1A DC-DC buck converters maintain light-load efficiency

August 10, 2016 // By Graham Prophet
AP3401 and AP3428 DC-DC step-down converters (Diodes Inc.) supply loads up to 1A with excellent line- and load-regulation provided by a constant-frequency PWM control that requires no external compensation.

Developed for set-top boxes, TVs, routers, Wi-Fi modules and security systems, these buck converters feature low power consumption and highly-efficient light-load operation. The AP3401/3428 operate from an input voltage between 2.5V and 5.5V, suiting them for use with a single Li+/Li-polymer cell, multiple Alkaline/NiMH cells and other power sources; they also deliver an output voltage from 0.6V up to the full input voltage with an output current up to 1A. The high-current and low-dropout threshold performance is achieved with integrated ultra-low R DS(ON) MOSFETs and the ability to operate at 100% duty cycle with a switching frequency up to 1.5 MHz. The AP3401 also features a power-good output.

 

An integrated soft-start reduces start-up current spikes to avoid system damage when switching power on or off. Other features for protection of the IC and system include over-current, under-voltage lockout and over-temperature with thermal shutdown. The DFN2020 package has exposed pads for the power handling capability in thermally demanding consumer applications.

 

The AP3401 and AP3428 are priced at $0.12/unit (10,000).

 

Diodes Inc.; www.diodes.com