Patent ID: 7529317

Claim:
An oscillator circuit having an output frequency independent of a supplied voltage, comprising: an operational amplifier, having a threshold voltage input and second voltage input, wherein the operational amplifier generates an output voltage equal to: a first output voltage when the threshold voltage input is greater than the second voltage input voltage; and a second output voltage when the threshold voltage input is less than the second voltage input; a resistive-capacitive (RC) network, including a first resistor and a first capacitor coupled in series, wherein the first resistor couples to an output of the operational amplifier, and the capacitor couples to ground, wherein a node between the first resistor and the first capacitor couples to the second voltage input; and a voltage divider network wherein the threshold voltage is sampled from within the voltage divider network and wherein the threshold voltage is proportional to the first output voltage supply based on the voltage divider network and the output frequency is determined by the RC network.