (hex) serial number enabled? yes serial number see note a unique serial number is generated and programmed into the mtp memory during device final test. pull down i/o pins in usb suspend disabled enabling this option will make the device pull down on the uart interface lines when in usb suspend mode ( pwren# is high). manufacturer name ftdi product description ft234x d basic uart max bus power current 90ma power source bus powered device type ft234xd usb version 0200 returns usb 2.0 device description to the host. note: the device is a usb 2.0 full speed device (12mb/s) as opposed to a usb 2.0 high speed devic e (480mb/s). remote wake up dis abled taking ri# low will wake up the usb host controller from suspend in approximately 20 ms. dbus drive current strength 4ma options are 4ma, 8ma, 12ma, 16ma dbus slew rate slow options are slow or fast dbus schmitt tri gger normal options are normal or schmitt
copyright ? 201 5 future technology devices international limited 29 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 parameter value notes enable cbus drive current strength 4ma options are 4ma, 8ma, 12ma, 16ma cbus slew rate slow options are slow or fast cbus schmitt trigger enable normal options are normal or schmitt load vcp driver enabled * * makes the device load the vcp driver interface for the device. cbus 0 txden default configuration of c bus0 C table 8 . 1 default internal mtp memory configuration 8.2 methods of programming the mtp memory 8.2.1 programming the mtp memory over usb the mtp memory on all ft - x devices can be programmed over usb. this method is the same as for the eeprom on other ftdi devices such as the ft232r. no additi onal hardware, connections or programming voltages are required. the device is simply connected to the host computer in the same way that it would be for normal applications, and the ft_prog utility is used to set the required options and program the devic e. the ft _ prog utility is provided free - of - charge from the ftdi website, and can be found at the link below. the user guide is also available at this link. http://www.ftdichip.com/s upport/utilities.htm#ft_prog additionally, d2xx commands can be used to program the mtp memory from within user applications. for more information on the commands available, please see the d2xx programmers guide below. http://www.ftdichip.com/support/documents/programguides/d2xx_programmer's_guide(ft_000071).p df
copyright ? 201 5 future technology devices international limited 30 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 8.3 memory map the ft - x family mtp memory has various areas which come under three main c ategories: ? user memory area ? configuration memory area (writable) ? configuration memory area (non - writable) memory area description word address user memory area 2 accessible via usb 0x3ff - 0x80 configuration memory area accessible via usb 0x7e - 0x50 configuration memory area can not be written 0x4e - 0x40 user memory area 1 accessible via usb 0x3e - 0x12 configuration memory area accessible via usb 0x10 - 0x00 figure 8 . 1 : simplified memory map for the ft - x user memory area the user memory areas are highlighted in green on the memory map. they can be read and written via usb on the ft234xd . all locations within this range are freely programmable; no areas have special functions and there is no checksum f or the user area. note that the application should take into account the specification for the number of write cycles in section 5.3 if it will be writing to the mtp memory multiple times. configuration memory a rea (writable) this area stores the configuration data for the device, including the data which is returned to the host in the configuration descriptors (e.g. the vid, pid and string descriptions) and also values which set the hardware configuration (the s ignal assigned to each cbus pin for example). these values can have a significant effect on the behaviour of the device. steps must be taken to ensure that these locations are not written to un - intentionally by an application which is intended to access o nly the user area. this area is included in a checksum which covers configuration areas of the memory, and so changing any val u e can also cause this checksum to fail. configuration memory area ( non - writable) this is a reserved area and the application shou ld not write to this area of memory. any attempt to write these locations will fail
copyright ? 201 5 future technology devices international limited 31 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 9 package parameters the ft234xd is available in a dfn - 1 2 package . the solder reflow profile is described in section 9.2 . 9.1 dfn - 12 package mechanical dimensions figure 9 . 1 dfn - 12 package dimensions the ft234xd is supplied in a rohs compliant leadless dfn - 12 package. the package is lead (pb) free, and uses a green compound. the p ackage is fully compliant with european union directive 2002/95/ec. this package is nominally 3 .00mm x 3 .00 mm. the solder pads are on a 0. 4 5 mm pitch. the above mechanical drawing shows the dfn - 12 package. refer to the wdfn column in figure 9 . 1 3 . all dimensions are in millimetres. the centre pad on the base of the ft234xd is internally connected to ground .
