Integrated circuit devices having oscillator circuits therein that support fixed frequency generation over process-voltage-temperature (PVT) variations
Oscillator circuits that support highly accurate fixed frequency generation over process, voltage and temperature (PVT) variations include a reference voltage generator, which is configured to generate a reference voltage across a resistor (e.g., high precision poly-resistor) therein. An auto-zeroing comparator is provided, which is configured to generate a differential clock signal (e.g., Ck, Ckb) at an output thereof. First and second switched capacitor circuits are further provided, which include matching first and second trim capacitors therein, respectively. The first and second switched capacitor circuits are configured to periodically drive respective first and second input terminals of the comparator at a first voltage level in an alternating back-and-forth sequence, in response to the reference voltage and a pair of switching signals derived from the differential clock signal.
