3A, synchronous buck regulator accepts 4-36V

July 29, 2015 // By Graham Prophet
A8654 from Allegro MicroSystems Europe is a high-output current synchronous buck regulator IC that can produce a 3A steady-state load current from an input voltage ranging from 4 to 36V.

It device integrates low “on” resistance high-side MOSFETs and low-side n-channel MOSFETs, and utilises external compensation to accommodate a wide range of power components. It uses pulse-width modulation (PWM) current mode control to provide simple compensation, good loop stability and fast transient response.

The A8654 regulates nominal input voltages from 4 to 36V, and remains operational even when the input drops as low as 2.6V. When the input voltage approaches the output voltage, the duty cycle is maximised to maintain the output voltage.

Key features include externally set soft-start time, an external compensation network for power-train optimisation, an “enable” input to enable the output voltage, a “SYNC/FSET” input to synchronise or set the PWM switching frequency, and an “NPOR” output validated by the output voltage.

Protection features include input undervoltage lockout, cycle-by-cycle overcurrent protection, “hiccup” mode short-circuit protection, overvoltage protection and thermal shutdown. The A8654 provides open-circuit, adjacent pin short-circuit, and short-to-ground protection at every pin, for automotive and non-automotive applications. The maximum junction temperature is 150ºC.

This buck regulator IC is targeted at the automotive, industrial and instrumentation markets with typical end applications to include infotainment and GPS systems, automobile audio and camera systems, home audio, and industrial systems. It comes in a 16-pin eTSSOP package with exposed pad for enhanced thermal dissipation; data sheet here.

Allegro MicroSystems; www.allegromicro.com