50W white LED headlight driver circuit diagram based on LT3755

　　The LT3755 senses output current on the high-side side of the LED string. High-side current sensing is the most flexible solution for driving LEDs. The PWM input provides a dimming ratio of up to 3000:1, while the CTRL input provides additional analog dimming. Light ability. The LT3755 is available in 16-pin (3mm × 3mm) QFN and MS0P packages. The main technical characteristics of LT3755
are as follows: 　　(1) Wide input voltage range (4.5~40V).
　　(2) Output voltage up to 75V.
　　(3) Fixed current and constant voltage regulation.
　　(4) 100mV high-end current detection.
　　(5) Boost, buck, buck-boost, SEPIC or flyback topologies can be used to drive LEDs.
　　(6) It has programmable under-voltage lockout protection function with LED open circuit and hysteresis.
　　(7) Open LED status pin.
　　(8) PWM disconnect switch driver.
　　(9) The CTRL pin provides analog dimming function.
　　(10) Low shutdown current: <1uA.