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datashee t product structure silicon monolithic integrated circuit this product has no designed protec tion against radioactive rays 1/15 ? 2012 rohm co., ltd. all rights reserved. www.rohm.com tsz22111 ? 14? 001 tsz02201-0g3g0cz10310-1-2 26.feb.2014 rev.002 16-channel, 8-bit pwm led driver with i 2 c compatible and 2-wire serial interface BD7844AEFV-LB general description this is the product guarantees long time support in industrial market. BD7844AEFV-LB is led display driver. it can control 16ch nch open drain output for led drive. it can control the luminance of the leds by the setting of the internal register, with 256 steps pwm control. it supports i 2 c interface. htssop-b28 (with back-side metal for heat radiation) package. features ? long time support product for industrial applications ? 16ch 80ma (absolute maximum rating) ? conforming to i 2 c -bus i/f (1mhz fast mode plus) ? either of interactive or single direction can be selected with the i2cs el pin. (2mhz clock frequency on single direction) ? independent setting of output brightness is possible by register setting for each channel. (pwm 256 steps) ? built-in thermal shutdown (tsd circuit ? built-in power-on reset circuit key specifications ? operating power supply voltage range: 4.5v to 5.5v ? led output terminal current: 80ma (max.) ? operating temperature range: -40 to +85 package w(typ.) x d(typ.) x h(max.) applications industrial equipment, led indicators and illuminators for industrial or home appliance led signboards large led displays traffic signboards, amusement, hobby, etc. typical application circuit pin configuration [top view] htssop-b28 9.70mm x 6.40mm x 1.00mm 4.5v ? 5.5v resetb sda scl i2csel a0 out0 out1 vled (max 20v) gnd gnd gnd a1 a2 a3 vdd out15 4.7uf out14 BD7844AEFV-LB from c ontrolle r
2/15 datasheet datasheet BD7844AEFV-LB ? 2012 rohm co., ltd. all rights reserved. www.rohm.com tsz22111 ? 15? 001 tsz02201-0g3g0cz10310-1-2 26.feb.2014 rev.002 absolute maximum ratings (ta=25 ) parameter symbol ratings unit power supply voltage vddmax - 0.3 to 7.0 v output terminal voltage *1 voutmax - 0.3 to 20.0 v output terminal current *1 ioutmax 80 *3 ma/ch logic input terminal voltage *2 vinmax - 0.3 to vdd+0.3 Q 7.0 v permissible dissipation pd 1.45 *4 w 4.70 *5 w operating temperat ure range topr - 40 to 85 storage temperature range tstr - 55 to 150 junction temperature tjmax 150 please be careful that the anti-radiation design is not applied to this ic. *1) out0, out1, out2, out3, out4, out5 , out6, out7, out8, out9, out10, ou t11, out12, out 13, out14, out15 *2) i2csel, a0, a1, a2, a3, resetb, scl, sda *3) please take the ic?s power consumption & permissib le dissipation into consideration before using it. *4) mounted on rohm standard board (one layer), ta = 2 5 or more, it is reduced with 11.6mw/ . *5) mounted on rohm standard board (four layer) ta = 2 5 or more, it is reduced with 37.6mw/ . recommended operating ratings (ta=-40 to 85 ) parameter symbol ratings unit conditions power supply voltage vdd 4.5 to 5.5 v high level input voltage vih vddx0.7 to vdd v sda,scl,resetb, i2csel,a0,a1,a2,a3 low level input voltage vil 0 to vddx0.3 v low level output current iol 0 to 30 ma sda electrical characteristics (unless otherwise specified, ta=25 , vdd=5.0v, gnd=0v) parameter symbol limits unit conditions min. typ. max. vdd circuit current1(all ch off) idd1 8.7 11.9 ma input pin fixed vdd circuit current2(all ch full on) idd2 9.5 13.0 ma input pin fixed input/output leak current ileak1 1.0 a sda,scl,a0,a1,a2,a3 input voltage = vdd or output voltage = gnd pull up resistor rrstb 30 60 90 k ? resetb ri2c 55 110 165 k ? i2csel output pin leak current ileak2 1.0 a out0 to out15 vout = 20v power on reset voltage vpor 2.4 v low level output current iol 30 ma sda vol = 0.4v low level output voltage vol 200 550 mv out0 to out15 iout = 80ma resistor at on ron 2.5 6.875 ? out0 to out15 iout = 80ma input capacitance ci 6 pf scl,resetb,i2csel, a0,a1,a2,a3 i/o capacitance cio 12 pf sda
