Charge-pump based frequency regulator for precision supply generation

The attenuation of supply noise is crucial in those sensor interface circuits that require the detection of the small signal capacitance. This paper presents an integrated charge-pump based continuous frequency regulator for precision supply voltage generation. The circuit is able to operate with external supply voltage ranging from 3.0 V to 5.5 V. The charge-pump generates a nominal voltage of 3.6 V and is able to operate with 1.3 mA and 2.5 mA load currents while the minimum input noise attenuation is around 53 dB. The output noise of the system is 91.32 μV_rms and the active area of the circuit is 0.18 mm². The technology used for the implementation is 0.35 μm CMOS.