A digital-to-analog converter (DAC) circuit includes a pair of output stages, each including a DAC configured to convert a digital audio signal into an analog audio signal. A low-pass filter circuit includes an operational amplifier in signal communication with the DAC. The operation amplifier generates a filtered analog signal based on the analog audio signal. An amplifier network generates an amplified audio signal based on the filtered analog signal. The operational amplifier includes a feedback circuit path including a first node connected to the output of the amplifier network and a second node connected to the input of the operational amplifier. The amplifier network is electrically nested in the feedback circuit path.

A device includes a sensor signal input node and a high-pass filter stage. The high-pass filter stage includes an operational amplifier and a feedback integrator. The operational amplifier includes an input node coupled to the sensor signal input node. The feedback integrator is coupled between an output node of the operational amplifier and the input node of the operational amplifier to set a high-pass pole frequency of the high-pass filter stage.

Numerous embodiments of analog neural memory arrays are disclosed. In one embodiment, a system comprises a first array of non-volatile memory cells, wherein the cells are arranged in rows and columns and the non-volatile memory cells in one or more of the columns stores W+ values, and wherein one of the columns in the first array is a dummy column; and a second array of non-volatile memory cells, wherein the cells are arranged in rows and columns and the non-volatile memory cells in one or more of the columns stores W− values, and wherein one of the columns in the second array is a dummy column; wherein pairs of cells from the first array and the second array store a differential weight, W, according to the formula W=(W+)−(W−).

A system for a differential trans-impedance amplifier circuit comprising: an amplifier having a pair of input nodes and configured to generate an amplified replica of a differential voltage on said pair of input nodes; a photodiode; a pair of DC-blocking capacitors coupling said photodiode to said pair of input nodes; at least one resistance coupled between said pair of input nodes of said amplifier; and a bias network comprising two identical photodiode biasing resistances each photodiode biasing resistance coupled in series between said photodiode and a respective DC voltage. A feedback loop for the amplifier may include source followers that are operable to level shift voltages prior to coupling capacitors that couple said photodiode to said amplifier to ensure stable bias conditions for said amplifier. The source followers may include CMOS transistors. The amplifier may be integrated in a complementary metal-oxide semiconductor (CMOS) chip, which may include a CMOS photonics chip.

The present invention discloses a programmable gain amplifier having mode-switching mechanism. An operational amplifier includes a first input terminal, a second input terminal and an output terminal. The second input terminal is coupled to a ground terminal. The output terminal generates an output signal. A variable resistor and a first switch are coupled in series between a first terminal and a second terminal that coupled to the first input terminal. A first variable capacitor and a second switch are coupled in series between the first terminal and the second terminal. A second variable capacitor and a third switch are coupled in series between the first terminal and the ground terminal. A low-pass resistor and a low-pass capacitor are coupled in parallel between the first input terminal and the output terminal. An input resistor is coupled between a signal input terminal and the first terminal to receive an input signal from the signal input terminal. The first, the second and the third switches receive a set of mode-switching signals to switch to form a path or an open-circuit.

A program gain amplifier includes an operational amplifier and a capacitor array. The capacitor array includes a first, second, and third capacitors selectively coupled to the operational amplifier or ground according to a first, second, and third switches, respectively. The first, second, and third capacitors have a first, second, and third capacitance, respectively. The third capacitance equals a sum of the first and second capacitance. In a first configuration, the first and second switches are operated at a first conductive state, and the third switch is operated at a second conductive state. When converting to a second configuration from the first configuration, the third switch is operated at the first conductive state, and the first and second switches are operated at the second conductive state. The gain being provided to an input signal in the first and second configurations are the same.

Equalizer circuitry includes a differential target voltage input, an equalizer output, a first operational amplifier, and a second operational amplifier. The differential target voltage input includes a target voltage input node and an inverted target voltage input node. The first operational amplifier and the second operational amplifier are coupled in series between the differential target voltage input and the equalizer output. The first operational amplifier is configured to receive a target voltage signal and provide an intermediate signal based on the target voltage input signal. The second operational amplifier is configured to receive the intermediate signal and an inverted target voltage signal and provide an output signal to the equalizer output. The first operational amplifier and the second operational amplifier are interconnected with one or more passive components such that a transfer function between the differential target voltage input and the equalizer output is a second-order complex-zero function.

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.

There may be provided detection circuit that may include (i) a photodiode that may be configured to convert radiation to a photodiode electrical signal; (ii) a photodiode bias circuit that may be configured to bias the photodiode, wherein the photodiode bias circuit may include a photodiode bias voltage supply and a photodiode bias capacitor; and (iii) a differential transimpedance amplifier that may be configured to amplify the photodiode electrical signal to provide a differential voltage. The differential transimpedance amplifier may include an amplification circuit and an additional circuit, wherein the amplification circuit may include a positive input port, a negative input port, a positive output port, a negative output port and a common mode input port. The photodiode bias voltage supply may be a floating voltage supply.