1/4 rev. a structure silicon monolit hic integrated circuit product name white led driver for car navigation back light type bd1fm features ?step-up dc/dc converter ?built in uvlo built in osc ?built in ovp ?4 parallel current output output current is set with external resister ?led open detection circuit ?built in tsd ?pwm adjustment ?built in ocp ?fail output (self diagnosis) absolute maximum ratings (ta=25) parameter symbol limits unit power supply voltage(pin : 1 v cc 3 6 v load switch output voltage(pin : 2 v loadsw 3 6 v led output voltage(pin : 12, 14, 15, 17) v led 3 6 v fail output voltage(pin : 3, 20) v ol 7 v input voltage(pin : 5, 6, 10, 11, 24) v in -0.37 < vcc v vdac input voltage(pin : 8) v dac -0.37 < vcc v power dissipation pd 2.20 1 w junction temperature tjmax 150 operating temperature range topr -40+95 strage temperature range tstg -55+150 led drive current(pin : 12, 14, 15, 17) i led 150 23 m a 1 70mm70mm1.6mm glass epoxy mounting. decline by 17.6mw/ 2 it is correlate led drive current with vf dispersion each of current outputs. refer to the technical note. 3 current maximum for 1ch. do not however exceed pd. operating range(ta=25) parameter symbol limits unit power supply voltagepin : 1 v cc 4 . 5 3 0 v oscillation freq uency(pin : 26) f osc 50550 khz external synchronous frequency(pin : 6) 4 5 f sync fosc550 khz external synchronous pulse(pin : 6) f sduty 4060 % 4 sync have to be connected to gnd when external synchronizin g frequency is not needed. 5 dont change external synchronous frequency to internal osc illation frequency when external synchronous frequency is input ted. * this product is not designed for protection against radioacti ve rays.
2/4 rev. a electrical characteristicsunless otherwise specified ta=25, vcc=12v parameter symbol limit unit conditions min typ max circuit current i cc 2.5 6 10 ma en=2v, sync=vreg, rt=open pwm=open, iset=open, c in =1f standby current i st - 0 2 a en=low [vreg] (pin : 4) vreg output voltage v reg 4.5 5 5.5 v i reg =-10ma, c reg =1f [sw] (pin : 22, 23) swout upper on resistance r onh 0.05 3 7 i on =-10ma swout lower on resistance r onl 0.05 2 5 i on =10ma over current protection limited voltage v dcs 0.3 0.4 0.5 v v cs =sweep up [error amp] (pin : 12, 14, 15, 17, 27, 28) led control voltage v led 0.7 0.8 0.9 v comp shink current i skcp 40 100 200 a v led =2v, vcomp=1v comp source current i sccp -200 -100 -40 a v led =0v, vcomp=1v ss charge current i ss -14 -10 -6 a v ss 1.0v ss maximum voltage v mxss 2 2.5 3 v enhigh ss standby current i stss - 0 2 a enlow [frequency] (pin : 23, 26) oscillation frequency f osc 250 300 350 khz r t =100k [ovp] (pin : 25) over voltage detection voltage v dovp 1.86 2.0 2.14 v vovp=sweep up ovp hysteresis range v dohs 0.35 0.45 0.55 v vovp=sweep down [uvlo] (pin : 4) uvlo detection voltage v duvlo 2.5 2.8 3.1 v vreg=sweep down uvlo hysteresis range v duhs 50 100 200 mv vreg=sweep up [load sw] (pin : 2) load sw low voltage v ldl 0.05 0.15 0.3 v i load =10ma [led output] (pin : 5, 9, 12, 14, 15, 17, 25) led current relative dispersion width i led1 -6 0 6 % i led =50ma led current absolute dispersion width i led2 0 3 6 % i led =50ma iset voltage v iset 1.96 2.00 2.04 v i led =50ma pwm frequency duty 0.38 - 99.5 % f pwm =150hz, i led =50ma 1, 2, 3 pwm adjustment f pwm 0 - 20 khz duty=50%i led =50ma 2, 3 open detection voltage1 v dop1 0.05 0.15 0.3 v vled= sweep down, vovpvdop2, vssRvmxss open detection voltage2 v dop2 1.56 1.7 1.84 v vovp= sweep up, vled vdop1, vssRvmxss [logic input] (pin : 5, 6, 10, 11, 24) input high voltage v inh 2.6 - 5.5 v input low voltage v inl gnd - 0.8 v input current i in 18 35 53 a v in =5v (pin : 5, 6, 10, 11) input current i en 13 25 38 a v en =5v (pin : 24) [fail output] (pin : 3, 20) fail low voltage v fll 0.05 0.1 0.2 v i ol =1a this product is not designed for protection against radioactive rays. 1 0%, 100% input possible 2 iled=vdacriset3300 3 iled=visetriset3300, vdacviset physical dimensions?marking hsop-m28 unit:mm BD8118FM product series lot no. max 18.85 (include burr)
