Datasheet LED Drivers for LCD Backlights White LED Driver for large LCD Panels (DCDC Converter type) BD93941EFV BD93941FP General Description Features BD93941EFV and BD93941FP is a high efficiency driver 4ch LED constant current driver and DC/DC converter for white LEDs and designed for large LCDs. These ICs Maximum LED Current: 200mA are built-in a boost DCDC converters that employ an LED Feedback Voltage: 0.37V ( ADIM=2.5V) array of LEDs as the light source. BD93941EFV and so lower heat. Adjustable Feed Back Voltage BD93941FP have some protect function against fault by following LED Current setting. conditions, such as the over-voltage protection (OVP), 2% LED current accuracy (ADIM=2.5V, the over current limit protection of DCDC (OCP), the when each LED is set to 100mA) short circuit protection (SCP), the open detection of LED Analog current (Linear) dimming at ADIM pin string. Therefore BD93941EFV and BD93941FP are LED pin rating 60V available for the fail-safe design over a wide range Individual detection and individual LED OFF for both output voltage. open and short circuits Built-in ISET pin short-circuit protection circuit Key Specification Set Soft-Start time by external capacitor. Operating power supply voltage range: 9.0V to 35.0V FETs Gate (N pin) is driven by 5.8V swing LED minimum current 30mA Built-in Vout discharge circuit for shutdown LED maximum current: 200mA Built-in Vout overvoltage protection (OVP) / Oscillator frequency: 150kHz (RT=100k) reduced voltage protection (SCP) circuit Operating Current: 4.5mA (Typ.) HTSSOP-B20 and HSOP20 package with high heat Operating temperature range: -40C to +85C radiation efficiency Applications TV, Computer Display, Notebook, LCD Backlighting Package W(Typ.) x D(Typ.) x H(Max.) HTSSOP-B20 6.50mm x 6.40mm x 1.00mm HSOP20 14.90mm x 7.80mm x 2.10mm Figure 1(b). HSOP20 Figure 1(a). HTSSOP-B20 (BD93941FP) (BD93941EFV) Typical Application Circuit VIN Inductor VIN Diode CIN COUT EXPOSED REG58 PAD CREG RN2 FET ON/OFF REG58 STB RVCC N VCC RCS DN RN1 CVCC DCDC GND PGND LED4 CS RRT CLED4 RT LED3 AGND ROVP1 CLED3 COVP OVP LED GND ROVP2 RFB CFB1 FB LED2 CLED2 CFB2 LED1 CLED1 PWM SS PWM CSS AGND ISET RISET AUTO CAUTO ADIM ADIM Figure 2. Typical Application Circuit Product structureSilicon monolithic integrated circuit This product has not designed protection against radioactive rays . www.rohm.com TSZ02201-0F1F0C100270-1-2 2013 ROHM Co., Ltd. All rights reserved. 1/27 TSZ2211114 001 12.Aug.2015 Rev.003DatasheetDatasheet BD93941EFV BD93941FP Absolute maximum ratings (Ta=25C) Parameter Symbol Ratings Unit Power supply voltage VCC 36 V STB, ADIM, OVP, PWM terminal voltage STB, ADIM, OVP, PWM 36 V LED1 to 4 terminal voltage LED1 to 4 60 V AUTO, REG58, CS, N, ISET, SS, FB, RT terminal AUTO, REG58, CS, N, 7 V voltage ISET, SS, FB, RT Power dissipation (HTSSOP-B20) Pd1 3.20 *1 W (HSOP20) Pd2 2.18 *2 Operating temperature range Topr -40 to +85 C Storage temperature range Tstg -55 to +150 C Junction temperature Tjmax 150 C *1 Ta = 25C or more, diminished at -25.6mW/C in the case of HTSSOP-B20 (when 4-layer / 70.0 mm x 70.0 mm x 1.6 mm board is mounted) *2 Ta = 25C or more, diminished at -17.4mW/C in the case of HSOP20 (when 4-layer / 70.0 mm x 70.0 mm x 1.6 mm board is mounted) Operating Ratings Parameter Symbol Limits Unit VCC supply voltage VCC 9.0 to 35.0 V Min. output current of LED1 to 4 ILED MIN 30 mA *1 mA Max. output current of LED1 to 4 ILED MAX 200 *1,2 0.2 to 2.7 (normal op.) ADIM input voltage1 (use ADIM function) VADIM1 V *3 1.0 to 2.7 (start up) ADIM input voltage1 (dont use ADIM function) VADIM2 REG58 to 35.0 V DC/DC oscillation frequency Fsw 100 to 800 kHz Min. on-duty time for PWM light modulation PWM MIN 30 s *1 The amount of current per channel. *2 If LED makes significant variations in its reference voltage, the driver will increase power dissipation, resulting in a rise in package temperature. To avoid this problem, design the board with thorough consideration given to heat radiation measures. *3 To avoid unused LED pins misdetection, set ADIM within 1.0V to 2.7V at start up stage. After unused LED pins detection, set ADIM within 0.2V to 2.7V in normal operation. Pin Configuration HSOP20 HTSSOP-B20 1 20 VCC AUTO 2 19 ADIM REG58 3 18 RT CS 4 17 FB N 5 16 SS DCDC GND 6 15 OVP ISET 7 14 STB PWM 8 13 LED1 LED4 9 12 LED2 LED3 10 11 LED GND N.C. Figure 3. Pin Configuration www.rohm.com TSZ02201-0F1F0C100270-1-2 2013 ROHM Co., Ltd. All rights reserved. 2/27 TSZ22111 15 001 12.Aug.2015 Rev.003