BD9421F-GE2

Datasheet LED Drivers for LCD Backlights White LED Driver for large LCD Panels (DCDC Converter Type) BD9421F General Description Key Specifications BD9421F is high efficiency driver for white LED. This is designed for large sized LCD. BD9421F is built-in DCDC converters that supply appropriate voltage for light source. BD9421F is also built-in protection function for abnormal state such as OVP: over voltage protection, OCP: over current limit protection of DCDC, SCP: short circuit protection, open detection of LED string. Thus this is used for conditions of large output voltage and load conditions.     VCC Supply Voltage Range: 9.0V to 35.0V DCDC Oscillation Frequency: 150kHz(RT=100kΩ) Operation Circuit Current: 5mA(Typ) Operating Temperature Range: -40°C to +85°C Applications  LED driver for TV, Monitor and LCD Back Light Package W(Typ) x D(Typ) x H(Max) 15.00mm x 7.80mm x 2.01mm Pin Pitch 1.27mm SOP24 Features 6ch LED constant current driver(External PNP Tr Type)  Maximum LED setting current 500mA(VREF Pin setting)  ±2% LED current accuracy(VREF=0.9V setting)  Built-in DC/DC converter  Analog Dimming(Linear) function  LED protection function(OPEN/SHORT protection)[PWM-independent Type]  Individual detection and individual LED OFF for both OPEN and SHORT circuit  VOUT Over Voltage Protection(OVP) and reduced voltage protection(SCP) circuit  Built-in under voltage lockout function(UVLO) and over voltage protection(OVP)  Built-in VOUT discharge circuit while shutdown  Figure 1. SOP24 Typical Application Circuit STB PWM REG75 N PGND CS OVP STB BSx PWM VCC AGND RT FB VREF CLx FAIL VREF Figure 2. Typical Application Circuit 〇Product structure : Silicon monolithic integrated circuit .www.rohm.com © 2013 ROHM Co., Ltd. All rights reserved. TSZ22111 • 14 • 001 〇This product has no designed protection against radioactive rays 1/27 TSZ02201-0F1F0C100310-1-2 25.Sep.2015 Rev.003 Datasheet BD9421F Absolute Maximum Ratings(Ta = 25°C) Parameter Symbol Rating Unit VCC -0.3 to +36 V STB,OVP -0.3 to +36 V BS1-6 -0.3 to +60 V CS,CL1-6,FB,RT -0.3 to +7 V REG75,N -0.3 to +14 V PWM,VREF -0.3 to +20 V Supply Voltage STB,OVP Voltage BS1-6 Voltage CS,CL1-6,FB,RT Voltage REG75,N Voltage PWM,VREF Voltage 0.68 (Note 1) W Power Dissipation for SOP24 Pd Operating Temperature Range Topr -40 to +85 °C Storage Temperature Range Tstg -55 to +150 °C Maximum Junction Temperature Tjmax 150 °C (Note 1) Derating in done 5.5mW/°C for operating above Ta≧25°C (Mount on 1-layer 70.0mm x 70.0mm x 1.6mm board) 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. Recommended Operating Conditions(Ta= -40°C to +85°C) Parameter Symbol Min Typ Max Unit VCC 9 24 35 V DC/DC Oscillation Frequency FSW 100 - 800 kHz Analog Dimming Setting Input Range VREF 0.6 0.9 3.0 V Supply Voltage External Component Recommended Range Parameter VCC pin connecting capacity REG75 pin connecting capacity RT pin connection resistance range Symbol Specification Unit CVCC 1 to 100 uF C_REG 1.0 to 10 uF RRT 18.75 to 150 kΩ The operating conditions listed above are constants for the IC alone. To make constant setting with practical set devices, utmost attention should be paid. Pin Configuration Marking Diagram and Physical Dimension (TOP VIEW) BD9421F 1PIN MARK LOT No. SOP24 Figure 3. Pin Configuration www.rohm.com © 2013 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 Figure 4. Physical Dimension 2/27 TSZ02201-0F1F0C100310-1-2 25.Sep.2015 Rev.003 Datasheet BD9421F Electrical Characteristics(Unless otherwise specified VCC=24V Ta=25°C) Parameter Symbol Limit Min. Typ. Max. Unit Condition [Whole Device] Operation Current ICC － 5 10 mA VSTB=3V Standby Current IST － 40 80 uA VSTB=0V Operation Voltage （VCC） VUVLO_VCC 6.5 7.5 8.5 V VCC=SWEEP UP Hysteresis Voltage （VCC） VUHYS_VCC 150 300 600 mV VCC=SWEEP DOWN VEAMP 0.55 0.60 0.65 V BSx pin, VREF=0.9V FCT 142.5 150.0 157.5 kHz