A device measures the current in an inductive load using two separate current-measuring paths to detect the current in the inductive load. The inductive load is connected between first and second nodes, and the first node connected to a first voltage. The device includes first and second transistors cascaded together between the first node and a third node that is connected to a second voltage. First and second sense amplifiers measure the current in the inductive load. The first and second sense amplifiers are connected to at least one terminal of the first and second transistors. Two blocks sample and hold signals from the first and second sense amplifiers, which represent, respectively, the currents in the two separate current-measuring paths. The two currents are subtracted in a comparison node for generating an error signal that is compared with a predefined window and if outside the window a failure signal is generated.

A front-end amplifier circuit for receiving a biological signal includes a signal channel. The signal channel amplifies the biological signal to generate a detection current and includes a capacitive-coupled transconductance amplifier. The capacitive-coupled transconductance amplifier amplifies the biological signal with a transconductance gain to generate a first current.

Techniques are described for frequency-division-coordination of automatic power control (APC) in a transceiver of a near-field reader. Such frequency-division-coordinated APC (FDC-APC) can enable continuous APC updates concurrent with communication frames to achieve field strength specifications without conventional degradations in communication reliability. For example, a transceiver implements a FDC-APC loop that received a detuning signal from signals received and/or transmitted over a near-field communication link, generates an error signal by comparing the detuning signal with a reference detuning level, and updates a power control signal according to an update frequency (e.g., corresponding to a APC loop bandwidth) that is a function of at least a filter frequency profile and is out-of-band with respect to a modulation frequency band. Modulated signals can be transmitted over the near-field communication link according to variable power settings controlled to the power control signal.

A power amplification apparatus which is a Doherty power amplification apparatus includes a main amplifier configured to amplify an input signal, and an auxiliary amplifier configured to amplify the input signal when a level of the input signal is higher than a predetermined level. The power amplification apparatus includes an auxiliary amplifier threshold value shift detector configured to detect a threshold value shift in the auxiliary amplifier; and an auxiliary amplifier bias voltage adjustment circuit configured to adjust a bias voltage of the auxiliary amplifier based on the detected threshold value shift in the auxiliary amplifier.

A device for measuring current by means of integration, includes a first operational amplifier connected as an integrator, and a second operational amplifier connected as an original current generator which can compensate for leakage current in the circuit measurement state and reset the Q0 charge of the integration capacitor in the reset state.

The present disclosure relates to a device comprising two error amplifier stages having their first inputs interconnected, their second inputs interconnected and their outputs coupled to an output of the device, each stage comprising an operational amplifier; a circuit for calibrating the amplifier; a switch coupling an input of the amplifier to the first input; a switch coupling another input of the amplifier to the second input; a switch coupling an output of the amplifier to the stage output; a switch having on state which short-circuits the inputs of the amplifier; and a switch coupling the output of the amplifier to the calibration circuit.

Techniques for improving current sensing via a shunt resistance are provided. In an example, an apparatus for sensing current can include a substrate, and a plurality of metal layers stacked on the substrate and separated from the substrate and from each other by an insulation material. In certain examples, a first one or more metal layers can form a sense resistance configured to pass current between a source and a load, and a second one or more metal layers can form one or more gain resistances coupled to the sense resistance and configured to couple to a current sense amplifier. In some example, a metal layer can include portions of both the sense resistance and the gain resistance to compensate for environmental anomalies, material anomalies or manufacturing anomalies.

A detection apparatus for unbalanced DC link capacitor voltage, the DC link provides a DC voltage and includes a plurality of capacitors coupled in series to two ends of the DC link and a plurality of balanced resistors coupled in series to two ends of the DC link and corresponding to the capacitors. The detection apparatus includes a plurality of sense resistors and a current sensor. One end of each sense resistor is coupled to a common-connected node of two capacitors, and the other end thereof is coupled to a common-connected node of two balanced resistors. The current sensor is coupled to one of the sense resistors and measures a current value of a current flowing through the sense resistor coupled to the current sensor.

A power amplifier device includes: a first power supply terminal for inputting a first power supply voltage; a first transistor for power amplification that (i) includes a first gate to which a bias voltage is applied, and (ii) is supplied with power from the first power supply terminal; a second power supply terminal for inputting a second power supply voltage lower than the first power supply voltage; a second transistor for monitoring that (i) includes a second gate to which the bias voltage is applied, (ii) is supplied with power from the first power supply terminal or the second power supply terminal, and (iii) imitates an operation of the first transistor; and a bias circuit that is supplied with power from the second power supply terminal and generates and adjusts the bias voltage according to a drain current or a source current of the second transistor.

Certain aspects of the present disclosure are generally directed to circuitry and techniques for current sensing. For example, certain aspects provide a circuit for signal amplification including a first amplifier, a second amplifier, and a third amplifier. The circuit also includes a first capacitive element coupled between a first output of the first amplifier and a first input of the third amplifier, a second capacitive element coupled between a second output of the first amplifier and a second input of the third amplifier, a third capacitive element coupled between a first output of the second amplifier and the first input of the third amplifier, and a fourth capacitive element coupled between a second output of the second amplifier and the second input of the third amplifier.