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product structure : silicon monolithic integrated circuit this product has no designed protection against radioactive rays . 1 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 tsz22111 ? 14 ? 001 www.rohm.com resistive touch screen controller lsi series 4 - wire resistive touch screen controller BU21026MUV general description BU21026MUV is a low power 4 - wire resistive touch screen controller. BU21026MUV measures coordinates and touch pressures with a 12bit a /d converter. BU21026MUV has a digital filter for noise reduction. features ? 4 - wire resistive touch screen controller ? single 1.65v to 3.60v supply. ? low standby current ( 0.8ua max) ? 12bit sar a/d converter ? 2 - wire serial interface ? command base interface ? digi tal filter ? touch pressure measurement ? auto power down control ? built - in clock oscillation circuit . applications ? equipment with a built in user interface of 4 - wire resistive touch screen ? portable device such as smart phone, tablet, pda. ? digital still camer a, digital video camera, portable tv. ? pc / pc peripheral equipment such as laptop pc, touch screen monitor, printer. key specification s ? power supply voltage 1.65v to 3.60v ? temperature rang e - 30 to 85 ? standby current 0.8ua (max.) ? operating current 120ua (typ.) ? coordinate resolution 12bits package vqfn020v4040 4.00mm x 4.00mm x 1.00mm typical application circuit (s) 1. 4 - wire resistive touch screen 2. pull - up resistor for 2 - wire serial interface 3. bypass capacitors 4. diodes for e sd protection 5. low pass filter for noise reduction w(typ) x d(typ) x h(max) x p y p x n y n v d d b u 2 1 0 2 6 g n d a d 0 a d 1 s d a a u x i n t s c l a u x i l a r y i n p u t s d a s c l g p i o v d d g n d g n d g n d 1 . 0 f 2 . 2 k 0 . 1 f 2 . 2 k m a s t e r ( 2 - w i r e s e r i a l i n t e r f a c e ) 0 . 1 f 0 . 1 f 0 . 1 f 0 . 1 f 1 0 1 0 1 0 1 0 g n d t o u c h s c r e e n 3 2 5 1 4 datashee t
2 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 www.rohm.com tsz2211 1 ? 15 ? 001 b u21026muv contents general description ................................ ................................ ................................ ................................ ................................ ........ 1 features ................................ ................................ ................................ ................................ ................................ .......................... 1 applications ................................ ................................ ................................ ................................ ................................ .................... 1 key specifications ................................ ................................ ................................ ................................ ................................ ........... 1 package ................................ ................................ ................................ ................................ ................................ .......................... 1 typical application circuit(s) ................................ ................................ ................................ ................................ ........................... 1 contents ................................ ................................ ................................ ................................ ................................ ......................... 2 pin configuration(s) ................................ ................................ ................................ ................................ ................................ ........ 3 pin description(s) ................................ ................................ ................................ ................................ ................................ ........... 3 equivalent circuit ................................ ................................ ................................ ................................ ................................ ............. 3 block diagram(s) ................................ ................................ ................................ ................................ ................................ ............ 4 description of block(s) ................................ ................................ ................................ ................................ ................................ .... 4 power on reset ................................ ................................ ................................ ................................ ................................ ........... 4 a/d converter ................................ ................................ ................................ ................................ ................................ ............. 4 touch screen i/f ................................ ................................ ................................ ................................ ................................ ......... 4 touch detection ................................ ................................ ................................ ................................ ................................ .......... 5 digital filter ................................ ................................ ................................ ................................ ................................ ................. 5 absolute maximum ratings ................................ ................................ ................................ ................................ ............................ 6 thermal resistance (note 1) ................................ ................................ ................................ ................................ ............................... 6 recommended operating conditions ................................ ................................ ................................ ................................ ............. 6 electrical characteristics ................................ ................................ ................................ ................................ ................................ . 6 power on reset timing chart ................................ ................................ ................................ ................................ ......................... 7 2 - wire serial interface timing chart ................................ ................................ ................................ ................................ ................ 7 2 - wire serial interface ................................ ................................ ................................ ................................ ................................ ..... 8 start condition ................................ ................................ ................................ ................................ ................................ ............. 8 stop condition ................................ ................................ ................................ ................................ ................................ ............. 8 data transfer ................................ ................................ ................................ ................................ ................................ .............. 8 acknowledge bit (sending) ................................ ................................ ................................ ................................ .......................... 8 acknowledge bit (receiving) ................................ ................................ ................................ ................................ ........................ 8 address byte ................................ ................................ ................................ ................................ ................................ ............... 8 command byte ................................ ................................ ................................ ................................ ................................ ........... 9 write protocol ................................ ................................ ................................ ................................ ................................ ............ 11 read protocol ................................ ................................ ................................ ................................ ................................ ........... 12 operation ................................ ................................ ................................ ................................ ................................ ...................... 13 position detection of touch screen ................................ ................................ ................................ ................................ ........... 13 touch pressure measurement ................................ ................................ ................................ ................................ .................. 13 a/d conversion time ................................ ................................ ................................ ................................ ................................ 14 a/d sampling time with 2 - wire serial interface ................................ ................................ ................................ ........................ 14 oper ational notes ................................ ................................ ................................ ................................ ................................ ......... 15 ordering information ................................ ................................ ................................ ................................ ................................ ..... 17 marking diagrams ................................ ................................ ................................ ................................ ................................ ......... 17 phy sical dimension, tape and reel information ................................ ................................ ................................ ........................... 18 revision history ................................ ................................ ................................ ................................ ................................ ............ 19
3 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 www.rohm.com tsz2211 1 ? 15 ? 001 b u21026muv pin con f iguration (s) pin descriptio n(s) pin no. pin n ame i/o function figure 1 ad1 i slave a ddress b it1 i nput a 2 scl i/o serial c lock b 3 sda i/o serial d ata b 4 ad0 i slave a ddress b it 0 i nput a 5 int o interrupt o utput. pin polarity is active low. a 6 - - (n.c.) - 7 aux i auxiliary i nput c 8 vdd - power s u pply - 9 - - (n.c.) - 10 - - (n.c.) - 11 xp i/o screen i nterface c 12 yp i/o screen i nterface c 13 - - (n.c.) - 14 xn i/o screen i nterface c 15 yn i/o screen i nterface c 16 - - (n.c.) - 17 - - (n.c.) - 18 gnd - ground - 19 - - ( n.c.) - 20 - - (n.c.) - e quivalent circuit figure. a figure. b figure. c 1 6 1 7 1 8 1 9 2 0 1 a d 1 2 s c l 3 s d a 4 a d 0 5 i n t 1 0 9 8 7 6 ( n . c . ) ( n . c . ) v d d a u x ( n . c . ) 1 5 y n 1 4 x n 1 3 ( n . c . ) 1 2 y p 1 1 x p t o p v i e w ( n . c . ) ( n . c . ) g n d ( n . c . ) ( n . c . ) p a d p a d p a d
4 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 www.rohm.com tsz2211 1 ? 15 ? 001 b u21026muv block diagra m(s) description of block(s) pow er on reset BU21026MUV requests that the power on reset timing should be observed . if the power on rese t timing not be observed , BU21026MUV may wakeup with a random state. the touch detection and 2 - wire serial interface is enabled after taking the device ready time. a/d converter BU21026MUV has a 12 - bit successive approximation resistor (sar) analog to dig ital (a/d) converter. this a/d converter is used for measuring x and y position and auxiliary input voltage. o utput format is in str aight binary as shown in below table . a/d convertor output format input voltage output (vref - 1.5lsb) ~ vref fffh (vref - 2.5lsb) ~ (vref - 1.5lsb) ffeh (vref - 3.5lsb) ~ (vref - 2.5lsb) ffdh : : 1.5lsb ~ 2.5lsb 002h 0.5lsb ~ 1.5lsb 001h 0 ~ 0.5lsb 000h note: vref = vrefp vrefn, lsb = vref / 4095 touch screen i/f a touch screen interface is consisted many switche s . these switches are used for the driving screen voltage and selection an input of the a/d converter. state of these switches is selected by a command that sent from the master. t o u c h s c r e e n i n t e r f a c e c l o c k o s c i l l a t o r a / d c o n v e r t e r c o n t r o l l o g i c & 2 - w i r e s e r i a l i n t e r f a c e i n t d i g i t a l f i l t e r t o u c h d e t e c t i o n s d a s c l a d 1 a d 0 p o w e r o n r e s e t x p y p x n y n a u x v d d g n d
5 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 www.rohm.com tsz2211 1 ? 15 ? 001 b u21026muv t ouch detection a touch detection function of BU21026MUV is automati cally enabled after wakeup. BU21026MUV inform that touch screen is touched or not by int pin when touch detection is enabled. o utput level of int become s low during screen is touched. in this state , xp pin is pull ed - up high by pull - up resistor (r pu ) and yn pin is connected to gnd. a resistance of r pu is selectable from either 50 kohm (default) or 90 kohm by the setup command. when the screen lvq?w touched, xp is connected to vdd trough the pull - up resistor. w hen the screen is touched, xp is connected to gnd trough the screen and BU21026MUV detect touch. when a received command is not setup (1011), t he touch detection is disabled and r pu is disconnect ed from xp pin. and o utput level of int is fixed high or low by each command (see table 3 for details about op eration code). when BU21026MUV receive s software reset command (0101), touch detection is enabled after the 2 nd acknowledge timing. when BU21026MUV receive s a/d conversion with pd=0 command touch detection is enabled after an a/d conversion is finished. wh en BU21026MUV receive s a driving screen voltage or an a/d conversion with pd=1 command , touch detection is not enable automatically. a method for re - enable the touch detection is sending new command that return to enable touch detection . the set power comm and is almost same as an a/d conversion command. touch detection circuit digital filter BU21026MUV has a median a vera ge f ilter (maf) as a digital filter for n oise reduction. w hen the maf is enabled, BU21026MUV operates a/d conversion 7 times and stores converted data. next, t hese stored data are sorted. an output data of ma f is an average va lue of middle three values of the sorted data . a n abnormal value becomes difficult to affect the results. so n oise reduction performance of maf is higher than one of normal average filter. w hen the maf is disabled , BU21026MUV operat es a/d conversion one times and output the converted data the maf is enabled in defaults and is changed by the setup command. y - p l a t e x - p l a t e o n g n d x p y p x n y n o n r p u i n t v d d o f f c o n t r o l l o g i c
