A high frequency, low jitter auto-calibration phase-locked loop with built-in-self-test

A phase-lock loop circuit which reacts to measured jitter by adjusting the VCO input control voltage is described. This self-calibration process alters the VCO response in order to lower the jitter in its 2.4 GHz output for Bluetooth application. As this adjustment takes place, it intrinsically adjusts the VCO output towards the desired operating frequency. The programmable synthesizer has a digitally controlled VCO that provides wide tuning range of 710 MHz. The auto-calibration technique adjusts the manufacture and process variation. The synthesizer, designed in TSMC 0.18-/spl mu/m technology, has an edge jitter standard deviation of 0.86-ps having a 20% improvement over PLL with no self-calibration.