RT=100kΩ NMAX_DUTY 90 95 99 % RT=100kΩ N Pin Source ON Resistance RNSO 2.5 5 10 Ω N Pin Sink ON Resistance RNSI 2 4 8 Ω RT Pin Voltage VRT 1.60 2.00 2.40 V RT=100kΩ RT_DET -0.3 - VRTx90% V RT=SWEEP DOWN RT Pin Low Resistance RRT_L - 2.0 4.0 kΩ FB Pin Source Current IFBSO -115 -100 -85 uA FB Pin Sink Current IFBSI 85 100 115 uA VSTB=0V VBSx=0V, VREF=0.9V, VFB=1.0V VBSx=2.0V, VREF=0.9V, VFB=1.0V Over Current Detect Voltage VCS 0.35 0.40 0.45 V CS=SWEEP UP CS Source Current ICS 15 30 60 uA VCS=0V OVP High Detect Voltage VOVPH 2.88 3.00 3.12 V VOVP SWEEP UP OVP Hysteresis Voltage VOVPH_HYS 150 200 250 V VOVP SWEEP DOWN VSCP 0.05 0.10 0.15 V VOVP SWEEP DOWN OVP_LK -2 0 2 uA VOVP=4V VCL 294.0 300.0 306.0 mV VREF=0.9V VCLMAX -3% 1.0 +3% V VREF max=3.0V VCLMIN -3% 200.0 +3% mV VREF min=0.6V RBS 55 80 120 Ω PWM=High, VCL=Low VREF_LK -2 0 2 uA VREF=1V [UVLO Block] [DC/DC Block] Error amp Base Voltage Oscillation Frequency N Pin MAX DUTY Output RT Short Protection Range [DC/DC Protection Block] Short Protection Detect Voltage OVP Pin Leakage Current [LED PNP Driver Block] CL Pin Current Setting Voltage CL Pin Current Setting Voltage (Analog MAX) CL Pin Current Setting Voltage (Analog MIN) PNP Driver Output Sink Resistance VREF Pin Leakage Current www.rohm.com © 2013 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 3/27 TSZ02201-0F1F0C100310-1-2 25.Sep.2015 Rev.003 Datasheet BD9421F Electrical Characteristics(Unless otherwise specified VCC=24V Ta=25°C) Parameter Symbol Limit Unit Condition Min. Typ. Max. VOPEN 0.05 0.10 0.15 V BSx=SWEEP DOWN VLSP 8.5 9.0 9.5 V BSx=SWEEP UP VCLLVP 0.05 0.10 0.15 V [LED Protection Block] LED OPEN Detect Voltage LED SHORT Detect Voltage CL Pin Low Detect Voltage [REG75 Block] REG75 Output Voltage REG75 7.425 7.50 7.575 V REG75 MAX Output Current | IREG75 | 10 － - mA Io=0mA REG75_UVLO Detect Voltage REG75_TH 3.6 4.0 4.4 V REG75_UVLO Hysteresis REG75_HYS 250 500 750 mV REG75 Discharge Resistance REG75_DIS 0.65 1.00 1.35 MΩ STB Pin High Voltage STBH 2.0 - VCC V STB=SWEEP UP STB Pin Low Voltage STBL -0.3 - 0.8 V STB=SWEEP DOWN STB Pin Pull Down Resistance RSTB 600 1000 1400 kΩ STB=3.0V PWM Pin High Detect Voltage PWM_H 1.5 - 18 V PWM=SWEEP UP PWM Pin Low Detect Voltage PWM_L -0.3 - 0.8 V PWM=SWEEP DOWN PWM Pin Pull Down Resistance RPWM 300 500 700 kΩ PWM=3.0V REG75=SWEEP DOWN STB=ON->OFF, REG75=SWEEP UP STB=ON->OFF, REG75=7.5V [STB Block] [PWM Input Block] www.rohm.com © 2013 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 4/27 TSZ02201-0F1F0C100310-1-2 25.Sep.2015 Rev.003 Datasheet BD9421F Pin Descriptions Pin No. Pin Name Function 1 REG75 2 N 3 PGND 4 CS DCDC external NMOS current monitor pin 5 FB DCDC phase-compensation pin 6 VREF 7 BS1 PNP Tr Base connecting pin1 8 BS2 PNP Tr Base connecting pin2 7.5V regulator output for N output pin DC/DC switching output pin Power GND LED voltage setting pin 9 BS3 PNP Tr Base connecting pin3 10 BS4 PNP Tr Base connecting pin4 11 BS5 PNP Tr Base connecting pin5 12 BS6 PNP Tr Base connecting pin6 13 CL6 PNP Tr collector ・current detection pin6 14 CL5 PNP Tr collector ・current detection pin5 15 CL4 PNP Tr collector ・current detection pin4 16 CL3 PNP Tr collector ・current detection pin3 17 CL2 PNP Tr collector ・current detection pin2 18 CL1 PNP Tr collector ・current detection pin1 19 PWM Dimming signal input pin 20 OVP Overvoltage protection detection pin 21 RT 22 AGND 23 STB Enable pin 24 VCC Power supply pin www.rohm.com © 2013 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 DCDC frequency setting resistor connection pin Analog GND 5/27 TSZ02201-0F1F0C100310-1-2 25.Sep.2015 Rev.003 Datasheet BD9421F Block Diagram Vo VIN + CIN OVP REF4V OVP UVLO (VCC) VCC Protection STB REG75 VREG TSD OPEN SHORT Detect CP counter OCP ・・・ REG75 OSC CLK Control Logic RT N OSC PGND CS ERROR OSC CLK PGND Soft Start SS counter - AGND - FB ERR AMP RFB CFB + VREF*2/3 