6 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 www.rohm.com tsz2211 1 ? 15 ? 001 b u21026muv absolute maximu m ratings p arameter symbol r ating u nit power supply voltage vdd - 0.3 to 4.5 v input v oltage vin - 0.3 to vdd+0.3 v storage temperature range tstg - 50 to 125 caution: operating the ic over the absolute maximum ratings may damage the ic. the damage can either be a short circuit between pins or an open circuit between pins and the internal circuitry. therefore, it is important to consider circuit protection measures, such as adding a fuse, in case the ic is operated over the absolute maximum ratings. th ermal resistance ( note 1) p arameter s ymbol thermal resistance (typ) unit 1s ( note 3 ) 2s2p ( note 4) vqfn020v4040 junction to ambient j a 153.9 37.4 c /w junction to top characterization parameter ( note 2 ) jt 13 7 c /w (note 1) based on jesd 51 - 2a(still - air) (note 2) the thermal characterization parameter to report the difference between junction temperature and the temperature at the to p center of the outside surface of the component package. (note 3) using a pcb board based on jesd 51 - 3. layer number of measurement board material board size single fr - 4 114.3mm x 76.2mm x 1.57mmt top copper pattern thickness footprints and t races 70 m (note 4) using a pcb board based on jesd 51 - 5, 7. layer number of measurement board material board size thermal via (note 5) pitch diameter 4 layers fr - 4 114.3mm x 76.2mm x 1.6mmt 1.20mm - 0.30mm top 2 internal layers bottom copper pattern thickness copper pattern thickness copper pattern thickness footprints and traces 70 m 74.2mm x 74.2mm 35 m 74.2mm x 74.2mm 70 m ( note 5 ) this thermal via connects with the copper pattern of all layers. . recommended operating conditions p arameter s ymbol min . typ . max . unit power supply voltage vdd 1.65 3.00 3.60 v operating temperature range t j - 3 0 25 85 electrical characteristics p arameter s ymbol min . typ . max . unit condition low - level input voltage vil - 0.3 - 0. 3 xvdd v high - level input voltage vih 0. 7 xvdd - vdd+0.3 v low - level output voltage vol 0 - 0. 2 v il = 3.6ma high - level output voltage voh vdd - 0. 2 - vdd v il = - 3.6ma a / d converter r esolution ad - - 12 bits programmable 8/12 bits differential n on - linear ity e rror dnl - 3.5 - 3.5 lsb integral n on - linear ity e rror inl - 5 - 5 lsb internal clock frequency freq 2.6 4 .0 5.1 mhz active current idd - 120 450 ua 8.2ksps (operation ) standby current ist - - 0.8 ua a fter reset releasing (unless otherwise specified t j=25[ ], vdd=3.00[v], gnd=0.00[v])
7 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 www.rohm.com tsz2211 1 ? 15 ? 001 b u21026muv power on reset t iming chart p arameter s ymbol rating unit condition min . typ . max . off period of vdd t off_vdd 0 .3 - - s r ise time for vdd t r _vdd 10 - 100 us f all time for vdd t f _vdd 0.5 - - ms r eady time for device t rdy - - 2 ms 2 - wire serial interface t iming chart p arameter s ymbol rating unit condition min . typ . max . scl clock frequency f scl - - 400 khz hold time for (repeated) start condition t hd_sta 0.6 - - us low period of scl t low 1.3 - - us high period of scl t high 0.6 - - us setup time for repeated start condition t su_sta 0.6 - - us data hold time t hd_dat 0 - 0.9 us data setup time t su_dat 100 - - ns rise time for both scl and sda t r 20 - 3 00 ns fall time for both scl and sda t f 20 - 3 00 ns setup time f or stop condition t su_sto 0.6 - - us bus free time between a stop and start condition t buf 1.3 - - us (unless otherwise specified tj=25[ ], vdd=3.00[v], gnd=0.00[v]) (unless otherwise specified tj=25[ ], vdd=3.00[v], gnd=0.00[v]) 1 . 4 v 0 . 2 v 1 . 6 5 3 . 6 0 v 0 v t o f f _ v d d t r d y t f _ v d d t r _ v d d v d d t h d _ s t a t h i g h t s u _ s t a t h d _ d a t t s u _ d a t t r t l o w t f t h d _ s t a t s u _ s t o t b u f s t a r t c o n d i t i o n r e p e a t e d s t a r t c o n d i t i o n s t o p c o n d i t i o n s t a r t c o n d i t i o n s d a s c l
8 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 www.rohm.com tsz2211 1 ? 15 ? 001 b u21026muv 2 - wire serial interface BU21026MUV supports a 2 - wire serial interface a device that controls transfer is called a master. a device that controlled by the master is called a slave. BU21026MUV is a slave device. BU21026MUV has a write protocol and a read protocol. t he write protocol consists of a start condition, an address byte, a command byte, and a stop condition. the read protocol consists of a st art condition, an address byte, one or two data bytes, and a stop condition. start condition BU21026MUV recognizes as a start condition that falling edge of sda while scl is set 3 h . if the start condition is received, BU21026MUV will be in the state that can be transfer and received data. when the start condition is fulfilled, BU21026MUV recognize the (repeated ) start condition also in data transfer. stop condition BU21026MUV recognizes as a stop condition that rising edge of sda while scl is set 3 h . if the stop condition is received, BU21026MUV will be in the state that cannot be transfer and received data. data t ransf er data is transferred with the mos t significant bit (msb) first a nd 8 - bits long . each byte has to be followed by an acknowledge bit. a timing of sda data receiving is rising edge of scl. a state of sda can only change when scl set to 3 l . i f sda is changed while scl is set 3 h , a start or stop condition will recognize d by BU21026MUV . a cknowledge bit (sending) after the master sends a byt e to BU21026MUV, an acknowledge bit is used in order that BU21026MUV may return a response to the master. at this time, the master needs to set sda into a high impedance state. when BU21026MUV receives effectively data, it sets sda to 3 l (ack). otherwise sda is set to 3 h (nack). a cknowledge bit ( receiving ) after the master receives a byte from BU21026MUV, an acknowledge bit is used for judgment of whether BU21026MUV continues data transfer. i n this case, the master needs to set sda. when sda is set to 3 l (ack), BU21026MUV continues data transfer. w hen sda is set to 3+ nack), BU21026MUV ends data transfer. address byte BU21026MUV recognize s one byte data as an address byte after a start condition. the address byte is consisted a 7 - bit slave address an d a read - write bit. if a received slave address is matched with its one, BU21026MUV issues an acknowledge to the master. o therwise BU21026MUV grhvq?w issue an acknowledge to the master and stops data transfer . u pper 5 bits of the 7 - bit slave address are 3 1 0010 . and lower 2 bits of the 7 - bit slave address are programmable by ad1 and ad0. the read - write bit (r/wb) determines direction. w hen it is 1 ? the master read s from BU21026MUV . when it is 0 ? , the master writes to BU21026MUV . table 1. address byte bi t msb 7 6 5 4 3 2 1 lsb 0 name s6 s5 s4 s3 s2 s1 s0 r/wb slave 1 0 0 1 0 ad1 ad0 - bit 7 - 1 : s6 - 0 s lave address bit 0 : r/wb 0: the master writes to BU21026MUV 1: the master reads from BU21026MUV .