3/15 datasheet datasheet BD7844AEFV-LB ? 2012 rohm co., ltd. all rights reserved. www.rohm.com tsz22111 ? 15? 001 tsz02201-0g3g0cz10310-1-2 26.feb.2014 rev.002 logic signal timing specification (unless otherwise specified, ta=25 , vdd=5.0v, gnd=0v) parameter symbol limits unit conditions min. typ. max. scl clock frequency 1 f scl1 - - 1.0 mhz i2csel=h : sda=i/o scl clock frequency 2 f scl2 - - 2.0 mhz i2csel =l : sda=input bus free time between a stop and start condition *1 t buf 500 - - ns hold time (repeated) start condition. after this period, the first clock is generated t hd;sta 260 - - ns set-up time for a repeated start condition t su;sta 260 - - ns set-up time for stop condition t su;sto 260 - - ns sda data hold time t hd;dat 0 - - ns sda data valid acknowledge time *2 t vd;ack - - 450 ns i2csel =h : sda=i/o sda data valid time *3 t vd;dat - - 450 ns i2csel =h : sda=i/o sda data set-up time t su;dat 50 - - ns scl clock low period1 t low1 500 - - ns i2csel =h : sda=i/o scl clock high period1 t high1 260 - - ns i2csel =h : sda=i/o scl, sda fall time1 t f1 - - 120 ns i2csel =h : sda=i/o scl, sda rise time1 t r1 - - 120 ns i2csel =h : sda=i/o scl clock low period2 t low2 230 - - ns i2csel =l : sda=input scl clock high period2 t high2 250 - - ns i2csel =l : sda=input scl, sda fall time2 t f2 - - 50 ns i2csel =l : sda=input scl, sda rise time2 t r2 - - 50 ns i2csel =l : sda=input pulse width of spikes which must be suppressed by scl, sda filter t sp - 50 - ns reset pulse width *4 t w - 10 - ns *1) keep more than 100s bus free time after power on. *2) tvd;ack :time for acknowledge signal from scl=?l? to sda(output)=?l? *3) tvd;dat :time for from scl=?l? to sda valid data output *4) miss-operation is likely to happen with reset in accessing i 2 c bus.
4/15 datasheet datasheet BD7844AEFV-LB ? 2012 rohm co., ltd. all rights reserved. www.rohm.com tsz22111 ? 15? 001 tsz02201-0g3g0cz10310-1-2 26.feb.2014 rev.002 pin descriptions pin no pin name i/o pull up register unused terminal setting esd diode functions for power for ground 1 i2csel i 110k ? gnd vdd gnd i 2 c access mode select for sda (h: i/o, l: input only) 2 a0 i - gnd vdd gnd slave address setting 3 a1 i - gnd vdd gnd slave address setting 4 a2 i - gnd vdd gnd slave address setting 5 a3 i - gnd vdd gnd slave address setting 6 out0 o - gnd - gnd open drain output 7 out1 o - gnd - gnd open drain output 8 out2 o - gnd - gnd open drain output 9 out3 o - gnd - gnd open drain output 10 gnd - - gnd vdd - ground 11 out4 o - gnd - gnd open drain output 12 out5 o - gnd - gnd open drain output 13 out6 o - gnd - gnd open drain output 14 out7 o - gnd - gnd open drain output 15 out8 o - gnd - gnd open drain output 16 out9 o - gnd - gnd open drain output 17 out10 o - gnd - gnd open drain output 18 out11 o - gnd - gnd open drain output 19 gnd - - gnd vdd - ground 20 out12 o - gnd - gnd open drain output 21 out13 o - gnd - gnd open drain output 22 out14 o - gnd - gnd open drain output 23 out15 o - gnd - gnd open drain output 24 gnd - - gnd vdd - ground 25 resetb i 60k ? gnd vdd gnd reset input pin (l: reset, h: reset cancel) 26 scl i - gnd - gnd serial clock input pin 27 sda i/o - gnd - gnd serial data i/o pin 28 vdd - - gnd - gnd power supply - thermal pad - - gnd vdd - heat radiation pad of back side connect to gnd * please connect the unused led pins to the ground. * it is prohibition to set the registers for unused led.
