Differential amplifier circuitry including: first and second main transistors of a given conductivity type; and first and second auxiliary transistors of an opposite conductivity type, where the first and second main transistors are connected along first and second main current paths passing between first and second main voltage reference nodes and first and second output nodes, respectively, with their source terminals connected to the first and second output nodes, respectively, and with their gate terminals controlled by component input signals of a differential input signal; and the first and second auxiliary transistors are connected along first and second auxiliary current paths passing between first and second auxiliary voltage reference nodes and the first and second output nodes, respectively, with their drain terminals connected to the first and second output nodes, respectively, and with their gate terminals controlled by the component input signals of the differential input signal.

Differential amplifier circuitry including: first and second main transistors of a given conductivity type: and first and second auxiliary transistors of an opposite conductivity type, where the first and second main transistors are connected along first and second main current paths passing between first and second main voltage reference nodes and first and second output nodes, respectively, with their source terminals connected to the first and second output nodes, respectively, and with their gate terminals controlled by component input signals of a differential input signal; and the first and second auxiliary transistors are connected along first and second auxiliary current paths passing between first and second auxiliary voltage reference nodes and the first and second output nodes, respectively, with their drain terminals connected to the first and second output nodes, respectively, and with their gate terminals controlled by the component input signals of the differential input signal.

An operational amplifier includes a first transistor, a second transistor, a third transistor, a first constant current source, an output state, a first switch, and a second switch. The first transistor has a first gate configured to receive an output voltage from an output node. The second transistor has a second gate. The third transistor has a third gate configured to receive an input voltage. The first constant current source is coupled to sources of the first transistor, the second transistor, and the third transistor. The output stage is configured to drive the output voltage on the output node based on a first current through the first transistor, a second current through the second transistor, and a third current through the third transistor. The first switch is coupled between the second gate of the second transistor and the third gate of the third transistor; and the second switch is coupled between the output node and the second gate of the second transistor.

Differential amplifier circuitry including: first and second main transistors of a given conductivity type; and first and second auxiliary transistors of an opposite conductivity type, where the first and second main transistors are connected along first and second main current paths passing between first and second main voltage reference nodes and first and second output nodes, respectively, with their source terminals connected to the first and second output nodes, respectively, and with their gate terminals controlled by component input signals of a differential input signal; and the first and second auxiliary transistors are connected along first and second auxiliary current paths passing between first and second auxiliary voltage reference nodes and the first and second output nodes, respectively, with their drain terminals connected to the first and second output nodes, respectively, and with their gate terminals controlled by the component input signals of the differential input signal.

Differential amplifier circuitry including: first and second main transistors of a given conductivity type: and first and second auxiliary transistors of an opposite conductivity type, where the first and second main transistors are connected along first and second main current paths passing between first and second main voltage reference nodes and first and second output nodes, respectively, with their source terminals connected to the first and second output nodes, respectively, and with their gate terminals controlled by component input signals of a differential input signal; and the first and second auxiliary transistors are connected along first and second auxiliary current paths passing between first and second auxiliary voltage reference nodes and the first and second output nodes, respectively, with their drain terminals connected to the first and second output nodes, respectively, and with their gate terminals controlled by the component input signals of the differential input signal.

Differential amplifier circuitry including: first and second main transistors of a given conductivity type; and first and second auxiliary transistors of an opposite conductivity type, where the first and second main transistors are connected along first and second main current paths passing between first and second main voltage reference nodes and first and second output nodes, respectively, with their source terminals connected to the first and second output nodes, respectively, and with their gate terminals controlled by component input signals of a differential input signal; and the first and second auxiliary transistors are connected along first and second auxiliary current paths passing between first and second auxiliary voltage reference nodes and the first and second output nodes, respectively, with their drain terminals connected to the first and second output nodes, respectively, and with their gate terminals controlled by the component input signals of the differential input signal.

An operational amplifier includes an output transistor having a gate coupled to an output node, at least one intermediate transistor each having a common gate node, an input transistor having a gate coupled to an input node, and a load device coupled to sources of the output transistor, the at least one intermediate transistor, and the input transistor. The operational amplifier further includes an output stage coupled to the output node, configured to drive the voltage on the output node based on currents through the output transistor, the at least one intermediate transistors, and the input transistor. The operational amplifier further includes a first switch coupled between the common gate node of the at least one intermediate transistor and the gate of the input transistor, and a second switch coupled between the output node and the common gate node of the at least one intermediate transistors.

Differential amplifier circuitry including: first and second main transistors of a given conductivity type; and first and second auxiliary transistors of an opposite conductivity type, where the first and second main transistors are connected along first and second main current paths passing between first and second main voltage reference nodes and first and second output nodes, respectively, with their source terminals connected to the first and second output nodes, respectively, and with their gate terminals controlled by component input signals of a differential input signal; and the first and second auxiliary transistors are connected along first and second auxiliary current paths passing between first and second auxiliary voltage reference nodes and the first and second output nodes, respectively, with their drain terminals connected to the first and second output nodes, respectively, and with their gate terminals controlled by the component input signals of the differential input signal.

A programmable gain amplifier that comprises: a transconductance amplifier, a switch leakage compensation circuit and a transimpedance amplifier. The transconductance amplifier provides a transconductance amplifier current signal and includes a switchable resistance network. The switch leakage compensation circuit provides a compensation current signal and comprises a switchable compensation resistance network. The transimpedance amplifier provides the output voltage signal based on the difference between the transconductance amplifier current signal and the compensation current signal. The switchable compensation resistance network comprises a plurality of branches in parallel with each other, wherein each branch includes: a gain-mimicking switch that has a corresponding gain-setting switch in the switchable resistance network; and a leakage-current-conducting switch in series with the gain-mimicking switch. The leakage-current-conducting switch is openable and closable in accordance with the complement of a switch control signal that is used to control the gain-mimicking switch in the same branch.

Provided is a receiver including an oscillator (OSC) configured to generate an oscillation signal based on a radio signal, a clocked envelope detector (ED) configured to detect an envelope of the oscillation signal and hold a peak value of the envelope during a time interval, and an analog-to-digital converter (ADC) configured to convert the peak value of the envelope into a digital signal.