AMIS-70020 Datasheet | AMI SEMICONDUCTOR

AMIS-70020 Power Failure Elapsed Time Counter 1.0 General Description The AMIS-70020 is a timer IC 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 the full scale autonomously using the energy stored in a 10m F capacitor. As soon as VCC es up again counting stops. The value of the counter is shifted to the digital Q_OUT output pin and is municated to a microprocessor. After shifting the full counted value, the internal RC-oscillator signal is put on the Q_OUT output pin. Using this data the microcontroller can calculate the duration of the power failure. The internal power management circuit manages the recharge of the external buffer capacitor. Data Sheet The few external ponents required to build the AMIS70020 into its application result in a cost effective solution and in a footprint of less than 2cm2. The bination of an internal oscillator and a microcontroller software algorithm eliminate the requirement for a space and cost consuming external crystal. Typical applications are those sensitive to power failures that do not have a built-in UPS function. Examples are: - Power inverters/Motordrivers/Soft starters - Accurate I2t protection possible even after power loss - Thermal protection devices for electrical motors without integrated thermistor - Motor controllers for electrical motors without integrated thermistor - Process control - Chemical processes - Industrial mixers - Mixing reactors 2.0 Key Features - Measures the time elapsed during a power failure -...