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

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 provides a circuit structure for reducing input offset voltage of a two-stage operational amplifier, which comprises a switching control circuit, a first-stage differential amplification circuit, a second-stage common-source amplification circuit and a compensation network, wherein the output end of the switching control circuit is connected with the input end of the first-stage differential amplification circuit, the output end of the first-stage differential amplification circuit is connected with the input end of the second-stage common-source amplification circuit, and the compensation network is further connected between the input end and the output end of the second-stage common-source amplification circuit. The circuit structure has the benefits that the offset of theoperational amplifier is reduced by adopting an MOS (metal oxide semiconductor) switching tube to control and exchange signals at the positive and the negative input ends and the signals at the output end of the operational amplifier; as only the MOS switching tube is increased in the circuit, the circuit structure only needs very small area and very low power consumption; and the circuit does not affect the gain of the operational amplifier, the phase margin, the power supply voltage rejection ratio, the common-mode input range and other performance indexes while reducing the input offset voltage of the operational amplifier, and can be applied in mainstream CMOS (complementary metal oxide semiconductor) circuit systems.

The invention provides a high-performance digital self-calibration chopper precision amplifier which is low in cost and easy to implement and an implementation method. The amplifier mainly comprises a digital self-calibration loop and a chopper circuit. After the amplifier is energized, the amplifier is configured as a digital self-calibration state within a period of time, and the chopper circuit and an amplifier output circuit are switched off. The calibrated digital quantity is stored in a register, and input offset voltage of the amplifier is calibrated through a digital analog converter. After the digital self-calibration state is finished, a comparison output circuit is switched off, the amplifier is configured as a chopper magnifying state, and the chopper circuit and the amplifier output circuit work, so that the input offset voltage of the amplifier, temperature drift of the offset voltage and flicker noise are lowered.

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.

A method for reducing offset voltage in an operational amplifier without the need for switched-capacitors, includes introducing a tapped resistor chain between the common connected terminals of the transistors of the input differential pair of the operational amplifier and connecting the tail current source/sink of the differential amplifier to a selected tap of the resistor chain. The invention further provides an improved operational amplifier in accordance with the above method.

The invention provides a driving circuit of a voice coil motor. The driving circuit comprises a driving stage operational amplifier, a switch K1, a switch K2, an imbalance detection and control circuit and an imbalance adjustment control circuit. The first input end of the driving stage operational amplifier is connected with an input voltage through the switch K1, and is grounded through the switch K2. The imbalance detection and control circuit comprises a switch K3, a switch K4, an MOS tube MN1, a resistor Rs, a reference constant-current source, a current comparator and a logic circuit. The MN1 and the resistor Rs are sequentially connected between the first input end and the grounding end of the current comparator. The control end of the MN1 is connected with the output end of the driving stage operational amplifier through the switch K3. The switch K4 is connected between the second input end of the driving stage operational amplifier and the second connecting end of the MN1. Thereference constant-current source is connected between the second input end and the grounding end of the current comparator. The logic circuit outputs a calibration control signal based on a comparison result output by the current comparator. The imbalance adjustment control circuit outputs a current control signal based on the calibration control signal so as to perform the imbalance calibrationon the driving operational amplifier.

The invention discloses a differential voltage detection circuit with a wide voltage input range. The circuit comprises a P-type input stage module which is used for receiving a voltage differential input signal and converting the voltage differential input signal into a single-ended output current, a P-type bias module which is used for providing bias voltage and voltage clamping protection for a transistor in the P-type input stage module, an N-type bias module which is used for providing bias current for the P-type bias module and the P-type input stage module and an N-type output stage module. The N-type bias module provides bias voltage or bias current for the N-type output stage module, and the N-type output stage module outputs a signal representing the relative voltage level of the differential input signal according to the difference value of the single-end output current and the bias reference current. Two differential input voltage signals can be detected and output, a wide input voltage range can be realized, the input offset voltage of the circuit can be effectively reduced, and the circuit can be used as a high-voltage comparator and a high-voltage operational amplifier and is high in practicability.