1/10 + Comp REF4V ・・・ + + SHORT_DET 1/10 + - 0.9V 0.9V OPEN_DET Comp REG75 + 0.1V Analog 1/3 VREF Dimming PWM Figure 5. Blockdiagram www.rohm.com © 2013 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 6/27 TSZ02201-0F1F0C100310-1-2 25.Sep.2015 Rev.003 Datasheet BD9421F Pin ESD Type REG75 / N / PGND / CS PWM FB STB VREF BS(1-6) / CL(1-6) OVP RT OVP Figure 6. Pin ESD Type www.rohm.com © 2013 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 7/27 TSZ02201-0F1F0C100310-1-2 25.Sep.2015 Rev.003 Datasheet BD9421F Description of pin function P in 1: REG75 The REG pin is used in the DC/DC converter driver block to output 7.5V power. The maximum operating current is 10mA. Using the REG pin at a current higher than 10mA can affect the N pin output pulse, causing the IC to malfunction and leading to heat generation of the IC itself. To avoid this problem, it is recommended to make load setting to the minimum level.  Pin 2:N The N pin is used to output power to the external NMOS gate driver for the DC/DC converter in the amplitude range of approx. 0 to 7.5V. Frequency setting can be made with a resistor connected to the RT pin. For details of frequency setting, refer to the description of the ＜RT pin＞.  Pin 3: PGND The PGND pin is a power ground pin for the driver block of the N output pin.  Pin 4: CS CS pin is current detect for DC/DC current mode inductor current control pin. Current flowing through the inductor is converted into voltage by the current sensing resistor RCS connected to the CS pin and this voltage is compared with voltage set with the error amplifier to control the DC/DC output voltage. The CS pin also incorporates the overcurrent protection (OCP) function. If the CS pin voltage reaches 0.4V (Typ.) or more, switching operation will be forcedly stopped.  Pin 5: FB Current mode control DC/DC converter error amplifier output pin. By monitoring voltage of BS（1～6）pin, the highest Vf of LED column will set 2/3(typ.) of applied VREF voltage to BS pin voltage to control inductor current. The phase compensation setting has described separately. In addition, PWM pin will become High Impedance when all PWM signals are in low state, and will maintain FB voltage.  Pin 6: VREF LED current setting pin.1/3(typ) of applied voltage to VREF pin will be LED current feedback voltage, 2/3(typ.) of its voltage will be DCDC feedback voltage（the lowest BSx pin feedback voltage）. Basically, because high accuracy of resistor divider is inputted to VREF pin externally, the IC internally will be OPEN（High Impedance）state. Please use external power to design it. It cannot be used in OPEN state.  Pin 7-12: BS1-BS6 LED DRIVER output pin. Please connect to Base Terminal of external PNP Tr.  Pin 13-18: CL6 – CL1 LED current detect pin. By monitoring voltage of CLx pin to detect LED current. Please connect resistor to collector pin of external PNP Tr. CLx pin of no use channel set CLx>3.3V.  Pin 19: PWM ON/OFF terminal of LED driver pin. It inputs PWM dimming signal directly to adjust output DUTY dimming. High/Low level of PWM terminal is shown as follows: State PWM Voltage LED ON state PWM= 1.5V~18.0V LED OFF state PWM= -0.3V～0.8V  Pin 20: OVP The OVP pin is an input pin for overvoltage protection and short circuit protection of DC/DC output voltage. When voltage of it over 3.0V or higher, CP counting start. When OVP pin voltage 4count・・・Detect protection because it is out of interval time Please verify enough to operate narrow PWM. Figure 13-2. Timing chart of Timer count www.rohm.com © 2013 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 14/27 TSZ02201-0F1F0C100310-1-2 25.Sep.2015 Rev.003 Datasheet BD9421F And then mean input current IIN required for the whole system is given by the following equation. I IN V [V ]  I OUT [ A]  OUT [ A]　 VIN [V ] [%] CS Rcs IOUT(total) ●Selection of DC/DC Components OCP setting / DCDC component