STMicroelectronics A7987: Versatile Automotive Switching Regulator with Wide Voltage Range

The STMicroelectronics A7987 is a high‑performance automotive switching regulator designed for wide‑range applications, from traditional 24 V buses to hybrid and electric vehicles.

With an input voltage tolerance up to 61 V, the A7987 can be powered directly from a standard 24 V battery while delivering a tightly regulated output even under challenging conditions such as load dump.

The regulator offers a fully adjustable output from 0.8 V up to the input voltage, low dropout, and up to 3 A of current, making it suitable for logic circuits, lighting, infotainment, and telematics subsystems.

External pulldown resistors set the current limit and switching frequency (up to 1.5 MHz), allowing designers to size the output inductor for a compact module. Pulse‑by‑pulse current sensing combined with digital frequency foldback protects against short‑circuit stress, enhancing reliability.

Integrated thermal protection provides shutdown and auto‑recovery, reducing the need for external monitoring. The low‑resistance N‑channel MOSFET keeps conduction losses minimal, while pulse skipping at light load maintains regulation. A bias‑voltage input and switchover enable powering analog circuitry from an external source for maximum efficiency.

The A7987 supports up to five regulators in a synchronized arrangement to avoid phase noise and lower the RMS current in the input capacitor. Enable and Power‑Good pins, each with adjustable delay, support precise power‑up sequencing. An adjustable soft‑start limits inrush current. The device is AEC‑Q100 certified and available in a 5 mm × 6.4 mm HTSSOP‑16 exposed‑pad package.