3/4 rev. a block diagram pin no, pin name, function pin no pin name function pin no pin name function 1 v cc power supply 15 led3 led output open drain 2 loadsw fet pin for load sw open drain 16 - n.c 3 fail1 fail signal output open drain 17 led4 led output ope n drain 4 vreg internal voltage regulator 18 - n.c. 5 pwm pwm adjustment input 19 - n.c. 6 sync external synchronizing input 20 fail2 fail signal output (open det : open drain 7 gnd ground pin 21 pgnd led output gnd pin 8 vdac dc flexible input 22 cs dc/dc output current detection p in 9 iset led output current set resistor 23 swout dc/dc sw output pin 10 leden1 led output enable pin1 24 en enable pin 11 leden2 led output enable pin2 25 ovp ovp pin over voltage de tection pin 12 led1 led output open drain 26 rt frequency set resistor 13 - n.c. 27 ss softstart pin 14 led2 led output open drain 28 comp error amp output comp err amp vreg vcc en rt ovp osc ss control logic uvlo tsd ovp soft start pwm led1 led2 led3 current driver iset pgnd driver pwm comp swout ocp cs fail1 loadsw vreg sync vdac gnd open detect iset led4 leden1 leden2 fail2
4/4 rev. a operation notes (1) absolute maximum ratings use of the ic in excess of absolute maximum ratings such as the applied voltage or operating temperature range may result in i c damage. assumptions should not be made r egarding the state of the ic (short mode or open mode) when such damage is suffered. a physical safety measure such as a fuse should be implemented when use of the ic in a special mode where the absolute maximum ratings may be exceeded is anticipated. (2) reverse connection of a power supply connector if the connector of power is wrong connected, it may result in ic breakage. in order to prevent the breakage from the wrong connection, the diode should be connected between external powe r and the power terminal of ic as protection solution. (3) power supply and ground lines. fluctuating voltage on the power supply and ground lines may da mage the device. be sure to connect a bypass filter capacitor a s close as possible to the ic between th e power supply an d ground pins. check that the selected capacit ance will not have an adverse i nfluence on any characteristics, such as a drop in the electrolytic capa citor value that can occur at low temperatures. (4) gnd potential ensure a minimum gnd pin potentia l in all operating conditions. (5) setting of heat use a setting of heat that allows for a sufficient margin in li ght of the power dissipation (pd ) in actual operating condition s. (6) pin short and mistake fitting use caution when orienting and positioning the ic for mounting on printed circuit boards.improper mounting may result in damag e to the ic. use of the ic in excess of absolute maximum ratings such as the applied voltage or operating temperature range may result in ic damage. (7) actions in strong magnetic field use caution when using the ic in the presence of a strong elect romagnetic field as doing so may cause the ic to malfunction. (8) thermal shutdown circuit(tsd) this ic built-in a thermal shutdown circuit (tsd circuit). if c hip temperature becomes 175(typ.), make the output an open state. eventually, warmly clearing the circuit is decided by th e condition of whether the heat excesses over the assigned limi t, resulting the cutoff of the circuit of ic, and not by the purpose of prev enting and ensuring the ic. therefore, the warm switch-off shou ld not be applied in the premise of continuous employing and operation af ter the circuit is switched on. (9) testing on applic ation boards when testing the ic on an application board, connecting a capacitor to a pin with low impedance subjects the ic to stress. always discharge capacitors after each process or step. ground the ic during assembly steps as an antistatic measure, and use similar caution when transporting or storing the ic. always turn the ic 's power supply off before connecting it to or removing it from a jig or fixture during the inspection process (10) ic terminal input this monolithic ic contains p+ isolation and p substrate layers between adjacent elements in order to keep them isolated. p/n junctions are formed at the intersection of these p layers with the n layers of othe r elements to create a variety of parasitic elements. for example, when a resistor and transistor are connected to pi ns. (see the chart below.) ? the p/n junction functions as a parasitic diode when gnd > (pin a) for the resistor or gnd > (pin b) for the transistor (npn) . ? similarly, when gnd > (pin b) for the transistor (npn), the pa rasitic diode described above combines with the n layer of othe r adjacent elements to operate as a parasitic npn transistor. the formation of parasitic elements as a result of the relation ships of the potentials of diffe r ent pins is an inevitable resu lt of the ic's