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.

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.

A current sensor including a measurement circuit and an electrical conductor having at least one first measurement path defined by a first pickup contact and a second pick-up contact at which a first voltage can be detected across the first measurement path, a first connection contact for electrically contacting a connection element, a second connection contact for electrically contacting a battery pole terminal, and a current feed contact for electrically contacting a device for providing a calibration current. The first measurement path is in series between the first connection contact and the second connection contact. A calibration current supplied at the current feed contact induces a current density distribution in the first measurement path, which converges with a current density distribution in the first measurement path, induced by a load current of equal current intensity supplied at the first connection contact.

The present invention relates to a half-bridge signal processing circuit comprising a first and a second branch. The first branch comprises a first stimulus responsive sense element and a first current source arranged to provide a current to the first sense element. The second branch comprises a second stimulus responsive sense element and a second current source arranged to provide a current to said second sense element. The first and the second branch have a terminal in common. The first branch comprises a first node between said the current source and the first stimulus responsive sense element configured to generate a first signal related to a voltage over the first sense element. The second branch comprises a second node between the second current source and the second stimulus responsive sense element configured to generate a second signal related to a voltage over the second sense element.

A detection device includes a light refraction structure and a resistance detection circuit. The light refraction structure includes a substrate, a conductive layer, and a refraction layer. The conductive layer and the refraction layer are formed on the substrate. The conductive layer includes a resistance. The resistance detection circuit is electrically coupled to the conductive layer and is adapted to detect the resistance of the conductive layer. The resistance detection circuit generates a detection signal according to a change in the resistance, and the detection signal represents a state of the refraction layer.

Disclosed is a measuring bridge arrangement containing: a measuring bridge comprising at least one first half bridge having a first measuring connection and a second half bridge having a second measuring connection; a reference voltage divider having at least one first and a second test connection; a differential amplifier having at least one first and a second amplifier input and at least one amplifier output, a voltage amplification, and having an output voltage working range. In the arrangement, the first amplifier input is wired to a first capacitor and the second amplifier input is wired to a second capacitor, and the amplifier inputs can be selectively connected to the measuring connections or to the test connections.

A connection quality system can include a resistance test module, a first line connected to the resistance test module and configured to connect to a wire connection assembly past one or more physical connections of the wire connection assembly, and a second line connected to the resistance test module and configured to connect to the wire connection assembly directly or indirectly on an opposite side of the one or more physical connections of the wire connection assembly such that the first line and the second line are in electrical communication through the wire connection assembly. The resistance test module can be configured to determine if the one or more physical connections are degraded or broken based on a resistance of the wire connection assembly.

A Wheatstone bridge array comprising a tunneling magnetoresistive (TMR) sensor and a method for manufacturing is disclosed. The bottom lead for the TMR sensor has a very small surface roughness due to not only chemical mechanical planarization (CMP) but also due to forming the bottom lead from multiple layers. The multiple layers include at least a bottom first metal layer and a top second metal layer disposed on the first metal layer. The second metal layer generally has a lower surface roughness than the first metal layer. Additionally, the second metal layer has a slower polishing rate. Therefore, not only does the second metal layer reduce the surface roughness simply be being present, but the slower polishing rate enables the top second metal film to be polished to a very fine surface roughness of less than or equal to 2 Angstroms.

The present disclosure generally relates to a Wheatstone bridge array comprising TMR sensors and a method of fabrication thereof. In the Wheatstone bridge array, there are four distinct TMR sensors. The TMR sensors are all fabricated simultaneously to create four identical TMR sensors that have synthetic antiferromagnetic free layers as the top layer. The synthetic antiferromagnetic free layers comprise a first magnetic layer, a spacer layer, and a second magnetic layer. After forming the four identical TMR sensors, the spacer layer and the second magnetic layer are removed from two TMR sensors. Following the removal of the spacer layer and the second magnetic layer, a new magnetic layer is formed on the now exposed first magnetic layer such that the new magnetic layer has substantially the same thickness as the spacer layer and second magnetic layer combined.

The present disclosure generally relates to a Wheatstone bridge that includes a plurality of resistors comprising dual free layer (DFL) TMR structures. The DFL TMR structures include one or more hard bias structures on the side of DLF. Additionally, one or more soft bias structures may also be present on a side of the DFL. Two resistors will have identical hard bias material while two other resistors will have hard bias material that is identical to each other, yet different when compared to the first two resistors. The hard bias materials will provide opposite magnetizations that will provide opposite bias fields that result in two different magnetoresistance responses for the DFL TMR.