9 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 www.rohm.com tsz2211 1 ? 15 ? 001 b u21026muv command byte BU21026MUV has a command byte aft er the address byte. u pper 4 bits of the command byte select an operation code. and lower 4 bits of the command byte select an operand. effects of the operands are changed by the operation code. table 2. command byte bit msb 7 6 5 4 3 2 1 lsb 0 nam e c3 c2 c1 c0 o3 o2 o1 o0 bit 7 - 4 : c3 - 0 operation code : i t is select an operation of the command. d etail is shown in table 3. bit 3 - 0 : o3 - 0 operand : it has 3 type s. the operand type is selected by the operation code . when the operation code is not 3 0101 or 3 1011 , the option type is 0. when it is 3 1011 , the option type is 1. when it is 3 0101 option type is 2. d etail is shown in table 3 and 4 . t able 3. operation code function c3 c2 c1 c0 function ad - input x - driver y - driver int p olarity operand typ e 0 0 0 0 set power off off off h 0 0 0 0 1 reserved - - - - - 0 0 1 0 measure aux aux off off h 0 0 0 1 1 reserved - - - - - 0 1 0 0 set power off off off h 0 0 1 0 1 software reset off off off h 2 0 1 1 0 reserved - - - - - 0 1 1 1 reserved - - - - - 1 0 0 0 drive x off on off l 0 1 0 0 1 drive y off off on l 0 1 0 1 0 drive z off xn - on yp - on l 0 1 0 1 1 setup keep keep keep keep 1 1 1 0 0 measure x yp on off l 0 1 1 0 1 measure y xp off on l 0 1 1 1 0 measure z1 yn xn - on yp - on l 0 1 1 1 1 measure z2 xp xn - on yp - on l 0 set power (0000, 0100) t his code is used for returning to a state for touch detection without a/d conversion after sending screen drive command. a fter this command, a/d converted data is set to 0. software reset (0101) bu2 1026muv reset s an a/d converted data, setup settings , and state of analog blocks to the initial state. i f BU21026MUV receives this code during an a/d conversion, the a/d conversion is stopped . drive x (1000), drive y (1001), drive z (1010) BU21026MUV s tar t s driving screen voltage by each code. pd is not effective. so, driving is continuous until reserv ing another command that changes state of driving screen voltage. measure aux (0010), measure x (1100), measure y (1101), measure z1 (1110), measure z2 (111 1) BU21026MUV s tart s driving screen voltage and a/d conversion. a pd of operand set, state of BU21026MUV after a/d conversion is finished. setup (1011) t he setup command has a special operand (type is 1). t he operand has maf and pull - up resistor settings. d etail is shown in table 4.
