Allegro MicroSystems, Inc. Announces New 12 V Hot Swap Controller

Allegro® announces a new 12 V hot swap controller with power good indication. The ACS761 is a highly integrated Hall-effect current sensor with an integrated charge pump, gate driver, and multiple levels of load fault protection. Hot swap control and short circuit protection are provided in a single IC without the need for an external shunt resistor. The resistance of the ACS761 internal current conductor is typically 1.5 m¦¸, resulting in substantial power savings relative to shunt resistor based hot swap solutions without a reduction in sensing accuracy. The ACS761 is a further enhancement on the ACS760, the world¡¯s only Hall-effect based hot swap controller with 240 VA protection. The ACS761 includes the following architecture enhancements:

• Fixed Over Current Fault Threshold - Set internally to 40 A
• Inclusion of PGOOD and PGOOD pins - Provides feedback to host system that the 12 V supply is enabled and eliminates external system logic components.

Allegro¡¯s ACS761 combines Allegro® Hall-effect current sense technology with an integrated charge pump, FET driver, and a hot-swap controller. The integrated protection in the ACS761 incorporates three levels of fault protection, which includes a Power Fault with user-selectable delay, an Overcurrent Fault threshold with user selectable delay, and Short Circuit protection, which disables the gate of an external pass FET in less than 2 µs. These faults are indicated to the host system via the Fault pin and are cleared upon reasserting the chip enable pin to the high state.

The ACS761 is targeted at the computer/office automation market, most specifically for server applications.