Transimpedance amplifiers

A transimpedance amplifier circuit comprising:

• an input stage for receiving an input current and outputting a corresponding output voltage, the input stage comprising a first transistor configured as an input transistor in a first circuit branch;
• a reference controller configured to provide a reference voltage with a value equal to a DC value of the output voltage, wherein the reference controller is configured to control an input current to a dummy input stage to generate the voltage reference at an output of the dummy input stage, wherein the dummy input stage is a replica of the input stage;
• and
• a voltage regulator configured to receive a supply voltage and generate a regulated voltage with a voltage offset to the reference voltage, wherein the voltage offset does not substantially vary with variation in at least one of the supply voltage, temperature and process variations, wherein the regulated voltage is supplied as a supply voltage to the input stage;
• and
• control circuitry for controlling an effective transconductance of the first transistor to a defined value.

A transimpedance amplifier circuit comprising:

• an input stage for receiving an input current and outputting a corresponding output voltage, the input stage comprising a first transistor configured as an input transistor in a first circuit branch;
• a reference controller configured to provide a reference voltage with a value equal to a DC value of the output voltage;
• a voltage regulator configured to receive a supply voltage and generate a regulated voltage with a voltage offset to the reference voltage, wherein the voltage offset does not substantially vary with variation in at least one of the supply voltage, temperature and process variations, wherein the regulated voltage is supplied as a supply voltage to the input stage, wherein the voltage regulator is configured to generate said voltage offset by passing a first defined current through a reference resistor, where the first defined current corresponds to a current from applying a bandgap voltage to a first resistance having the same properties as the reference resistor;
• and
• control circuitry for controlling an effective transconductance of the first transistor to a defined value.

A transimpedance amplifier circuit comprising:

• an input stage for receiving an input current and outputting a corresponding output voltage, the input stage comprising a first transistor configured as an input transistor in a first circuit branch;
• a reference controller configured to provide a reference voltage with a value equal to a DC value of the output voltage;
• a voltage regulator configured to receive a supply voltage and generate a regulated voltage with a voltage offset to the reference voltage, wherein the voltage offset does not substantially vary with variation in at least one of the supply voltage, temperature and process variations, wherein the regulated voltage is supplied as a supply voltage to the input stage;
• and
• control circuitry for controlling an effective transconductance of the first transistor to a defined value, wherein said control circuitry comprise a supplemental current generator configured to inject a supplemental current into the first circuit branch, wherein the supplemental current generator comprises a first current source configured to generate a current proportional to absolute temperature, a current mirror for mirroring the current proportional to absolute temperature to provide an output current, and a bandgap current source for subtracting part of the output current to provide the supplemental current.