10 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 www.rohm.com tsz2211 1 ? 15 ? 001 b u21026muv table 4. operands of each type operand type o3 o2 c1 c0 0 x pd m x 1 l1 l0 ma f pu90 2 x x x x operand type 0 o3 : x 'rq?w care o2 : pd power down setting. 0 : the analog blocks off and touch detection is enable automatic ally after a/d conversion is finished. 1 : the analog blocks keep measuring state after a/d conversion is finished. o1 : m a/d comversion mode setting. 0 : the resolution of a/d conversion is 12 - bit. the conversion clock frequency is 1mhz. 1 : the resoluti on of a/d conversion is 8 - bit. the c o nversion clock frequency is 2mhz o0 : x 'rq?w care operand type 1 o3 - 2: l1 - 0 fixed. must write 3 00 . o1 : maf median average filter ( maf) setting 0 : maf is enable d (default). 1 : maf is dis able d. o0 : pu90 pull - up resistor setting . 0 : 50 kohm (default). 1 : 90 kohm operand type 2 o3 - 0: x 'rq?w care
11 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 www.rohm.com tsz2211 1 ? 15 ? 001 b u21026muv write protocol an command write is started in BU21026MUV when the master sends the start condition , the slave address of BU21026MUV , and zero in bit 0( 8 th bit) for writing , as shown in t able 1. if the slave address is matched with its own , BU21026MUV issues an acknowledge to the master. when the master receives the acknowledge from BU21026MUV , the master send the command byte. when BU21026MUV received next 8 bits, i t issues another ack nowledge to the master. after the acknowledge is received by the master, the master sends the stop or repeated start condition for ending write. figure 1. write protocol if a receiving command in bu21026m uv is not the software reset or setup, BU21026MUV starts driving screen voltage when c0 is latched by rising edge of scl. next, i f the received type of operation code is measurement, BU21026MUV starts acquisition in a/d converter whe n next falling edge of scl. BU21026MUV stops acquisition and start s a/d conversion when BU21026MUV receive the stop or repeated start condition. when BU21026MUV receives a command other than software reset during the a/d conversion, the command is ignored. and if the command is ignored, BU21026MUV grhvq?w return an acknowledge at the ack timing behind the command byte. (18 th timing in fig ure . 1) a d 1 0 0 1 1 0 0 0 c 3 c 2 c 1 c 0 o 3 o 2 o 1 o 0 a d 0 0 r / w b s l a v e a d d r a c k f r o m b u 2 1 0 2 5 a d d r e s s b y t e c o m m a n d b y t e a c q u i s i t i o n c o n v e r s i o n d r i v i n g s c l s d a a c k f r o m b u 2 1 0 2 5 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 s t o p o r r e p e a t e d s t a r t s t a r t
12 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 www.rohm.com tsz2211 1 ? 15 ? 001 b u21026muv read protocol a d ata read is started in BU21026MUV when the master sends the start condition , the slave address of BU21026MUV , and one in bit 0( 8 th bit) for r eading , as shown in table 1. if the slave address is matched with its own , BU21026MUV issues an acknowledge to the master. next, BU21026MUV send upper 8 - bit (d11 - 4) of an a/d converted 12 - bit data as data byte 1 and wait an acknowl edge from the master. a fter receiving the acknowledge, the data byte 2 is sent. u pper 4 bits of it are lower 4 bits (d3 - 0) of the a/d converted 12 - bit data, and lower 4 bits of it are all zero. i n next acknowledge timing, the master send a not - acknowledge and the stop or repeated start condition for ending read. i n the last acknowledge timing, BU21026MUV do es n ? t check the acknowledge and stop sending data. so if the master send an acknowledge and continue reading a byte, the read data become 0xff. in the 8 - bit mode, all of an a/d converted 8 - bit data is in the data byte 1. so, the pdvwhugrhvq?w need to read the data byte 2. figure 2. read protocol if an a/d conversion is not finished until falling edge scl after first acknowle dge timing with read mode, scl pin is stretch ed by BU21026MUV. in this state , scl pin is forced to low by BU21026MUV and sda value is invalid data. this state is ended when the a/d conversion is finished. a fter this state end , the master can control the scl line and read converted data. with stretch function, the master can access immediately after s ending a conversion command. if performance of an a/d conversion is needed, the master send the read command after the a/d conversion is finished. detail of a a/ d conversion time is shown in table 5 . figure 3 . read with stretch a d 1 0 0 1 1 0 0 1 d 1 1 d 1 0 d 9 d 8 d 7 d 6 d 5 d 4 a d 0 0 r / w b s l a v e a d d r a c k f r o m m a s t e r a d d r e s s b y t e d a t a b y t e 1 s c l s d a a c k f r o m m a s t e r 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 d 3 d 2 d 1 d 0 d a t a b y t e 2 1 0 0 0 0 1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7 s t a r t s t o p o r r e p e a t e d s t a r t n a c k f r o m m a s t e r a d 1 0 0 1 1 0 0 1 d 1 1 d 1 0 d 9 d 8 d 7 d 6 d 5 d 4 a d 0 0 r / w b s l a v e a d d r a c k f r o m m a s t e r a d d r e s s b y t e d a t a b y t e 1 s c l s d a a c k f r o m m a s t e r 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 d 3 d 2 d 1 d 0 d a t a b y t e 2 1 0 0 0 0 1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7 s t o p o r r e p e a t e d s t a r t n a c k f r o m m a s t e r c o n v e r s i o n x s t r e t c h s c l l o w f o r c e b y b u 2 1 0 2 5 i n v a l i d d a t a
13 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 www.rohm.com tsz2211 1 ? 15 ? 001 b u21026muv o peration position detection of touch screen the 4 - wire resistive touch screen is mainly constituted in two resistive plates, x and y. i f screen is pressed , these 2 plates are connected. a position of touch screen is detected by applying voltage to one plate and measuring voltage of another plate. t his measurement voltage is divided by touch position. i n x - position detection, x - plate is applied voltage. and voltage of y - plate is measured. i n y - position detection, y - plate is applied voltage. and voltage of y - plate is measured. t he master needs to detection 2 times for detecting x and y position w hen screen is not touch ed , a measuring plate is high impedance f rom another plate. so, it can ? t get voltage. a nd a value of the a/d conversion became unknown . if unknown values are used for calculating the coordinates, the coordinates will not show touch points. so it is require to filter unknown values when the calcul ate coordinates. figure 4 . x - position detection mode figure 5 . y - position detection mode t ouch p ressure m easurement these are two methods for measuring touch resista nce. t he first method requires that a resistance of x - plate (r x - plate ) is known. i n this method, the calculation of touch resistance (r touch ) needs x position and 2 additional measurement data (z 1 and z 2 ) that shown in f igure 6 and 7 . t he equation is as fo llow s, t he second method requires that both resistance of x - plate and resistance of y - plate (r y - plate ) are known. in this method, the calculation of r touch needs x and y position and z1. t he equation is as follow s, figure 6 . z1 - position detection mode figure 7 . z2 - position detection mode y - p l a t e x - p l a t e v d d o n o n a i n v r e f p v r e f n g n d x p y p x n y n ? ? ? ? ? ? ? ? ? ? ? 