Ultra-low IQ buck regulator targets automotive infotainment systems

The new A8591 from Allegro MicroSystems Europe is a buck regulator IC designed to meet the power-supply requirements of the latest automotive infotainment systems. It is available in fixed 5V or 3.3V regulated output voltage configurations. The AEC-Q100-qualified device provides all the control and protection circuitry of a 2A regulator circuit with ±1% output voltage accuracy. An ultra-low-IQ mode employs pulse-frequency modulation (PFM) to draw less than 33µA from a 12V input while supplying a 5V/40µA output, making the A8591 ideal for automotive battery-powered 'keep-alive' applications. A 'sleep' feature is included which reduces the standby current down to 5µA. When operational, the A8591 operates down to at least 3.6V input to accommodate idle-stop battery input requirements. The regulator PWM switching frequency can be set between 300 kHz and 2.4 MHz and 'dithered' or synchronised to an external clock. The A8591 has extensive protection features including pulse-by-pulse current limit, 'hiccup' mode short-circuit protection, open/short-circuit asynchronous diode protection, boot open / short-circuit voltage protection, input-voltage under-voltage lockout, power-on reset (NPOR), and thermal shutdown. This new regulator is targeted at the automotive and industrial markets, including applications such as infotainment, centre stack and instrument clusters, advanced driver assistance systems (ADAS), head-up displays, HVAC systems and industrial controls. The A8591 is supplied in a 3mm × 3mm 10-pin wettable flank DFN package (suffix EJ) with exposed power pad for enhanced thermal dissipation. It is lead (Pb) free, with 100% matt-tin leadframe plating.