US 2026/0100685 A1Published application

Current mirror operational transconductance amplifier

AssigneeSemiconductor Components Industries, LLC

InventorsBharat BALAR, Mehak SOOD

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Abstract

Systems, devices, and methods are described to provide an improved current mirror operational transconductance amplifier (OTA). Improved OTAs may include an input circuit arranged to receive a differential voltage input, a load circuit arranged to measure a positive branch current and negative branch current from the input circuit, a bias circuit arranged to determine a bias voltage based on the negative branch current, a folded current branch circuit arranged to generate an adaptive bias current and a pass transistor configured to adjust an amount of the adaptive bias current based on the bias voltage, and a push-pull output circuit configured to sink current based on the adjusted adaptive bias current. The folded current branch circuit may generate the adaptive bias current based on the measured negative branch current. The output circuit may source current based on the measured positive branch current. Advantageously, most transistors may be of minimum size.

Claims20

Dependent claims

An operational transconductance amplifier, comprising:

an input circuit comprising a first input transistor coupled in parallel with a second input transistor, wherein the first and second input transistors are controllable according to a differential voltage input signal;
a load circuit coupled with the input circuit, the load circuit comprising a first reference transistor coupled in series with the first input transistor and a second reference transistor coupled in series with the second input transistor, wherein the first reference transistor is configured to measure a first current through the first input transistor and the second reference transistor is configured to measure a second current through the second input transistor;
an output circuit comprising a sourcing transistor coupled in series with a sinking transistor, wherein the sourcing transistor is coupled with the sinking transistor at an output terminal;
a folded current branch circuit coupled with the output circuit and comprising a pass transistor, wherein the pass transistor is configured to control a third current flowing through the folded current branch circuit based on a bias voltage and the folded current branch circuit is configured to control the sinking transistor based on the third current;
and
a bias circuit coupled with the load circuit and the folded current branch circuit and configured to determine the bias voltage based on the measured first current.

3 more elements

An operational transconductance amplifier, comprising:

an input circuit configured to generate a positive branch current based on a positive differential input voltage and a negative branch current based on a negative differential input voltage;
a load circuit coupled with the input circuit and configured to measure the positive branch current and the negative branch current;
a bias circuit coupled with the load circuit and configured to determine a dynamic bias voltage based on the measured negative branch current;
an output circuit coupled with the load circuit, wherein the output circuit comprises a push-pull pair of transistors and is configured to source current to an output terminal based on the measured positive branch current;
and
a folded current branch circuit coupled with the bias circuit and the output circuit and configured to control the output circuit to sink current from the output terminal based on the dynamic bias voltage.

3 more elements

An operational transconductance amplifier, comprising:

an input circuit comprising a first input transistor coupled in parallel with a second input transistor, wherein a gate of the first input transistor is configured to receive a negative differential input voltage and a gate of the second input transistor is configured to receive a positive differential input voltage;
a load circuit coupled with the input circuit, the load circuit comprising a negative branch current mirror configured to measure a negative branch current through the first input transistor and a positive branch circuit mirror configured to measure a positive branch current through the second input transistor, wherein the negative branch current mirror and positive branch current mirror are cross coupled;
a folded current branch circuit coupled with an output circuit, wherein:
the folded current branch circuit comprises a pass transistor configured to adjust an amount of an adaptive current based on a bias voltage;
and
the folded current branch circuit is configured to control the output circuit to sink an output current at an output terminal based on the adjusted adaptive current;
and
a bias circuit coupled with the load circuit and the folded current branch circuit and configured to determine the bias voltage based on the measured negative branch current.

5 more elements

Dependencies are inferred from the claim text.