Patent ID: 7733169

Claim:
An operational amplifier comprising: a 3-stage amplifier having first and second input conductors conducting a differential input signal and an output conducting an output signal, wherein the 3-stage amplifier includes: a first amplifier stage having an input coupled to the input signal; a second amplifier stage having an input coupled to an output of the first amplifier stage; a third amplifier stage having an input coupled to an output of the second amplifier stage and an output conducting the output signal of the 3-stage amplifier; and a feed-forward amplifier stage having an input coupled to the input signal and an output coupled to the input of the third amplifier stage; and a slew rate and settling time improvement circuit having an input coupled to the input signal and an output, the slew rate and settling time improvement circuit including: first circuitry coupled to the input signal for producing a slew detection current when the magnitude of the input signal exceeds a predetermined level; second circuitry for converting the slew detection current to a control signal on the output of the slew rate and settling time improvement circuit; and first switch controlled by the control signal coupled to prevent signal charge from building up on capacitances associated with the output of the first amplifier stage during slewing of the operational amplifier.