ISL6161CB

Application

The ISL6161CB is mainly used in hot swap applications. A hot swap circuit allows the safe insertion or removal of a board from a live backplane without interruption. This is typically seen in parallel redundant power systems and microprocessors. In these applications, the ISL6161 provides a gate drive to an external N-channel MOSFET to control the in-rush waveform. The device also supports a number of safety features like current limit protection and overtemperature protection.

Working Principle

At power-up, the INT pin voltage starts from 0V, a low-current connection between the power source CH (Output) and the load PVCC is enabled by the external N-channel MOSFET. As the voltage at INT pin rises and reaches the control threshold voltage VTH, the internal voltage regulator retriggers until the INT and EXT (Fault) pins reach the reference voltage VREF.

When the voltage at the INT pin reaches VTH, the internal comparator compares the voltage between the INT pin and VREF. If the voltage is detected to be lower than VREF, the comparator notifies the pulse generator to output a pulse and turn on the MOSFET. Then the voltage between INT and VCC pins would be reset and the comparator is reset.

When the voltage at INT pin is above VTH, the external MOSFET is turned off, providing a safe power-off to the system. If the output overvoltage exceed the upper limit, the device will shut down. Normal operations will resume when the external load is removed, allowing the device to restart.

Conclusion

The ISL6161CB is a monolithic device specifically designed for reliable hot swap application. It provides an internal voltage regulator, which retains the voltage at the INT pin, allowing it to achieve a steady supply of power. The device is also equipped with many safety features such as current limit protection, overvoltage protection, and overtemperature protection to protect the system from damage. With the integrated protection features, the ISL6161CB is ideal for hot swap applications.