LED Driver Series for LCD Backlight Simple Structure Constant Current Backlight Driver for LCD panels (Non-step type) No.09040EAT03 BD9206EFV ●Description BD9206EFV is an IC with a built-in 6ch high-accuracy (absolute accuracy:±4%) constant-current driver. Capable of lighting a maximum of 36 white LEDs with 6 rows×6 lines. Due to the wide input voltage range (8V~30V), it can be widely used from a backlights of Note PC and PDA etc. to LED light sources of Scanner and PPC etc. Moreover, it restrain the generation of heat at the time of large current drive because of adoption of high-heat-radiation package(HTSSOP-B20). ●Features 1) A wide input voltage range（8V～30V） 2) Capable of driving a maximum of 36 white LEDs of 6 series×6 parallel 3) Value of constant current is set by the VSET terminal 4) Due to the STBY terminal, the consumption current at the time of standby is low 5) PWM dimming is possible due to the clock input to the EN terminal 6) Built-in 5V regulator 7) High-heat-radiation package of HTSSOP-B20 6.4×6.5×0.85mm ●Applications For use in LED light source of PPC and Scanner etc., LED lighting fixture, and LCD backlight lights of monitor and note PC etc. ●Absolute maximum ratings（Ta＝25℃） Item Symbol Rating Unit Power Supply Voltage Vcc 36 V VLED 28 V LED output voltage Power Dissipation Pd 3.2 *1 W Topr -40～+85 ℃ Operational Temperature Range Storage Temperature Range Tstg -55～+150 ℃ ILED 30 *2 mA LED Maximum Current *1 Reduce with 25.6mW at 1℃ if Ta= 25℃ or above at the time of mounting a base-plate of glass epoxy in 4 layer of 70mm×70mm×1.6mm. *2 It is value per LED driver 1ch. Please set inside the range which does not exceed the allowable loss value of the package. www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 1/12 2009.07 - Rev.A Technical Note BD9206EFV ●Recommended Operational condition（Ta=25℃） Item Symbol Rating Unit Vcc 8～30 V VENCLK 100～10000 Hz VSET input possible range VSET 0.6～3 V Applied voltage range for LED terminal VLED 0.6～28 V Power Supply Voltage EN terminal clock input possible range ●Electrical Characteristics（Unless specified, Ta=25℃,Vcc=24V） Ratings Item Symbol Unit Conditions Min. Typ. Max. IOFF - 17 28 μA STBY=L, EN=L, TEST=L IST - 1.8 3.6 mA STBY=H, EN=L, TEST=L ICC - 2.5 5.0 mA STBY=H, EN=H, TEST=L ILED 19.2 20.0 20.8 mA VSET=2.0V, VLED=1V ILEDLK - 0.0 5.0 μA VLED=26V IINVSET - -0.05 -0.10 μA VSET=2V Output voltage VREG 4.7 5.0 5.3 V Io=1mA Output current IOMAX 10 30 - mA Vo=VREG×0.9 Detection voltage VUVREG 2.4 2.9 3.4 V VREG fall down Hysteresis voltage VUHYVREG 0.05 0.1 0.2 V VREG rise up Input Low level VIL -0.3 - 0.8 V Input high level VIH 2.0 - Vcc V Input current RPD 33 47 66 μA 【Whole】 Circuit electric current when OFF Circuit electric current when stand by Circuit electric current when operating 【LED Driver 1~6】 Output current Leak electric current when OFF Influx electric current to VSET terminal 【VREG】 【UVLO】 【STBY, EN, TEST】 Vin=3V It is not the radiation-proof design for this product. www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 2/12 2009.07 - Rev.A Technical Note BD9206EFV ●Block diagram VCC STBY 20 2 PREREG 100k AGND ●Package outline drawing 5V REG REF 1 UVLO 4 Vo 5VREG Current Driver 6 5VREG EN VREG LED1 ENH1 3 100k BD9206EFV ISET1 PREREG ・・・・ 5VREG TSD LED2～5 5VREG VSET 18 Driver Current Setting 6 ISET2～5 Lot No. 4 ・・・・・ RSET 5VREG 15 TEST LED6 PGND1～2 17 ISET6 HTSSOP-B20（Unit：mm） Fig..1 Fig..2 ●Terminal placement diagram ●Terminal explanation Terminal number Terminal name 1 VREG 2 STBY EN VREG 1 20 STBY 2 19 N.C. EN 3 18 VSET AGND 4 17 TEST PGND1 5 16 PGND2 3 LED1 6 15 LED6 4 LED2 7 14 LED5 5 LED3 8 13 LED4 N.C. 9 12 N.C. N.C. 10 11 N.C. VCC Terminal name Power supply for internal circuit 11 N.C. (Not yet connected terminal) Stand by terminal (Low:OFF,High:stand by, operation) 12 N.C. (Not yet connected terminal) LED1～16 Enable terminal(Active:High) 13 LED4 Output terminal 4 for LED driver AGND GND for internal standard section 14 LED5 Output terminal 5 for LED driver PGND1 POWER GND for LED driver 15 LED6 Function Output