1 1 2 postion -plate x touch z z 4096 x r r y - p l a t e x - p l a t e v d d o n o n a i n v r e f p v r e f n g n d x p y p x n y n y - p l a t e x - p l a t e o n a i n v r e f p v r e f n g n d x n y n v d d o n x p y p ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? y - p l a t e x - p l a t e o n a i n v r e f p v r e f n g n d x n y n v d d o n x p y p
14 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 www.rohm.com tsz2211 1 ? 15 ? 001 b u21026muv a/d conversion time w hen maf is disabled, an a/d conversion takes 66 inter nal cor e clocks (cclk) with 12 - bit mode and 38 cclk with 8 - bit mode . when maf is enabled, it takes 476 cclk with 12 - bit mode and 244 cclk with 8 - bit mode . in maf mode, the number of sampl ing becomes 7. so the a/d conversion cycles become large. the a/d conversion clocks and time are shown in table 5 . the number of cclk and time are counted from a stop or repeated start condition after sending a conversion command. in this table, the time is calculated by cclk is 4mhz in typically. table 5 . a/d conversion time (cc lk = 4mhz) ma f mode number of cclk time [us] enable 12 - bit 47 6 11 9 . 0 8 - bit 24 4 6 1 . 0 disable 12 - bit 6 6 16. 5 8 - bit 3 8 9. 5 a/d sampling time with 2 - wire serial interface t he master need to send a conversion command and a read command for getti ng an a/d converted data. so, a t hroughput rate is affected by 2 - wire serial interface frequency. each write cycle takes 20 scl and each read cycle takes 29 scl (12 - bit mode) or 20 scl (8 - bit mode). note that each a start and a stop condition take 1 scl in this count. when the 2 - wire serial interface frequency is 400 khz , one period become 2.5us. each a/d sampling time takes 241.5us (49 x 2.5 us + 119.0 us) with 12 - bit mode and maf . so, a control t hroughput rate becomes 4.14 ksps. in maf mode, BU21026MUV o perates a/d conversion 7 times . i t means that an operation throughput rate is increased 7 times. it becomes 28.99 ksps. table 6 . control and operation throughput 2 - wire serial interface freqency ma f mode number of scl a/d conversion time [us] cycle time [ us] control throughput [ksps] operation throughput [ksps] 100 khz (10us period) enable 12 - bit 49 11 9.0 60 9.0 1.64 11. 49 8 - bit 40 6 1.0 46 1.0 2.17 15. 18 disable 12 - bit 49 16. 5 506. 5 1.9 7 - 8 - bit 40 9. 5 409. 5 2.44 - 400 khz (2. 5us period) enable 12 - bit 49 11 9.0 241. 5 4.1 4 28.99 8 - bit 40 6 1.0 16 1.0 6.2 1 43. 48 disable 12 - bit 49 16. 5 13 9.0 7. 19 - 8 - bit 40 9. 5 109. 5 9.1 3 -
15 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 www.rohm.com tsz2211 1 ? 15 ? 001 b u21026muv operational notes 1. reverse c onnection of p ower s upply connecting the power supply in reverse pol arity can damage the ic. take pr ecautions against reverse polarity when connecting the power supply , such as mounting an external diode between the power supply and the ic ? s power supply pin s. 2. power s upply l ines design the pcb layout pattern to provide lo w impedance supply lines. furthermore, connect a capacitor to ground at all power supply pins . consider the effect of temperature and aging on the capacitance value when using electrolytic capacitors. 3. g round voltage ensure that no pins are at a voltage be low that of the ground pin at any time, even during transient condition. 4. g round w iring p attern when using both small - signal and large - current ground traces, the two ground traces should be routed separately but connected to a single ground at the referenc e point of the application board to avoid fluctuations in the small - signal ground caused by large currents. also ensure that the ground traces of external components do not cause variations on the ground voltage. the ground lines must be as short and thick as possible to reduce line impedance. 5. thermal c onsideration should by any chance the maximum junction temperature rating be exceeded the rise in temperature of the chip may result in deterioration of the properties of the chip. in case of exceeding this absolute maximum rating, increase the board size and copper area to prevent exceeding the maximum junction t emperature rating. 6. recommended o perating c onditions these conditions represent a range within which the expected characteristics of the ic can be a pproximately obtained . the e lectrical characteristics are guaranteed under the conditions of each parameter . 7. inrush current when power is first supplied to the ic, it is possible that the internal logic may be unstable and inrush current may flow instanta neously due to the internal powering sequence and delays, especially if the ic has more than one power supply. therefore, give special consideration to power coupling capacitance, power wiring, width of ground wiring, and routing of connections. 8. operation u nder s trong e lectromagnetic f ield operating the ic in the presence of a strong electromagnetic field may cause the ic to malfunction . 9. testing on a pplication b oards when testing the ic on an application board, connecting a capacitor directly to a low - imp edance output pin may vxemhfwwkh,&wrvwuhvv$ozd\vglvfkdujhfdsdflwruvfrpsohwho\diwhuhdfksurfhvvruvwhs7kh,&?vsrzhuvxsso\ should always be turned off completely before connecting or removing it from the test setup during the inspection proce ss. to prevent damage from static discharge, ground the ic during assembly and use similar precautions during transport and storage. 