GM7620

PRELIMINARY GM7620 FIXED FREQUENCY STEP-UP DC/DC CONVERTER www.DataSheet4U.com 1.2MHz Fixed Frequency Switching Inherently Matched LED Current Adjustable Control of LED Current Drives Five White LEDs from 2V Drives Six White LEDs from 2.7V Drives Eight White LEDs from 3V Disconnects LEDs In Shutdown Uses Tiny Ceramic Capacitors Uses Tiny 1mm-Tall Inductors Regulates Current Even When VIN > VOUT Operates with VIN as Low as 1V Up to 80% Efficiency The GM7620 is a fixed frequency step-up DC/DC converter designed to operate as a constant-current source. Because it directly regulates output current, the GM7620 is ideal for driving light emitting diodes (LEDs) whose light intensity is proportional to the current passing through them, not the voltage across their terminals. With an input voltage range of 1V to 10V, the device works from a variety of input sources. The GM7620 accurately regulates LED current even when the input voltage is higher than the LED voltage, greatly simplifying batterypowered designs. A single external resistor sets LED current between 5mA and 40mA, which can then be easily adjusted using either a DC voltage or a pulse width modulated (PWM) signal. When the GM7620 is placed in shutdown, the LEDs are disconnected from the output, ensuring a quiescent current of under 1mA for the entire circuit. The device’s 1.2MHz switching frequency permits the use of tiny, low profile chip inductors and capacitors to minimize footprint and cost in space-conscious porta...