Trans-impedance amplifier for high speed optical-electrical interfaces

摘要

A differential or pseudo-differential TIA includes an auxiliary differential amplifier input transistor pair cross-coupled to the output nodes to cancel undesired output signal components. The advantages of a classical differential topology are retained while performance at a high data rate is significantly improved.

主权项

1. A differential trans-impedance amplifier circuit comprising:
a positive voltage bias node and a negative voltage bias node; a photodiode comprising an anode and a cathode; a pair of identical series impedances coupling said anode to said negative voltage bias node and coupling said cathode to said positive voltage bias node respectively; a pair of load impedances; a pair of output nodes; a first differential input transistor pair, comprising a first pair of input nodes coupled to said anode and cathode respectively, and coupled to said pair of load impedances to generate on said pair of output nodes a first amplified replica of a differential voltage on said first pair of input nodes; a second differential input transistor pair being identical to said first differential input transistor pair, said second differential input transistor pair
sharing said pair of load impedances with said first differential input transistor paircomprising a second pair of input nodes, andconfigured to generate on said pair of output nodes a second amplified replica of the differential voltage on said second pair of input nodes in phase opposition to the first amplified replica of the differential voltage on said first pair of input nodes; and a pair of blocking capacitors coupling said second pair of input nodes to said positive voltage bias node and said negative voltage bias node respectively.