Area-efficient programmable switched-capacitor-based peak detector

An area-efficient programmable switched-capacitor-based peak detector (PD) is presented. A programmable switched-capacitor resistor (SCR) is used to replace the small discharging current source in the conventional PD. The SCR can be programmable from megohms to gigaohms to ensure that the proposed PD works properly and achieves small detection errors over a wide input frequency range. The proposed PD has been fabricated in a 0.18 m CMOS process and occupies an area of only 0.014 mm². Measurement results show that the proposed PD consumes 0.2 mA from a 1.8 V power supply and the detection errors are within 2% when the input frequency varies from 2 kHz to 4 MHz and the input peak varies from 0.45 to 1.75 V.