A system for determining electrical characteristics of an electric load can comprise a signal modulation circuit that can include a first integral controller configured to control AC reference voltage based on a requested maximum AC current and an estimated maximum AC current, a second integral controller configured to control DC reference voltage based on a requested DC current and an estimated DC current, a signal demodulation circuit including an AC current estimation circuit configured to generate the estimated maximum AC current for the signal modulation circuit, a DC current estimation circuit configured to generate the estimated DC current for the signal modulation circuit, and a resistance and inductance (RL) estimation circuit configured to determine inductance of the electric load based on the estimated maximum AC current and phase shift, wherein the estimated maximum AC current is a value lower than a DC offset current value.

An electric circuit according to an embodiment of the present disclosure includes only a single amperemeter configured to measure either a positive current or a negative current through a respective measurement resistance between a respective high voltage potential and a common ground potential. The respective actual measurement resistance value of the unmeasured measurement resistance is calculated by applying a respectively calculated actual measurement resistance value of the respective measured measurement resistance, a calculated actual positive isolation resistance value, and a calculated negative isolation resistance value.

An electric circuit according to an embodiment of the present disclosure includes only a single amperemeter configured to measure either a positive current or a negative current through a respective measurement resistance between a respective high voltage potential and a common ground potential. The respective actual measurement resistance value of the unmeasured measurement resistance is calculated by applying a respectively calculated actual measurement resistance value of the respective measured measurement resistance, a calculated actual positive isolation resistance value, and a calculated negative isolation resistance value.

The invention provides a semiconductor testkey pattern, the semiconductor testkey pattern includes a high density device region and a plurality of resistor pairs surrounding the high density device region, wherein each resistor pair includes two mutually symmetrical resistor patterns.

A signal measurement apparatus and signal measurement method are provided. The measurement apparatus includes a compensation signal generating circuit configured to generate a target compensation signal that reduces a carrier frequency component in a voltage signal that is input into an amplifier based on an output signal of the amplifier, and the amplifier amplifies the voltage signal to which the target compensation signal is applied, wherein the compensation signal generating circuit is configured to determine a signal value of a subsequent compensation signal based on a signal value of the output signal of the amplifier amplified by applying a previous compensation signal, when determining the target compensation signal.

Disclosed are a high-precision resistance measurement system and method combining a micro-differential method and a ratiometric method. The system includes a constant-current source, a reference resistor, a first differential amplifier, a programmable gain amplifier (PGA), an ADC, a microprocessor, a DAC and a to-be-measured resistor interface. The reference resistor and a to-be-measured resistor are connected in series between the constant-current source and ground. The voltage across the reference resistor is inputted to the first differential amplifier, and the output of the first differential amplifier is used as the reference voltage for the ADC and the DAC. The single-ended voltage to ground of the to-be-measured resistor and the output voltage of the DAC are inputted to the PGA in differential manner, and the PGA outputs the amplified difference voltage to the ADC. The output terminal of the ADC and the input terminal of the DAC are both connected to the microprocessor.

A method for monitoring a cable harness. In the method, at least one value of at least one electrical variable in the cable harness is acquired and at least one signal, which represents this at least one value, is transmitted to at least one evaluator. A number of containers, which in turn represent a value range for the allocated electrical variable in each case, is allocated to each evaluator. The at least one signal is evaluated in such a way that the acquired values are allocated to the containers while taking the respective value range into account. The values allocated to the container are counted in each container. If a threshold value allocated to the container is exceeded, an action is triggered.

In a circuit arrangement for determining a resistance change, a measuring resistor can be connected by first and second supply leads and first and second sensor leads in a four-wire arrangement, such that the first supply lead and the measuring resistor form a first resistor of a first voltage divider, and the second supply lead and a supplementary resistor form a second resistor of the first voltage divider. The circuit arrangement has a second voltage divider with third and fourth resistors. The first and second voltage dividers form a Wheatstone bridge. The circuit arrangement is configured to apply a supply voltage across the Wheatstone bridge, to determine first and second supply voltage drops across the first and second supply leads, and to determine an ascertainment voltage in proportion to a reference voltage. The ascertainment voltage depends on a bridge voltage applied between the first and second voltage dividers.

In a circuit arrangement for determining a resistance change, a measuring resistor can be connected by first and second supply leads and first and second sensor leads in a four-wire arrangement, such that the first supply lead and the measuring resistor form a first resistor of a first voltage divider, and the second supply lead and a supplementary resistor form a second resistor of the first voltage divider. The circuit arrangement has a second voltage divider with third and fourth resistors. The first and second voltage dividers form a Wheatstone bridge. The circuit arrangement is configured to apply a supply voltage across the Wheatstone bridge, to determine first and second supply voltage drops across the first and second supply leads, and to determine an ascertainment voltage in proportion to a reference voltage. The ascertainment voltage depends on a bridge voltage applied between the first and second voltage dividers.

The present invention discloses an AC impedance measurement circuit with a calibration function, which is characterized in that only one calibration impedance is needed, associated with a switch circuit. Based on the measurement results of the two calibration modes, an equivalent impedance of the switch circuit, circuit gain and phase offset can be calculated. Based on the above results, the equivalent impedance of the internal circuit is deducted from the measurement result of the measurement mode to accurately calculate an AC conductance and a phase of the AC conductance for impedance to be measured. In addition, by adjusting a phase difference between an input sine wave signal and a sampling clock signal, impedance of the same phase and impedance of the quadrature phase can be obtained, respectively, and the AC impedance and phase angle of the impedance to be measured can be calculated.