1V to 16V, Single-Channel, Hot-Swap Controllers with Precision Current-Sensing Output

The MAX5977A/MAX5977B hot-swap controllers provide complete protection for systems with a 1V to 16V single-supply voltage.

During the initial insertion, the hot-swap controllers limit the inrush current from damaging the board or from shorting out the backplane. When the input voltage is above the undervoltage threshold and below the overvoltage threshold, a 5µA current source powered from the internal 5V charge pump drives the gate of an external n-channel MOSFET providing a slow turn-on response. An internal current-sense amplifier in the IC monitors the current across an external shunt resistor providing current sensing for wide input-sense voltage range. The devices provide two levels of overcurrent circuit-breaker protections: a fast-trip threshold for a fast turn-off and a lower slow-trip threshold for a delayed turn-off.

Exceeding either of the overcurrent circuit-breaker thresholds will force the device into fault mode where the external n-channel MOSFET is disabled. The MAX5977 is available in two versions which provide a latched off (MAX5977A) or autoretry (MAX5977B) output when the device is in fault mode.

A calibration mode allows further calibration of the integrated transconductance amplifier for production testing of the final design. The devices are offered in a 20-pin, 4mm x 4mm, TQFN-EP package and are fully specified from -40°C to +85°C.

Applications

* General Hot-Swap * Network Switches and Routers * Servers * Storage Systems

* 1% Accurate Current-Sense Amplifier Output

* Hot-Swap Monitors Operation from 1V to 16V

* Integrated Charge Pump Fully Enhances the External n-Channel FET (VGATE = VIN + 5V)

* VariableSpeed/BiLevel™ Fault Protection Provides Electronic Circuit-Breaker Function

* Output Latched Off After Fault Condition (MAX5977A)

* Autoretry After Fault Condition (MAX5977B)

* Power-Good Indicator

* Calibration Mode

* Small, 20-Pin, 4mm x 4mm, TQFN-EP Package