39results about How to "Eliminate Offset Voltage" patented technology

A low offset comparator includes a preamplifier and a latch. The preamplifier includes a first output offset storage stage, a cascade of input offset storage stages and a second output offset storage stage. The first output offset storage stage receives an input voltage. The cascade of input offset storage stages is connected to follow the first output offset storage stage. The second output offset storage stage is connected to follow the input offset storage stages. The latch is connected to follow the preamplifier. The low offset comparator is characterized in that the cascade of input offset storage stages, the second output offset storage stage and the first output offset storage stage are configured to sequentially leave an offset cancellation mode, and the input offset storage stages, when leaving the offset cancellation mode, are to open their unity-gain feedback loops before disconnecting their input offset storages from a ground voltage.

In a Hall sensor in which a Hall element and elements serving as heat sources out of components of a circuit for driving the Hall element are arranged close to each other on a silicon substrate, two directions of control currents by spinning current for the Hall element are selected in a vector manner based on signals from temperature sensors arranged close to a periphery of the Hall element, thereby enabling the elimination of a magnetic offset caused by heat generation of the heat sources.

An amplifier installation which can remove the offset voltage comprises an offset voltage removing device, an input stage circuit, an output stage circuit, a false output stage circuit, a commutation circuit and a voltage output terminal. The commutation circuit is coupled to a part among the input stage circuit, the output stage circuit and the false output stage circuit, is used for choosing according to an operation mode to conduct one preamplifier signals which are outputted by the input stage circuit to the output stage circuit and to feed back a first feedback voltage which is outputted by the output stage circuit to the input stage circuit; or to conduct the preamplifier signals which are outputted by the input stage circuit to the false output stage circuit and to feed back the second feedback voltage output by the false output stage circuit to the input stage circuit.

When an external magnetic field is applied to a sensor unit 12 for various causes, a characteristics curve does not pass through an intersection point of resistance (voltage) and a magnetic field and is offset. That is, an offset voltage (Roff) occurs. In the present invention, in order to determine a correction value for canceling the offset voltage, a difference between output voltages is determined from two stages in which a bias magnetic field is inverted, and the bias magnetic field is controlled until the difference becomes approximately zero. Then, the corresponding bias magnetic field (the electrical current value) when the difference between the output voltages becomes approximately zero is set as a correction value (correction bias). As a result, since correction can be performed even if an offset voltage is applied, it is possible to accurately perform magnetic detection.

The invention relates to a method used for a liquid crystal display (LCD) to eliminate a bias voltage of a source driving device. The source driving device comprises at least one circuit breaker. The method comprises the following steps: measuring the equivalent load resistor and equivalent load capacitor of a panel of the LCD relative to the source driving device; calculating the lowest effective frequency of the at least one circuit breaker according to the equivalent load resistor and the equivalent load capacitor; and adjusting at least one switch frequency of the at least one circuit breaker according to the lowest effective frequency so as to carry out low-pass filtering on signals output by the source driving device by virtue of the panel and further eliminate the bias voltage.

The invention provides a method for improving the measuring precision of a resistance type temperature sensor. Improving from the aspect of the temperature measuring method, the temperature is measured by measuring the temperature difference between a temperature sensor and a reference resistor, and the bias voltage is eliminated by designing the resistance value of the reference resistor, so thatthe digit of an AD converter is used to the largest extent, the temperature measuring resolution is improved, and then the temperature measuring precision is effectively improved.

A voltage generating section applies first and second voltages having inverted polarities to a sensor section. The sensor section outputs a voltage value corresponding to a change in geomagnetism. A bias magnetic field generating section applies an alternating current bias magnetic field to the sensor section. A detecting section detects voltages with respect to the first and second voltages when the alternating current bias magnetic field is applied in positive and negative directions. By taking the difference between the detected voltages, an offset voltage to be outputted from a magnetism detecting circuit is eliminated.

An optical disc device for changing intensities of light beams illuminated on an optical disc. The optical disc device comprises the following elements. A photo detecting device divided into a plurality of photo detectors is used for detecting the reflected light beams illuminated on an optical disc. A plurality of amplifiers is used for changing gains to respectively amplify the output signals of the photo detectors when recording and reproducing on/from the optical disc. A calculating device is used for calculating the output signals of the amplifiers to generate the servo signals. By adding the correction offset signals for correcting the offset voltages of the amplifiers and the photo detectors to the amplifiers, the correction offset signals are amplified. It is, therefore, not necessary to change the correction offset voltages even though the gain of the amplifier is changed and not necessary to change the offset voltage and is independent of the gain-switching of the amplifier.

A Hall sensor includes a Hall element and a heat source element in a circuit configured to drive the semiconductor Hall element, and capable of eliminating an offset voltage without increasing a chip size. In the Hall sensor, a Hall element control current flowing between one pair of terminals out of two pairs and a Hall element control current flowing between another pair of terminals cross each other as vectors, the Hall element has a shape that is line-symmetrical to the straight line along a vector sum of the Hall element control current and the Hall element control current, and the heat source element is arranged so that the center of the heat source is positioned on the straight line along the vector sum of the Hall element control current and the Hall element control current.

An offset removal circuit (10) includes a removal circuit (1) and a removal circuit (2). The removal circuit (1) digitally removes offset voltage from an input voltage Vin. The removal circuit (2) removes offset voltage, in an analog manner, from the voltage subjected to offset voltage removal by the removal circuit (1). Then, the removal circuit (2) outputs the voltage subjected to the offset voltage removal to a non-inverting input terminal of a differential amplifier (20).

The invention relates to a diode infrared detector readout integrated circuit with a self-stabilization zero circuit. The diode infrared detector readout integrated circuit comprises a transistor, wherein the drain end of the transistor is connected with the self-stabilization zero circuit; the self-stabilization zero circuit comprises a main operational amplifier and a secondary operational amplifier; the same-phase end of the main operational amplifier is connected with the phi 1 end of a first single-pole double-throw switch and the same-phase end of the secondary operational amplifier; the output end of the secondary operational amplifier is connected with the single end of a second single-pole double-throw switch; the phi 1 end of the second single-pole double-throw switch is connected with the first end of a secondary operational amplification capacitor and the auxiliary input end of a secondary operational amplifier; the second end of the secondary operational amplification capacitor is connected with the second end of a main operational amplification capacitor; and the first end of the main operational amplification capacitor is connected with the phi 2 end of the second single-pole double-throw switch and the auxiliary input end of a main operational amplifier. By the diode infrared detector readout integrated circuit, the problem of large breakover voltage drop in a diode infrared detector can be solved effectively, offset voltage and low-frequency noise are eliminated, and the integration level and signal to noise ratio of a system are improved; and the diode infrared detector readout integrated circuit is large in dynamic range, safe and reliable.

The invention discloses an anti-interference pulse signal conditioner. The anti-interference pulse signal conditioner comprises a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a diode, a first power source, a second power source and an amplifier. The anti-interference pulse signal conditioner can filter and amplify input signals, remove direct current and extremely-low frequency interference signals, restrain high frequency interference, amplify useful pulse signals, and eliminate bias voltage, is simple in circuit structure and is suitable for being used for pulse testing instruments.