The AMIS-70020 is a timer that measures the duration of power failures of up to five hours. The AMIS-70020 starts and stops counting automatically as it is triggered by the voltage of the input signal VCC. When VCC gets lower than the reference signal VDD-VTH, a power cut-off is flagged and the AMIS-70020 starts counting.
During the counting phase the AMIS-70020 is powered by an external capacitor or by a primary battery and consequently operates independently of an external power supply. Due to the low power design of the AMIS-70020, the device can count autonomously the full scale on the energy stored in a 10mF capacitor.