Allegro® Introduces a New Hot-Swap Protection IC Using Hall-Effect Current Sensing

Worcester, MA, June 28, 2007 — Allegro® MicroSystems, Inc. new ACS760 hot-swap protection IC is designed for 12 V hot-swap applications. The new device combines Allegro’s Hall-effect current sensing technology with hot-swap control circuitry, resulting in a highly efficient integrated controller. No external sense resistor is required, resulting in greatly reduced I2R losses in the power path.

The ACS760 incorporates an external high-side FET gate drive, and produces an analog output voltage (factory trimmed for gain and offset), which is proportional to the applied current. The user-controlled soft-start/hot-swap function is accessed via the logic ‘enable’ input pin.

When the ACS760 is externally enabled and the voltage rail is above the internal under-voltage lockout threshold, the internal charge pump drives the gate of the external FET. When a fault is detected, the gate is disabled while simultaneously alerting the application that a fault has occurred.

Three levels of fault protection are integrated within the ACS760: 240 VA power fault protection with user-programmable delay; user-programmable overcurrent fault threshold with programmable delay; and short-circuit protection, which disables the gate in less then 2 µs.

In the event of the external high-side FET failing in a short-circuit condition, the ACS760 detects the failure, immediately disables the gate, and alerts the host system. The IC is designed for single-supply operation from 10.8 V to 13.2 V, and has 1.5 mΩ internal conductor resistance. It is protected against electrostatic discharge at up to 2 kV for all pins.

Allegro’s ACS760 is supplied in 24-lead QSOP package (suffix LF), which is lead (Pb) free and RoHS compliant. Operating temperature range is -40°C to +85°C.

About Allegro

Allegro MicroSystems, Inc. is a leader in developing, manufacturing and marketing high-performance power and Hall-effect sensor integrated circuits. Allegro's innovative solutions serve high-growth applications within the automotive, communications, computer/office automation, consumer and industrial markets. Allegro is headquartered in Worcester, Massachusetts (USA) with design and applications centers located in North and South America, Asia, and Europe. Further information about Allegro can be found at www.allegromicro.com.

Editorial Contact:
Stephanie Fennelly
Director - Marketing Communications
Tel: (508) 854-5363
sfennelly@allegromicro.com