33results about How to "Reduce gain error" patented technology

A motor control apparatus of the present invention comprises a velocity detector for detecting a rotation velocity of a mover of a motor, a position detector for detecting a position of the mover, a differentiator for performing time differentiation with respect to the position detected by the position detector to obtain a velocity calculation value, a feedback signal generating circuit for generating a feedback signal including the velocity detection value obtained by the velocity detector as a high frequency component and the velocity calculation value obtained by the differentiator as a low frequency component, and a linear amplifier and an integrating amplifier for performing PI control, the linear amplifier and the integrating amplifier performing linear amplification and integrating amplification of a difference between the velocity instruction and the feedback signal, respectively.

The invention provides a pipelined successive approximation analog-to-digital converter and a conversion method. The pipelined successive approximation analog-to-digital converter comprises a first-stage successive approximation analog-to-digital conversion module, a second-stage successive approximation analog-to-digital conversion module and a digital code error correction logic module, whereinthe first-stage successive approximation analog-to-digital conversion module comprises a first capacitor array unit, an amplification unit, a latch comparison unit, a first register logic control unitand a control switch, and the amplification unit is multiplexed as a residual amplifier and a pre-amplifier of a comparator in the first-stage successive approximation analog-to-digital converter. Bymultiplexing the residual amplifier pre-amplifier, input offset voltage mismatch existing between the residual amplifier pre-amplifier and the residual amplifier pre-amplifier is completely eliminated, the input swing of the residual amplifier is stabilized, the linearity of the residual amplifier is improved, and the area of a chip is saved; and the gain error is obtained by multiplexing the second-stage successive approximation type analog-to-digital conversion module, so that the gain error of the residual amplifier is reduced, and the conversion accuracy of the whole pipelined successiveapproximation type analog-to-digital converter is improved.

The invention relates to a water quality data preprocessing circuit. A high input impedance differential amplifier circuit receives water quality data detected by a water quality detection sensor andpreset reference water quality data; the detected water quality data and the preset reference water quality data are output to a differential amplifier after being respectively amplified by a high input impedance frequency selective amplifier and followed by a high input impedance circuit; water quality deviation data is calculated; then the water quality deviation data is output to a voltage stabilization circuit through emitter following; after emitter following, a signal amplitude is also fed back to a base of a triode Q2 and a base of a triode Q1 level by level so as to regulate an amplitude of the water quality deviation data and reduce a gain error caused by amplification; the voltage stabilization circuit outputs a determined voltage to a division operation circuit after voltage stabilization of a feedback voltage regulation circuit; the determined voltage and the delayed reference water quality data are subjected to a division operation; and an obtained water quality index is transmitted to a water quality monitoring server to carry out monitoring and early warning so as to carry out preprocessing and solve problems that the received data is real-time water quality data, the task load is high and efficiency is low.

The invention relates to a multiplication-type A/D (Analog/Digital) converter capable of correcting a limited gain error, which comprises an amplifying circuit unit and a limited gain error correcting circuit unit. According to the invention, two compensation capacitors and an amplifier constitute the limited gain error correcting circuit unit, part of output quantity is adjustably compensated into the input end of an operation amplifier, nonzero /virtual earth/ is adjusted, and the limited gain error is greatly reduced; after the adoption of the limited gain error correcting circuit unit, the limited gain error of the whole streamlined A/D converter is reduced by one order of magnitude; and in the invention, gain of the amplifier is adjustable, and therefore the limited gain error causedby temperature and process changes is effectively offset. According to the invention, the limited gain error correcting circuit has the characteristics of small limited gain error, low power consumption and high reliability and is suitable for the fields of high-speed, high-precision, low power-consumption streamlined A/D converters.

The invention discloses a band-gap reference circuit and an operational amplifier thereof. The operational amplifier comprises a first input end, a second input end and a first output end, and furthercomprises a power supply circuit; the first input end comprises a first audion, and the second input end comprises a second audion; the area of an emitter of the first audion is larger than that of an emitter of thee second audion; the first output end is used for outputting driving voltage. By improving the operational amplifier in the band-gap reference circuit, the structure of the operationalamplifier in an existing band-gap reference circuit is simplified, and gain errors of the circuit caused by mismatching of the operational amplifier are reduced; meanwhile, the structure is simple, an additional biasing circuit is not needed, thus an additional circuit structure is not needed, and the current loss is reduced.

Disclosed is a dual control voltage dB linear VGA (Variable Gain Amplifier) circuit with large gain range and high precision, relating to a gain control level circuit, and solving the problem that the gain range and gain error of the existing gain reduction structured variable gain amplifier restrict each other. The output end of a preamplifier is connected with the signal input end of a large range gain control level, the output end of the large range gain control level is connected with the signal input end of a high precision gain control level, the output end of the high precision gain control level is connected with the input end of a fixed gain amplifier, the first control voltage Vctrl1 is input by the control voltage input end of the large range gain control level, and the second control voltage Vctrl2 is input by the control voltage input end of the high precision gain control level. The circuit is suitable for amplifying or reducing signals.

