Enhanced power-on-reset/low voltage detection circuit

摘要

A comprehensive power-on-reset (POR) and low voltage detection circuit combines a Power Supply Voltage Level Detection (PSVLD) circuit with an Enhanced Retriggering (ER) circuit. The PSVLD circuit establishes lower and upper thresholds of the desired operating voltage range, and provides initial POR triggering and retriggering when the supply voltage is within the desired range. The ER circuit senses a predetermined amount of drop in the power supply voltage being monitored, and generates an independent pulse at the POR node whenever such a drop occurs. Total DC current is limited to less than 2.5 microamps, while power supply voltages can be monitored over the range of 2.5 to 5.5 volts. A simplified POR and low voltage detection circuit establishes a single threshold and generates an initial POR signal when the supply voltage exceeds this threshold. The low voltage detection circuit causes a retrigger POR signal to be generated if the supply voltage then falls below this threshold. Total DC current is limited to less than 12 microamps, while power supply voltages can be monitored over the range of 2.5 to 5.5 volts.