All of the flexible timing circuitry required to debounce the on/off pushbutton is integrated within the LTC2950. For applications that need additional time during power down, it also provides an adjustable timer.
The LTC2950 can handle a wide range of input power supply because it runs across a broad input voltage range of 2.7V to 26.4V. The LTC2950 is perfectly suited for battery-powered applications due to its extremely low quiescent current (6µA average). The part comes in two versions to support either positive or negative enable polarities.
The turn-on time can be adjusted by placing an external capacitor on the ONT pin and the turn-off time on the OFFT pin. Open-drain interrupt output INT pin triggers after the pushbutton turn-off event is detected. LTC2950 interrupts the system (µP) by bringing the INT pin low. Once the system finishes its power-down and housekeeping tasks, it sets KILL low, which in turn releases the enable output. If at the end of the power-down timer (1024ms) KILL is still high, the enable output is released immediately.