5/15 datasheet datasheet BD7844AEFV-LB ? 2012 rohm co., ltd. all rights reserved. www.rohm.com tsz22111 ? 15? 001 tsz02201-0g3g0cz10310-1-2 26.feb.2014 rev.002 vco resetb sda scl enable i2 c f il t e r i2csel a0 lo g i c resetb tsd po r gnd 16mhz ou t0 ndmos output sink type pwm0 out1 pwm1 gnd gnd a1 a2 a3 vdd out15 pwm15 block diagram notes on using BD7844AEFV-LB ? please do not make output terminal current per one terminal exceed 80ma by putting current limit resistor for open drain output terminal from out0 to out15. output termi nal current iledmax formulate by the following. iledmax[a] = ( vled[v] ? vf[v] ) / (rc[ ] + ron[] ) 0.080[a] vled ron rc vf iledmax ? low output drive ability of sda terminal becomes high, which cause undershoot noise at low output. it is possible to remove undershoot noise by inserting damping resistor as close as sda terminal. ? it is recommended that power supply vdd and led power supply vled should be used with separated power supply. if using both vdd and vled with common power supply, malfunc tion might be occurred by transmitting noise associated with pwm signal of open drain output terminal from vled wiring to vdd wiring. in case of using vdd and vled with common power supply, please insert bypass capacitor as close as vdd terminal after separating vdd wiring and vled wiring from the end in order to make common impedance minimum. in addition, please insert bypass capacitor on vled wiring as necessary in order to prevent noise of vled wiring side from being transmitted to vdd side as much as p ossible.
6/15 datasheet datasheet BD7844AEFV-LB ? 2012 rohm co., ltd. all rights reserved. www.rohm.com tsz22111 ? 15? 001 tsz02201-0g3g0cz10310-1-2 26.feb.2014 rev.002 definition of logic signal timing figure 1. definition of logic signal timing t w 50% 50% scl sda resetb start ack or read cycle outx led off t buf t su:sta t low t high 1/f scl t hd:sta t su:dat t r t f t hd:dat t vd:dat t vd:ack t su:sto sda scl protocol start condition (s) bit 7 msb (a7) bit 6 (a7) bit 7 (d1) bit 8 (d0) acknowledge (a) stop condition (p) t sp t hd:sta t su:sta t su:sto t su:dat t high t hd:sta t hd:dat t low t buf t r t f sr p p s sda scl
7/15 datasheet datasheet BD7844AEFV-LB ? 2012 rohm co., ltd. all rights reserved. www.rohm.com tsz22111 ? 15? 001 tsz02201-0g3g0cz10310-1-2 26.feb.2014 rev.002 function explaining 1. slave address led driver BD7844AEFV-LB is a slave device. the master device outputs the transmission clock and the transmission data, and BD7844AEFV-LB who is the slave returns the a cknowledgement. the master device transmits the slave address of BD7844AEFV-LB following the start condition. afterwards, BD7844AEFV-LB can be controlled in the command by transmitting the register address and t he register data continuously , and doing the transmission completion under the stop condition. figure 2 shows basic format (i 2 c) of the control command of BD7844AEFV-LB. s=start, p=stop figure 2. basic format of control command i 2 c BD7844AEFV-LB has three kinds of slave addresses (for usually, for all calls, and for software reset). 1-1. usual slave address figure 3 shows the slave address of BD7844AEFV-LB. because an internal pull-up resistor has not placed to the address terminal (a[3:0]) that can be selected with hardware to save power consumption, it is necessary to connect them with high ( =vdd ) or low ( =gnd ). 