Single-stage fully recycling folded cascode OTA for switched-capacitor circuits

A single-stage multi-path operational transconductance amplifier (OTA) is presented. The proposed amplifier uses the transconductance enhancing technique in an upgraded folded cascode (FC) amplifier. It significantly improves the DC gain, unity-gain bandwidth and slew rate compared with previous FC amplifiers with the same power consumption. Simulation results in 90 nm complementary metal-oxide semiconductor (CMOS) technology show that the proposed OTA achieves a 59.1 dB DC gain and a gain bandwidth of 650 MHz, which makes it suitable for fast-settling switched-capacitor circuits.