Patent ID: 7116181

Claim:
An integrated temperature-compensated RC oscillator circuit including: an inverter having an input and an output; a resistor having a first terminal and a second terminal, the first terminal coupled to the output of the inverter; a capacitor coupled between the second terminal of the resistor and a fixed potential; a first analog comparator having an inverting input coupled to a first reference voltage, a non-inverting input coupled to the second terminal of the resistor, and an output; a second analog comparator having a non-inverting input coupled to the second terminal of the resistor, an inverting input coupled to a second reference voltage, and an output; a set-reset flip-flop having a set input coupled to the output of the first analog comparator, a reset input coupled to the output of the second analog comparator, and an output coupled to the input of the inverter; the first and second analog comparators comprising differential amplifiers each having a diode-connected current mirror MOS transistor in series with a non-inverting-input MOS transistor and a mirrored MOS transistor in series with an inverting-input transistor, the diode-connected current mirror MOS transistor having a width larger than the width of the mirrored MOS transistor, the differential amplifier further having a MOS bias transistor having a drain coupled to the sources of the inverting-input and non-inverting-input input transistors, a source coupled to ground, and a gate coupled to a bias-voltage supply.