Semtech Corporation

Matthew George Hagman

Behzad Farzaneh

Darrell Iaian Smith

Ryan P MacDonald

Christopher John Born

A transimpedance amplifier (TIA) for converting an input current at an input node into an output voltage at an output node, the TIA comprising: a first amplifier stage having a first input coupled to the input node and a first output; a feedback path between the first output and the first input; a second amplifier stage in the feedback path having a second input, the second input coupled to the first output of the first amplifier stage; a feedback resistor in the feedback path coupled between an output of the second amplifier stage and first input of the first amplifier stage; and an output stage, comprising: a load resistor coupled between a reference voltage node and a T-coil, the T-coil comprising first and second inductors coupled in series at an inductor node, the T-coil coupled between the first output and the load resistor, the inductor node coupled to the output node of the TIA.

Transimpedance amplifier

This application relates to transimpedance amplifier (TIA) apparatus, in particular to a TIA apparatus suitable for receiving data using burst mode communication. The apparatus has a transimpedance amplifier configured to generate a first voltage based on a current at an input node for an input signal. A controlled voltage source, such as a dummy TIA, generates a second voltage based on a first control current. A controller is configured to collectively control the first control current and a second control current based on an indication of input signal magnitude. The first control current controls the second voltage which may be used as a slicing level. The second control current is subtracted from the current at the input node and can provide a DC restore current.

Transimpedance amplifiers

An automatic gain controller comprises an amplifier including a variable gain. A resonant low-pass filter includes an input coupled to an output of the amplifier. The resonant low-pass filter is a second order low-pass filter. The second order low-pass filter includes a Sallen-Key topology. The Sallen-Key topology comprises a quality factor between 1.4 and 1.6. A threshold detection circuit includes an input coupled to an output of the second order low-pass filter to compare an output signal of the second order low-pass filter to a threshold and an output of the threshold detection circuit coupled to control the variable gain of the amplifier. A state machine is coupled between the output of the threshold detection circuit and the amplifier. The state machine is configured to transition based on a current state of the state machine. The resonant low-pass filter exhibits overshoot to trigger a hysteresis of the threshold detection circuit.

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Gatineau, Canada

Matthew George Hagman