A stress sensor is provided, including a substrate and a bridge circuit disposed thereon. The bridge circuit is coupled between an output node and a ground node. The bridge circuit includes a first branch and a second branch, the first having a first resistor, R1, having a first orientation and coupled to a tuning resistor, Rtune, at a first intermediate node. The second branch includes a second resistor, R2, having a second orientation that is different from the first orientation, and coupled to a variable resistor, Rvar, at a second intermediate node. The bridge circuit includes an amplifier having a positive input terminal coupled to the second intermediate node, and a negative input terminal coupled to the first intermediate node. The amplifier generates a voltage output at the output node as a function of mechanical stress applied to the substrate. Rvar is non-linearly tunable based on the voltage output.

The invention relates to a circuit containing a transimpedance amplifier for converting two input currents into two output voltages, having a first amplifier part containing a first input, to which a first input voltage is applied, and into which a first input current flows, and having a second amplifier part containing a second input, to which a second input voltage is applied and into which a second input current flows, wherein the first amplifier part and the second amplifier part are connected to a common supply voltage, the first amplifier part and the second amplifier part are connected to a common current source, the input of the first amplifier part and the input of the second amplifier part have a differing direct voltage, and the first amplifier part and the second amplifier part are designed such that an output voltage of the first amplifier part is proportional to the input current of the first amplifier part and an output voltage of the second amplifier part is proportional to an input current of the second amplifier part.

Systems and methods for amplifying an input signal include amplifier circuitry, an itail connection coupled between a positive voltage circuitry and the negative voltage circuitry and operable to generate an itail voltage corresponding to a greater of the positive voltage input signal (Vp) and the negative voltage input signal (Vn), a first resistor rgp disposed to receive the itail voltage and a first voltage corresponding to Vp, and a second resistor rgn disposed to receive the itail voltage and a second voltage corresponding to Vn. A first current output node is coupled to the output of rgp and operable to output a positive output current (Ioutp) corresponding to the current flowing through rgp, and a second current output is coupled to the output of rgn and operable to output a negative output current (Ioutn) corresponding to the current flowing through rgn.

pHEMT-based switch circuits, devices including same, and methods of improving the linearity thereof. In one example, an antenna switch module includes a pHEMT switching circuit connected in series between an input signal terminal and a load terminal, the pHEMT switching circuit including at least one pHEMT configured to produce a first harmonic signal at the load terminal responsive to being driven by an input signal of a fundamental frequency received at the input signal terminal, the first harmonic signal having a first phase, and a gate resistance circuit connected to a gate of the at least one pHEMT and having a resistance value selected to produce a second harmonic signal at the load terminal, the second harmonic signal having a second phase opposite to the first phase.

Transimpedance amplifiers with feedforward current are provided herein. In certain embodiments, an amplifier system includes a transimpedance amplifier that amplifies an input current received at an input to generate an output voltage at an output. The amplifier system further includes a controllable current source that is coupled to the output of the transimpedance amplifier, and operable to provide a feedforward current that changes in relation to the input current of the transimpedance amplifier. By providing a feedforward current in this manner, gain and speed performance of the transimpedance amplifier is enhanced.

A preamplifier comprises an input stage and a capacitive coupling stage. The input stage is arranged to receive a differential signal from a magnetic resistor which indicates a magnetic field sensed on a magnetic disk of a hard disk drive (HDD) when the preamplifier is powered on from an off state. The capacitive coupling stage has an input arranged to receive the differential signal from the input stage, a filter comprising a first resistor, a second resistor, a first capacitor, a second capacitor, and switches arranged in parallel with respective resistors, where the switches are closed when the preamplifier is powered on from the off state to an on state. A switch control is arranged to determine that an offset of the differential signal has settled and open the switches based on the determination.

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 variable-current trans-impedance amplifier (TIA) for an ultrasound device is described. The TIA may be coupled to an ultrasonic transducer to amplify an output signal of the ultrasonic transducer representing an ultrasound signal received by the ultrasonic transducer. During acquisition of the ultrasound signal by the ultrasonic transducer, one or more current sources in the TIA may be varied. The variable-current trans-impedance amplifier may include multiple stages, including a first stage having N-P transistor pairs configured to receive an input signal and produce a single-ended amplified signal.

An apparatus for controlling the gain and phase of an input signal input to a power amplifier comprises a gain control loop configured to control the gain of the input signal based on power levels of the input signal and an amplified signal output by the power amplifier, to obtain a predetermined gain of the amplified signal, and a phase control loop configured to obtain an error signal related to a phase difference between a first signal derived from the input and a second signal derived from the amplified signal, and control the phase based on the error signal, to obtain a predetermined phase of the amplified signal. The phase control loop delays the first signal such that the delayed first signal and the second signal used to obtain the error signal correspond to the same part of the input signal. The apparatus may be included in a satellite.

A bias current circuit includes: an N-type MOSFET in which a gate terminal and a drain terminal are connected to a current source, and N-type MOSFETs in which respective drain terminals are connected to respective bias current output terminals and source terminals are grounded. The bias current circuit further includes: an N-type MOSFET in which one terminal type, either a drain terminal or a source terminal, is connected to the gate terminal of the N-type MOSFET, and the other terminal type is connected to the gate terminals of the N-type MOSFETs, and an N-type MOSFET in which a drain terminal is connected to the gate terminals of the N-type MOSFETs and a source terminal is grounded. A control signal, that is LOW when the bias current is supplied and is HIGH when the bias current is not supplied, is input to the gate terminal of the N-type MOSFET, and an inverse signal of the control signal is input to the gate terminal of the N-type MOSFET.