An amplifying circuit includes a reference voltage generating circuit, a common-mode voltage conversion circuit, a common-mode negative feedback circuit, and an amplifying sub-circuit. The reference voltage generating circuit generates a first reference voltage, a second reference voltage, and a reference common-mode voltage according to a post-stage common-mode voltage. The common-mode voltage conversion circuit converts the pre-stage output differential signal into a differential input signal according to the reference common-mode voltage. The common-mode negative feedback circuit generates a control voltage to quickly establish a common-mode negative feedback of the amplifying sub-circuit, wherein the first reference voltage and the second reference voltage are used to cancel a baseline signal of the pre-stage output differential signal. The amplifying circuit can eliminate the baseline signal, convert the common-mode voltage and quickly establish the common-mode negative feedback.

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.

The present invention includes a current integrator for an organic light-emitting diode (OLED) panel. The current integrator includes an operational amplifier, which includes an output stage. The output stage, coupled to an output terminal of the current integrator, includes a first output transistor, a second output transistor, a first stack transistor and a second stack transistor. The first stack transistor is coupled between the first output transistor and the output terminal. The second stack transistor is coupled between the second output transistor and the output terminal.

An apparatus includes a differential current-to-voltage conversion circuit that includes an input sampling stage circuit, a differential integration and DC signal cancellation stage circuit, and an amplification and accumulator stage circuit. An input common mode voltage of the differential current-to-voltage circuit is independent of an output common mode voltage of the differential current-to-voltage circuit.

The present invention includes a current integrator for an organic light-emitting diode (OLED) panel. The current integrator includes an operational amplifier, which includes an output stage. The output stage, coupled to an output terminal of the current integrator, includes a first output transistor, a second output transistor, a first stack transistor and a second stack transistor. The first stack transistor is coupled between the first output transistor and the output terminal. The second stack transistor is coupled between the second output transistor and the output terminal.

A chopper-stabilized amplifier includes a first transconductance amplifier and a first chopper circuit coupled to an input of the first transconductance amplifier. A second chopper circuit is coupled to an output of the first transconductance amplifier. The chopper-stabilized amplifier also includes second and third transconductance amplifiers having inputs coupled to the output of the first transconductance amplifier. The second transconductance amplifier produces an output responsive to a first notch clock signal having a first phase relative to the chopping of the second chopper circuit. The third transconductance amplifier produces an output responsive to a second notch clock signal having a second phase relative to the first phase. The output signals produced by the second and third transconductance amplifiers are added to filter ripple noise at the outputs of the second and third transconductance amplifiers.

A current integrator includes an operational amplifier, an integration capacitor and an offset cancelation capacitor. The operational amplifier includes a first input stage and a second input stage. The first input stage is coupled to an input terminal of the current integrator. The integration capacitor is coupled between the first input stage of the operational amplifier and an output terminal of the current integrator. The offset cancelation capacitor is coupled to the second input stage of the operational amplifier.

A chopper-stabilized amplifier includes a first transconductance amplifier and a first chopper circuit coupled to an input of the first transconductance amplifier. A second chopper circuit is coupled to an output of the first transconductance amplifier. The chopper-stabilized amplifier also includes second and third transconductance amplifiers having inputs coupled to the output of the first transconductance amplifier. The second transconductance amplifier produces an output responsive to a first notch clock signal having a first phase relative to the chopping of the second chopper circuit. The third transconductance amplifier produces an output responsive to a second notch clock signal having a second phase relative to the first phase. The output signals produced by the second and third transconductance amplifiers are added to filter ripple noise at the outputs of the second and third transconductance amplifiers.

An amplifier arrangement has a first differential stage with a first transistor pair, a second differential stage with a first and a second transistor pair, each pair having a common source connection. The amplifier arrangement further has a first complementary differential stage with a transistor pair having opposite conductivity type, and a second complementary differential stage with a first and a second transistor pair of the complementary conductivity type. The first and the second complementary differential stage are connected symmetrically compared to the first and the second differential stage. The transistors of the second differential stage and the second complementary differential stage are symmetrically connected to form respective first, second, third and fourth current paths. A pair of output terminals is coupled to the first and the fourth current path. Gate terminals of the transistors are coupled to a respective pair of input terminals.

A voltage detection device comprises a voltage detection circuit, which is a fully-differential type and a control circuit for controlling an operation of the voltage detection circuit. The voltage detection circuit includes a switched capacitor circuit, a differential amplifier, a common mode feedback circuit for controlling a common mode level of an output voltage of the differential amplifier and a bias circuit for supplying biases to the differential amplifier and the common mode feedback circuit. The control circuit controls the voltage detection circuit to execute intermittently a detection operation for detecting the voltage. The control circuit controls the voltage detection circuit to execute a pseudo operation of an execution period, which is shorter than that of the detection operation, during a transition period from a stop state, in which no detection operation is executed, to the operation state, in which the detection operation is executed.