
Unisonic Technologies
DESCRIPTION
The UTC L5101 is a fixed frequency step-up PWM DC/DC converter and designed for white LEDS driving with a constant current to provide backlight in handheld devices. The device switches at a high frequency 1.2MHz by an internal N-channel MOSFET switch to be capable of minimum external components using.
The UTC L5101 can drive up to 5 LEDs in series by a Li-Ion cell. Series connection of LEDS provides identical LED currents resulting in uniform brightness without ballast resistors. The low 95mV feedback voltage minimizes power loss in the current setting resistor can have better efficiency.
FEATURES
* Built-In Open Circuit Protection
* Built-In Over Voltage Protection
* High Efficiency(Up to 84% at VIN=4.2V, 3 LEDs, ILED=20mA)
* 1.2MHz fixed switching frequency
* Low supply current: 70µA
* Matches LED current
* Requires tiny inductor and capacitors