current tolerance selection guide The OCP detection function that is one of the functions of the CS pin will stop the DC/DC converter operating if the CS pin voltage becomes larger than 0.4V.Consequently, it is needed to calculate a peak current flowing through the coil L and then review the resistance of RCS. Furthermore, a current tolerance for DC/DC components should be larger than that for peak current flowing through the coil L. The following describes the peak coil current calculation procedure, CS pin connection resistor RCS selection procedure, and DC/DC component current tolerance selection procedure . ○Peak coil current Ipeak calculation VOUT Ripple voltage generated at the CS pin is determined by conditions L for DC/DC application components first, Assuming the conditions as VIN below: IL 「output voltage=VOUT[V] 」 「LED total current=IOUT[A] 」 fsw 「DCDC input voltage=VIN[V] 」 「DCDC efficiency=η[%] 」 N PGND Further, according to drive operation with the DC/DC converter switching frequency fsw [Hz], inductor ripple current ΔIL [A] generated at the inductor L (or H) is given by the following equation. Δ IL  (VOUT [V ]  V IN [V ])  V IN [V ] [ A] L[ H ]  VOUT [V ]  f SW [ Hz ] As a result, the peak current Ipeak of IL is given by the following equation. Ipeak  I IN [ A]  IL[ A] 2 [ A] (1) ○CS pin connection resistor RCS selection procedure The current Ipeak flows into RCS to generate voltage.（See the timing chart shown to the right）The voltage VCSpeak is given by the following equation. VCS peak  Rcs  Ipeak [V ] If VCSpeak voltage reaches 0.4V, DC/DC output will stop. Consequently, to select RCS resistance, the following condition should be met. Rcs  Ipeak [V ]  0.4 [V ] ○DC/DC component current tolerance selection procedure Iocp current needed for OCP detection voltage CS to reach 0.4V is given by the following equation: I OCP  0.4[V ] [ A] ( 2) Rcs[ ] The relation among Ipeak current (Equation (1)), Iocp current (Equation (2)), and Maximum current tolerance for component should meet the following equation. I peak  I OCP  MAX current tolerance DC/DC application components including FETs, inductors, and diodes should be selected so that the Equation shown above will be met. In addition, it is recommended to use continuous mode in DCDC application. And the lower limit value of coil ripples current Imin so as to meet the following equation: I min  I IN [ A]  IL[ A] [ A]  0 2 A failure to meet this condition is referred to as discontinuous mode and this failure may result in an inadequate rise in output voltage. www.rohm.com © 2013 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 15/27 TSZ02201-0F1F0C100310-1-2 25.Sep.2015 Rev.003 Datasheet BD9421F 【Setting example】 Output=VOUT[V]=40V LED 1ch current=120mA, total LED current IOUT[A]=120mA×6ch=0.72A DCDC input voltage=VIN [V] =24V DCDC efficiency=η[%]=90% Mean input current IIN required for the whole system is given by the following equation: DCDC switching frequency=fsw[Hz]=200kHz Inductor [H]=33μH The inductor ripple current ΔIL [A] is given by the following equation: Δ IL  (VOUT [V ]  V IN [V ])  V IN [V ] ( 40[V ]  24[V ])  24[V ] 　   1.45 [ A] L[ H ]  VOUT [V ]  f SW [ Hz ] 33  10  6 [ H ]  40[V ]  200  10 3 [ Hz ] As a result, the peak current Ipeak of IL is given by the following equation. When RCS resistance is set to 0.1ohm, the VCS peak voltage will be given by the following equation: Consequently, the result meets the condition. Furthermore, IOCP current at which OCP is detected is given by the following equation: I OCP  0.4[V ]  4 . 0 [ A] 0.1[ ] So must select the component of about 5A in order to meet the above result. I peak  I OCP  Max. Current tolerance for component Particularly, To select DC/DC components, give consideration to IC variations as well as individual component variations, and then conduct thorough verification on practical systems.. The lower limit value of coil ripple current Imin is given by the following equation, the component will not be put into discontinuous mode. I min I IN [ A] IL[ A] [ A] 1. 