The SGM3759 is a high efficiency white LED driver with a 1.2MHz boost converter. With the fixed switching frequency and an internal 40V/3A switch FET, the SGM3759 is designed for powering single or parallel LED strings for various size panel backlighting and ideal for smart phone image capture using display device as a flash mode light source, as it is capable of driving up to 200mA current at 30V for 320ms when the strobe signal is active.
The FB feedback voltage is regulated at 200mV typically. The backlight mode default LED current is programmed by an external RSET resistor. During the operation, the LED current can be controlled by applying a PWM signal to the CTRL pin. The feedback voltage depends on the PWM signal duty cycle. For PWM dimming control, there are no audible noises on the output capacitor.
The SGM3759 integrates LED open protection. It prevents the device from damaging due to the over-voltage during LED open conditions.
When the device is in operation and the STROBE pin is pulled up, the SGM3759 will enter flash mode within 100μs. The feedback voltage is regulated to 5× of thebacklight mode voltage that is determined by the PWM signal duty cycle. When the STROBE pin is pulled down or the strobe signal remains high for longer than the 320ms timer, the SGM3759 will enter backlight mode within 100μs.
The SGM3759 is available in a Green TSOT-23-6 package. It operates over an ambient temperature range of -40℃ to +85℃.