H03F2203/45521

MEMS SENSOR

A MEMS sensor (1) comprises a MEMS transducer (10) being coupled to a MEMS interface circuit (20). The MEMS interface circuit (20) comprises a bias voltage generator (100), a differential amplifier (200), a capacitor (300) and a feedback control circuit (400). The bias voltage generator (100) generates a bias voltage (Vbias) for operating the MEMS transducer. The variable capacitor (300) is connected to one of the input nodes (I200a) of the differential amplifier (200). At least one of the output nodes (A200a, A200b) of the differential amplifier is coupled to a base terminal (T110) of an output filter (110) of the bias voltage generator (100). Any disturbing signal from the bias voltage generator (100) is a common-mode signal that is divided equally on the input nodes (I200a, I200b) of the differential amplifier (200) and is therefore rejected.

DC offset cancellation and crosspoint control circuit
10484213 · 2019-11-19 · ·

A circuit and method in an amplifier circuit for filtering a DC offset in differential input signals and inserting a programmable adjustable crosspoint offset in differential output signals. An amplifier circuit includes a differential amplifier circuit configured to amplify differential input signals into differential output signal. The amplifier circuit further includes a feedback circuit coupled between the differential output signals and the differential input signals. The feedback circuit is configured to generate a programmably adjustable crosspoint offset in the differential output signal and a programmably adjustable cutoff frequency of the feedback circuit. An amplifier method includes amplifying differential input signals into differential output signals, generating a programmably adjustable crosspoint offset in the differential output signal, and generating a programmably adjustable cutoff frequency of a feedback circuit between the differential output signals and the differential input signals.

PROTECTION CIRCUIT AND DISPLAY PANEL
20190348836 · 2019-11-14 ·

The present disclosure provides a protection circuit and a display panel. The protection circuit comprises: a power supply circuit for outputting a first voltage; an overvoltage protection circuit connected to the power supply circuit for feedback regulation of the first voltage, such that a first protection voltage outputted by the overvoltage protection circuit is maintained within a preset range; and an output regulator circuit connected to the overvoltage protection circuit for regulated output of a second protection voltage. Through the above embodiments, the present disclosure can always stabilize the outputted voltages within a preset range to achieve the purpose of providing a stable voltage for the display panel, thereby realizing accurate and rapid overvoltage protection of the display panel.

Dynamic correction of gain error in current-feedback instrumentation amplifiers

A current feed-back instrumentation amplifier (CFIA) comprises a differential pair with degeneration for amplifying small differential voltages in the presence of large common-mode voltages. The CFIA includes input and feedback transconductors and a chopping modulator circuit that continuously swaps tail current sources between the transconductors. This tail current swapping reduces the contribution to the CFIA's gain error caused by random mismatch between the tail currents of the input and feedback transconductors. The modulator circuit operates on a clock cycle to periodically swap the tail current sources. As a result, even if the tail currents are mismatched, on average the tail currents (transconductor gains) will approximately equal out, and the contribution of the tail current difference to the gain error is canceled out.

Methods of adjusting gain error in instrumentation amplifiers

A current feed-back instrumentation amplifier (CFIA) comprises a differential pair with degeneration for amplifying small differential voltages in the presence of large common-mode voltages. The CFIA includes input and feedback transconductors and a trimming circuit that trims the back-bias voltages of the transistors in each transconductor. The trimming circuit includes a plurality of selectable resistors disposed in the signal path of the tail current in each transconductor. Each of the plurality of selectable resistors has a switch coupled to it. When a switch is closed, only the resistors up to the respective switch are in the signal path of the bulk-to-source voltage of the differentially paired transistors. The resistor trimming circuit reduces the mismatch between transconductances of the respective differential pair transistors, in turn reducing mismatch of the overall transconductances of the transconductors, and thereby reducing the CFIA's gain error.

Low drop out regulator compatible with type C USB standard
10423179 · 2019-09-24 · ·

A low dropout voltage regulator unit includes an error amplifier and a power stage having an output terminal that is looped back onto the error amplifier and is capable of delivering an output current to a load. The unit includes multiple main supply inputs that are intended to potentially receive, respectively, multiple different supply voltages. The power stage includes multiple power paths that are connected, respectively, between the main supply inputs and the output terminal, are individually selectable and each comprise an output transistor. The unit also includes a selector circuit connected to the main supply inputs and configured to select one of the power paths according to a selection criterion. The error amplifier includes an output stage configured to selectively control the output transistor of the selected power path.

Low Drop out Regulator Compatible with Type C USB Standard
20190235551 · 2019-08-01 ·

A low dropout voltage regulator unit includes an error amplifier and a power stage having an output terminal that is looped back onto the error amplifier and is capable of delivering an output current to a load. The unit includes multiple main supply inputs that are intended to potentially receive, respectively, multiple different supply voltages. The power stage includes multiple power paths that are connected, respectively, between the main supply inputs and the output terminal, are individually selectable and each comprise an output transistor. The unit also includes a selector circuit connected to the main supply inputs and configured to select one of the power paths according to a selection criterion. The error amplifier includes an output stage configured to selectively control the output transistor of the selected power path.

METHODS OF ADJUSTING GAIN ERROR IN INSTRUMENTATION AMPLIFIERS

A current feed-back instrumentation amplifier (CFIA) comprises a differential pair with degeneration for amplifying small differential voltages in the presence of large common-mode voltages. The CFIA includes input and feedback transconductors and a trimming circuit that trims the back-bias voltages of the transistors in each transconductor. The trimming circuit includes a plurality of selectable resistors disposed in the signal path of the tail current in each transconductor. Each of the plurality of selectable resistors has a switch coupled to it. When a switch is closed, only the resistors up to the respective switch are in the signal path of the bulk-to-source voltage of the differentially paired transistors. The resistor trimming circuit reduces the mismatch between transconductances of the respective differential pair transistors, in turn reducing mismatch of the overall transconductances of the transconductors, and thereby reducing the CFIA's gain error.

Amplifier circuit and filter
10348260 · 2019-07-09 · ·

An OTA circuit includes a first input stage that includes a first pair of transistors having sources coupled to a reference potential and converts a differential input voltage input to gates of the first pair of transistors into a first control current, a second input stage that includes a second pair of transistors having sources coupled to the reference potential and converts the differential input voltage input to gates of the second pair of transistors into a second control current, a first output circuit that generates one output current out of the differential output currents in accordance with the first control current, and a second output circuit that generates the other output current out of the differential output currents in accordance with the second control current.

Low drop out regulator compatible with type C USB standard
10303192 · 2019-05-28 · ·

A low dropout voltage regulator unit includes an error amplifier and a power stage having an output terminal that is looped back onto the error amplifier and is capable of delivering an output current to a load. The unit includes multiple main supply inputs that are intended to potentially receive, respectively, multiple different supply voltages. The power stage includes multiple power paths that are connected, respectively, between the main supply inputs and the output terminal, are individually selectable and each comprise an output transistor. The unit also includes a selector circuit connected to the main supply inputs and configured to select one of the power paths according to a selection criterion. The error amplifier includes an output stage configured to selectively control the output transistor of the selected power path.