The MP1528, a step-up converter designed to drive nine white LEDs in series at 20mA from a single cell Li-Ion battery, is new from Monolithic Power Systems. With an input voltage range of 2.7V to 36V, the MP1528 is suitable for applications such as PDA, mobile phones and cameras, but is also useful for LCD backlight applications in home appliances and industrial systems. The integrated power switch is said to ensure a maximum drive current of at least 20mA, even under challenging input/output voltage conditions.
The MP1528 operates at high efficiency and regulates LED current via a fixed off-time switch control loop determined by a 0.4V feedback threshold. LED brightness is adjusted by applying a DC voltage or a PWM signal to the driver. Additional features of the MP1528 include integrated soft-start, over-current, thermal and output over-voltage protection.
The MP1528 is available in a 6 pin 3mm x 3mm QFN package and requires as few as six external components to build a solution. Sample and evaluation boards are available for immediate delivery. Pricing starts at US$1.15 in 1k piece quantities.