Description

TIDA-00748 is a 60W Synchronous Boost Design for automotive LED application utilizing the Synchronous Boost Converter LM5122-Q1.  This design applies to automotive lighting for exterior lighting such as headlights and taillights and also interior LED lighting systems. The design accepts an input voltage of 8Vin to 15Vin and can drive multiple strings of 6 to 7 LEDS (16V to 24V) in series at 3A constant current. It is a low cost solution and provides undervoltage as well as overvoltage protection. This solutions offers 97% efficiency compared to inefficient nonsynchronous Boost solutions.The TIDA-00748 can also be modified to a Boost-to-Battery configuration by connecting the cathode of the LED string (9V to 12V) to the input rather than ground and connecting the output capacitors from input to output. In this configuration: the 8V to 15V input can power strings of LEDs that require voltages lower than: higher than: or equal to the input voltage which would not work with the standard Boost configuration which requires the output voltage to be higher than the input voltage. See Figure 1 for the Boost-to-Battery configuration along with the internal block diagram of the LM5122.