Dual synchronous low-voltage buck regulator IC drops to 0.8V

April 16, 2014 // By Graham Prophet
Allegro MicroSystems’ A8651 is a dual synchronous low-voltage buck regulator IC that combines flexibility, robustness and automotive (AEC-Q100) qualification for use in multiple output systems with a 2.5 V to 5.5 V system rail.

The device is a dual 2-A, low input voltage synchronous regulator with an adjustable-frequency integrated high-side P-channel MOSFET and a low-side N-channel MOSFET. It incorporates current-mode control to provide simple compensation as well as loop stability.

The A8651 uses external compensation to optimise the transient response without sacrificing stability. It regulates input voltages from 2.5 V to 5.5 V down to output voltages as low as 0.8 V, and is able to supply up to 2A of load current per regulator.

Features include an externally adjustable and synchronisable switching frequency, an externally set soft start time to minimise inrush currents, independent “enable” inputs and independent open-drain fault indication outputs with 7.5 msec delay. The “sleep” mode current of the A8651 control circuitry is less than 5 μA.

Protection features include input undervoltage lockout, cycle-by-cycle overcurrent protection, “hiccup” mode short-circuit protection, overvoltage protection and thermal shutdown. It provides open-circuit, adjacent pin short-circuit, and short-to-ground protection at every pin to satisfy the most demanding automotive applications.

Use it in automotive infotainment, GPS, telecom, networking and home/professional entertainment system applications; it comes in a 20-pin eTSSOP package with exposed thermal pad for enhanced thermal dissipation (suffix LP).

Allegro MicroSystems; www.allegromicro.com