33[ A] 0. 73[ A] 0. 60[ A] 2 0 ※For the selection of DC/DC components, please also consider the inaccuracy of each componentts. www.rohm.com © 2013 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 16/27 TSZ02201-0F1F0C100310-1-2 25.Sep.2015 Rev.003 Datasheet BD9421F ○Selection of inductor L The value of inductor has significant influence on the input ripple current. As shown by Equation (1), the larger the inductor and the higher the switching frequency, the inductor ripple current ∆IL becomes increasingly lower. ΔIL ΔIL  VIN (VOUT  V IN )  V IN [ A]　　　　・・・・・　 　 　 (1) L  VOUT  f SW Expressing efficiency as shown by Equation (2), peak input current is given as Equation (3). IL L VOUT  I OUT 　　　　　・・・・・　　 (2) V IN  I IN ΔIL VOUT  I OUT ΔIL  　　  　　 　・・・・・　　 (3) ILMAX  I IN  2 2 VIN    VOUT Here, RCS L：Inductor value[H] VIN：input voltage[V] IIN：input current[A] COUT VOUT：DC/DC output voltage[V] IOUT：output total current[A] FSW：Oscillation frequency[Hz] Basically, make setting of ∆IL to approximately 30% to 50% of the output load current. If a current in excess of the rated current of the inductor applies to the coil, the inductor will cause magnetic saturation, resulting in efficiency degradation. Select an inductor with an adequate margin so that peak current will not exceed the rated current of the inductor. ※ To reduce power dissipation from and increase efficiency of inductor, select an inductor with low resistance component (DCR or ACR). ※ ○Selection of output capacitor COUT VIN IL Select a capacitor on the output side taking into account the stability region of output voltage and equivalent series resistance necessary to smooth ripple voltage. Note that higher output ripple voltage may result in a drop in LED pin voltage, making it impossible to supply set LED current. The output ripple voltage ∆VOUT is given by Equation (4). ΔVOUT  ILMAX  R ESR  L VOUT 1 C OUT  I OUT   1 f SW 　 [V ]　・・・・・　　 (4) Here, RESR  Equivalent series resistance of COUT. RESR RCS ※ ※ COUT Select capacitor ratings with an adequate margin for output voltage. To use an electrolytic capacitor, an adequate margin should be provided for permissible current. Particularly to apply PWM light modulation to LED, note that a current higher than the set LED current transiently flows. www.rohm.com © 2013 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 17/27 TSZ02201-0F1F0C100310-1-2 25.Sep.2015 Rev.003 Datasheet BD9421F ○Selection of switching MOSFET transistors There will be no problem for switching MOSFET transistors having absolute maximum rating higher than rated current of the inductor L and VF higher than “COUT breakdown voltage  Rectifier diode”. However, to achieve high-speed switching, select transistors with small gate capacity (injected charge amount). Note: Rated current larger than overcurrent protection setting current is recommended. Note: Selecting transistors with low on resistance can obtain high efficiency. ○Selection of rectifier diodes Select Schottky barrier diodes having current capability higher than the rated current of the inductor L and inverse breakdown voltage higher that COUT breakdown voltage, particularly having low forward voltage VF. ○Selection of Load switch MOSFET and soft start function In usual DC/DC converter, because there is no switching to a path leading from VIN to VOUT resulting in output voltage is also occurring even if IC is in OFF state. Please insert PMOSFET between VIN and inductor if you want voltage to 0V until the IC starts to operate. In addition, FAIL pin can be used for driving load switch after confirmed the logic theory, and the breakdown voltage of drain-source needed to be selected larger than