10. inter - pin short and mounting errors ensure that the direction and position are correct when mounting the ic on the pcb. in correct mounting may result in damaging the ic. avoid nearby pins being shorted to each other especially to ground , power supply and output pin . inter - pin shorts could be due to many reasons such as metal particles, water droplets (in very humid environmen t) and unintentional solder bridge deposited in between pins during assembly to name a few. 11. unused input pin s input pin s of an ic are often connected to the gate of a mos transistor. the gate has extremely high impedance and extremely low capacitance. if left unconnected, the electric field from the outside can easily charge it. the small charge acquired in this way is enough to produce a significant effect on the conduction through the transistor and cause unexpected operation of the ic. so unless otherwi se specified, unused input pin s should be connected to the power supply or ground line. 12. regard ing the i nput p in of the ic in the construction of this ic, p - n junctions are inevitably formed creating parasitic diodes or transistors. the operation of these parasitic elements can result in mutual interference among circuits, operational faults, or physical damage. therefore, conditions which cause these parasitic elements to operate, such as applying a voltage to an input pin lower than the ground voltage sho uld be avoided. furthermore, do not apply a voltage to the input pin s when no power supply voltage is applied to the ic. even if the power supply voltage is applied, make sure that the input pin s have voltages within the values specified in the electrical characteristics of this ic.
16 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 www.rohm.com tsz2211 1 ? 15 ? 001 b u21026muv operational notes C
17 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 www.rohm.com tsz2211 1 ? 15 ? 001 b u21026muv ordering informatio n b u 2 1 0 2 6 m u v - e 2 part number package muv : vqfn020v4040 packaging and forming specification e2: embossed tap e and reel ( vqfn020v4040 ) marking diagram s part number marking package orderable part number BU21026MUV vqfn020v4040 BU21026MUV - e2 vqfn020v4040 (top view) 2 6 m u v part number marking lot number 1pin mark b u 2 1 0
18 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 www.rohm.com tsz2211 1 ? 15 ? 001 b u21026muv physical dimension , tape and reel information package name vqfn020v4040
19 / 19 tsz02201 - 0l5l0ff00890 - 1 - 2 ? 20 16 rohm co., ltd. all rights reserved. 4.aug.2016 rev.001 www.rohm.com tsz2211 1 ? 15 ? 001 b u21026muv revision history date revision changes 04.aug .201 6 001 new release
notice - p ga - e rev.00 3 ? 201 5 rohm co., ltd. all rights reserved. notice precaution on using rohm products 1. our p roducts are designed and manufactured for application in ordinary electronic equipment s ( such as av equipment, oa equipment, telecommunication equipment, home elec tronic appliances, amusement equipment, etc.). if you intend to use our products in devices requiring extremely high reliability ( such as medical equipment ( n ote 1 ) , transport equipment, traffic equipment, aircraft/spacecraft, nuclear power controllers, f uel controllers, car equipment including car accessories, safety devices, etc.) and whose malfunction or failure may cause loss of human life , bodily injury or serious damage to property ( specific applications ) , please consult with the rohm sales represe ntative in advance. unless otherwise agreed in writing by rohm in advance, rohm shall not be in any way responsible or liable for any damages, expenses or losses incurred by you or third parties arising from the use of any rohm s products for specific appl ications. ( n ote1) m edical e quipment c lassification of the s pecific applications japan usa eu china class 2. rohm designs and manufactures its products subject to strict quality control system. however, semiconductor products can fail or malfunction at a certain rate. please be sure to implement, at your own responsi bilities, adequate safety measures including but not limited to fail - safe design against the physical injury, damage to any property, which a failure or malfunction of our products may cause. the following are examples of safety measures: [a] installation of protection circuits or other protective devices to improve system safety [b] installation of redundant circuits to reduce the impact of single or multiple circuit failure 3. our p roducts are designed and manufactured for use under standard conditions a nd not under any special or extraordinary environments or conditions, as exemplified below . accordingly, rohm shall not be in any way responsible or liable for any damages, expenses or losses arising from the use of any rohms p roduct s under any special or extraordinary environments or conditions . if you intend to use our products under any special or extraordinary environments or conditions (as exemplified below), your independent v erification and confirmation of product performance, reliability, etc, pri or to use, must be necessary : [a] use of our products in any types of liquid, including water, oils, chemicals, and organic solvents [b] use of our products outdoors or in places where the p roducts are exposed to direct sunlight or dust [c] use of our prod ucts in places where the p roducts are exposed to sea wind or corrosive gases, including cl 2 , h 2 s, nh 3 , so 2 , and no 2 [d] use of our products in places where the p roducts are exposed to static electricity or electromagnetic waves [e] use of our products in p roximity to heat - producing components, plastic cords, or other flammable items [f] s ealing or coating our p roducts with resin or other coating materials [g] use of our products without cleaning residue of flux (even if you use no - clean type fluxes, cleanin g residue of flux is recommended); or washing our products by using water or water - soluble cleaning agents for cleaning residue after soldering [h] use of the p roducts in places subject to dew condensation 4 . the p roducts are not subject to radiation - proo f design . 5 . please verify and confirm characteristics of the final or mounted products in using the products. 6 . in particular, if a transient load (a large amount of load applied in a short period of time, such as pulse. is applied, confirmation of pe rformance characteristics after on - board mounting is strongly recommended. avoid applying power exceeding normal rated power; exceeding the power rating under steady - state loading condition may negatively affect product performance and reliability. 7 . de - rate power dissipation d epending on a mbient temperature . when used in sealed area, confirm that it is the use in the range that does not exceed the maximum junction temperature. 8 . confirm that operation temperature is within the specified range described in the product specification. 9 . rohm shall not be in any way responsible or liable for f ailure induced under devian t condition from what is defined in this document . precaution for mounting / circuit board design 1. when a highly active halogenous (chlorine, bromine, etc.) flux is used, the residue of flux may negatively affect product performance and reliability. 2. in principle, the reflow soldering method must be used on a surface - mount products, the flow soldering method must be used on a through hole mount products. i f the flow soldering method is preferred on a surface - mount products , please consult with the roh m representative in advance. for details , please refer to rohm mounting specification
