A system has an output and receives an input signal. An operational amplifier has an input, an output and an offset at the input. A switched capacitor network samples the input signal at a switched capacitor frequency. An autozeroing capacitor connected to the input of the operational amplifier captures the offset during an offset capture interval according to an autozeroing frequency. Chopping and autozeroing switches, connected between the autozeroing capacitor and the switched capacitor network, chop the sampled input signal according to a chopping frequency and autozero the captured offset according to the autozeroing frequency. De-chopping switches, connected between the output of the operational amplifier and the output of the system, operate on the output of the operational amplifier at the chopping frequency to chop the autozeroed captured offset and de-chop the chopped sampled input signal processed by the operational amplifier.

A receiver includes a first T-coil circuit at an input of the receiver and configured to receive an input signal, a termination impedance coupled to the first T-coil circuit and configured to match an impedance of a transmission line coupled to the first T-coil circuit, and an amplifier including a first input and a second input and configured to amplify a differential signal at the first and second inputs, a calibration switch coupled to the amplifier and configured to selectively electrically connect or disconnect the first and second inputs of the amplifier, and a first receive switch configured to selectively electrically connect or disconnect a center node of the first T-coil circuit and the amplifier.

The present invention corresponds to a method and a circuit for compensating the offset voltage of electronic circuits, where the circuit implementing the method comprises: a dynamic comparator (1); a phase detector (6) connected to the dynamic comparator (1), the phase detector (6); a finite-state machine (9) connected to the phase detector (4), a first digital-analog converter (12) connected to an output of the finite-state machine (9); a second digital-analog converter (13) connected to another output (11) of the finite-state machine (9); a polarization block (14) with a first input (15) connected to the output of the first digital-analog converter (12) and a second input (16) connected to the output of the second digital-analog converter (13); where the polarization block (14) polarizes an electronic circuit (17) and the dynamic comparator (1), the phase detector (6), and the finite-state machine (9) are connected to a clock signal (3). The method is characterized by the following steps: a) connecting a dynamic comparator to the output of the electronic circuit; b) measuring the phase change of the dynamic comparator outputs of step a by means of a phase detector; c) controlling the output signals of a finite-state machine according to the phase detector output of step b, which can be coded forward, backward or in phase; c) converting the output of the finite-state machine of step c to an analog signal using two digital-analog converters; d) connecting the output of the two digital-analog converters of step d to the control terminal of the electronic circuit polarization block; and, e) modifying the polarization current of the electronic circuit polarization block by means of the output signals of the two digital-analog converters connected in step e.

A control apparatus for driving a display panel and a method thereof are provided. The control apparatus includes an image flickering detector and a chopper selector. The image flickering detector detects whether a present image pattern displayed on the display panel is flickering or not. The chopper selector selects a first chopper mode from a plurality of chopper modes for adjusting gamma voltages of a display image data, and detects whether the present image displayed on the display panel according to the display image data is flickering or not by the image flickering detector. The chopper selector selects a second chopper mode to adjust the gamma voltages of the display image data in response to the present image being flickering. The first chopper mode is different from the second chopper mode.

This disclosure describes auto-zero amplifier circuit that include an additional capacitor (or other capacitive component) that can be switchably coupler to a reference voltage. The auto-zero amplifier circuit can generate an auto-zero compensation signal using a difference between the reference voltage stored on the additional capacitor and a voltage stored on another auto-zero capacitor.

An apparatus includes an amplifier, an input port, a first modulator circuit connected to the input port, and a correction circuit. The correction circuit is configured to determine a common mode voltage of the input port and receive a first clock signal. The correction circuit is further configured to manipulate, based at least in part upon the common mode voltage of the input port, the first clock signal to generate a second clock signal. The second clock signal is produced for the first modulator circuit. The correction circuit is further configured to determine whether the second clock signal is out of phase with a third clock signal, and, based upon a determination that the second clock signal is out of phase with the third clock signal, reset the second clock signal.

A difference amplifier can he used for providing an amplified representation of a sensed current through a load device. A separate signal path can be used to provide fast fault detection, without requiring use of the difference amplifier. For example, a voltage scaling circuit can be used to scale a differential input signal indicative of the load current. The scaled representation can then be compared against a specified threshold corresponding to a fault current value. In this manner, a high-speed low-voltage comparator can be used to provide detection of a fault current that otherwise exceeds an input range of the difference amplifier, where the difference amplifier is used separately for precision current monitoring. As an illustrative example, such a scheme can provide fault detection even when an input of the difference amplifier is saturated.

The present invention corresponds to a method and a circuit for compensating the offset voltage of electronic circuits, where the circuit implementing the method comprises: a dynamic comparator (1); a phase detector (6) connected to the dynamic comparator (1), the phase detector (6); a finite-state machine (9) connected to the phase detector (4), a first digital-analog converter (12) connected to an output of the finite-state machine (9); a second digital-analog converter (13) connected to another output (11) of the finite-state machine (9); a polarization block (14) with a first input (15) connected to the output of the first digital-analog converter (12) and a second input (16) connected to the output of the second digital-analog converter (13); where the polarization block (14) polarizes an electronic circuit (17) and the dynamic comparator (1), the phase detector (6), and the finite-state machine (9) are connected to a clock signal (3). The method is characterized by the following steps: a) connecting a dynamic comparator to the output of the electronic circuit; b) measuring the phase change of the dynamic comparator outputs of step a by means of a phase detector; c) controlling the output signals of a finite-state machine according to the phase detector output of step b, which can be coded forward, backward or in phase; c) converting the output of the finite-state machine of step c to an analog signal using two digital-analog converters; d) connecting the output of the two digital-analog converters of step d to the control terminal of the electronic circuit polarization block; and, e) modifying the polarization current of the electronic circuit polarization block by means of the output signals of the two digital-analog converters connected in step e.

A preamplifier circuit includes a first transconductor and a floating transconductor. The first transconductor receives a differential voltage from a sample-and-hold circuit and drives the floating transconductor. The first and floating transconductors output amplified versions of the differential voltage that are not affected by capacitive division, which makes the preamplifier circuit fast. The preamplifier circuit also has a low input capacitance because the floating transconductor is not connected to any external circuitry.

A method for improving threshold accuracy in an RFID-device through offset cancellation, and including the steps of providing a comparator including a first and a second amplifiers, providing a current output digital-to-analogue converter, AC-coupling in an RF-signal into the detector circuit, during a first phase, applying a signal based on the RF-signal into the first amplifier while a current of the DAC is set to zero, and applying a current of the DAC into the second amplifier while a signal based on the RF-signal is set to zero, during a second phase, applying the current of the DAC into the first amplifier while the signal based on the RF-signal is set to zero, and applying the signal based on the RF-signal into the second amplifier while the current of the DAC is set to zero.