terminal 6 for LED driver Power GNDPOWER GND for LED driver Terminal for test mode shift (Use at usual time：Low) Standard voltage terminal for fixed electric current setting 6 LED1 Output terminal 1 for LED driver 16 PGND2 7 LED2 Output terminal 2 for LED driver 17 TEST LED3 Output terminal 3 for LED driver 18 VSET 9 N.C. (Not yet connected terminal) 19 N.C. (Not yet connected terminal) 10 N.C. (Not yet connected terminal) 20 VCC Terminal of power supply 8 Fig..3 Terminal number Function www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 3/12 2009.07 - Rev.A Technical Note BD9206EFV ●Reference data(Unless specified,VCC=24V, Ta=25℃) 0.05 3.0 STBY=L EN=L 2.5 3 ICC [mA] 0.02 STBY=H EN=H 4 2.0 0.03 ICC [mA] ICC [mA] 0.04 5 STBY=H EN=L 1.5 2 1.0 1 0.5 0 0.01 0.00 0 4 8 12 16 20 VCC [V] 24 28 32 36 0 0 4 8 12 16 20 24 28 32 8 12 32 30 28 24 28 32 36 24 VSET=2V VSET=2V 23 24 25 20 Fig..4-3 Circuit electric current (at the time of operating mode) Fig..4-2 Circuit electric current (at the time of stand by mode) 35 16 VCC [V] 36 VCC [V] Fig..4-1 Circuit electric current (at the time of OFF mode) 4 0.0 22 21 15 10 ILED [mA] 20 ILED [mA] ILED [mA] 20 16 12 8 5 0 0 0.5 1 1.5 2 2.5 3 3.5 17 0 1 2 VSET [V] 3 4 5 -40 6 -20 0 VSET [V] Fig..4-4 VSET Constant electric current Characteristics 5.3 7 5.2 6 5.1 60 80 100 8 Io=0mA 5.4 8 40 Fig..4-6 Constant electric current temperature characteristic 5.5 Io=0mA 9 20 TEMP [℃] Fig..4-5 VLED Dependency of ILED 10 7 6 5 4 5 VREG [V] VREG [V] VREG [V] 19 18 4 0 20 5.0 4.9 3 4.8 2 4.7 1 4.6 0 4.5 4 3 2 0 4 8 12 16 20 24 28 32 36 1 0 -40 -20 0 20 40 TEMP [℃] VCC [V] Fig..4-7 VREG_VCC characteristic Fig..4-8 VREG temperature characteristic 60 80 100 0 0.5 1 1.5 2 2.5 3 VSTBY [V] Fig..4-9 STBY Threshold voltage 8 7 6 VRED [V] 5 4 3 2 1 0 0 0.5 1 1.5 2 2.5 3 VEN [V] Fig..4-10 EN Threshold voltage www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 4/12 2009.07 - Rev.A Technical Note BD9206EFV ● Block functional descriptions ■PREREG, REF, 5VREG PREREG is an circuit of constant voltage supplied to REF and 5VREG in which the voltage applied to VCC terminal is made to be constant. REF is a temperature-compensated reference voltage resource and used as reference voltage of TSD (Thermal Shutdown Circuit). 5VREG is a 5V constant-voltage source and used as a power supply of constant-current driver. The 5V constant voltage is output to VREG terminal. Moreover, it is recommended to attach a 1μF ceramic capacitor using for phase correction, to VREG terminal. ■UVLO（Under Voltage Lock Out） The LED driver is turned OFF when the VREG voltage is less than 2.9V(typ). The operation of lighting up is reset when VREG becomes more than 3.0V(typ). ■ TSD（Thermal Shutdown Circuit） TSD circuit protects the IC from thermo runaway or thermal damage. TSD circuit detects the chip temperature and turns the circuit off if the chip temperature reaches 175℃. The hysteresis of 20℃ is set for TSD detection and release so as to prevent malfunction caused by temperature fluctuations. ■Current Driver（Constant-current driver）, Driver Current Setting Current Driver(Constant-current driver) is an circuit that generates a constant current for lighting of LED. Constant-current circuit of BD9206EFV consists of the constant current setting part and the constant current driver part. The constant-current driver part operates in such a manner that the voltage of Point a is equal to the voltage of point b because the part serves as a buffer, the input of which is the voltage VX that is set by the constant current setting part. Therefore, the current ILED that flows into the VLED terminal is as follows: ILED = Vb/RSET = Va/RSET = VX/RSET = VSET*A/RSET = VSET*B （A and B are numerical constants） For BD9206EFV, the numerical constants inside the IC are set in such a way that the following formula is brought into existence: ILED(mA) = VSET ＊10 (VSET=0.6～3.0V) If VSET is fixed, then the Vb is fixed, therefore the current ILED always flows independent of the fixed voltage of VLED. However, the constant current operation is stopped