Patent ID: 6977549

Claim:
A differential circuit comprising: a first pair of transistors, conductivity thereof being a first-type; a second pair of transistors, conductivity thereof being a second-type, outputs of said first pair of transistors connected respectively to outputs of said second pair of transistors; a first current source and a first switch, connected in parallel between commonly connected tails of said first pair of transistors and a first power supply; a second current source and a second switch, connected in parallel between commonly connected tails of said second pair of transistors and a second power supply; and connection changeover means for changing over the first and second pairs of transistors between a differential pair driven by a current source and having a pair of inputs for receiving differential input voltages and a current mirror circuit having a pair of inputs coupled together, one transistor of said current mirror circuit being diode-connected, said current mirror circuit functioning as a load of said differential pair, wherein, when one pair of said first and second pairs of transistors is the differential pair, the other pair is the current mirror circuit.