31results about How to "Lower Input Offset Voltage" patented technology

A differential amplifier circuit in which an input offset voltage is very small. The differential amplifier circuit includes an input-stage differential amplifier section and a cascode-connected single-ended output section connected to the input-stage differential amplifier section. The input-stage differential amplifier section has a folded-cascode-connection. An inverted signal and non-inverted signal on the input side and output side, respectively, of the input-stage differential amplifier section are switched alternatingly in time-shared fashion by switches that are operated by two chopping clock signals of opposite phase.

Provided is an operational amplifier circuit capable of operating with lower current consumption. An amplifier stage, a FIR filter, and a sample and hold circuit are connected in series, thus enabling reduction of an input offset voltage and amplification of an input signal voltage without using an integral circuit. Current consumption of the operational amplifier circuit is reduced because the integral circuit is not used.

The invention discloses a hall-sensor-based electrostatic field tester, comprising an electrostatic field acquisition unit, a signal amplifying unit, an A / D (analog / digital) conversion module, a single-chip microcomputer storage system and a display unit; the electrostatic field acquisition unit comprises a hall sensor and a constant-current power module providing stable operating voltage for the hall sensor; the signal amplifying unit comprises a differential input circuit, an in-phase amplifying circuit, an inverse phase amplifying circuit, a displacement circuit and a selector circuit, selection is made by the selector circuit, and a forward electric field or a reverse electric field is output. The hall-sensor-based electrostatic field tester is low in cost, small in size and high in sensitivity, has wide adaptive frequency and temperature ranges, and is suitable for measuring both constant electric fields and alternating electric fields.

The invention relates to a zero-crossing detection circuit.The zero-crossing detection circuit comprises a sampling circuit unit, a feedforward access circuit unit and a comparison circuit unit.The sampling circuit unit receives a reference signal and a zero-crossing signal, outputs a first output signal according to the reference signal and outputs a second output signal according to the zero-crossing signal; the feedforward access circuit unit receives the first output signal and the second output signal, outputs a third output signal according to the first output signal and outputs a fourth output signal according to the second output signal; the comparison circuit unit outputs a first voltage signal according to the second output signal and the third output signal, outputs a second voltage signal according to the first output signal and the fourth output signal and outputs a zero-crossing detection control signal according to the first voltage signal and the second voltage signal.The first output signal and the second output signal are transmitted to the comparison circuit unit in a reverse superposition mode, an input of the comparison circuit unit is increased, and therefore transconductance of the comparison circuit unit is improved, and a transient response of the zero-crossing detection circuit is accelerated.

The invention provides a dynamic comparator. The dynamic comparator comprises a pre-amplification circuit, a dynamic latch circuit and an output-stage circuit which are connected in sequence, wherein the pre-amplification circuit comprises a first-stage amplification unit adopting an input detuning storage technology and a second-stage amplification unit adopting an output detuning storage technology; the dynamic latch circuit is used for amplifying the output signal of the pre-amplification circuit, and transforming the amplified signal into a digital logical output level; the output-stage circuit is used for outputting the digital logical output level at a latched phase, and outputting logic zero at a rest phase. The dynamic comparator provided by the invention adopts a detuning canceling technology and a structure isolating kickback noise in the pre-amplification circuit, thus effectively reducing the input detuning voltage, and greatly meeting the demands for design of high speed and high precision analog-digital convertors.

The invention discloses a differential voltage detection circuit with a wide voltage input range, comprising: a P-type input stage module for accepting voltage differential input signals and converting it into a single-ended output current; a P-type bias module for The transistors in the P-type input stage module provide bias voltage and voltage clamping protection; the N-type bias module is used to provide bias current for the P-type bias module and the P-type input stage module; the N-type output stage module, N The N-type bias module provides bias voltage or bias current for the N-type output stage module. The N-type output stage module outputs a signal representing the relative voltage level of the differential input signal according to the difference between the single-ended output current and the bias reference current. The present application can detect two differential input voltage signals and output signals, can achieve a wide input voltage range, can effectively reduce the input offset voltage of the circuit, can also be used as a high-voltage comparator and a high-voltage operational amplifier, and has strong practicability.

A sensor control circuit comprises a sensor (201), a filtering circuit (202), a buffering circuit (203), and an amplifying circuit (204). An output end of the sensor (201) is connected to an input end of the filtering circuit (202), an output end of the filtering circuit (202) is connected to an input end of the buffering circuit (203), and an output end of the buffering circuit (203) is connected to an input end of the amplifying circuit (204). Because the buffering circuit (203) is disposed between the filtering circuit (202) and the amplifying circuit (204), the sensor circuit has an advantage of full sampling. Further provided is an electronic apparatus using the sensor control circuit.

The present invention provides a PTAT current source circuit, comprising: an error operational amplifier; a first transistor including a first PN junction, and a P-type region of the first PN junction is connected to a first current source and an inverter of the error operational amplifier a phase terminal; a second transistor, including a second PN junction, the P-type region of the second PN junction is connected to the second current source and the non-inverting terminal of the error operational amplifier through a series resistor; wherein, the error operational amplifier The output terminal is connected to the first current source, the second current source and the output current source, and is used to control the first current source, the second current source and the output current source, and the output current source has The output is the output of the PTAT current source circuit. The circuit of the invention is simple and effective, the layout area is small, the cost is low, the power consumption is small, and the offset voltage and area of ​​the error operational amplifier are greatly reduced.

The present invention relates to the technical field of power supplies and correction circuits, in particular to a method and application for controlling a reference voltage correction circuit of a step-down converter. G, the field effect tube source S is connected to the constant current source 2I input signal line, one end of the constant current source 2I output signal line is connected to the other end of the capacitor C and the tap line is grounded, and the field effect tube drain D is the output voltage point C of the comparator VREF , and connected to one end of the resistor R and one end of the output signal line of the constant current source I, the other end of the input signal line of the constant current source I is connected to the power supply VDD, the other end of the resistor R is connected to the reverse input terminal of the comparator EA, and the reverse input of the comparator EA There is a voltage VREF on the end, and a voltage FB is set on the non-inverting input end of the comparator EA. The output voltage C of this circuit is controlled by the voltage VREF and FB. Compared with the prior art, the invention has small input offset voltage, can eliminate the output voltage error caused by the COT structure, and improve the output voltage precision.

The invention provides an ultrahigh-speed comparator with low offset, and belongs to the technical field of composite signal integrated circuits. The comparator comprises a preamplification circuit, adynamic latch circuit and an output latch circuit which hare connected in sequence, wherein, the preamplification circuit comprises a fully differential input structure with a positive resistor and anegative resistor serially connected as load and is used for amplifying difference value between input signals and reference signals; the dynamic latch circuit is equipped with a bistable structure which is connected from head to tail by an inverter, and used for amplifying the output signals of the preamplification circuit and establishing preceding stage output to digital logic output level; and the output latch circuit is composed of two cross-coupled NMOS transistors and PMOS common source amplification input, and used for outputting preceding stage output in a latch time, and keeping output result of the dynamic latch circuit at high impedance state in a reset stage so as to reduce input offset voltage of the comparator, increase speed of the comparator and well meet requirements ofhigh-speed analog-to-digital converter design.