A current sensing circuit includes a filtering circuit, an amplifier, a first resistor, a first transistor and a second transistor. The filtering circuit is coupled to two terminals of a sensing resistor. The amplifier has a first input terminal, a second input terminal and an output terminal. The second input terminal is coupled to the filtering circuit. The first resistor is coupled between the filtering circuit and the first input terminal of amplifier. A control terminal of the first transistor is coupled to the output terminal of amplifier, and its first terminal is coupled to the first input terminal of amplifier and its second terminal is grounded through a second resistor. A control terminal of the second transistor is coupled to the output terminal of amplifier, and its first terminal is coupled to the second input terminal of amplifier and its second terminal is grounded through a third resistor.

A control circuit for controlling the operation of a main switch device which manages an electrical current delivered to an inductive load device, the control circuit including: a current sense circuit configured to be coupled to the switch device and to output a signal representative of an electrical current through the inductive load device; a current comparator circuit configured to receive an actuation command signal, compare the signal representative of the electrical current through the inductive load device with a signal representative of a predetermined current, and to output a control signal based on the comparison for controlling the operation of the main switch device when the actuation command signal indicates that the inductive load device is to be activated; and a recirculation circuit configured to recirculate current through the inductive load device, such that the current used to activate the inductive load device is selectively provided by the main switch device and the recirculation circuit.

A control circuit for controlling the operation of a main switch device which manages an electrical current delivered to an inductive load device, the control circuit including: a current sense circuit configured to be coupled to the switch device and to output a signal representative of an electrical current through the inductive load device; a current comparator circuit configured to receive an actuation command signal, compare the signal representative of the electrical current through the inductive load device with a signal representative of a predetermined current, and to output a control signal based on the comparison for controlling the operation of the main switch device when the actuation command signal indicates that the inductive load device is to be activated; and a recirculation circuit configured to recirculate current through the inductive load device, such that the current used to activate the inductive load device is selectively provided by the main switch device and the recirculation circuit.

Aspects of the present disclosure provide measurement devices and methods for detecting electrical characteristics of devices under test (DUTs), such as semiconductor nanowires. Techniques described herein provide programmable measurement devices that may be implemented in a compact form factor while being able to perform reliable measurements. In some embodiments, measurement devices described herein may be programmed to modulate signals for transmitting to a DUT, and may demodulate signals from the DUTs adaptively using self-programming techniques described herein. Such self-programming may include applying a programmable phase delay to oscillator signals used during demodulation. In some embodiments, such measurement devices may be implemented on a single circuit board, in a single integrated circuit package, or even on a single solid-state semiconductor die. Techniques described herein may enable reliable, inexpensive, and small-scale fluid sample measurement devices.

Devices, systems, and processes for testing capacitors are disclosed. A system includes a digital signal processor configured to execute non-transient computer executable instructions for testing a device over at least three operating modes. The operating modes may include a start-up mode, during which the digital signal processor is configured to control initial charging of the device to a desired initial condition, a charge mode, during which the digital signal processor is configured to control replenishment of electrical energy in the device, and a test mode, during which the digital signal processor is configured to control testing of the device in accordance with at least one testing protocol. The device may include an energy capture circuit configured to capture recovered energy arising during a first test cycle and to provide the recovered energy to the device for use during a second test cycle.

Devices, systems, and processes for testing capacitors are disclosed. A system includes a digital signal processor configured to execute non-transient computer executable instructions for testing a device over at least three operating modes. The operating modes may include a start-up mode, during which the digital signal processor is configured to control initial charging of the device to a desired initial condition, a charge mode, during which the digital signal processor is configured to control replenishment of electrical energy in the device, and a test mode, during which the digital signal processor is configured to control testing of the device in accordance with at least one testing protocol. The device may include an energy capture circuit configured to capture recovered energy arising during a first test cycle and to provide the recovered energy to the device for use during a second test cycle.

A detection circuit includes an open circuit detection branch and a current detection branch. The open circuit detection branch includes a comparator and a digital logic branch. A positive input terminal of the comparator is connected to one end of the sampling resistor adjacent to the stimulation source, a negative input terminal of the comparator is connected to one end of the sampling resistor facing away from the stimulation source, and an output terminal of the comparator is connected to the digital logic branch. The current detection branch includes an amplifier and a first switch. A negative input terminal of the amplifier is connected to the one end of the sampling resistor facing away from the stimulation source, an output terminal of the amplifier is connected to a control terminal of the first switch.

A detection circuit includes an open circuit detection branch and a current detection branch. The open circuit detection branch includes a comparator and a digital logic branch. A positive input terminal of the comparator is connected to one end of the sampling resistor adjacent to the stimulation source, a negative input terminal of the comparator is connected to one end of the sampling resistor facing away from the stimulation source, and an output terminal of the comparator is connected to the digital logic branch. The current detection branch includes an amplifier and a first switch. A negative input terminal of the amplifier is connected to the one end of the sampling resistor facing away from the stimulation source, an output terminal of the amplifier is connected to a control terminal of the first switch.

The application provides an attenuator and a differential voltage probe, comprising a forward attenuation circuit and a reverse attenuation circuit which are symmetrical with each other, a first compensation unit and a third compensation unit which are symmetrical with each other, a second compensation unit and a fourth compensation unit which are symmetrical with each other, and a differential amplifier; the four compensation units are all adjustable capacitor units composed of constant capacitance; a positive-going signal to be tested is attenuated by the forward attenuation circuit, and frequency characteristics of a preset frequency point are adjusted by the first compensation unit and second compensation unit; a negative-going signal to be tested is attenuated by the reverse attenuation circuit, and frequency characteristics of a preset frequency point are adjusted by the third compensation unit and fourth compensation unit; finally, the difference value is calculated by the differential amplifier, amplified and output.

A current sensor automatically adjusting an offset voltage, includes an input corrector, upon receiving a first voltage, a second voltage, and a control signal, configured to correct either one or both of the first voltage and the second voltage to reduce an absolute value of a difference between the first voltage and the second voltage based on the control signal, and output a correction result; an input amplifier configured to amplify a voltage output from the input corrector; an output amplifier configured to generate an output voltage when a voltage amplified by the input amplifier is input; a controller including a switch connected to one of voltages amplified by the input amplifier to be grounded when a difference between the first voltage and the second voltage is larger than a first threshold value; and a correction circuit controller configured to generate the control signal to input to the input corrector.