Low-voltage G/sub m/-enhanced class-AB pseudodifferential OTA for switched-capacitor circuits

A new low-voltage, rail-to-rail output swing, class-AB pseudodifferential operational transconductance amplifier (OTA) for high-speed switched-capacitor applications is proposed. Positive feedback is employed to enhance the input transconductance, which increases the open-loop DC gain and the unity-gain frequency of the OTA. Using a 0.35-/spl mu/m CMOS process, the proposed OTA can obtain 78-dB DC gain, 72.5/spl deg/ phase margin, 100-V//spl mu/S slew rate with 1-pF load capacitor, while draining 170-/spl mu/A quiescent supply current from a single 1-V power supply voltage.