Patent ID: 7332971

Claim:
A multi-Gigabit/s amplifier for optical networks, comprising: an amplifier having a large bandwidth for picking up current pulses from a photodiode and converting and amplifying said current pulses into voltage pulses, said amplifier further comprising; a first amplifier circuit having an input, connected to said photodiode, for receiving said current pulses and producing a voltage signal at a first single-ended output; a second amplifier circuit having a feedback input for feedback summing and producing a voltage signal at a second single ended output; a single-ended to differential converter coupled to said first and second single ended output of said first and said second amplifier circuit, said single-ended to differential converter providing a differential output; an output driver coupled to said single-ended to differential converter, said output driver matching a load impedance; and frequency-selective negative feedback applied to said feedback input of said second amplifier, where said frequency-selective negative feedback is active only from DC to a break frequency to limit the frequency range of said feedback, said frequency-selective negative feedback further comprising: a bandwidth-limited operational amplifier using Miller multiplication for bandwidth restriction of said feedback; and a transconductance amplifier coupled between said operational amplifier and said feedback input of said second amplifier, said transconductance amplifier converting the output of said operational amplifier into current for feedback summing.