1 0 1 a3 a2 a1 a0 r/w figure 3. usual slave address the last rw bit of the slave address byte defines the executed operation. reading is selected when setting it to logic 1, and writing is selected when setting it to logic 0. fixed a3 a2 a1 a0 r/w function 101 0 0 0 0 r/w usual 1 101 0 0 0 1 r/w usual 2 101 0 0 1 0 r/w usual 3 101 0 0 1 1 r/w usual 4 101 0 1 0 0 r/w usual 5 101 0 1 0 1 r/w usual 6 101 0 1 1 0 r/w usual 7 101 0 1 1 1 r/w usual 8 101 1 0 0 0 r/w all call 101 1 0 0 1 r/w usual 9 101 1 0 1 0 r/w usual 10 101 1 0 1 1 0 software reset 101 1 1 0 0 r/w usual 11 101 1 1 0 1 r/w usual 12 101 1 1 1 0 r/w usual 13 101 1 1 1 1 r/w usual 14 table1. slave address slave address fixed it is optional with the address terminal s slave address register address register data p a a a ?0? = write from master to slave from slave to maste r s p a a a s a slave address register address slave address register data r/w ?0? = write ?1? = read r/w r/w master transmits data master receives data
8/15 datasheet datasheet BD7844AEFV-LB ? 2012 rohm co., ltd. all rights reserved. www.rohm.com tsz22111 ? 15? 001 tsz02201-0g3g0cz10310-1-2 26.feb.2014 rev.002 function explaining - continued 1-2. slave address for all call [1011000] is used as a slave address for all call. (figure 4) 1 0 1 1 0 0 0 r/w figure 4. slave address for all call all BD7844AEFV-LB on the bus can control in the command at the same time by the slave address for all call. it enters the state that can respond to all call when power supply (vdd) is turned on. it can be selected not to respond when the all call bit of mode1 register is set to logic ?0?. because the register data is returned from all bd7844aef v-lb on the bus when the last r/w bit of the slave address byte is set to logic "1" (read) when the slave address for all ca lls is used, the master cannot read the register data of specific BD7844AEFV-LB. please use a usual slave address to read the register data of specific BD7844AEFV-LB. 1-3. slave address for software reset [1011011] is used as a slave address for software reset. (figure 5) 1 0 1 1 0 1 1 0 figure 5. slave address for software reset all BD7844AEFV-LB on the bus can be reset at the same time by the slave address for software reset. it is necessary to use the slave address for software rese t with r/w=0. BD7844AEFV-LB doesn't recognize software reset for r/w=1. please refer to "3 -2. software reset" for details. take care: because slave address [1011011] for softwa re reset is a reserved address, it is not possible to use it as a usual slave address. take care: slave address [1011000] for all calls must not use as a usual slave address because it becomes enable when power supply (vdd) is turned on. slave address for all call unavailable in address terminal slave address for software reset unavailable in address terminal r/w
9/15 datasheet datasheet BD7844AEFV-LB ? 2012 rohm co., ltd. all rights reserved. www.rohm.com tsz22111 ? 15? 001 tsz02201-0g3g0cz10310-1-2 26.feb.2014 rev.002 function explaining - continued 2. register address after completing the acknowledgement of the slave address, the master device transmits the register address to BD7844AEFV-LB. figure 6 shows the register address. figure 6. register address the auto increment option is s pecified for msb 3bit.the address of the register that wants to be controlled is specified for lsb 5bit. sending register data continuously with the auto increment option in the three high rank bits can continuously set each brightness control register. (mode1 regi ster cannot be set by the auto increment option.) the register of BD7844AEFV-LB is shown in table 2 and the auto increment option is shown in table 3 register address(hex) register name initial value after reset access function 00 pwm0 [7:0] 00h r/w brightness control (256steps) out0 01 pwm1 [7:0] 00h r/w brightness control (256steps) out1 02 pwm2 [7:0] 00h r/w brightness control (256steps) out2 03 pwm3 [7:0] 00h r/w brightness control (256steps) out3 04 pwm4 [7:0] 00h r/w brightness control (256steps) out4 05 pwm5 [7:0] 00h r/w brightness control (256steps) out5 06 pwm6 [7:0] 00h r/w brightness control (256steps) out6 07 pwm7 [7:0] 00h r/w brightness control (256steps) out7 