STEVAL-ILL035V1 Multi-channel LED driver with integrated boost controller for medium, large LCD panel backlight based on LED7708 and STM32F103C6T6A Data brief Features Wide DC input voltage: 10 V to 28 V Integrated boost converter with adaptive output voltage for minimum power dissipation Up to 92% boost converter efficiency 16 channels with up to 85 mA/ch current capability and independent PWM brightness control Up to 15 white LEDs per channel On-board STM32 microcontroller for total device control through 4-wire serial interface STEVAL-ILL035V1 Embedded open-channel and LED short-circuit Embedded, programmable fault detection and faults management management circuitry can be set to automatically USB connection for device control through disconnect faulty channels without the need for dedicated PC-GUI intervention by the host controller. Expansion connector to support slave devices The board has been designed as a demonstration (daughterboard) of a solution for medium/large LCD panel RoHS compliant backlight drivers, but is suitable for any application involving several LEDs assembled in strings (e.g. advertisement panels, signs, gaming, etc.). Description The purpose of the STEVAL-ILL035V1 demonstration board is to provide an application example of a compact LED backlight driver using the LED7708 device. The board is equipped with a 16-channel LED driver with integrated boost controller (the LED7708), power section components, and an STM32 microcontroller to easily control all the features via a USB connection. The output voltage required by the LED strings connected to the output channels is derived from a single input rail and continuously adjusted to minimize the voltage drop (and power dissipation) across them, despite an independent PWM duty cycle for each one. The brightness of each LED string is digitally controlled with 12- or 16-bit dimming resolution. June 2012 Doc ID 023200 Rev 1 1/6 For further information contact your local STMicroelectronics sales office. www.st.com 6 * * 90 6* 3* 9 6/ 9, )2 6<1 9) )6 Schematic diagrams STEVAL-ILL035V1 1 Schematic diagrams Figure 1. LED driver 11 && -- // 7 %9 XX // 77 33 66 && && && NN 55 55 ( 1 BB 11 && & & XX 6 : 5 XX 9 , 1 B 1 , && & & 7 & 1 % 5 ( ,1 1 7( 1 6 : 1 &+ 6 < *6<6 &+ B , 1 , 1 &+ 9 6 , 7 2 8 7 &+ . &/ . &+ 7 / 8 5 /( &+ 13 ) 4 . & *6&. & + -- 7/ ) /7 &+ &+ .2 2. & )9 )9 &+ .6 .6 &+ 37+ : & 6& 32( 30 (+7 (7/ 1 1 33 ,, 55 9 & & 7 : 6 B ) 9 6 : 5 /( 7(6 , 5 & 1 & 6 : N Q B 2 ) 5 & & 1 5 N N 0-3- 2/6 Doc ID 023200 Rev 1 / 2 &/ ,0 /5 &2 * ,6 ,6 &616 &+ &+ &+ &+ 5 & S N 6& 6(/ & 5 73 9& & - - N /B6 N 5 N && 6(/ 73 73 73 3 - - 73 73 73 73 6: 6767 0 0 2 2 + 9 9 ,2 ,2 ) *6 N N /( B9 B /( 5 ) &/ 28 X & 96, 6(/ *6 96, 96, 9 9& 73 8 8 73 73 73 73 73 73 3 73 X X &2&2 1 1 Q & & Q Q 9& 7373 90 6(/ N N N & & 5 5 7373 9,9, 6(/6(/ 90 /5 - - N N 5 5 6:6: - - 3 3 5 5 5 5 - - - - - - 5 5 5 5 1&1& & & 5 5 X X X X X X X X X X X X X X X X X X & & & & & & & & & & & & 1)1) 7676 4 4 N N 5 5 6767 36 36 226 - -