notice - p ga - e rev.00 3 ? 201 5 rohm co., ltd. all rights reserved. precautions regarding application examples and external circuits 1. if change is made to the constant of an external circuit, please allow a sufficient margin considerin g variations of the characteristics of the p roducts and external components, including transient characteristics, as well as static characteristics. 2. you agree that application notes, reference designs, and associated data and information contained in t his document are presented only as guidance for products use . therefore, in case you use such information, you are solely responsible for it and you must exercise your own independent verification and judgment in the use of such information contained in t his document. rohm shall not be in any way responsible or liable for any damages, expenses or losses incurred by you or third parties arising from the use of such information. precaution for electrostatic this p roduct is e lectrostatic sensitive product, which may be damaged due to e lectrostatic discharge. please take proper caution in your manufacturing process and stor age so that voltage exceeding the product s maximum rating will not be applied to p roducts. please take special care under dry condition (e .g. grounding of human body / equipment / solder iron, isolation from charged objects, setting of ionizer, friction prevention and temperature / humidity control). precaution for storage / transportation 1. product performance and soldered connections may deteriorate if the p roducts are stored in the places where : [a] the p roducts are exposed to sea winds or corrosive gases, including cl2, h2s, nh3, so2, and no2 [b] the temperature or humidity exceeds those recommended by rohm [c] the products are exposed to direct sunshine or condensation [d] the products are exposed to high electrostatic 2. even under rohm recommended storage condition, solderability of products out of recommended storage time period may be degraded. it is strongly recommended to confirm solderability before using p roducts of which storage time is exceeding the recommended storage time period. 3. store / transport cartons in the correct direction, which is indicated on a carton with a symbol. otherwise bent leads may occur due to excess ive stress applied when dropping of a carton. 4. use p roducts within the specified time after opening a humidity barrier bag. baking is required before using p roducts of which storage time is exceeding the recommended storage time period . precaution for p roduct l abel a two - dimensional barcode printed on rohm p roduct s label is for rohm s internal use only . precaution for d isposition when disposing p roducts please dispose them properly using a n authorized industry waste company. precaution for foreign e xchange and foreign t rade act since concerned goods might be fallen under listed items of export control prescribed by foreign exchange and foreign trade act, please consult with rohm in case of export. precaution regarding intellectual property rights 1. all information an d data including but not limited to application example contained in this document is for reference only. rohm does not warrant that foregoing information or data will not infringe any intellectual property rights or any other rights of any third party reg arding such information or data. 2. rohm shall not have any obligations where the claims, actions or demands arising from the combination of the products with other articles such as components, circuits, systems or external equipment (including software). 3. no license, expressly or implied, is granted hereby under any intellectual property rights or other rights of rohm or any third parties with respect to the products or the information contained in this document. provided, however, that rohm will not assert it s intellectual property rights or other rights against you or your customers to the extent necessary to manufacture or sell products containing the products, subject to the terms and conditions herein. other precaution 1. this document may not be reprinted or reproduced, in whole or in part, without prior written consent of rohm. 2. the products may not be disassemble d, converted, modified, reproduced or otherwise changed without prior written consent of rohm. 3. i n no event shall you use in any way whatso ever the products and the related technical information contained in the products or this document for any military purposes , including but not limited to, the development of mass - destruction weapons . 4. the proper names of companies or products described in this document are trademarks or registered trademarks of rohm, its affiliated companies or third parties.
datasheet datasheet notice ? we rev.001 ? 2015 rohm co., ltd. all rights reserved. general precaution 1. before you use our pro ducts, you are requested to care fully read this document and fully understand its contents. rohm shall n ot be in an y way responsible or liabl e for fa ilure, malfunction or acci dent arising from the use of a ny rohms products against warning, caution or note contained in this document. 2. all information contained in this docume nt is current as of the issuing date and subj ec t to change without any prior notice. before purchasing or using rohms products, please confirm the la test information with a rohm sale s representative. 3. the information contained in this doc ument is provi ded on an as is basis and rohm does not warrant that all information contained in this document is accurate an d/or error-free. rohm shall not be in an y way responsible or liable for an y damages, expenses or losses incurred b y you or third parties resulting from inaccur acy or errors of or concerning such information.
datasheet part number BU21026MUV package vqfn020v4040 unit quantity 2500 minimum package quantity 2500 packing type taping constitution materials list inquiry rohs yes BU21026MUV - web page

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