A switched capacitor amplifier comprises a switched capacitor module, an amplifier module and a sample hold output module, the switched capacitor module uses a first control clock, a second control clock and a third control clock which have different phases to control opening and closing of corresponding switches, and adds a first input voltage and a second input voltage in proportion, and the switched capacitor amplifier is particularly suitable for adding the voltage with a positive temperature coefficient and the voltage with a negative temperature coefficient in a reference voltage sourceaccording to the temperature coefficient proportion to obtain the reference voltage with the zero temperature coefficient. The amplifier module only uses two MOS transistors, the structure is simple,and in combination with the effect of the switched capacitor module, under the condition that the open-loop gain of the amplifier is small, a small gain error can still be obtained. In addition, underthe condition of the same output voltage precision, the power supply voltage and the reference voltage can be effectively reduced, and the design of a low-voltage low-power-consumption circuit is facilitated.

The present invention is directed to electrical circuits and techniques thereof. More specifically, an embodiment of the present invention provides a variable gain amplifier that includes a first transistor and a second transistor whose gate terminals are coupled to a first input terminal. A first drain terminal of the first transistor and a first source terminal of the second transistor is coupled to a voltage gain control switch. There are other embodiments as well.

The invention discloses a multi-stage cascaded broadband variable gain amplifier and an in-band adjustment method thereof. A plurality of single-stage variable gain amplifiers are cascaded in the multi-stage cascaded broadband variable gain amplifier; each single-stage variable gain amplifier comprises a first gain amplification unit GM1, a second gain amplification unit GM2, a feedback amplification unit GMf, a first load resistor Ro1, a second load resistor Ro2, a third load resistor Ro3, a fourth load resistor Ro4, a first load capacitor C1, a second load capacitor C2, a third load capacitor C3 and a fourth load capacitor C4. According to the multi-stage cascade broadband variable gain amplifier designed by the invention, a relatively small chip area, low power consumption and low gain error are ensured, and relatively high precision and a relatively large gain range can be achieved.

The invention discloses a broadband programmable gain amplifier with a high-precision dB linear characteristic, which comprises a first gain amplification unit GM1, a second gain amplification unit GM2, a feedback amplification unit GMf, an MOS (Metal Oxide Semiconductor) tube differential pair M3, an MOS tube differential pair M4, an MOS tube differential pair M5, an MOS tube differential pair M6, an MOS tube differential pair M7, a common-mode feedback circuit CMFB1 and a common-mode feedback circuit CMFB2, according to the broadband programmable gain amplifier, precise dB linear gain control is achieved through a near pseudo-exponential function by means of the binary weighted switch technology, and an additional exponential generation circuit is not needed; the change of the voltage gain is determined by the ratio of the transconductance values of the MOS transistors of the same type, so that the gain of the circuit is insensitive to the change of process, voltage and temperature; the wide-3dB bandwidth, the precise dB linear characteristic and the wide gain adjusting range can be achieved.

The invention discloses a common-mode voltage calibration method, a circuit for executing the method comprises a voltage sampling circuit which is used for sampling N groups of series-connected to-be-sampled voltages and comprises N + 1 sampling channels, N is a positive integer greater than or equal to 2, and the method comprises the following steps: sampling a group of to-be-sampled voltages by using every two adjacent sampling channels; sequentially measuring each group of to-be-sampled voltage obtained by sampling through each sampling channel to obtain a to-be-sampled voltage measurement value; and by using each group of to-be-sampled voltage measurement values distributed from the low-voltage side to the high-voltage side, carrying out step-by-step calibration on the higher-level to-be-sampled voltage measurement values so as to eliminate voltage measurement errors caused by common-mode voltage changes. The sampling channel group with the minimum gain error is utilized, and the measurement voltage of the sampling channel group closest to the positive electrode of the battery pack is calibrated upwards step by step, so that the influence caused by the gain error is eliminated, the measurement error is reliably reduced, and the judgment accuracy of the state of each single-junction battery of the battery pack is generally improved.

The invention provides a pipeline analog-to-digital conversion circuit, and relates to the field of pipeline circuits. The circuit comprises N stages of analog-to-digital converters, N-1 margin amplifiers and N-1 digital filters, and N is an integer greater than or equal to 2; the margin output end of the i-level analog-to-digital converter is electrically connected with the first input end of a margin amplifier, the output end of the margin amplifier is electrically connected with the analog input end of the (i+1)-level analog-to-digital converter, and i is any positive integer smaller than N; wherein the first-stage analog-to-digital converter is an analog-to-digital converter with a noise shaping function, and the digital output end of each stage of analog-to-digital converter after the first-stage analog-to-digital converter is electrically connected with a digital filter. Compared with the prior art, the problem of overlarge circuit hardware and time overhead in the prior art is avoided.