architecture. the operation of parasitic elements can cause interference with cir cuit operation as well as ic malfunction and damage. for these reasons, it is necessary to use caution so that the ic is not used in a way that will tr igger the operation of parasitic elements, such as by the appli cation of voltages lower than the gnd (pcb) voltage to input pins. (11) ground wiring patterns when using both small signal and large current gnd patterns,it is recommended to isolate the two ground patterns,placing a sin gle ground point at the applicatio n's reference point so that the pattern wiring resistance and voltage variations caused by large curren ts do not cause variations in the small signal ground voltage. be careful not to change the gnd wiring patterns of any external componen ts. (12) led output terminal dont connect capacitor to led ou tput terminal (pin : 12,14,15, 17), as doing so may cause led short detection to malfunction. fig of chart of parasitic diode p substrate (pin a) parasitic diode near by other element p substrate (pin b) (pin b) parasitic diode parasitic diode
r0039 a www.rohm.com ? 2009 rohm co., ltd. all rights reserved. notice rohm customer support system http://www.rohm.com/contact/ thank you for your accessing to rohm product informations. more detail product informations and catalogs are available, please contact us. notes no copying or reproduction of this document, in part or in whole, is permitted without the consent of rohm co.,ltd. the content specied herein is subject to change for improvement without notice. the content specied herein is for the purpose of introducing rohm's products (hereinafter "products"). if you wish to use any such product, please be sure to refer to the specications, which can be obtained from rohm upon request. examples of application circuits, circuit constants and any other information contained herein illustrate the standard usage and operations of the products. the peripheral conditions must be taken into account when designing circuits for mass production. great care was taken in ensuring the accuracy of the information specied in this document. however, should you incur any damage arising from any inaccuracy or misprint of such information, rohm shall bear no responsibility for such damage. the technical information specied herein is intended only to show the typical functions of and examples of application circuits for the products. rohm does not grant you, explicitly or implicitly, any license to use or exercise intellectual property or other rights held by rohm and other parties. rohm shall bear no responsibility whatsoever for any dispute arising from the use of such technical information. the products specied in this document are intended to be used with general-use electronic equipment or devices (such as audio visual equipment, ofce-automation equipment, commu- nication devices, electronic appliances and amusement devices). the products specied in this document are not designed to be radiation tolerant. while rohm always makes efforts to enhance the quality and reliability of its products, a product may fail or malfunction for a variety of reasons. please be sure to implement in your equipment using the products safety measures to guard against the possibility of physical injury, re or any other damage caused in the event of the failure of any product, such as derating, redundancy, re control and fail-safe designs. rohm shall bear no responsibility whatsoever for your use of any product outside of the prescribed scope or not in accordance with the instruction manual. the products are not designed or manufactured to be used with any equipment, device or system which requires an extremely high level of reliability the failure or malfunction of which may result in a direct threat to human life or create a risk of human injury (such as a medical instrument, transportation equipment, aerospace machinery, nuclear-reactor controller, fuel-controller or other safety device). rohm shall bear no responsibility in any way for use of any of the products for the above special purposes. if a product is intended to be used for any such special purpose, please contact a rohm sales representative before purchasing. if you intend to export or ship overseas any product or technology specied herein that may be controlled under the foreign exchange and the foreign trade law, you will be required to obtain a license or permit under the law.
|