if the voltage of VLED terminal is less than 0.6V, so please ensure VLED>0.6V. Vo 定 電 setting 流設定 [Constant【current part]部 】 [Constant 【 定current 電 流 driver ド ラ イpart] バ部】 IL E D Condenser for phase 位相 補 償用コンデンサ compensation a VLED + - VX =VS ET*A b 電圧 Voltage shift 変 circuit 換 VSET 回路 RSET VX EN Fig..5 www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 5/12 2009.07 - Rev.A Technical Note BD9206EFV Rise time and Fall time of LED Driver’s constant current ● In the state of STBY=H, the rise time of constant current at the time of EN=L→H and the fall time at the time of EN=H→L are as shown in the following table. As shown in Fig.5, the constant current driver is formed in such a way that the NMOS of the driver output is made to be operated or stopped by the EN signal. Therefore, the rise time for the second time or later is shorter than the one for the first time because the electrical charge of the capacitor for phase compensation is reopened from the charged state. First time Second time or later Remarks The time interval between the moment of EN=L→H and the Rise time 2.9μs ± 7% 2.6μs ± 7% moment at which the ILED reaches 90% of the set value The time interval between the moment of EN=H→L and the Fall time 0.7μs ± 11% 0.7μs ± 11% moment at which the ILED reaches 10% of the set value On the condition that VCC=Vo=24V, VF（LED）=3.2V 5-stage connection, RL=15Ω ■STBY, EN At the time of STBY=L, it becomes the OFF mode, then only a portion of the circuit inside the IC is operating, so the circuit current is restricted to 17μA (typ). At the time of STBY=H, it becomes the Standby mode, then 5VREG is started and UVLO is released before the LED driver gets into the state of Ready. After that, if EN=L→H, then the current flows into the LED driver and the LED is lighted up. Note: If STBY and EN are simultaneously made to be L→H, then the rising edge of the LED driver gets late because the starting time of 5VREG is necessary. If it is used after PWM dimming, then please let STBY=H beforehand and input the CLK to EN before using. ●Operation logic of LED driver EN L H L Stop Stop H Stop Operation STBY STBY EN UVLO TSD LED Driver active : High ●Logic of LED driver protection circuit Function Stop Operation UVLO VREG < 2.9V(typ) VREG > 3.0V(typ) TSD Ta > 175℃ Ta < 155℃ ■TEST terminal TEST terminal is only used in ROHM’s testing process before delivery, so please use the IC with the terminal fixed at Low in normal times. www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 6/12 2009.07 - Rev.A Technical Note BD9206EFV ●Timing chart VCC VSET STBY EN VREG 3.0V 2.9V ① VCC input. ② VSET Setting ③ It moves to OFF mode due to STBY = L -> H. 5VREG (VREG) start. Rising time ms. ④ It becomes UVLO = H depending upon VREG >3.0V, it moves to stand-by mode. As for LED driver, it is ready state. ⑤ LED Lighting with EN = L -> H . ⑥ LED lighting out with EN = H → L ⑦ it is same with ⑤ ⑧ Detecting TSD with Ta > 175℃, LED lighting out ⑨ Deleting TSD with Ta < 155℃, LED lighting ⑩LED lighting out with STBY,EN=H→L ⑪Detecting UVLO=L with VREG<2.9V UVLO internal signal UVLO(内部信号) TSD internal signal TSD(内 部信 号) ILED ①②③④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩⑪ Fig..7 ※Please be careful about a current flowing to the VCC side via the diode for electrostatic breakdown protection if a voltage is applied to STBY terminal or EN terminal earlier than to VCC terminal. www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 7/12 2009.07 - Rev.A Technical Note BD9206EFV ●Recommendation of Circuit figure Fig..8 When you use VCC=24V ILED=20mA Variety Resistance Symbol Usage Type Maker Value Unit R1～R6 For reducing IC thermal loss MCR03Series15R0 ROHM 15Ω CVCC For input by-pass capacitor GMR55DB31H106 murata 10uF CVREG For VREG phase compensation GMR188R71A105 murata 1uF capacitor ●The points of manufacturing substrate For this IC, at the time of LED lighting, the temperature of the package increases due to heat generation of the constant current driver. Therefore, please bring the radiating fin on the back side of the