A buffer circuit for a radio frequency (RF) signal includes a single leg and a feedback mesh. The single leg is coupled between a voltage supply and ground. The single leg includes a pMOS FET and an nMOS FET, and an output terminal defined at drain terminals of the pMOS FET and the nMOS FET. The buffer circuit includes an input terminal capacitively coupled to gates of the pMOS FET and the nMOS FET. The input terminal is configured to receive the RF signal, and a buffered signal is provided on the output terminal. The feedback mesh is coupled to the output terminal and coupled to the gates of the pMOS FET and the nMOS FET. The feedback mesh includes a series-coupled inductive-resistive feedback impedance, and a resistive feedback impedance in parallel with the series-coupled inductive-resistive feedback impedance.

The present invention provides a circuit having a filter with an amplifier circuit for filtering and amplifying an input signal to generate an output signal, wherein a corner frequency of the filter is adjustable to control a settling time of the output signal.

A circuit for filtering a signal corresponding to a time of flight (TOF) of light from a laser reflected off an object to a photo detector, the circuit includes a preamplifier, a DC cancelation loop, and an AC cancelation loop. The preamplifier may be configured to receive the signal from the photo detector corresponding to an output of the laser reflected off an object remote from the laser and photo detector. The DC cancelation loop includes a current feedback DC servo loop. The AC cancelation loop includes a feedback network driven by a floating class AB output stage, and the preamplifier configured to drive the floating class AB output stage, wherein the preamplifier is driven by an error signal of the feedback network and creates an AC signal path with the feedback network and floating class AB output stage.

A PA module includes: a multilayer substrate having a ground pattern layer connected to a ground of a power source; amplifier transistors disposed on the multilayer substrate; a bypass capacitor having one end connected to the collector of the amplifier transistor; a first wiring line connecting the emitter of the amplifier transistor and the ground pattern layer to each other; a second wiring line connecting the emitter of the amplifier transistor and the ground pattern layer to each other; a third wiring line connecting the other end of the bypass capacitor and the ground pattern layer to each other; and a fourth wiring line formed between the amplifier transistor and the ground pattern layer and between the bypass capacitor and the ground pattern layer and connecting the first wiring line and the third wiring line to each other.

A sensor arrangement includes a sensor having a first terminal and a second terminal, and an amplifier having an amplifier input for applying an input signal and an amplifier output for providing an amplified input signal, the amplifier input being coupled to the second terminal. A quantizer having a quantizer input and a quantizer output is configured to provide a multi-level output signal on the basis of the amplified input signal and a feedback circuit having a feedback circuit input coupled to the quantizer output and a feedback circuit output coupled to the first terminal. The feedback circuit includes a digital-to-analog converter configured to generate an analog signal on the basis of the multi-level output signal, the analog signal being the basis of a feedback signal provided at the feedback circuit output, a feedback capacitor coupled between the feedback circuit output and an output of the digital-to-analog converter, and a voltage source coupled to the feedback circuit output.

Techniques for monitoring a distortion signal of a power amplifier circuit, where the output of a distortion monitoring circuit includes little or no fundamental signal and closely represents the actual distortion of the amplifier circuit of a wired communications system. The power amplifier circuit can generate a distortion feedback signal that does not affect the power amplifier's output power capability, e.g., no inherent loss in the fundamental output of the amplifier. That is, using a distortion monitor circuit, the power amplifier circuit can resolve a distortion feedback signal from the intended output signal of the output power amplifier circuit.

An analog discrete current mode negative feedback amplifier circuit for use with a micro-fused strain gauge is disclosed. The amplifier circuit includes a Wheatstone bridge coupled to a first power supply and a second power supply. The first power supply and the second power supply can be configured such that the periodically alternate between two voltage levels. The Wheatstone bridge can be coupled to a negative feedback amplifier circuit with common mode detection. The amplifier circuit can comprise a differential amplifier with a negative feedback configuration coupled to a common mode amplifier. In addition, the output of each of the amplifiers can be coupled to a common-mode amplifier. In a pressure sensing application, the output of the common mode amplifier serves to output the temperature while the differential amplifiers serve to output the pressure.

An error amplifier for a pulse width modulation circuit is described. The amplifier includes an operational amplifier configured as an integrator and a feedback loop coupled between a signal output of the operational amplifier and an inverting input of the operational amplifier. The feedback loop comprises a feedback capacitor coupled to the signal output, a feedback resistor coupled to the feedback capacitor, and an integrator resistor coupled to the feedback resistor and the inverting input of the operational amplifier. A junction between the feedback resistor and the integrator resistor is configured to receive an input signal and a junction between the feedback capacitor and the feedback resistor is configured to receive a feedback signal from the pulse width modulation circuit.

A power amplifier (PA) circuit includes a circuit for generating a supply voltage at an upper voltage rail for a power amplifier (PA). The circuit includes a DC-to-DC converter for generating a voltage from which the supply voltage is generated; a linear amplifier for sourcing or sinking current to or from the upper voltage rail via a capacitor for performing fine adjustment of the supply voltage; a first switching device coupled between an output of the linear amplifier and a lower voltage rail to selectively assist the linear amplifier sink current through the capacitor to deal with actual or anticipated transient response of the supply voltage; and a second switching device coupled between the upper voltage rail and the lower voltage rail to selectively discharge the capacitor in response to actual or anticipated transient response of the supply voltage.

A PA module includes: a multilayer substrate having a ground pattern layer connected to a ground of a power source; amplifier transistors disposed on the multilayer substrate; a bypass capacitor having one end connected to the collector of the amplifier transistor; a first wiring line connecting the emitter of the amplifier transistor and the ground pattern layer to each other; a second wiring line connecting the emitter of the amplifier transistor and the ground pattern layer to each other; a third wiring line connecting the other end of the bypass capacitor and the ground pattern layer to each other; and a fourth wiring line formed between the amplifier transistor and the ground pattern layer and between the bypass capacitor and the ground pattern layer and connecting the first wiring line and the third wiring line to each other.