S T E VA L - I L L 0 6 7 V 1 Six-channel ALED7707-based LED driver with embedded boost converter for automotive interior lighting and TFT backlighting Data brief Description The purpose of this evaluation board is to provide an application example of a six-channel, medium- current LED driver using the ALED7707 chip. The monolithic boost converter provides the required LED supply voltage starting from a single supply rail, while the brightness of the LED strings connected to the six outputs is controlled through a PWM signal. Open LED and LED short-circuit fault conditions are detected and managed. The board has been designed to provide a compact reference solution for automotive applications involving several LEDs arranged in multiple strings (e.g. interior lighting, infotainment LCD backlighting, etc.). Features Wide DC input voltage (6 V - 32 V) Six 70 mA output channels (capable of 30 mA to 85 mA each) PWM brightness control (10 s minimum dimming on-time) Up to 10 white LEDs per channel (36 V OVP threshold) > 90% efficiency (VIN=12 V, VBOOST=30 V, f =1 MHz, no snubber) SW On-board input filter for conducted EMI reduction RoHS compliant All automotive-grade components June 2015 DocID027964 Rev 1 1/10 www.st.com For further information contact your local STMicroelectronics sales office Board description and efficiency measurement STEVAL-ILL067V1 1 Board description and efficiency measurement Figure 1: Basic connection of the STEVAL-ILL067V1 evaluation board - + GSPG10062015DI1514 For a quick evaluation of the STEVAL-ILL067V1 performance, just connect a DC power supply (e.g. 12 V & 3 A current capability) between the V (J1) and GND (J2) terminals IN and a set of suitable LED strings between the VBOOST (J3) & ROW1-ROW6 (J10 through J15) terminals. The SW1 & SW2 jumpers should be both set in the lower postion, while the SW4 jumper should be in the right position (FSW & MODE pins forced high, DIM pin high, see Table 3 for details) as per default setting. As soon as the supply input is powered, the EN pin (floating) is internally pulled-up, a soft-start sequence takes place and the LED strings are powered at full-brightness. By pressing SW3 (EN pin tied low), the device shuts- down. This pushbutton allows to easily reset the device in case a latched turn-off occurs as 2/10 DocID027964 Rev 1