The LT3763 from Linear Technology is a fixed frequency, synchronous, step-down DC/DC controller designed to accurately regulate output currents up to 20A.
Its constant current and constant voltage regulation makes it ideal for applications ranging from driving high brightness LEDs to battery and supercap charging.
The True Color PWM dimming capability of this device offers dimming ranges as wide as 3,000:1 for LED applications while the device can utilize either analogue or PWM dimming as required by the application. Furthermore, its switching frequency can be programmed between 200kHz and 1MHz through an external resistor on the RT pin or synchronized to an external clock.
The LT3763's unique design utilizes four control loops to monitor input current, LED /output current, output and input voltage to deliver optimum performance and reliability.
This LED driver device uses two external switching MOSFETs and can deliver from 5W to over 300W of continuous LED power with efficiencies up to 96%. LED current accuracy of ±6% ensures constant lighting while ±1.5% output voltage accuracy offers several LED protection features and also enables the converter to operate as a constant voltage/constant current source for charging applications.
The average current mode controller will maintain inductor current regulation over a wide output voltage range from 0V to 55V. Output current is set by analogue voltages on the CTRL pins and an external sense resistor. Voltage regulation and overvoltage protection are set with a voltage divider from the output to the FB pin.
Additional features include an accurate external reference voltage for use with the CTRL pins, open/short protection, C/10 detection, input and output current monitors, integrated fault protection and thermal shutdown.
The LT3763EFE is available in a 28-lead thermally enhanced TSSOP package. An extended temperature version, or I grade, the LT3763IFE, is also available along with a high temperature version, or H grade, the LT3763HFE.
For more information, visit www.linear.com/product/LT3763.
