The present disclosure relates to a magnetic field sensor circuit including at least one coil for measuring a magnetic field, a first stage amplifier circuit coupled to the coil and having a first transfer function with a pole at a first frequency, and a second stage amplifier circuit coupled to an output of the first stage amplifier circuit and having a second transfer function with a zero at the first frequency. In some embodiments, a temperature dependent frequency drift of the pole of the first transfer function corresponds to a temperature dependent frequency drift of the zero of the second transfer function.

In at least one embodiment, a differential amplifier including first and second current transfer systems, a current difference producing system, and a feedback network circuit is provided. The first current transfer system generates a first differential current signal. The second current transfer system generates a second differential current signal. The current difference producing system receives the first differential current signal and the second differential current signal and generates a voltage difference signal that is indicative of a difference between a first current signal and a second current signal. The feedback network circuit converts the voltage difference signal into at least two converted current signals and provides the at least two converted current signals to one of the first and second current transfer systems or the current difference producing system to minimize the difference between the first current signal and the second current signal.

Control device for aerosol inhalation device, includes operational amplifier including output terminal configured to generate voltage according to voltage applied to load configured to heat aerosol source and having correlation between temperature and electrical resistance value, control unit including input terminal and configured to perform processing based on voltage applied to the input terminal, and voltage dividing circuit configured to electrically connect the output terminal of the operational amplifier and the input terminal of the control unit. Power supply voltage of the operational amplifier is higher than power supply voltage of the control unit, and equals voltage applied to aerosol generation circuit including the load, and one of inverting input terminal and noninverting input terminal of the operational amplifier is electrically connected to the aerosol generation circuit.

A current source circuit can include a first amplifier circuit and a second amplifier circuit. Each of the first and second amplifier circuits can be configured to generate respective amplifier output voltages based on a corresponding input voltage and respective feedback voltage. The current source circuit can further include a cross-coupling circuit that can include a first set of resistors and a second set of resistors. The first set of resistors can be configured to establish a first cross-coupling voltage based on the first amplifier output voltage and the second set of resistors can be configured to establish a second cross-coupling voltage based on the second amplifier output voltage. The first and second amplifier circuits can be configured to maintain the first and second cross-coupling voltage at a given voltage amplitude to provide a constant current at an output node of the current source circuit.

A detecting device includes a pyroelectric element that generates charge by a pyroelectric effect in a first detection terminal and a second detection terminal, a chopper amplifier circuit that generates an amplified signal in response to the charge generated in the first detection terminal and the second detection terminal by chopping, and an initialization switch that controls electrical connection between the second detection terminal and a power source for generating an initialized voltage, and the initialization switch is turned on before a start of an amplification operation by the amplifier circuit and is off during the amplification operation.

A wide dynamic range trans-impedance amplifier includes a first trans-impedance amplifier configured to receive a first input current and produce a first voltage as a function of the first input current, and a second trans-impedance amplifier configured to receive a second input current and produce a second voltage as a function of the second input current. A current steering element causes a first portion of current from a current source to flow to the first trans-impedance amplifier until the first current portion reaches the first threshold current, and causes a second portion of current from the current source to flow to the second trans-impedance amplifier, until the second current portion reaches the second threshold current. The second current portion is current from the current source that exceeds the first threshold current. The wide dynamic range trans-impedance amplifier may receive, for example, ion collector current from a hot cathode ionization gauge (HCIG).

One embodiment provides an analog front-end circuit. When a chopping signal has a first logical value, a non-inverting instrumentation preamplifier subtracts a second input voltage from a first input voltage and generates a first output voltage by amplifying a subtraction voltage while outputting the second input voltage as a second output voltage. When the chopping signal has a second logical value, the non-inverting instrumentation preamplifier subtracts the first input voltage from the second input voltage and generates the first output voltage by amplifying and then inverting the polarity of a subtraction voltage while outputting the second input voltage as the second output voltage.

A FBDDA amplifier comprising: a first differential input stage, which receives an input voltage; a second differential input stage, which receives a common-mode voltage; a first resistive-degeneration group coupled to the first differential input; a second resistive-degeneration group coupled to the second differential input; a differential output stage, generating an output voltage; a first switch coupled in parallel to the first resistive-degeneration group; and a second switch coupled in parallel to the second resistive-degeneration group. The first and second switches are driven into the closed state when the voltage input assumes a first value such that said first input stage operates in the linear region, and are driven into the open state when the voltage input assumes a second value, higher than the first value, such that the first input stage operates in a non-linear region.

The present disclose generally relates to a multichannel low-noise amplifier. At each input to the multichannel low-noise amplifiers, a plurality of transistors can be connected in parallel. This parallel connection decreases the voltage noise beyond what is possible using a single input transistor at each input. As an additional benefit, the initial operating region of the input transistors is not changed. The multichannel low-noise amplifier can be incorporated on a single integrated circuit chip to amplify biological signals to facilitate selective recording of a property (e.g., amplifying neural signals to facilitate selective recording of neural activity).

The present invention provides automatic zeroing and electronic level adjustment of pressure transducer in relation to patient, applied to vital signs monitors, where the automatic zeroing of circuit of pressure consists of circuit and software able to remove the value of the virtual ground voltage from the pressure calculation, and the electronic level adjustment of transducer in relation to patient consists of compensating, through software, the value in mmHg related to level difference in cmH.sub.2O informed by the user by means of monitor interface.