08 pwm8 [7:0] 00h r/w brightness control (256steps) out8 09 pwm9 [7:0] 00h r/w brightness control (256steps) out9 0a pwm10 [7:0] 00h r/w brightness control (256steps) out10 0b pwm11 [7:0] 00h r/w brightness control (256steps) out11 0c pwm12 [7:0] 00h r/w brightness control (256steps) out12 0d pwm13 [7:0] 00h r/w brightness control (256steps) out13 0e pwm14 [7:0] 00h r/w brightness control (256steps) out14 0f pwm15 [7:0] 00h r/w brightness control (256steps) out15 1a* mode1 [7:0] 03h r/w mode 1 setting *mode1 register cannot be set by the auto increment option. table2. register ai2 ai1 ai0 function 0 0 0 auto increment none 0 0 1 address auto increment (+1) for brightness control register pwm0 to 15only. 0 1 0 prohibited 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1 table3. auto increment option auto increment option register address ai 2 ai 1 ai 0 ra 4 ra 3 ra 2 ra 1 ra 0
10/15 datasheet datasheet BD7844AEFV-LB ? 2012 rohm co., ltd. all rights reserved. www.rohm.com tsz22111 ? 15? 001 tsz02201-0g3g0cz10310-1-2 26.feb.2014 rev.002 function explaining - continued 2-1. pwm0 to pwm15 register data the brightness of output terminal out0 to out15 is set by the register data of pwm0(address:00h) to pwm15(address:0fh). the pwm brightness control in 256 steps is possible from 00h (complete off) to ffh (complete on). brightness can formulate by followings (pwm n [7:0] means each register value of pwm0-pwm15). iled = iledmax x pwm n [7:0] / 256 (pwm n [7:0] = 00h-feh) iled = iledmax (pwm n [7:0] = ffh) 2-2. mode1 registers data the operation mode of BD7844AEFV-LB is set accord ing to mode1 register (address: 1ah) data. table 4 shows the allocation of the bit of mode1 register data. bit bit name access value function 7 limitreset r/w 0 * device limitation software reset : off 1 device limitation software reset : on 6 protect0 r/w 0 please write ?0?. it is not recognized as mode1 register data at ?1?. 5 reservation r/w 0 * please write ?0? 1 prohibited 4 pwmslow r/w 0 * pwm period is 60khz 1 pwm period is 2khz 3 reservation r/w 0 * please write ?0?. 1 prohibited 2 reservation r/w 0 * please write ?0?. 1 prohibited 1 protect1 r/w 1 please write ?1?. it is not recognized as mode1 register data at ?0?. 0 allcall r/w 0 it doesn't respond to the slave address for all call. 1 * it responds to the slave address for all call. *default value after reset table4. mode1 register (address: 1ah) data mode1 register data cannot be set by the auto increment option. please set it alone by the following format. in the correct execution, there should not be device that monopolizes the bus. 2-3. mode1 register data setting procedure the start condition is sent by the i 2 c bus master. 1. the slave address of BD7844AEFV-LB that wants to be set by mode1 register is sent by the master. 2. when the slave address is sent and re cognized, the master sends mode1 r egister address [00011010] (1ah). it is recognized only when lsb 5bit are [11010] and the auto increment option in msb 3bit are [000]. 3. when mode1 register address is sent and recogni zed, the master sends mode1 register data. it recognizes it as data only when the data confirmation bit (bit 6=0 and bit1=1) is all correct. 4. when correct mode1 register data is sent and recognized, the master se nds the stop condition to end mode1 setting command. afterwards, limitreset, pw mslow, and allcall become effective. 3. reset BD7844AEFV-LB has four kinds of resets (power on , software, device limitation software, external,). 3-1. power-on reset when the power supply is forced to vdd, internal power-on reset maintains BD7844AEFV-LB in the state of reset until vdd reaches vpor. reset is liberated at vpor, and the register and the i 2 c bus state machine of BD7844AEFV-LB are initialized in the state of default.
