An embodiment voltage-current converter circuit comprises a first amplifier and a second amplifier having homologous first input nodes configured to receive a voltage signal therebetween as well as homologous second input nodes having a resistor coupled therebetween. First and second current mirror circuits are provided comprising first input transistors having their control terminal coupled to the output nodes of the amplifiers. First and second current sensing circuitry having first and second current output nodes are coupled to the current mirror output nodes of the current mirror circuits and configured to provide therebetween a current which is a function of the voltage signal between the homologous first input nodes of the amplifier.

An active electrode has an electrode for sensing an electric potential and generating an input signal, and a shield placed near the electrode but being electric insulated from the electrode. An integrated amplifier (10) has an input connected to the at least one electrode for receiving the input signal, and providing a buffered path outputting a buffered output signal. The shield being connected to the output of the integrated amplifier to actively drive the electrical potential of the shield, thereby providing an active shielding of the electrode. The buffered path includes a first mixer (11) in front of the integrated amplifier for frequency shifting the input signal from a basic frequency range to a higher frequency range, and a second mixer (12) on the output of the integrated amplifier for frequency shifting the amplified signal from the higher frequency range back to the basic frequency range. The active electrode may be used for recording EEG signals.

A readout circuit has a first transistor which have a first terminal, a second terminal, and a control terminal, a second transistor having a first terminal, a second terminal, and a control terminal, a first variable resistance having a first terminal connected to a first reference voltage line, and a second terminal connected to the first terminal of the first transistor, a first resistance having a first terminal connected to the first reference voltage line, and a second terminal connected to the first terminal of the second transistor, a second resistance having a first terminal connected to the second terminal of the first transistor, and a second terminal connected to a second reference voltage line, and a second variable resistance which has a first terminal connected to the second terminal of the second transistor, and a second terminal connected to the second reference voltage line.

A high CMRR neural signal amplifier is configured for supply rail common mode feedback (SR-CMFB) whereby a set of CMFB signals is provided to supply rails of front end LNAs. High CMRR is maintained through buffering outputs of front end signal LNAs and a reference LNA coupled to signal and reference inputs of second stage amplifiers, respectively; and buffering the reference LNA output using an active/guard buffer pair, whereby across a plurality of distinct multiplexing time intervals, during each multiplexing time interval one buffer of the pair functions as an active buffer that drives second stage amplifier reference inputs corresponding to second stage amplifier outputs being multiplexed to a set of multiplexor outputs, and the other buffer of the pair functions as a guard buffer coupled to other second stage amplifier reference inputs corresponding to second stage amplifier outputs not being multiplexed to the set of multiplexor outputs.

An electronic control apparatus that controls actuation of an inductive load includes: a current detector that detect current flowing through the inductive load and outputs a current detection signal in an analog signal; an analog-digital converter that takes in the current detection signal at a fetch timing, and converts the current detection signal into a current detection value; and a controller that calculates a current arithmetic value by executing arithmetic processing for the current detection value, and controls the current based on the current arithmetic value. The controller obtains a sample data value of the current arithmetic value for each of a plurality of fetch timings. The controller calculates a deflection between an ideal value of the current arithmetic value and the sample data value of the current arithmetic value, and learns the fetch timing, causing the deflection with the ideal value of the current arithmetic value to be minimized.

In one implementation, a circuit can include a reference pin and an operational amplifier that can include an output pin, an inverting input pin and a non-inverting input pin. The inverting input pin can be electrically coupled to the output pin via a first impedance and to the reference pin via a second impedance. The non-inverting input pin can be electrically coupled to the reference pin via a third impedance and can be configured to receive a detection signal. The reference pin can be configured to receive a detection reference signal associated with the detection signal.

A high dynamic range sensing front-end for bio-signal recording systems in accordance with embodiments of the invention are disclosed. In one embodiment, a bio-signal amplifier includes an input signal, where the input signal is modulated to a predetermined chopping frequency, a first amplifier stage, a parallel-RC circuit connected to the first amplifier stage and configured to generate a parallel-RC circuit output by selectively blocking an offset current, a second amplifier stage connected to the parallel-RC circuit that includes a second input configured to receive the parallel-RC circuit output and generate a second output that is an amplified version of the input signal with ripple-rejection. Further, the bio-signal amplifier can also include an auxiliary path configured for boosting input impedance by pre-charging at least one input capacitor. In addition, the bio-signal amplifier can also include a DC-servo feedback loop that includes an integrator that utilizes a duty-cycled resistor.

An ultrasound probe buffer is provided. The ultrasound probe buffer may include a high impedance amplifier having a common-source core stage with series-series local feedback. The high impedance amplifier may include a first MOSFET and a second MOSFET, wherein a source terminal of the first MOSFET is coupled to a source terminal of the second MOSFET.

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.

A detection device includes a driving circuit which drives a vibrator, and a detection circuit which detects a desired signal. The driving circuit includes a current-voltage conversion circuit which receives a feedback signal, and performs a current-voltage conversion, a drive signal output circuit which amplifies an input voltage signal after being subjected to the current-voltage conversion, and outputs a drive signal of a sine wave, and a gain control circuit which controls a gain of amplification of the drive signal in the drive signal output circuit. When a resistance for a current-voltage conversion is set to RI, the gain of the amplification of the drive signal in the drive signal output circuit is set to K, and an equivalent series resistance in a fundamental wave mode of the vibrator is set to R, the gain control circuit performs a gain control such that K×RI=R is satisfied.