Disclosed is a high accurate measurement circuit, and the feature is using bias switching circuit for compensating front end offset, and the back end offset of amplifier is also cancelled. In the real measurement environment, offset exists in the amplifier of the measurement circuit has, and non-ideal effects also exist in the interface between measurement terminal and the measurement circuit, such as leakage current of chip package pins or mismatch of the circuit. The above non-ideal effects belong to front end offset and cannot be compensated by the prior arts. The disclosed structure uses the bias switch circuit and uses different switching method in the two measurement timings. By subtracting the measurement results for the two measurement timings, the front end offset is compensated, and the back end offset of the amplifier is also cancelled.

An amplifier circuit with novel design is provided. The amplifier circuit includes an input stage, a resistor, an output stage, an intermediate stage and a gm circuit. The input stage is coupled to a first supply voltage, and is arranged to receive an input voltage and a feedback current. The resistor is coupled between the input voltage and the input stage. The output stage is coupled to a second supply voltage, and is arranged to provide an output voltage for driving a load. The intermediate stage is coupled between the input stage and the output stage, and includes a level shifter. The gm circuit is coupled to the input stage, and is arranged to compare the input voltage with a common mode voltage, and thereby generates a compensate current for the input stage.

An amplifier circuit with novel design is provided. The amplifier circuit includes an input stage, a resistor, an output stage, an intermediate stage and a gm circuit. The input stage is coupled to a first supply voltage, and is arranged to receive an input voltage and a feedback current. The resistor is coupled between the input voltage and the input stage. The output stage is coupled to a second supply voltage, and is arranged to provide an output voltage for driving a load. The intermediate stage is coupled between the input stage and the output stage, and includes a level shifter. The gm circuit is coupled to the input stage, and is arranged to compare the input voltage with a common mode voltage, and thereby generates a compensate current for the input stage.

Various embodiments of the present technology may comprise methods and apparatus for an amplifier circuit. Methods and apparatus for an amplifier circuit according to various aspects of the present invention may comprise a first cross-connect circuit configured to receive an input signal at an input terminal and transmit the input signal to an input stage circuit. The amplifier circuit may further comprise a second cross-connect circuit connected between the input stage circuit and an output stage circuit, and a voltage adjustment circuit connected to the input stage circuit. Each cross-connect circuit may comprise a plurality of switches.

Disclosed is a high accurate measurement circuit, and the feature is using bias switching circuit for compensating front end offset, and the back end offset of amplifier is also cancelled. In the real measurement environment, offset exists in the amplifier of the measurement circuit has, and non-ideal effects also exist in the interface between measurement terminal and the measurement circuit, such as leakage current of chip package pins or mismatch of the circuit. The above non-ideal effects belong to front end offset and cannot be compensated by the prior arts. The disclosed structure uses the bias switch circuit and uses different switching method in the two measurement timings. By subtracting the measurement results for the two measurement timings, the front end offset is compensated, and the back end offset of the amplifier is also cancelled.

A switched-capacitor gain stage circuit and method include an amplifier connected to an input sampling circuit with sampling switched capacitors for coupling an input voltage and a first or second reference voltage to one or more central nodes during a sampling phase and for coupling the one or more central nodes to an amplifier input during a gain phase, wherein a reference loading circuit uses a plurality of sampling switched capacitors connected in a switching configuration to selectively couple a first reference voltage and/or a second reference voltage to the central node by pre-charging the plurality of sampling switched capacitors with the first and second reference voltages during the sampling phase, and by coupling each of the first and second reference voltages to at least one of the plurality of sampling switched capacitors when connected to the central node during the gain phase.

A switched-capacitor gain stage circuit and method include an amplifier connected to an input sampling circuit with sampling switched capacitors for coupling an input voltage and a first or second reference voltage to one or more central nodes during a sampling phase and for coupling the one or more central nodes to an amplifier input during a gain phase, wherein a reference loading circuit uses a plurality of sampling switched capacitors connected in a switching configuration to selectively couple a first reference voltage and/or a second reference voltage to the central node by pre-charging the plurality of sampling switched capacitors with the first and second reference voltages during the sampling phase, and by coupling each of the first and second reference voltages to at least one of the plurality of sampling switched capacitors when connected to the central node during the gain phase.

A semiconductor device includes a magnetic switch provided on a semiconductor substrate. The magnetic switch includes: a Hall element, first and second power supply terminals; a current source driving the Hall element; a switch circuit switching a differential output voltage supplied from two electrodes of the Hall element to a first or second state based on a control signal supplied from a control terminal; an amplifier amplifying a signal from the switch circuit; a reference voltage circuit generating a reference voltage based on a reference common mode voltage and a control signal; a comparator receiving an output signal of the amplifier and the reference voltage; and a latch circuit latching an output voltage of the comparator. The reference voltage of the reference voltage circuit is controlled by switching from a reference value to a voltage with a high or low adjustment value according to the output voltage of the comparator.

An analog circuit including a pair of input nodes and a pair of output nodes is coupled to a mismatch reduction circuit including an input node, an output node, a phase controller that times even and odd phases, an input switch, and an output switch. The input switch electrically connects the mismatch reduction circuit input node to a first node of the pair of analog circuit input nodes during each even phase and to electrically connects the mismatch reduction circuit input node to a second node of the pair of analog circuit input nodes during each odd phase. The output switch electrically connects a first node of the pair of analog circuit output nodes to the mismatch reduction circuit output node during each even phase and electrically connects a second node of the pair of analog circuit output nodes to the mismatch reduction circuit output node during each odd phase.

An analog circuit including a pair of input nodes and a pair of output nodes is coupled to a mismatch reduction circuit including an input node, an output node, a phase controller that times even and odd phases, an input switch, and an output switch. The input switch electrically connects the mismatch reduction circuit input node to a first node of the pair of analog circuit input nodes during each even phase and to electrically connects the mismatch reduction circuit input node to a second node of the pair of analog circuit input nodes during each odd phase. The output switch electrically connects a first node of the pair of analog circuit output nodes to the mismatch reduction circuit output node during each even phase and electrically connects a second node of the pair of analog circuit output nodes to the mismatch reduction circuit output node during each odd phase.