11/15 datasheet datasheet BD7844AEFV-LB ? 2012 rohm co., ltd. all rights reserved. www.rohm.com tsz22111 ? 15? 001 tsz02201-0g3g0cz10310-1-2 26.feb.2014 rev.002 function explaining - continued 3-2. software reset all BD7844AEFV-LB on the i 2 c bus can be reset in the power supply on condition by software reset. in the correct execution, there should not be device that monopolizes the bus. soft ware reset is defined as follows. 1. the start condition is sent by the i 2 c bus master. 2. the slave address for software reset that the r/ w bit is set to "0" (write) is sent by the i 2 c bus master. 3. only when it is recognized that the slave address for software reset is [10110110] (b6h), BD7844AEFV-LB executes reset. when the r/w bit is set to logic "1" (read), it is not recognized. even r/w bit is logic "0" and "1", the acknowledgement is returned. but it is only logic "0" that reset is recognized. 4. when the slave address for software reset is sent and re cognized, the master sends two bytes with two specific values. 5. byte 1= a5h: BD7844AEFV-LB recognizes only this value. when byte 1 is not a5h, BD7844AEFV-LB doesn't recognize it. 6. byte 2= 5ah: BD7844AEFV-LB recognizes only this value. when byte 2 is not 5ah, BD7844AEFV-LB doesn't recognize it. 7. the master sends the stop condition to terminate the software reset command when correct two bytes are sent and it is recognized correctly. afterwards, BD7844AEFV-LB is reset in the power supply on condition. 3-3. device limitation software reset only BD7844AEFV-LB selected in the slave address can be re set in the power supply on condition by making the limitreset bit of the mode1 register logic 1. 3-4. external reset external reset is executed by maintaining resetb terminal for the period of minimum t w . the register and the i 2 c bus state machine of BD7844AEFV-LB is maintained in the state of default until becoming resetb input becomes ?h? level. take care: please connect the resetb terminal with ?h?, when you do not use an active connection. 4. i2csel function it can be set that the sda terminal accepts only the i nput by connecting the i2csel terminal with ?l?. take care : because the acknowledge and reading data of t he register is not returned to the master device, control software for i 2 c cannot be used as it is. power dissipation (on the rohm?s standard board) figure 7. power dissipation 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 0 25 50 75 100 125 150 ta power dissipation pd w) 1.45w
12/15 datasheet datasheet BD7844AEFV-LB ? 2012 rohm co., ltd. all rights reserved. www.rohm.com tsz22111 ? 15? 001 tsz02201-0g3g0cz10310-1-2 26.feb.2014 rev.002 operational notes 1. absolute maximum ratings an excess in the absolute maximum ratings, such as supply voltage, temperature range of operating conditions, etc., can break down devices, thus making impossible to identify breaking mode such as a short circuit or an open circuit. if any special mode exceeding the absolute maximum ratings is assumed, consideration should be given to take physical safety measures including the use of fuses, etc. 2. power supply and ground line design pcb pattern to provide low impedance for the wiring between the power supply and the ground lines. pay attention to the interference by common impedance of layout pattern when ther e are plural power supplies and ground lines. especially, when there are ground pattern for small signal and ground pattern for large current included the external circuits, please separate each ground pattern. furthe rmore, for all power supply pins to ics, mount a capacitor between the power supply and the ground pin. at the same ti me, in order to use a capacitor, thoroughly check to be sure the characteristics of the capacitor to be used pres ent no problem including the occurrence of capacity dropout at a low temperature, thus determining the constant. 3. ground voltage make setting of the potential of the ground pin so that it will be maintai ned at the minimum in any operating state. furthermore, check to be sure no pins are at a potential lower than the ground voltage including an actual electric transient. 