GM2102

www.DataSheet4U.com PRELIMINARY GM2102 CONSTANT CURRENT DC/DC WHITE LED DRIVER GENERAL DESCRIPTION The GM2102 is a member of Gamma Microelectronics’s family of white LED drivers. The GM2102 is a fixed frequency step-up DC/DC converter designed to operate as a constant-current source. It is ideal for driving light emitting diodes (LEDs) whose light intensity is proportional to the current passing through them and not on the voltage across their terminals as it directly regulates the output current. The wide input voltage range allows the device to work from a variety of input sources. A single external resistor sets LED current between 5mA and 40mA, which can then be easily adjusted using either a DC voltage or a PWM signal. In Shutdown mode, the LED’s are disconnected from the output with the maximum quiescent current of 1µA for the entire circuit. FEATURES Drives Six White LED’s from 1.8 V 1.2Mhz Fixed Frequency Switching Minimum operating input voltage 1.2V 90% efficiency Accurately adjustable LED current Current Regulation even when Vin > Vout Disconnects LED’s in Shutdown mode Available in SOT23 Package ideal for space conscious portable applications TYPICAL APPLICATION 6.8 uH D1 APPLICATIONS Cellular Phones Digital Cameras Handheld Computers Portable Audio players Pagers Other White LED applications Vin 2.7V to 4.2V 6 C1 4.7 uF 1 SW C2 1 uF Vin PWM DIMMING CONTROL SIGNAL 5 GM2102 SHDN Rset 4 Rset 1.5K LED GND 2 3 15mA Revisio...