A differential circuit including: a first MOS transistor and a second MOS transistor that constitute a differential pair; a determination unit to determine a level of a determination target signal that is based on at least one of differential inputs being input to gate of the first MOS transistor and a gate of the second MOS transistor; and a voltage changing unit to change a back gate voltage that is supplied to both back gates of the first MOS transistor and the second MOS transistor according to a determination result of the determination unit, and an OP-amp will be provided.

A differential amplifier circuit includes a differential pair including a first field-effect transistor (FET) and a second FET, a first current source that generates a current which flows in the first FET and the second FET, and an output circuit that outputs an output voltage corresponding to a difference between a gate voltage of the first FET and a gate voltage of the second FET in accordance with an operation of the differential pair. A back gate of the first FET is connected to a gate of the first FET, and a back gate of the second FET is connected to a gate of the second FET. A first feedback voltage corresponding to the output voltage is input to the gate of the second FET.

A differential circuit includes a differential pair and a back gate bias circuit. The differential circuit includes a first MOS transistor and a second MOS transistor provided between a first power supply line, to which a first power supply voltage is applied, and a second power supply line, to which a second power supply voltage is applied. The back gate bias circuit applies a bias voltage closer to the first power supply voltage than source potentials of the first MOS transistor and the second MOS transistor to back gates of the first MOS transistor and the second MOS transistor.

An operational amplifier circuit is provided. The operational amplifier circuit includes a differential input stage circuit and a loading stage circuit. The differential input stage circuit includes an input circuit, a voltage maintaining circuit, and a current source. The input circuit includes a first input transistor and a second input transistor, for receiving a first and a second input signals, respectively. The voltage maintaining circuit includes a first branch circuit and a second branch circuit. The first branch circuit is coupled to the first input transistor for receiving the first input signal, and the second branch circuit is coupled to the second input transistor for receiving the second input signal. The current source is coupled to the first input transistor and the second input transistor. The loading stage circuit is coupled to the voltage maintaining circuit.

A current feed-back instrumentation amplifier (CFIA) comprises a differential pair with degeneration for amplifying small differential voltages in the presence of large common-mode voltages. The CFIA includes input and feedback transconductors and a trimming circuit that trims the back-bias voltages of the transistors in each transconductor. The trimming circuit includes a plurality of selectable resistors disposed in the signal path of the tail current in each transconductor. Each of the plurality of selectable resistors has a switch coupled to it. When a switch is closed, only the resistors up to the respective switch are in the signal path of the bulk-to-source voltage of the differentially paired transistors. The resistor trimming circuit reduces the mismatch between transconductances of the respective differential pair transistors, in turn reducing mismatch of the overall transconductances of the transconductors, and thereby reducing the CFIA's gain error.

Embodiments of the present disclosure provide a circuit structure and method for power amplifier control with forward and reverse voltage biases to transistor back-gate regions. A circuit structure according to the disclosure can include: a power amplifier (PA) circuit having first and second transistors, the first and second transistors each including a back-gate region, wherein the back-gate region of each of the first and second transistors is positioned within a doped substrate separated from a semiconductor region by a buried insulator layer; and an analog voltage source coupled to the back-gate regions of the first and second transistors of the PA circuit, such that the analog voltage source alternatively supplies a forward bias voltage or a reverse bias voltage to the back-gate regions of the first and second transistors of the PA circuit to produce a continuously sloped power ramping profile.

An amplifier circuit, a voltage sensing apparatus, and an amplification method are disclosed. The amplifier circuit comprises (1) an input stage comprising a first set of transistors to which an input signal to be amplified is applied, the transistors of the first set comprising a semiconductor body, and (2) a processing stage comprising a second set of transistors for processing the signal from the input stage and generating an output signal. The transistors of the first set have a thicker gate oxide than the transistors of the second set, and are therefore suitable for higher voltage operation. The first and second sets of transistors are supplied by the same voltage supply of the amplifier circuit. The semiconductor body of the first set of transistors is connected to a reference potential to lower the threshold voltage.

In a folded cascode operational amplifier circuit, a source is connected to a back gate in each of third and fourth transistors that are cascode-connected to first and second transistors, which are an electric current source that returns an electric current signal output by a differential pair of an input stage. In the third and fourth transistors, an active parasitic element exists due to its device structure. When a falling edge signal of a rectangular wave is input, and electric current is supplied to the source of the third transistor to increase its electric potential, electric current flows into the drain from the back gate via the active parasitic element in an on state, in order to rapidly charge a capacitor. Thereby, a fifth transistor turns on within a shorter time, in order to improve an internal slew rate.

In one example an amplifier includes a bias circuit, an open-loop gain stage including a first PMOS having a gate coupled to a first node, a source coupled to a second node, a drain coupled to a third node, and a bulk coupled to the bias circuit, a second PMOS having a gate coupled to a ground node, a source coupled to the second node, a drain coupled to a fourth node, and a bulk coupled to the bias circuit, a first NMOS having a drain and a gate coupled to the third node and a source coupled to a fifth node, a second NMOS having a drain coupled to the fourth node, a gate coupled to the third node, and a source coupled to the fifth node, an adjustable resistor coupleable between the third and fourth nodes, and a buffer stage coupled to the open-loop gain stage.

A device for generating a reference voltage includes a first non-volatile memory cell provided with a control-gate transistor and a reading transistor. The control-gate transistor includes a gate terminal, a body, a first conduction terminal and a second conduction terminal. The first conduction terminal and the second conduction terminal are connected together to form a control-gate terminal. The reading transistor includes a gate terminal that is connected to the gate terminal of the control-gate transistor to form a floating-gate terminal, a body, a third conduction terminal and a fourth conduction terminal. The device also includes a second, equivalent, memory cell. The source terminal of the first non-volatile memory cell and the source terminal of the second equivalent memory cell are connected together.