4. short circuit between pins and erroneous mounting in order to mount ics on a set pcb, pay thorough attention to the direction and offset of the ics. erroneous mounting can break down the ics. furthermore, if a short circuit occurs due to foreign matters entering between pins or between the pin and the power supply or the ground pin, the ics can break down. 5. operation in strong electromagnetic field be noted that using ics in the strong elec tromagnetic field can malfunction them. 6. input pins in terms of the construction of ic, parasitic elements are in evitably formed in relation to potential. the operation of the parasitic element can cause interference with circuit operati on, thus resulting in a malf unction and then breakdown of the input pin. therefore, pay thorough att ention not to handle the input pins, such as to apply to the input pins a voltage lower than the ground respectively, so that any parasitic element will operate. furthermore, do not apply a voltage to the input pins when no power supply voltage is applied to t he ic. in addition, even if the power supply voltage is applied, apply to the input pins a voltage lower than th e power supply voltage or within the guaranteed value of electrical characteristics. 7. external capacitor in order to use a ceramic capacitor as the external capacitor, determine the c onstant with consideration given to a degradation in the nominal capacitance due to dc bias and c hanges in the capacitance due to temperature, etc. 8. thermal shutdown circuit (tsd) this lsi builds in a thermal shutdown (tsd) circuit. when junction temperatures become detection temperature or higher, the thermal shutdown circuit operates and turns a swit ch off. the thermal shutdown circuit, which is aimed at isolating the lsi from thermal runaway as much as possible, is not aimed at the protection or guarantee of the lsi. therefore, do not continuously use the lsi with this circuit operating or use the lsi assuming its operation. 9. thermal design perform thermal design in which there ar e adequate margins by taking into account the permissible dissipation (pd) in actual states of use. 10. about the pin for the test, the un-use pin prevent a problem from being in the pin for the test and the un-use pin under the state of actual use. please refer to this datasheet. and, as for the pin that doesn't specia lly have an explanation, ask our company person in charge. 11. about the rush current for ics with more than one power supply, it is possible that rush current may flow instantaneously due to the internal powering sequence and delays. therefore, give special c onsideration to power coupling capacitance, power wiring, width of ground wiring, and routing of wiring.
13/15 datasheet datasheet BD7844AEFV-LB ? 2012 rohm co., ltd. all rights reserved. www.rohm.com tsz22111 ? 15? 001 tsz02201-0g3g0cz10310-1-2 26.feb.2014 rev.002 ordering information b d 7 8 4 4 a e f v - l b e 2 part number package efv:htssop-b28 product class lb for industrial applications packaging and forming specification e2: embossed tape and reel marking diagram htssop-b28 (top view) bd7844aefv lot number 1pin mark
14/15 datasheet datasheet BD7844AEFV-LB ? 2012 rohm co., ltd. all rights reserved. www.rohm.com tsz22111 ? 15? 001 tsz02201-0g3g0cz10310-1-2 26.feb.2014 rev.002 physical dimension tape and reel information package name htssop-b28 ? order quantity needs to be multiple of the minimum quantity. embossed carrier tape (with dry pack) tape quantity direction of feed the direction is the 1pin of product is at the upper left when you hold reel on the left hand and you pull out the tape on the right hand 2500pcs e2 () direction of feed reel 1pin
15/15 datasheet datasheet BD7844AEFV-LB ? 2012 rohm co., ltd. all rights reserved. www.rohm.com tsz22111 ? 15? 001 tsz02201-0g3g0cz10310-1-2 26.feb.2014 rev.002 revision history date revision changes 19.jun.2012 001 new release 26.feb.2014 002 delete sentence ?and log life cycle? in general description and futures. add ?industrial equipment? in applications. applied new style (?title? and ?physical dimension tape and reel information?).
