Patent ID: 8866536

Claim:
A process monitoring circuit, comprising: a bandgap reference circuit configured to generate a bandgap reference voltage; a clock generator configured to generate a first clock; a negative bias circuit coupled between the bandgap reference circuit and the clock generator and configured to generate a negative bias voltage according to the bandgap reference voltage for stabilizing operation of the clock generator; a temperature insensitive oscillator configured to generate a second clock; a low dropout voltage regulator coupled to the temperature insensitive oscillator and configured to generate a zero temperature coefficient voltage for stabilizing operation of the temperature insensitive oscillator; a counter coupled to the clock generator and the temperature insensitive oscillator and configured to count number of pulses of the second clock within each duty cycle of the first clock so as to generate a counted number; a comparison circuit coupled to the counter and configured to compare the counted number with at least one reference number to generate a comparison result; and a charge pump coupled to the comparison circuit and configured to generate an output voltage according to the comparison result.