Patent ID: 7180369

Claim:
An electrical circuit, comprising: a differential amplifier, comprising: an input circuit in communication with a differential input of the differential amplifier, the input circuit comprising: a first input transistor; and a second input transistor, wherein base electrodes of the first and second input transistors are in communication with the differential input, and wherein emitter electrodes of the first and second input transistors are in communication with each other and a first current source; a start-up circuit in communication with the input circuit, wherein the start-up circuit is configured to generate a start-up signal to enable subsequent operation of the differential amplifier, the start-up circuit comprising: a first start-up transistor; and a second start-up transistor, wherein base electrodes of the first and second start-up transistors are in communication with a bias input, wherein emitter electrodes of the first and second startup transistors are in communication with each other and with the first current source, and wherein collector electrodes of the first and second start-up transistors are in communication with collector electrodes of the first and second input transistors, respectively; and an output circuit in communication with the input circuit and the start up circuit, wherein the output circuit is in communication with a differential output of the differential amplifier, the output circuit comprising: a first output transistor; a second output transistor; a first impedance circuit; and a second impedance circuit, wherein base electrodes of the first and second output transistors are in communication with the first and second impedance circuits, respectively, and the collector electrodes of the first and second input transistors, respectively, wherein emitter electrodes of the first and second output transistors are in communication with each other and with the first current source, and wherein collector electrodes of the first and second output transistors are in communication with the first and second impedance circuits, respectively, and the differential output.