datasheet d a t a s h e e t notice - ss rev.002 ? 2014 rohm co., ltd. all rights reserved. notice precaution on using rohm products 1. if you intend to use our products in devices requiring extremely high reliability (such as medical equipment (note 1) , aircraft/spacecraft, nuclear power controllers, etc.) and whos e malfunction or failure may cause loss of human life, bodily injury or serious damage to property (?specific applications?), please consult with the rohm sales representative in advance. unless otherwise agreed in writ ing by rohm in advance, rohm shall not be in any way responsible or liable for any damages, expenses or losses in curred by you or third parties arising from the use of any rohm?s products for specific applications. (note1) medical equipment classification of the specific applications japan usa eu china class class class b class class 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 responsibilities, adequate safety measures including but not limited to fail-safe desi gn 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 products are not designed under any special or extr aordinary environments or conditi ons, 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 rohm?s products under an y 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 verification and confirmation of product performance, reliability, etc, prior to use, must be necessary: [a] use of our products in any types of liquid, incl uding water, oils, chemicals, and organic solvents [b] use of our products outdoors or in places where the products are exposed to direct sunlight or dust [c] use of our products in places where the products ar e 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 products are exposed to static electricity or electromagnetic waves [e] use of our products in proximity to heat-producing components, plastic cords, or other flammable items [f] sealing or coating our products with resin or other coating materials [g] use of our products without cleaning residue of flux (ev en if you use no-clean type fluxes, cleaning 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 products in places subject to dew condensation 4. the products are not subjec t to radiation-proof 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 per iod of time, such as pulse. is applied, confirmation of performance characteristics after on-boar d mounting is strongly recomm ended. avoid applying power exceeding normal rated power; exceeding the power rating under steady-state loading c ondition may negatively affect product performance and reliability. 7. de-rate power dissipation (pd) depending on ambient temper ature (ta). when used in seal ed area, confirm the actual ambient temperature. 8. confirm that operation temperat ure is within the specified range descr ibed in the product specification. 9. rohm shall not be in any way responsible or liable for fa ilure induced under deviant condi tion from what is defined in this document. precaution for mounting / circuit board design 1. when a highly active halogenous (chlori ne, bromine, etc.) flux is used, the resi due of flux may negatively affect product performance and reliability. 2. in principle, the reflow soldering method must be used; if flow soldering met hod is preferred, please consult with the rohm representative in advance. for details, please refer to rohm mounting specification
datasheet d a t a s h e e t notice - ss rev.002 ? 2014 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, pl ease allow a sufficient margin c onsidering variations of the characteristics of the products and external components, including transient characteri stics, as well as static characteristics. 2. you agree that application notes, re ference designs, and associated data and in formation contained in this document are presented only as guidance for products use. theref ore, 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 this 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 product is electrostatic sensitive product, which may be damaged due to electrostatic discharge. please take proper caution in your manufacturing process and storage so that voltage exceeding t he products maximum rating will not be applied to products. please take special care under dry condit ion (e.g. grounding of human body / equipment / solder iron, isolation from charged objects, se tting of ionizer, friction prevention and temperature / humidity control). precaution for storage / transportation 1. product performance and soldered connections may deteriora te if the products are stor ed in the places where: [a] the products are exposed to sea winds or corros ive gases, including cl2, h2s, nh3, so2, and no2 [b] the temperature or humidity exceeds those recommended by rohm [c] the products are exposed to di rect sunshine or condensation [d] the products are exposed to high electrostatic 2. even under rohm recommended storage c ondition, solderability of products out of recommended storage time period may be degraded. it is strongly recommended to confirm sol derability before using products of which storage time is exceeding the recommended storage time period. 3. store / transport cartons in the co rrect direction, which is indicated on a carton with a symbol. otherwise bent leads may occur due to excessive stress applied when dropping of a carton. 4. use products within the specified time after opening a hum idity barrier bag. baking is required before using products of which storage time is exceeding the recommended storage time period. precaution for product label qr code printed on rohm products label is for rohm?s internal use only. precaution for disposition when disposing products please dispose them proper ly using an authorized industry waste company. precaution for foreign exchange and foreign trade act since our products might fall under cont rolled goods prescribed by the applicable foreign exchange and foreign trade act, please consult with rohm representative in case of export. precaution regarding intellectual property rights 1. all information and data including but not limited to application example contain ed in this document is for reference only. rohm does not warrant that foregoi ng information or data will not infringe any intellectual property rights or any other rights of any third party regarding such information or data. rohm shall not be in any way responsible or liable for infringement of any intellectual property rights or ot her damages arising from use of such information or data.: 2. 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 information contained in this document. other precaution 1. this document may not be reprinted or reproduced, in whol e or in part, without prior written consent of rohm. 2. the products may not be disassembled, converted, modified, reproduced or otherwise changed without prior written consent of rohm. 3. in no event shall you use in any wa y whatsoever the products and the related technical information contained in the products or this document for any military purposes, incl uding 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 ? 2014 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.

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