VIN. Furthermore, if you would like to make soft start function to load switch, please insert a condenser between Gate and Source. www.rohm.com © 2013 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 18/27 TSZ02201-0F1F0C100310-1-2 25.Sep.2015 Rev.003 Datasheet BD9421F ●Phase Compensation Setting Procedure DC/DC converter application for current mode control includes one each of pole fp (phase delay) by CR filer consisting of output capacitor and output resistor (i.e., LED current) and zero (phase lead) fZ by the output capacitor and capacitor ESR. Furthermore, the step-up DC/DC converter includes RHP zero “fZRHP” as the second zero. Since the RHP zero has phase delay (90) characteristics like the pole, the crossover frequency fc should be set to not more than RHP zero. VIN VOUT L ILED VOUT + RCS i. CFB2 CFB1 Find Pole fp and RHP zero fZRHP of DC/DC converter. Here, I LED [　 Hz ] 　 2  VOUT  COUT ILED　＝LED Total current[A], D f ZRHP  VOUT  VIN VOUT VOUT  (1  D) 2 [　 Hz ]　　 2  L  I LED 　 Find phase compensation to be inserted to error amplifier.(set fc is 1/5 to fZRHP) R FB1  Here, iii. RFB1 COUT fp  ii. FB gm RESR f RHZP  RCS  I LED [　 ] 　 5  f p  gm  VOUT  (1  D) C FB1  1 [　 F ]　　 2  RFB1  f p gm  4.0  10 4 [ S ] Find zero used to compensate ESR (RESR) of COUT (electrolytic capacitor). C FB 2  RESR  C OUT [　 F ]　　 RFB1 ※Even if a ceramic capacitor (RESR of the order of milliohms) for COUT, it is recommended to insert CFB2 for stable operation. To improve transient response, it is necessary to increase RFB1 and reduce CFB1. However, this improvement reduces a phase margin. To avoid this problem, conduct thorough verification, including variations in external components, on practical systems. www.rohm.com © 2013 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 19/27 TSZ02201-0F1F0C100310-1-2 25.Sep.2015 Rev.003 Datasheet BD9421F I_discharge ILED ●The setting of REG75 capacity and shutdown procedure VOUT discharge function is built-in this IC when IC is shutdowned, the below decribes the operation sequence. PWM=L :STOP Figure 14.Timing chart of shutdown ○Explanation of shutdown sequence ①Set STB pin to “OFF” will stops DC/DC converter and REG75, but LED driver will remain operation. ②Discharge the REG75 pin voltage from 7.5V to 4.0V with 1MΩ. ③The VOUT voltage will be discharged with ILED current and the discharged VOUT voltage is no flow ILED current. ④When REG75 pin voltage will reach 4.0V (Typ.) or less to shut down all systems ○REG75 capacitance setting procedure The shutdown time “TOFF” can be calaulated by the following equation. TOFF [sec]  C REG [F]  R REG []  In REG75 t 0 [V] 7.5[V]  C REG [F]  1[M]  In  628.6  10 3  C REG [sec] REG75 UVLO [V] 4.0[ V ] The longest VOUT discharge time will be obtained when the PWM duty cycle is set to the minimum VOUT. Make REG capacitance setting with an adequate margin so that systems will be shut off after VOUT voltage is fully discharged. www.rohm.com © 2013 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 20/27 TSZ02201-0F1F0C100310-1-2 25.Sep.2015 Rev.003 Datasheet BD9421F ●Timing Chart VCC 7.5V STB 2.0V 0.8V PWM 4.5V REG75 RT 2.0V 4.0V Internal SS FB VOUT Protect Function LED OPEN disable disable LED SHORT disable disable OVP disable SCP disable OCP disable www.rohm.com © 2013 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 disable *Under SS term, Not charge CP disable disable 21/27 TSZ02201-0F1F0C100310-1-2 25.Sep.2015 Rev.003 Datasheet BD9421F ●List of Protection Functions ○List of protection detecting condition Protection names Detection Detection condition pin Detection pin condition BSx BSx < 0.1V LED OPEN CLx CLx < 0.1V BSx BSx > 9V BSx BSx < 0.1V RT Under RT x90% VCC UVLO VCC REG75 UVLO SS Release condition SS>4.0V BSx > 0.1V PWM H(Pulse over 4CLK) H(Pulse over 4CLK) H(Pulse over 4CLK) H(Pulse over 4CLK) Timer Protection type 215count Latch(Only