The invention discloses a differential input circuit, a control method of the differential input circuit, and a differential amplifier. The differential input circuit comprises: a first differential input stage connected in series with a first switch between a positive power supply terminal and a negative power supply terminal; a second differential input stage, wherein the second differential input stage and the second switch are connected in series between the positive power supply end and the negative power supply end; a differential detection circuit which is used for conducting one of thefirst switch and the second switch according to a first input signal and a second input signal, wherein the positive input ends of the first differential input stage and the second differential inputstage receive the first input signal, the negative input ends of the first differential input stage and the second differential input stage receive the second input signal, the size of the differential transistor pair in the first differential input stage is different from the size of the differential transistor pair in the second differential input stage, so that increase of input offset voltagecaused by asymmetry of the transistor pair of the single input stage under long-time large differential signal work can be prevented, and the precision of the amplifier is further prevented from being influenced.

The invention discloses a load sensor signal transmitting device in the technical field of sensors. The load sensor signal transmitting device comprises an AC filter circuit, a zero setting circuit, adifferential voltage amplification circuit and a sampling circuit. The zero setting circuit is connected to the AC filter circuit. The differential voltage amplification circuit is connected to the AC filter circuit and the zero setting circuit. The sampling circuit is connected to the zero setting circuit and the differential voltage amplification circuit. The AC filter circuit comprises a resistor R0, an electromotive force E1, a diode D1, a capacitor C1, a three-terminal regulator U1 and a capacitor C2. One end of the resistor R0 is connected to a + 24V power supply, and one end of the diode D1 is connected with the other end of the resistor R0. According to the invention, the interference of noise on a voltage signal on a transmission line can be effectively eliminated, and the signalloss is reduced.

The invention provides a switch control band-gap reference circuit with the low offset voltage. The switch control band-gap reference circuit comprises a switching signal module, an operational amplifier, a bipolar transistor module and a low-pass filtering module. The output end of the witching signal module is connected with the input end of the operational amplifier, the output end of the operational amplifier is connected with the bipolar transistor module, and the bipolar transistor module is connected with the low-pass filtering module. The switching signal module comprises a first switching signal output end and a second switching signal output end, the first switching signal output end is connected with the in-phase input end of the operational amplifier, and the second switching signal output end is connected with the inverted input end of the operational amplifier. The switch control band-gap reference circuit has the advantages that the input offset voltage of the operational amplifier is lowered, and the accuracy of band-gap reference voltage signals is improved.

An encoding and decoding method for an optical isolation amplifier including an encoder, an optical driver, a light source, an optical detector, and a decoder, and employing sigma-delta modulation technology is provided. The method includes: generating a plurality of first pulses, each having a predetermined pulse width, through the encoder when an input digital signal experiences an input pulse rising or falling edge; outputting an encoded signal having the plurality of first pulses to the optical driver; driving the light source through the optical driver, according to the plurality of first pulses, so as to output an encoded optical signal; generating a detected signal through the optical detector detecting the encoded optical signal, and the detected signal has a plurality of second pulses; and duplicating the input digital signal of the encoder through the decoder, according to the detected signal having the plurality of second pulses.

The invention discloses a flaw detection device and application thereof. The flaw detection device comprises a reference power supply, a current detection circuit, a first probe connected with the positive electrode output end of the reference power supply and a second probe connected with the negative electrode output end of the reference power supply, two input ends of the current detection circuit are respectively connected with a third probe and a fourth probe, and an output end of the current detection circuit is connected with an ampere meter; wherein the reference power supply is used for loading reference voltage to an object to be detected, and the current detection circuit is used for detecting current change on the object to be detected. The device is simple in structure, smallin size, convenient to use and operate, free of missing detection, high in detection precision, wide in application range and high in popularization and application value.