package down to the GND with wide substrate pattern in order to promote heat radiation. In addition, the heat radiation can be further promoted by putting a thermal VIA in. The heat radiation can be promoted similarly by connecting the unconnected terminals, TEST terminals and unused terminals of LED1~6 to GND. www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 8/12 2009.07 - Rev.A Technical Note BD9206EFV ●The calculation of electric power consumption for IC and the deciding method of external resistance value Electric power consumption of IC is decided with formula below. P(N)=ICC*VCC+[(Vo-RL*ILED)-(Vf+⊿Vf+⊿VfT)*M]*N*ILED ・・・・① IC Consumed electric ICC Vo ： current VCC ： Input voltage RL ： LED Vf voltage Vf ： （normal temperature typ） ⊿Vf ： LED Vf Variation V ⊿VfT ： LED Vf Temperature ＊M ： variation M ： Stage number around ： LED 1 line N ＊N ： LED line number LED Constant current ILED ILED value Voltage OF LED anode Vo side external resistance RL Fig..9 (external loss) Please insert the heat-radiation resistor RL in order to decrease the heat radiation at the IC. If the value of RL is made to be larger, then the heat radiation of the IC is decreased, but if the terminal voltage VLED of the LED driver is less than 0.6V, then the constant current operation becomes impossible, therefore please set the RL in such a way that the following expression is met: VLED=Vo-（Vf+⊿Vf+⊿VfT）*M-RL*ILED>0.6V Please set the ILED and RL in such a way that the relational expressions ① & ② are met. Moreover, the permissible loss of the package is as shown in the following graph. F HT SS OP- B2 0 Pd 4 .0 3 .5 3.20 ①1layer baseplate ①：1層基板 （Heat dissipation (表層放熱銅箔： copper foil on surface： Omm2） 0mm2 allowable loss 許容損失P d(W) 3 .0 2.30 2 .5 ③ ②2layer base―plate （Heat dissipation 2 .0 copper foil on Inside ②：2層基板 and outside layer： (表裏層放熱銅箔： 4900mm2) ② 1 .5 4900mm2) 1.00 1 .0 ① ③4layer base―plate ③：4層基板 （ Heat dissipation 0 .5 0 .0 0 25 50 75 100 125 150 (全層放熱銅箔： copper foil on whole layer：4900mm2） 4900mm2 Temperature around Ta（℃） 周囲温度Ta(℃) Fig..10 www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 9/12 2009.07 - Rev.A Technical Note BD9206EFV ●Input/output equivalent circuit 6：LED1, 7：LED2, 8：LED3, 13：LED4, 14：LED5, 15：LED6 2：STBY 3：EN, 17：TEST 18：VSET 1：VREG CL7V 9, 10, 11, 12, 19：N.C. N.C. pin is not connected ※The voltage clamp element of 7V is connected to CL7V. www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 10/12 2009.07 - Rev.A Technical Note BD9206EFV ●Notes for use 1.) The absolute maximum ratings We pay sufficient attention for quality control to this product but If the absolute maximum ratings are exceeded, such as with applied voltage or operational temperature range, a degradation or a destruction may occur. The short or open modes cannot be specified. so if special modes which exceed the absolute maximum ratings are assumed, physical safety precautions such as fuses should be in place. 2.) Reverse connection of power supply connector The reverse connection of power connector may cause damage to IC. Please take countermeasures such as inserting a diode between the power supply and IC’s external power supply pin for protection against the damage caused by the reverse connection. 3.) Power supply line The return of the regenerated current is caused by the back electromotive force of the external coil, so please take the measures such as inserting a capacitor between power supply and GND as a route of regenerated current, and determine the capacitance value after thoroughly ensuring that there is no problems in the Characteristics of electrolyte capacitor, such as no loss of capacitance at low temperature. Heat design should take into account of power dissipation (Pd) under actual usage conditions, with wide enough margins 4.) GND Potential The potential of the GND terminal should be the minimum potential under all operating conditions. 5.) Heat Design Heat design should take into account of power dissipation under actual usage conditions, with wide enough margins. 