A circuit includes an amplifier having first and second inputs and an output, and a feedback circuit configured to generate a feedback voltage in response to a voltage at the output of the amplifier. The feedback circuit is coupled to the first input of the amplifier to provide the feedback voltage to the first input of the amplifier. An output circuit is configured to generate a variable bias current in response to the voltage at the output of the amplifier. A switch circuit is configured to switch the second input of the amplifier from receiving a first reference voltage during a first mode of operation to receiving a second reference voltage during a second mode of operation.

A signal processing circuit for processing a sensing signal from a sensor includes an amplifier, an input capacitor group, a compensation capacitor group and first/second switch groups. The amplifier, coupled to a first floating node and a second floating node, is configured to amplify the sensing signal coupled from the first floating node and the second floating node. The first switch group is coupled between a first node group and the first and second floating nodes. The second switch group is coupled between a second node group and the first node group. The input capacitor group is coupled to the second node group and an input node group, and configured to receive the sensing signal coupled from the input node group. The compensation capacitor group is coupled between a compensation node group and the second node group, and configured to receive a compensation signal coupled from the compensation node group.

Various embodiments of the present technology comprise a method and apparatus for a dual mode operational amplifier. According to various embodiments, the operational amplifier functions as both a fully-differential amplifier and a single-ended amplifier. The operational amplifier may comprise additional transistors that function as switches, which can be selectively operated according to a desired mode.

A single-ended to differential circuit is presented. The circuit may be a single-ended to differential integrator or a single-ended to differential amplifier. The circuit determines a first output and a second output voltage based on an input voltage, first and second reference voltages. The circuit has a first, a second and a third input memory element. The circuit in a first phase, samples a voltage indicative of the input voltage on the first input memory element. The circuit in the first phase, samples a voltage indicative of the first reference voltage on the second input memory element. The circuit in the first phase, samples a voltage indicative of the second reference voltage on the third input memory element. The circuit, in a second phase, determines the first and second output voltage based on the sampled voltages on the first, second, and third input memory elements.

Sampling circuits and methods for sampling are provided. In a first operating phase, sampling capacitors are coupled to inputs, and in a second operating phase, to a common-mode signal.

A data storage apparatus includes storage, and a controller including an internal voltage trimming circuit and controlling the storage in response to a request from a host. The trimming circuit may include an integral circuit sampling a difference between a test voltage output by a device under test and a reference voltage, generating an integral signal by integrating a sampled signal, and including an offset cancellation unit cancelling an offset from the sampled signal, a comparison circuit generating a comparison signal by comparing the integral signal with the reference voltage, a code generation circuit receiving an initial trimming code and generating preliminary trimming codes by increasing or decreasing the initial trimming code in response to the comparison signal, and a code average signal generation circuit generating the final trimming code by averaging the preliminary trimming codes for a given time and provide the final trimming code to the storage.

Signal quality is improved in a circuit for amplifying and sampling an analog signal. An input signal is input to one end of an input-side resistor. An operational amplifier amplifies the input signal, and outputs the input signal from an output terminal as an amplified signal. One end of a filter capacitor is connected to an input terminal of the operational amplifier. A predetermined frequency component of the input signal passes through the filter capacitor. A sampling capacitor imports the amplified signal during a predetermined sampling period, and holds the amplified signal during a predetermined hold period. A sampling switch connects the output terminal of the operational amplifier to one end of the sampling capacitor during the sampling period, and disconnects the output terminal of the operational amplifier from one end of the sampling capacitor during the hold period. A cutoff circuit disconnects the input-side resistor from one end of the filter capacitor during the sampling period, and connects the input-side resistor to one end of the filter capacitor during the hold period.

A device for buffering a reference signal comprises a regulator circuit configured to generate at least two replicas of the reference signal as regulated output signals. The device further comprises a receiving circuit configured to receive the regulated output signals in a switchable manner. In this context, the regulated output signals are configured to have different performance characteristics.

An inverse pseudo fully-differential amplifier having a common-mode feedback control circuit and a method for maintaining a stable output common-mode level are provided. The inverse pseudo fully-differential amplifier includes the pseudo fully-differential operation circuit and a common-mode feedback control circuit. The pseudo fully-differential operation circuit includes inverter amplifiers (2) and (3). The inverter amplifiers (2) and (3) respectively have a first feedback control terminal and a second feedback control terminal. Input terminals of the common-mode feedback control circuit are respectively connected with output terminals of the inverter amplifier (2) and (3), and are configured to detect common-mode output voltages of the inverter amplifier (2) and (3). An output terminal of the common-mode feedback control circuit is connected with the first feedback control terminal and the second feedback control terminal, and is configured to generate common-mode feedback to the inverter amplifiers (2) and (3) to maintain a stable common mode output level.

Magnetic field sensors and associated techniques use a Hall effect element in a current spinning arrangement in combination with a rippled reduction feedback network configured to reduce undesirable spectral components generated by the current spinning and other circuit elements.