detected ch) 215count Latch(Only detected ch) SS>4.0V CLx > 0.1V SS>4.0V BSx < 9V SS>4.0V BSx > 0.1V - - Canceled RT=GND State VCC < 7.2V - - VCC>7.5V REG75 REG75 < 4.0V - - REG75>4.5V OVP OVP OVP>3.0V - - OVP 0.1V 215count Latch OCP CS CS>0.4V - - CS Pin A and GND > Pin B, the P-N junction operates as a parasitic diode. When GND > Pin B, the P-N junction operates as a parasitic transistor. Parasitic diodes inevitably occur in the structure of the IC. The operation of parasitic diodes can result in mutual interference among circuits, operational faults, or physical damage. Therefore, conditions that cause these diodes to operate, such as applying a voltage lower than the GND voltage to an input pin (and thus to the P substrate) should be avoided. Figure 15. Example of monolithic IC structure 12. Ceramic Capacitor When using a ceramic capacitor, determine the dielectric constant considering the change of capacitance with temperature and the decrease in nominal capacitance due to DC bias and others. 13. Area of Safe Operation (ASO) Operate the IC such that the output voltage, output current, and power dissipation are all within the Area of Safe Operation (ASO). 14. Thermal Shutdown Circuit(TSD) This IC has a built-in thermal shutdown circuit that prevents heat damage to the IC. Normal operation should always be within the IC’s power dissipation rating. If however the rating is exceeded for a continued period, the junction temperature (Tj) will rise which will activate the TSD circuit that will turn OFF all output pins. When the Tj falls below the TSD threshold, the circuits are automatically restored to normal operation. Note that the TSD circuit operates in a situation that exceeds the absolute maximum ratings and therefore, under no circumstances, should the TSD circuit be used in a set design or for any purpose other than protecting the IC from heat damage. 15. Over Current Protection Circuit (OCP) This IC incorporates an integrated overcurrent protection circuit that is activated when the load is shorted. This protection circuit is effective in preventing damage due to sudden and unexpected incidents. However, the IC should not be used in applications characterized by continuous operation or transitioning of the protection circuit. Status of this document The Japanese version of this document is formal specification. A customer may use this translation version only for a reference to help reading the formal version. If there are any differences in translation version of this document formal version takes priority www.rohm.com © 2013 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 25/27 TSZ02201-0F1F0C100310-1-2 25.Sep.2015 Rev.003 Datasheet BD9421F Ordering Information B D 9 4 2 1 Part Number F - Package F:SOP24 XX Packaging and forming specification XX: Please confirm the formal name to our sales. Physical Dimension, Tape and Reel Information SOP24 15.0 ± 0.2 (MAX 15.35 include BURR) Embossed carrier tape Quantity 2000pcs 13 24 Direction of feed 0.3MIN 5.4±0.2 7.8±0.3 Tape 1 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 ) 12 0.11 1.8±0.1 0.15 ± 0.1 1.27 0.4 ± 0.1 0.1 1pin (Unit : mm) www.rohm.com © 2013 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 Reel 26/27 Direction of feed ∗ Order quantity needs to be multiple of the minimum quantity. TSZ02201-0F1F0C100310-1-2 25.Sep.2015 Rev.003 Datasheet BD9421F Revision History Date Revision 11.Nov.2013 001 31.Jan.2014 002 25.Sep.2015 003 Changes New Release P14. Timing chart of Timer count add P22. Detection condition add P23. Timing of Error detection add P2. External Component Recommended Range add P8. No use channel setting add P22. Protection condition change www.rohm.com © 2013 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 27/27 TSZ02201-0F1F0C100310-1-2 25.Sep.2015 Rev.003 Datasheet Notice Precaution on using ROHM Products 1. Our Products