6.) Short-circuiting between Terminals and Incorrect Mounting When mounting to the PWB, pay special attention to the direction and proper placement of the IC. If the IC is attached incorrectly, it may be destroyed. Furthermore, there is also a possibility of breakdown, when the foreign body enters during outputting and between power supply and GND. 7.) The operation in the strong magnetic fields Please be careful that there is a possibility of malfunction which is happening when you use it in a strong electromagnetic field. 8.) ASO Please do the setting in such a way that the output Tr does not exceed the absolute maximum rating and ASO in case of using this IC. For CMOS IC and the IC with more than one power supply, a rush current may flow instantaneously at the time of power on, so please be careful about power supply coupling capacitance, power supply, GND pattern wiring width and length. 9.) Thermal shutdown circuit (TSD circuit) This IC incorporates a built-in thermal shutdown circuit (TSD circuit). The TSD circuit is that has designed only to shut the IC off to prevent the thermal runaway operation，not for IC protection or guarantee as purpose. Therefore, please do not continue to use the IC after operating this circuit and also do not use the IC designating operation as prerequisite. 10.) Inspection of the Set Substrate If a condenser is connected to a pin with low impedance when inspecting the set substrate, stress may be placed on the IC, so please be sure to discharge after each process. Moreover, please be sure to turn off the power supply before connecting & inspecting or before detaching when it is connected to jig at inspection process. 11.) About IC terminal input This IC is a monolithic IC, and there are a P+ isolation and the P substrate for separation of element between each element. There is a P-N junction formed between this P-layer and each element’s N-layer, forming every parasitic element, as shown in Fig.15, when resistance and transistor are connected with terminal 〇 In the case of GND>（terminal A ）with resistance or GND>(terminal B) with transistor(NPN), the P-N junction operates as a parasitic diode. 〇 In addition, when GND> (terminal B) with the transistor (NPN), the parasitic NPN transistor operates due to the aforementioned parasitic diode and the N layer of the other element approached With the IC’s configuration, the production of parasitic elements is inevitable. The operation of parasitic elements causes interferences between circuits, leading to malfunction and even destruction. Therefore, uses which cause the parasitic elements to operate, such as applying voltage to the input terminal which is lower than the GND (P-substrate), should be avoided. N P N P＋ B (NPN) P＋ N Ｎ P Substrate Parasitic Element P 基板 寄生素子 GND N E GND P P＋ N Parasitic寄生素子 Element Parasitic Element 寄生素子 N P Substrate P 基板 (terminalB) (端子B) (terminalA) (端子A) GND B C ～ C ～ (terminalB) (端子B) ～ P＋ Transistor トランジスタ Resistance 抵抗 ～ ～ (terminalA) (端子A) other element approached 近接する他の素子 E GND Parasitic Element 寄生素子 GND Fig..11 バイポーラ ICofの簡易構造例 Fig.11 Simple Structure bipolar IC (Sample) www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 11/12 2009.07 - Rev.A Technical Note BD9206EFV ●Ordering part number B D 9 Part No. 2 0 6 E Part No. F V Package EFV: HTSSOP-B20 - E 2 Packaging and forming specification E2: Embossed tape and reel HTSSOP-B20 <Tape and Reel information> 6.5±0.1 (MAX 6.85 include BURR) (4.0) 1 1.0±0.2 (2.4) 6.4±0.2 0.5±0.15 11 4.4±0.1 20 Tape Embossed carrier tape (with dry pack) Quantity 2500pcs Direction of feed E2 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 ) 10 0.325 1.0MAX +0.05 0.17 -0.03 0.08±0.05 0.85±0.05 S 0.08 S 0.65 +0.05 0.24 -0.04 1pin (Unit : mm) www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. Reel 12/12 Direction of feed ∗ Order quantity needs to be multiple of the minimum quantity. 2009.07 - Rev.A Notice Notes No copying or reproduction of this document, in part or in whole, is permitted without the consent of ROHM Co.,Ltd. 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