1 40 REG50 VCC 39 FAIL 2 N FAIL 3 PGND AGND 38 4 CS UVLO 37 5 OVP RT 36 6 CP SS 35 7 LSP FB 34 STB 8 STB VREF 33 VREF BSx CLx PWMx PWMx Datasheet LED Drivers for LCD Backlights White LED Driver for large LCD Panels (DCDC Converter type) BD9479FV General Description Features BD9479FV is a high efficiency driver for white LEDs 8ch LED constant current driver (external PNP Tr and designed for large LCDs. This IC is built-in a boost Type) DCDC converters that employ an array of LEDs as the Maximum LED setting current 500mA (VREF pin light source. BD9479FV has some protect function setting) against fault conditions, such as the over-voltage Build-in DC/DC converter protection (OVP), the over current limit protection of Analog Dimming (Linear) function DCDC (OCP), the short circuit protection (SCP), the Individual channel PWM Dimming function open detection of LED string. Therefore BD9479FV is LED protection function (Open Short protection) available for the fail-safe design over a wide range PWM-independent Type output voltage. Output short protection (OVP) Built-in Timer latch function (CP) Key Specification Built-in under voltage Lockout function (UVLO)over Operating power supply voltage range: 9.0V to 35.0V voltage protection (OVP) Oscillator frequency: 150kHz (RT=100k) Built-in FAIL indication function Built-in OVP voltage Feedback function Operating Current: 8.7mA (typ.) Built-in PWM-independent soft start circuit Operating temperature range: -40 to +85 SSOP-B40 Package Applications Package W(Typ.) D(Typ.) H(Max.) TV, Computer Display, Notebook, LCD Backlighting SSOP-B40: 13.6mm x 7.80mm x 1.80mm Pin Pitch: 0.65mm Typical Application Circuit Figure 1. SSOP-B40 Figure 2. Typical Application Circuit Product structureSilicon monolithic integrated circuit This product is not designed protection against radioactive rays . www.rohm.com TSZ02201-0F1F0C100020-1-2 2012 ROHM Co., Ltd. All rights reserved. 1/26 TSZ2211114001 25.Sep.2015 Rev.002DatasheetDatasheet BD9479FV Absolute maximum ratings (Ta=25) Parameter Symbol Ratings Unit Power supply voltage VCC 36 V BS1-8 terminal voltage BS1-8 40 V OVP, STB, PWM1-8,VREF,UVLO terminal voltage OVP, STB, PWM1-8,VREF,UVLO 20 V REG50, N, CS, CP, LSP, CL1-8, FB, SS, RT REG50, N, CS, CP, LSP, CL1-8, 7 V terminal voltage FB, SS, RT (Note1) Power dissipation (SSOP-B40)*1 Pd 1.125 W Operating temperature range Ta(opr) -40 to +85 Storage temperature range Tstg -55 to +150 Junction temperature Tjmax 150 (Note1) SSOP-B40 package at Ta25C or higher, de-rating power rating by 9.0mW/ C(70.0mm x 70.0mm x1.6mm with 1-layer board) Operating Ratings (Ta = 25) Parameter Symbol Limits Unit VCC supply voltage VCC 9.0 to 35.0 V Analog Dimming setting (VREF Pin) range VREF 0.6 to 3.0 V LSP setting voltage range VLSP 0.3 to 3.0 V DC/DC oscillation frequency FCT 100 to 800 kHz PWM pin input frequency range F PWM 0.05 to 20 kHz Above operating condition are the constants of IC itself. Please pay attention at the actual set. Recommended external component range Parameter Symbol Limits Unit VCC pin connecting capacity CVCC 1 to 100 uF DC/DC frequency setting resistant RRT 18.75 to 150 k REG50 pin connecting capacity CREG50 1.0 to 10 uF Soft start setting capacity CSS 0.001 to 1.0 uF Timer Latch setting capacity CCP 0.001 to 1.0 uF Above operating condition are the constants of IC itself. Please pay attention at the actual set. Pin Configuration Marking diagram and physical dimension Marking BD9479FV 1PIN MARK LOT No Figure 4. Physical Dimension SSOP-B40 Figure 3. Pin Configuration www.rohm.com TSZ02201-0F1F0C100020-1-2 2012 ROHM Co., Ltd. All rights reserved. 2/26 TSZ2211115001 25.Sep.2015 Rev.002