High speed operational amplifier

An amplifier receiving a pair of differential inputs and providing an output, comprising:

• current source means providing a source of constant current,
• a pair of coupled transistor means each for receiving a respective one of said differential inputs, said coupled transistor means connected to said current source means, each of said pair of coupled transistor means for conducting a respective portion of said constant current in response to said differential inputs,
• a pair of feedback current mirror means each for conducting said portion of said current through connection to a respective one of said pair of coupoled transistor means, each of said feedback means providing voltage and current signals responsive to said differential inputs,
• mirror stage means formed of curent mirror arrangement for shifting, converting and communicating said voltage and current signals from said feedback current mirror means to synchronously varying voltage signals,
• cascode stage means for receiving said varying signals from said mirror stage means and for providing said output, said cascode stage means having a first and second portion inversely conducting current and respectively receiving a first and a second portion of said varying signals, said first and second portions of said varying signals synchronously changing respecting the other portion of said varying signals, each of said portion of said varying signals respectively driving and dynamically biasing said first and second portions of said cascode stage means,
• said cascode stage means including a first pair of P-channel field effect transistors for providing a first portion of an output signal at said output, said first pair of transistors being connected in series between said output and a first power supply reference supplying current and power therethrough, each of said first pair of transistors having their gate terminals connected to receive said first portion of said varying signals changing in synchronism producing changing synchronized current through said first pair of transistors, and
• said cascode stage means further including a second pair of N-channel field effect transistors for providing a second portion of said output signal at said output, said second pair of transistors being connected in series between said output and a second power supply reference supplying current and power therethrough, said second pair of transistors having their gate terminals connected to receive said second portion of said varying signals changing in synchronism producing inversely synchronized changing current through said second pair of transistors, said first and second portions of said varying signals synchronously changing respecting the other portion of said varying signals.