Power chip can tightly regulate car battery voltages
09-08-2016 | By Paul Whytock
A power management IC that can implement a buck or buck/boost regulator to convert automotive battery voltages into a tightly regulated voltage whilst providing changes between buck and boost modes has been developed by Allegro MicroSystems Europe.
Designated the A4450 and qualified to AEC-Q100, the company says the device will find applications in automotive, industrial and instrumentation markets.
Automotive battery input voltage supply can alternate above and below the required output voltage. The wide input operating voltage range of 3V to 36V makes the A4450 suitable for automotive infotainment applications and handles idle stop/start, cold crank, double battery and load dump conditions.
The device has a high-voltage battery compatible enable (EN) input to accommodate switched battery input applications. It provides regulated output voltage ranging from 3V to 8V with load current of up to 1A DC. The Pulse Width Modulation switching frequency range is 250kHz to 2.4MHz, and frequency dithering and controlled switching transitions minimise EMI, claims the company.
The A4450 is designed to maintain stability even when input and output voltages are at nearly the same level as well as through line and load transient events.
Protection features in the device 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.
