A MOSFET has a current conduction path between source and drain terminals. A gate terminal of the MOSFET receives an input signal to facilitate current conduction in the current conduction path as a result of a gate-to-source voltage reaching a threshold voltage. A body terminal of the MOSFET is coupled to body voltage control circuitry that is sensitive to the voltage at the gate terminal of the MOSFET. The body voltage control circuitry responds to a reduction in the voltage at the gate terminal of the MOSFET by increasing the body voltage of the MOSFET at the body terminal of the MOSFET. As a result, there is reduction in the threshold voltage. The circuit configuration is applicable to amplifier circuits, comparator circuits and current mirror circuits.

A MOSFET has a current conduction path between source and drain terminals. A gate terminal of the MOSFET receives an input signal to facilitate current conduction in the current conduction path as a result of a gate-to-source voltage reaching a threshold voltage. A body terminal of the MOSFET is coupled to body voltage control circuitry that is sensitive to the voltage at the gate terminal of the MOSFET. The body voltage control circuitry responds to a reduction in the voltage at the gate terminal of the MOSFET by increasing the body voltage of the MOSFET at the body terminal of the MOSFET. As a result, there is reduction in the threshold voltage. The circuit configuration is applicable to amplifier circuits, comparator circuits and current mirror circuits.

An instrumentation amplifier including a pair of input amplifiers, each including an input transistor and a feedback current amplifier configured to amplify and feedback an error current from the input transistor. The arrangement can enable a current efficient solution where the amplifier can operate with very low input signals that are close to, or potentially below ground, without requiring a negative power supply voltage.

A MOSFET has a current conduction path between source and drain terminals. A gate terminal of the MOSFET receives an input signal to facilitate current conduction in the current conduction path as a result of a gate-to-source voltage reaching a threshold voltage. A body terminal of the MOSFET is coupled to body voltage control circuitry that is sensitive to the voltage at the gate terminal of the MOSFET. The body voltage control circuitry responds to a reduction in the voltage at the gate terminal of the MOSFET by increasing the body voltage of the MOSFET at the body terminal of the MOSFET. As a result, there is reduction in the threshold voltage. The circuit configuration is applicable to amplifier circuits, comparator circuits and current mirror circuits.

A circuit includes a first switch assembly having a first input node and a first output node, and a second switch assembly having a second input node and a second output node. The circuit further includes a third switch assembly an operational amplifier, and a buffer. The third switch assembly has a third input node and a third output node. The third input node is coupled to the second output node, and the third output node is coupled to the first output node. The buffer has a buffer input and a buffer output. The buffer input is coupled to an input stage of the operational amplifier. The buffer output is coupled to the third switch assembly.

A circuit includes a first switch assembly having a first input node and a first output node, and a second switch assembly having a second input node and a second output node. The circuit further includes a third switch assembly an operational amplifier, and a buffer. The third switch assembly has a third input node and a third output node. The third input node is coupled to the second output node, and the third output node is coupled to the first output node. The buffer has a buffer input and a buffer output. The buffer input is coupled to an input stage of the operational amplifier. The buffer output is coupled to the third switch assembly.

Embodiments of the present disclosure provide a circuit structure. An error amplifier of the structure includes an input terminal coupled to a voltage source, a reference terminal, and an output terminal coupled to a back-gate terminal of a power amplifier. A voltage at the output terminal of the error amplifier indicates a voltage difference between the input terminal and the reference terminal. A logarithmic current source may be coupled to the reference terminal of the error amplifier, the logarithmic current being configured to generate a reference current logarithmically proportionate to a voltage level of the voltage source. A plurality of serially coupled transistor cells, having a shared substrate and coupled between the reference terminal of the error amplifier and ground, each may include a back-gate terminal coupled to the output terminal of the error amplifier.

A cascade of amplifier stages has a differential input and a differential output. The cascade of amplifier stages includes at least one differential amplifier circuit including first and second transistors, at least one of the first and second transistors having a control terminal and a body terminal. A mismatch between the first and second transistors generates an input offset. A feedback network couples the differential output to the body terminal in order to cancel the input offset. The feedback network includes a low-pass filter and a differential amplifier stage.

A MOSFET has a current conduction path between source and drain terminals. A gate terminal of the MOSFET receives an input signal to facilitate current conduction in the current conduction path as a result of a gate-to-source voltage reaching a threshold voltage. A body terminal of the MOSFET is coupled to body voltage control circuitry that is sensitive to the voltage at the gate terminal of the MOSFET. The body voltage control circuitry responds to a reduction in the voltage at the gate terminal of the MOSFET by increasing the body voltage of the MOSFET at the body terminal of the MOSFET. As a result, there is reduction in the threshold voltage. The circuit configuration is applicable to amplifier circuits, comparator circuits and current mirror circuits.

Embodiments of the present disclosure provide a circuit structure. An error amplifier of the structure includes an input terminal coupled to a voltage source, a reference terminal, and an output terminal coupled to a back-gate terminal of a power amplifier. A voltage at the output terminal of the error amplifier indicates a voltage difference between the input terminal and the reference terminal. A logarithmic current source may be coupled to the reference terminal of the error amplifier, the logarithmic current being configured to generate a reference current logarithmically proportionate to a voltage level of the voltage source. A plurality of serially coupled transistor cells, having a shared substrate and coupled between the reference terminal of the error amplifier and ground, each may include a back-gate terminal coupled to the output terminal of the error amplifier.