Systems and method for improving operation of a radio frequency system are provided. One embodiment includes a switching power amplifier that outputs an amplified analog electrical signal based on an input electrical signal and voltage of an envelope voltage supply rail. The switching power amplifier includes a first transistor with a gate that receives the input electrical signal, a source electrically coupled to the envelope voltage supply rail, and a drain electrically coupled to an output of the switching power amplifier; a second transistor with a gate that receives the input electrical signal, a source electrically coupled to ground, and a drain electrically coupled to the output; and a third transistor with a gate that receives the input electrical signal, a drain electrically coupled to the envelope voltage supply rail, and a source electrically coupled to an output of another switching power amplifier.

A circuital system that includes a differential low-pass filter having a differential output and operable in a first voltage domain. Some embodiments include a differential integrator including a differential input and a differential output, and operable in a second voltage domain different from the first voltage domain. Some embodiments include a pair of AC coupling capacitors coupling the differential output of the differential low-pass filter to the differential input of the differential integrator.

A current feedback amplifier (CFA). The CFA includes a common-gate input stage, a biasing circuitry, and a differential pair coupled in parallel between the supply voltage node and the reference voltage node. The common-gate input stage amplifies an input signal received at an input node and supplies it to a gate of the complementary transistors of the differential pair. The biasing circuitry supplies a bias voltage to a gate of the transistors of the common-gate input stage. The input node of the common-gate input stage and a node between the complementary transistors in the first path of the differential pair are shorted.

A combination amplifier can include a “main amplifier circuit” for signal amplification, and a matching “compensation amplifier circuit” to monitor distortion in the main amplifier output signal. The compensation amplifier circuit provides a compensation signal to the main amplifier circuit to compensate for and servo out distortion therein. The compensation amplifier circuit includes a passive input network and an amplifier. The passive input network can connect to both the input and output nodes of the main amplifier circuit such that the input and output signals cancel within the passive input network, leaving only the low level distortion component introduced in the main amplifier. Thus, the compensation amplifier is then only operating on the low-level distortion introduced in the main amplifier to generate the compensation signal. Because the compensation amplifier is then only operating on the very low distortion signal, any distortion it introduces into the compensation signal is negligible.

An operational amplifier comprises: a first amplifier stage 4 comprising a first differential pair of transistors 8, 10 arranged to receive and amplify a differential input signal 18, 20 thereby providing a first differential output signal 22, 24; and a second amplifier stage 6 comprising a second differential pair of transistors 26, 28 arranged to receive and amplify the first differential output signal 22, 24 thereby providing a second differential output signal 38, 40.

Apparatus and methods for reducing input bias current of electronic circuits are provided herein. In certain implementations, an electronic circuit includes a first input terminal, a second input terminal, an input circuit, and a plurality of input switches including at least a first input switch and a second input switch. The first input switch is electrically connected between the first input terminal and a first input of the input circuit, the second input switch is electrically connected between the second input terminal and a second input of the input circuit, and the first and second input switches can be opened and closed using a clock signal. The electronic circuit further includes a charge compensation circuit for compensating for charge injection through the first and second input switches during transitions of the clock signal.

A sense amplifier circuit, memory device and related operation methods are provided. The sense amplifier circuit includes an amplification circuit for amplifying a voltage signal and a compensation circuit coupled to the amplification circuit. The amplification circuit includes a first inverting amplifier and a second inverting amplifier cross-coupled with each other, with the first inverting amplifier connected to a first bitline and the second inverting amplifier connected to a second bitline. The compensation circuit includes a first, a second, a third, and a fourth switch circuits, and is configured to generate a compensation voltage between the first bitline and the second bitline by conducting charge injections through operating the switch circuits to compensate an input-referred offset voltage of the amplification circuit.

A circuital system that includes a differential low-pass filter having a differential output and operable in a first voltage domain. Some embodiments include a differential integrator including a differential input and a differential output, and operable in a second voltage domain different from the first voltage domain. Some embodiments include a pair of AC coupling capacitors coupling the differential output of the differential low-pass filter to the differential input of the differential integrator.

A circuital system that includes a differential low-pass filter having a differential output and operable in a first voltage domain. Some embodiments include a differential integrator including a differential input and a differential output, and operable in a second voltage domain different from the first voltage domain. Some embodiments include a pair of AC coupling capacitors coupling the differential output of the differential low-pass filter to the differential input of the differential integrator.

An apparatus includes a differential current-to-voltage conversion circuit that includes an input sampling stage circuit, a differential integration and DC signal cancellation stage circuit, and an amplification and accumulator stage circuit. An input common mode voltage of the differential current-to-voltage circuit is independent of an output common mode voltage of the differential current-to-voltage circuit.