With a 40V rated integrated switch FET, the SGM3749 is a boost converter that drives up to 10 LEDs in series. The boost converter runs at a 1.25MHz fixed switching frequency with 1.5A switch current limit, and allows for the use of a high brightness LED in general lighting.
The default white LED current is set with the external sensor resistor R_SET, and the feedback voltage is regulated to 200mV, as shown in the typical application. During the operation, the LED current can be controlled using PWM signal through the CTRL pin, the pulse width modulation (PWM) signal determines the feedback reference voltage. In PWM mode, the SGM3749 does not burst the LED current; therefore, it does not generate audible noises on the output capacitor. For maximum protection, the device features integrated open LED protection that disables the SGM3749 to prevent the output voltage from exceeding the IC’s absolute maximum voltage ratings during open LED conditions.
The SGM3749 is available in Green TDFN-2×2-6L and TSOT-23-6 packages. It operates over an ambient temperature range of -40℃ to +85℃.