Design of high speed 2-stage OTA for high capacitive load of 120 pF and 2.96 V

High speed operational transconductance amplifier (OTA) is used to drive high capacitive loads to reduce the charging time while providing adequate gain and stability. A 2-stage amplifier is proposed to provide high slew rate and sufficient gain and stability. 45 nm process technology is used to compare performance with differential and telescopic amplifier designs. Resistive feedback and noise-gain compensation techniques are used to drive 120 pF load of a row driver circuit used in an active pixel sensor and provide 2.96 V at output for a high slew rate of 2.2 V/ μ s.