Hot-Swap Protection IC Exploits Hall-Effect Current Sensing

The ACS760, a hot-swap protection IC for 12V applications, combines the company’s Hall effect current sensing technology to eliminate the external sense resistor, resulting in lower I2R losses in the power path. The device operates with an external high-side FET gate drive and produces an analog output voltage proportional to the applied current. A user-controlled, soft-start/hot-swap function is accessible via the logic-enable pin. When externally enabled and the voltage rail is above the internal under-voltage lockout threshold, the chip's 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 on board: 240 VA power fault protection with user-programmable delay, programmable over-current fault threshold with programmable delay, and short-circuit protection that disables the gate in less then 2 µs. Available in a 24-lead QSOP with an operating temperature range from -40°C to +85°C, price for the ACS760 is $4 each/1,000. ALLEGRO MICROSYSTEMS INC., Worchester, MA. (508) 853-5000.