are designed and manufactured for application in ordinary electronic equipments (such as AV equipment, OA equipment, telecommunication equipment, home electronic appliances, amusement equipment, etc.). If you (Note 1) , transport intend to use our Products in devices requiring extremely high reliability (such as medical equipment equipment, traffic equipment, aircraft/spacecraft, nuclear power controllers, fuel 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 representative 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 Applications. (Note1) Medical Equipment Classification of the Specific Applications JAPAN USA EU CHINA CLASSⅢ CLASSⅡb CLASSⅢ CLASSⅢ CLASSⅣ CLASSⅢ 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 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 Products are designed and manufactured for use under standard conditions and 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 ROHM’s Products 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 verification and confirmation of product performance, reliability, etc, prior 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 Products are exposed to direct sunlight or dust [c] Use of our Products in places where the Products are exposed to sea wind or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2 [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 (even 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 subject 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 period of time, such as pulse. is applied, confirmation of performance 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 (Pd) depending on Ambient temperature (Ta). When used in sealed area, confirm the actual ambient 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 failure induced under deviant 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. If the flow soldering method is preferred on a surface-mount products, please consult with the ROHM representative in advance. For details, please refer to ROHM Mounting specification Notice-PGA-E © 2015 ROHM Co., Ltd. All rights reserved. Rev.001 Datasheet Precautions Regarding Application Examples and External Circuits 1. If change is made to the constant of an external circuit, please allow a sufficient margin considering variations of the characteristics of the Products 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 this 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 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 the Products maximum rating will not be applied to Products. 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 Products are stored in the places where: [a] the Products 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 Products 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 excessive stress applied when dropping of a carton. 4. Use Products within the specified time after opening a humidity 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 properly using an authorized industry waste company. Precaution for Foreign Exchange and Foreign Trade 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 and 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 regarding 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 its 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 disassembled, converted, modified, reproduced or otherwise changed without prior written consent of ROHM. 3. In no event shall you use in any way whatsoever 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. Notice-PGA-E © 2015 ROHM Co., Ltd. All rights reserved. Rev.001 Datasheet 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 ROHM’s 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 ect to change without any prior notice. Before purchasing or using ROHM’s 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. Notice – WE © 2015 ROHM Co., Ltd. All rights reserved. Rev.001