L5030

LINEAR INTEGRATED CIRCUIT

UNISONICTECHNOLOGIESCO.,LTD

3 of 6

www.unisonic.com.tw

QW-R125-001.D

DEVICE DESCRIPTION

The UTC L5030 is designed to supply a constant current to the external load, the circuit be powered a battery

supply. An external transistor is required for LED application. The UTC L5030 guarantees the start up voltage as low

as 0.92V and remains operation down to 0.8V.

The basic structure of UTC L5030 is a step-up DC/DC converter. It offers a Pulse Frequency Modulation (PFM)

operation, which controls the constant OFF time (1.7μs typically) for external transistor at the 200KHz maximum

frequency.

The external switching transistor is ON and kept on until the voltage across the current-sense resistor which is

Once the discharge cycle is completed, the external transistor is ON again. This charging and discharging sequence

will repeat and trigger the external transistor regardless the inductor current value.