Buck/Boost Controller with Integrated Buck FET

Allegro MicroSystems Europe has introduced a new automotive AEC-Q100 qualified power management IC. The A4450 can implement either a buck or buck/boost regulator to efficiently convert automotive battery voltages into a tightly regulated voltage, with seamless transition between the buck and boost modes. This new device is targeted at the automotive, industrial and instrumentation markets with end applications to include infotainment, instrument clusters, telematics, amplifiers, and control modules.

Allegro’s A4450 is designed for automotive input environments where battery input voltage supply can vary above and below the required output voltage and a single- inductor/single-stage conversion is desired. The wide input operating voltage range of 3 V to 36 V makes the A4450 suitable for a range of automotive infotainment applications and handles idle stop/start, cold crank, double battery and load dump conditions. The device features a high-voltage battery compatible enable (EN) input to accommodate for switched battery input applications.

The A4450 provides regulated output voltage ranging from 3V to 8V with load current of up to 1A. The pwm switching frequency range is 250kHz to 2.4MHz, and frequency dithering and controlled switching transitions minimize EMI. The A4450 maintains excellent stability even when the input and output voltages are at nearly the same level as well as through line and load transient events.

Protection features include pulse-by-pulse current limit, hiccup mode short-circuit protection, LX short-circuit protection, missing freewheeling diode (buck diode at LX node in A4450). The enable input is compatible to a high-voltage battery level, and a power-on reset output (NPOR) is integrated.

The device is available in a 20-lead, 4 mm x 4 mm QFN package (suffix “ES”), which is “wettable flank” and AEC-Q100 qualified.