copyright ? 201 5 future technology devices international limited 32 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 9.2 dfn - 12 package markings figure 9 . 2 dfn - 12 package markings the date code format is yy ww where xx = 2 digit week number, ww = 2 digit year number. this is followed by the revision number. the code xxxxxxx is the manufacturing lot code. ft di i xxxxxxxxxx ft234xd q 6 1 yyww - b 7 12
copyright ? 201 5 future technology devices international limited 33 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 9.3 solder reflow profile the ft234xd is supplied in a pb free dfn - 12 packa ge . the recommended solder reflow p rofile is shown in figure 9 . 3 5 . figure 9 . 3 ft234xd solder reflow profile the recommended values for the solder reflow profile are detailed in table 9 . 1 . values are shown for both a completely pb free solder process (i.e. the ft234xd is used with pb free solder), and for a non - pb free solder process (i.e. the ft234xd is used with non - pb free s older). profile feature pb free solder process non - pb free solder process average ramp up rate (t s to t p ) 3c / second max. 3c / second max. preheat - temperature min (t s min.) - temperature max (t s max.) - time (t s min to t s max) 150c 200c 60 to 120 seconds 100c 150c 60 to 120 seconds time maintained above critical temperature t l : - temperature (t l ) - time (t l ) 217c 60 to 150 seconds 183c 60 to 150 seconds peak temperature (t p ) 260c 240c time within 5c of actual peak temperature (t p ) 20 to 40 seconds 20 to 40 seconds ramp down rate 6c / second max. 6c / second max. time for t= 25c to peak temperature, t p 8 minutes max. 6 minutes max. table 9 . 1 reflow profile parameter values critical zone: when t is in the range t to t t e m p e r a t u r e , t ( d e g r e e s c ) time, t (seconds) 25 p t = 25 o c to t t p t p t l t preheat s t l ramp up l p ramp down t max s t min s
copyright ? 201 5 future technology devices international limited 34 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 10 contact information head office C glasgow, uk unit 1, 2 seaward place, centurion business park glasgow g41 1hh united kingdom tel: +44 (0) 141 429 2777 fax: +44 (0) 141 429 2758 e - mail (sales) sales 1 @ftdichip.com e - mail (support) support 1 @ftdichip.com e - mail (general enquiries) admin1@ftdichip.com branch office C taipei, taiwan 2f, no. 516, sec. 1, neihu road taipei 114 taiwan , r.o.c. tel: +886 (0) 2 8791 3570 fax: +886 (0) 2 8791 3576 e - mail (sales) tw.sales1@ftdichip.com e - mail (support) tw.support1@ftdichip.com e - mail (general enquiries) tw.admin1@ftdichip.com branch office C tigard , oregon, usa 7130 sw fir loop, tigard, or 97223 usa tel: +1 (503) 547 0988 fax: +1 (503) 547 0987 e - mail (sales) us.sales@ftdichip.com e - mail (support) us.support@ftdichip.com e - mail (general enquiries) us.admin@ftdichip.com branch office C shanghai, china room 408, 317 xianxia road, shanghai, 200051 china tel: +86 21 62351596 fax: +86 21 62351595 e - mail (sales) cn.sales@ftdichip.com e - mail (support) cn.support@ftdichip.com e - mail (general enquiries) cn.admin@ftdichip.com web site http://ftdichip.com system and equipment manufacturers and designers are responsible to ensure that their systems, and any future technology devices international ltd (ftdi) devices incorporated in their systems, meet all applicable safety, regulatory and system - level per formance requirements. all application - related information in this document (including application descriptions, suggested ftdi devices and other materials) is provided for reference only. while ftdi has taken care to assure it is accurate, this informatio n is subject to customer confirmation, and ftdi disclaims all liability for system designs and for any applications assistance provided by ftdi. use of ftdi devices in life support and/or safety applications is entirely at the users risk, a nd the user agr ees to defend, indemnify and hold harmless ftdi from any and all damages, claims, suits or expense resulting from such use. this document is subject to change without notice. no freedom to use patents or other intellectual property rights is implied by the publication of this document. neither the whole nor any part of the information contained in, or the product described in this document, may be adapted or reproduced in any material or electronic form without the prior written consent of the copyright hol der. future technology devices international ltd, unit 1, 2 seaward place, centurion business park, glasgow g41 1hh, united kingdom. scotland registered company number: sc136640
