Allegro Introduces New Hot-Swap Protection IC Using Hall-Effect Current Sensing
Allegro MicroSystems, Inc. announced its new ACS760 hot-swap protection IC that is designed for 12V hot-swap applications. The new device combines Allegro’s Hall-effect current sensing technology with hot-swap control circuitry, resulting in what is claimed to be 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: 240VA 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 2µs. 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 to 13.2V, and has 1.5mΩ internal conductor resistance. It is protected against electrostatic discharge at up to 2kV 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 to +85°C. It is priced at $4.00 in quantities of 1,000 and has a 12-week typical lead-time to market.
