A Bandgap Diode-Based Voltage Band Detection Circuit With Fast Response Time and Low Vmin on Intel 4 Logic Technology

A fast, accurate, single-rail voltage detection circuit (VDC) is presented. Low voltage operation is achieved by a variable gain Charge Pump (CP) followed by a Low-Dropout regulator (LDO). An Open-loop Band Gap Reference (BGREF), passed to a dynamic comparator, achieves an undervoltage trip point of 0.62V with 8.7mV sigma, and an overvoltage trip point of 1.22V with 12mV sigma, demonstrated on Intel 4 silicon prototype. The design operates without any filter cap, allowing a fast, power-on ramp of 2ls, and brown-out detection of <200ns. A voltage band detection of 0.48-1.22V is enabled through a finite-state machine (FSM) to modify CP and LDO gain depending on input voltage.