This push-button circuit can be used with a wide variety of PMICs. For example, this circuit can be used to drive a control pin, which enables and disables the buck converters, for the TPS65086 device. This report provides the necessary components and a detailed description on how the circuit operates. The typical operating range for this circuit is from 1.65 V to 5.5 V. The input voltage can come from the same source powering the PMIC, or from the PMIC itself. The input voltage for the SN74LVC1G175 device must not exceed the maximum voltage of the control pins on the target device. If the input voltage does exceed the maximum voltage, then a level shift is necessary, to match the operating voltage of the control pins.
The SN74LVC1G175 device, which has an asynchronous clear, is the D-type flip-flop chosen for this circuit. Using the asynchronous clear, the SN74LVC1G175 device can set the output low regardless of the clock. This functionality allows the circuit to differentiate between a short and long press.