copyright ? 201 5 future technology devices international limited 35 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 appendix a C references useful application notes http://www.ftdichip.com/support/documents/appnotes/an_232r - 01_bit_bang_mode_available_for_ft232r_and_ft245r.pdf http://www.ftdichip.com/documents/appnotes/an_107_advanceddriveroptions_an_000073.pdf http://www.ftdichip.com/documents/appnotes/an_121_ftdi_device_eeprom_user_area_usage.pdf http://www.ftdichip.com/documents/appnotes/an_12 0_aliasing_vcp_baud_rates.pdf http://www.ftdichip.com/documents/appnotes/an_100_using_the_ft232_245r_with_external_osc(ft_ 000067).pdf http://www.ftdichip.com/resources/utilities/an_126_user_guide_for_ft232_factory%20test%20utility. pdf http://www.ftdichip.com/documents/appnotes/an232b - 05_baudrates.pdf http://www.ftdichip.com/documents/installguides.htm http://www.ftdichip.com/support/documents/technicalnotes/tn_100_usb_vid - pid_guidelines.pdf http://www.ftdichip.com/support/documents/appnotes/an_175_battery%20charging%20over%20usb %20with%20ftex%20devices.pdf http://www.ftdichip.com/support/documents/programguides/d2xx_programmer's_guide(ft_000071).p df http://www.usb.org/developers/docs/devclass_docs/bcv1.2_070312.zip
copyright ? 201 5 future technology devices international limited 36 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 appendix b - list of figures and tables list of figures figure 2.1 ft234xd block diagram ................................ ................................ ................................ . 4 figure 3.1 dfn schematic symbol ................................ ................................ ................................ .. 7 figure 6.1 bus powere d configuration ................................ ................................ ........................... 20 figure 6.2 self powered configuration ................................ ................................ ........................... 21 figure 6.3 bus powered with power switching configuration ................................ ............................ 22 figure 7.1 application example showing usb to rs232 converter ................................ ..................... 23 figure 7.2 application example showing usb to rs485 converter ................................ .................... 24 figure 7.3 usb to rs422 converter configuration ................................ ................................ ........... 25 figure 7.4 usb battery charging detection ................................ ................................ .................... 26 figure 7.5 single led configuration ................................ ................................ .............................. 27 figure 8.1: simplified memory map for the ft - x ................................ ................................ ............ 30 figure 9.1 dfn - 12 package dimensions ................................ ................................ ......................... 31 figure 9.2 dfn - 12 package markings ................................ ................................ ............................ 32 figure 9.3 ft234xd solder reflow profile ................................ ................................ ...................... 33 list of tables table 3.1 power and ground ................................ ................................ ................................ .......... 7 table 3.2 common function p ins ................................ ................................ ................................ .... 8 table 3.3 uart interface and cbus group (see note 1) ................................ ................................ .... 8 table 3.4 cbus configuration control ................................ ................................ ........................... 10 table 5.1 absolut e maximum ratings ................................ ................................ ............................ 14 table 5.2 operating voltage and current ................................ ................................ ....................... 15 table 5.3 i/o pin characteristics vccio = +3.3v (except usb phy pins) ................................ ........... 16 table 5.4 i/o pin characteristics vccio = +2.5v (except usb phy pins) ................................ ........... 17 table 5.5 i/o pin characteristics vccio = +1.8v (except usb phy pins) ................................ ........... 18 table 5.6 usb i/o pin (usbdp, usbdm) ch aracteristics ................................ ................................ .. 19 table 5.7 mtp memory characteristics ................................ ................................ ........................... 19 table 5.8 internal clock characteristics ................................ ................................ ......................... 19 table 8.1 def ault internal mtp memory configuration ................................ ................................ ..... 29 table 9.1 reflow profile parameter values ................................ ................................ ..................... 33
copyright ? 201 5 future technology devices international limited 37 ft234xd usb to basic uart ic version 1.2 document no.: ft_000753 clearance no.: ftdi#324 appendix c - revision history document title: usb to basic uart ic ft234xd document reference no.: ft_000753 clearance no.: ftdi#32 4 product page: http://www.ftdichip.com/ft - x.htm document feedback: send feedback version 1.0 first release january 201 3 version 1.1 u pdated tid info. added clarification that we are 5v tolerant february 2013 version 1.2 added refere nce to wdfn chip dimensions aug 201 5

▲Up To Search▲

Price & Availability of FT234XD-R

	To Download FT234XD-R Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .