Datasheet LED Drivers for LCD Backlights 1ch Boost up type White LED Driver for large LCD BD9409F 1.1 General Description Key Specifications BD9409F is a high efficiency driver for white LEDs and is Operating power supply voltage range: designed for large LCDs. BD9409F has a boost DCDC 11.5V to 35.0V converter that employs an array of LEDs as the light Oscillator frequency of DCDC: 150kHz (RT=100k) source. Operating Current: 2.8 mA(Typ.) BD9409F has some protect functions against fault Operating temperature range: -40C to +105C conditions, such as over-voltage protection (OVP), over current limit protection of DCDC (OCP), LED OCP protection, and Over boost protection (FBMAX). 1.2 Package(s) W(Typ) x D(Typ) x H(Max) Therefore it is available for the fail-safe design over a SOP16 10.00mm x 6.20mm x 1.71mm wide range output voltage. Pin pitch 1.27mm Features DCDC converter with current mode LED protection circuit (Over boost protection(FB H), LED OCP protection) Over-voltage protection (OVP) for the output voltage Vout Adjustable soft start Adjustable oscillation frequency of DCDC UVLO detection for the input voltage of the power stage PWM Dimming and MS Dimming. Applications Figure 1. SOP16 TV, Computer Display, LCD Backlighting Typical Application Circuit Vout VCC VIN VCC UVLO OVP REG90 STB GATE RT CS SS DIMOUT FAIL PWM ISENSE FB Rs MS GND Figure 2. Typical Application Circuit Product structureSilicon monolithic integrated circuit This product has not designed protection against radioactive rays . www.rohm.com TSZ02201-0T2T0C100230-1-2 2016 ROHM Co., Ltd. All rights reserved. 1/33 TSZ2211114001 01.Nov.2016 Rev.001 BD9409F 1.3 Pin Configuration 1 16 VCC REG90 2 15 STB CS 3 14 OVP GATE 4 13 UVLO DIMOUT 5 12 SS GND 11 6 ISENSE PWM 7 10 FB FAIL 8 9 RT MS Figure 3. Pin Configuration 1.4 Pin Descriptions No. Pin name Function 1 VCC Power supply pin 2 STB IC ON/OFF pin 3 OVP Over voltage protection detection pin 4 UVLO Under voltage lock out detection pin 5 SS Soft start setting pin 6 PWM External PWM dimming signal input pin 7 FAIL Error detection output pin(Active High) 8 MS Mode Select Dimming input pin. 9 RT DC/DC switching frequency setting pin 10 FB Error amplifier output pin 11 ISENSE LED current detection input pin 12 GND - 13 DIMOUT Dimming signal output for NMOS 14 GATE DC/DC switching output pin DC/DC output current detect pin, 15 CS OCP input pin 16 REG90 9.0V output voltage pin www.rohm.com TSZ02201-0T2T0C100230-1-2 2016 ROHM Co., Ltd. All rights reserved. 2/33 TSZ2211115001 01.Nov.2016 Rev.001