SGM3755.pdf
No.10859
? 1:350 Stable Luminance Dimming
? Low EMI by Conducting Ringing Cancelling
? Improved PSRR for Waveless Lighting
? Input Voltage Range: 2.7V to 5.5V
? Integrated 40V, 1.5A Current Limit MOSFET
? 38V Open LED Protection for 10 LEDs in Series
? 600kHz Switching Frequency
? 300mV Reference Voltage
? PWM Brightness Control
? Under-Voltage Protection
? Up to 90% Efficiency
? Built-in Soft-Start Function
? Thermal Shutdown
? -40℃ to +85℃ Operating Temperature Range
? Available in Green TSOT-23-6 Package
With a 40V rated integrated switch FET, the SGM3755 is a boost converter that drives LEDs in series. The boost converter has a 40V, 1.5A internal MOSFET; thus it can drive single or parallel LED strings for small to large size panel backlighting.
The default white LED current is set with the external sensor resistor, RSET, and the feedback voltage is regulated to 300mV, as shown in the typical application. During the operation, the LED current can be controlled by using a pulse width modulation (PWM) signal applied to the CTRL pin, through which the duty cycle determines the feedback reference voltage. The SGM3755 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 SGM3755 to prevent the output voltage from exceeding the IC absolute maximum voltage ratings during open LED conditions.
