Method and system for a feedback transimpedance amplifier with sub-40khz low-frequency cutoff

摘要

A system for a feedback amplifier with sub-40 khz low-frequency cutoff is disclosed and may include amplifying electrical signals received via coupling capacitors utilizing an amplifier having feedback paths comprising source followers and feedback resistors. Gate terminals of the source followers may be coupled to output terminals of the amplifier circuit. The feedback paths may be coupled prior to the coupling capacitors at inputs of the amplifier circuit. Voltages may be level shifted prior to the coupling capacitors to ensure stable bias conditions for the amplifier circuit. The amplifier circuit may be integrated in a CMOS photonics chip with the source followers comprising CMOS transistors. The amplifier circuit may receive current-mode logic or voltage signals. The electrical signals may be received from a photodetector, which may comprise a silicon germanium photodiode differentially coupled to the amplifier circuit. Optical signals for the photodetector in the chip may be received via optical fibers.

主权项

1. A system for processing electrical signals, the system comprising:
an amplifier circuit having coupling capacitors, a gain stage, and feedback paths comprising source followers and feedback resistors, said feedback paths being coupled prior to said coupling capacitors at inputs of said gain stage, said gain stage amplifying electrical signals received via said coupling capacitors, and gate terminals of said source followers being coupled to output terminals of said gain stage.