Datasheet LED Drivers for LCD Backlights White LED Driver for large LCD Panels (DCDC Converter type) BD93942F General Description Features BD93942F is a high efficiency driver for white LEDs and 4ch LED constant current driver and DC/DC converter designed for large LCDs. These ICs are built-in a boost Maximum LED Current: 150mA DCDC converters that employ an array of LEDs as the LED Feedback Voltage: 0.45V ( ILED=150mA) light source. BD93942F have some protect function so lower heat. Adjustable Feed Back Voltage against fault conditions, such as the over-voltage by following LED Current setting. protection (OVP), the over current limit protection of 2% LED current accuracy (ADIM=2.5V, DCDC (OCP), the short circuit protection (SCP), the when each LED is set to 100mA) open detection of LED string. Therefore BD93942F are Analog current (Linear) dimming at ADIM pin available for the fail-safe design over a wide range LED pin rating 60V output voltage. Individual detection and individual LED OFF for both open and short circuits Key Specification Built-in ISET pin short-circuit protection circuit 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: 150mA Built-in Vout overvoltage protection (OVP) / Oscillator frequency: 150kHz (RT=100k) reduced voltage protection (SCP) circuit Operating Current: 3.7mA (Typ.) SOP16 package Operating temperature range: -40C to +85C Applications TV, Computer Display, Notebook, LCD Backlighting Package W(Typ.) x D(Typ.) x H(Max.) SOP16 10.00mm x 6.20mm x 1.71mm Typical Application Circuit Figure 1. SOP16 VIN Inductor VIN Diode CIN COUT REG58 CREG RN2 FET ON/OFF REG58 STB RVCC N VCC RN1 RCS DN CVCC GND PGND CS LED4 RRT CLED4 AGND RT LED3 ROVP1 CLED3 COVP OVP ROVP2 RFB CFB1 SSFB LED2 CLED2 ISET LED1 RISET CLED1 ADIM PWM ADIM PWM Figure 2. Typical Application Circuit Product structureSilicon monolithic integrated circuit This product has not designed protection against radioactive rays . www.rohm.com TSZ02201-0F5F0C100050-1-2 2015 ROHM Co., Ltd. All rights reserved. 1/26 TSZ2211114 001 12.Aug.2015 Rev.002 ConnectorDatasheetDatasheet BD93942F 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 REG58, CS, N, REG58, CS, N, ISET, SSFB, RT terminal voltage 7 V ISET, SSFB, RT Power dissipation (SOP16) Pd 0.62 *1 W 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 -5mW/C in the case of SOP16 (when 1-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 150 *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 1 16 REG58 VCC 2 15 CS ADIM 3 14 N RT 4 13 GND SSFB 5 OVP ISET 12 6 11 STB PWM 7 10 LED1 LED4 8 9 LED2 LED3 SOP16 Figure 3. Pin Configuration www.rohm.com TSZ02201-0F5F0C100050-1-2 2015 ROHM Co., Ltd. All rights reserved. 2/26 TSZ22111 15 001 12.Aug.2015 Rev.002