White LED Driver with PWM Brightness Control in Small Packages
SGM3749 SGM3749.pdf

No.10807

FEATURES
 Input Voltage Range: 3V to 20V 
 38V Open LED Protection for 10 LEDs 
 200mV Reference Voltage 
 600kΩ Pull-Down Resistor on CTRL Pin 
 1.5A Switch FET with 1.25MHz Switching Frequency 
 PWM Brightness Control 
 5kHz to 100kHz PWM Dimming Frequency Range 
 Dimming Stable in More than 1:500 PWM Range 
 Soft-Start Function 
 Up to 90% Efficiency 
 -40℃ to +85℃ Operating Temperature Range 
 Available in Green TDFN-2×2-6L and TSOT-23-6 
  Packages
DESCRIPTION

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 RSET, 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℃.

APPLICATION CIRCUIT
PIN CONFIGUTION
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