Abstract: An apparatus comprises a differential amplifier circuit and a current source. The differential amplifier circuit is configured to receive a voltage at an input, wherein the differential amplifier circuit generates an output voltage having a magnitude proportional to the received voltage over a voltage range to be measured at a specified output common mode voltage. The current source is electrically connected to an input of the differential amplifier circuit and is configured to subtract a midpoint of a voltage range of the battery voltage to be measured at the input of the differential amplifier, wherein a circuit supply voltage provided to the differential amplifier circuit and the current source is less than the voltage at the input.

Abstract: This document discusses, among other things, systems and methods to at least partially compensate for temperature sensitivity in a digital microphone system including, for example, a temperature sensitive membrane, such as an electrets condenser microphone (ECM).

Abstract: An apparatus comprises a differential amplifier circuit and a current source. The differential amplifier circuit is configured to receive a voltage at an input, wherein the differential amplifier circuit generates an output voltage having a magnitude proportional to the received voltage over a voltage range to be measured at a specified output common mode voltage. The current source is electrically connected to an input of the differential amplifier circuit and is configured to subtract a midpoint of a voltage range of the battery voltage to be measured at the input of the differential amplifier, wherein a circuit supply voltage provided to the differential amplifier circuit and the current source is less than the voltage at the input.

Abstract: This document discusses, among other things, an amplifier circuit including first and second amplifiers configured to receive an input signal and to provide a differential output signal using a feedback loop including a transconductance amplifier. A non-inverting input of a first amplifier can be configured to receive an input signal. The feedback loop can be configured to receive the outputs from the first and second amplifiers and to provide a feedback signal to the non-inverting input of the second amplifier, for example, to reduce a DC offset error or to increase a dynamic range of the amplifier circuit.

Abstract: This document discusses, among other things, apparatus and methods for controlling a hysteresis range of a voltage comparator. In an example, an apparatus can include an amplifier having a temperature dependency, a comparator configured to receive first and second currents and to provide an output voltage indicative of a hysteretic comparison of the first and second input voltages, wherein a range of hysteresis of the apparatus is controlled over a range of temperatures. In an example, the amplifier can be configured to receive first and second input voltages and to provide the first and second currents.

Abstract: Apparatus and methods for an integrated circuit, high-impedance network are provided. In an example, the network can include an anti-parallel diode pair coupled between first and second nodes. The anti-parallel diode pair can include a first diode including a P+/NWELL junction and a second diode including N+/PWELL junction. In an example, the first diode and the second diode can include a common substrate.

Abstract: This document discusses, among other things, systems and methods to at least partially compensate for temperature sensitivity in a digital microphone system including, for example, a temperature sensitive membrane, such as an electrets condenser microphone (ECM).

Abstract: Apparatus and methods for an integrated circuit, single ended-to-differential amplifier are provided. In an example, the amplifier can include an amplifier circuit having a first input configured to receive a single-ended signal, a second input, and a differential output configured to provide an amplified representation of the single-ended signal. The amplifier can include a filter circuit configured to balance a common-mode voltage between the first and second inputs of the amplifier circuit. The filter circuit can include a common-mode input configured to receive the common-mode voltage, a first impedance network coupled between the common-mode input and the first input of the amplifier circuit, and a second impedance network coupled between the common-mode input and the second input of the amplifier circuit. The filter circuit can provide a low frequency pole below 1 hertz.

Abstract: This document discusses, among other things, an amplifier circuit including first and second amplifiers configured to receive an input signal and to provide a differential output signal using a feedback loop including a transconductance amplifier. A non-inverting input of a first amplifier can be configured to receive an input signal. The feedback loop can be configured to receive the outputs from the first and second amplifiers and to provide a feedback signal to the non-inverting input of the second amplifier, for example, to reduce a DC offset error or to increase a dynamic range of the amplifier circuit.

Abstract: This document discusses, among other things, apparatus and methods for controlling a hysteresis range of a voltage comparator. In an example, an apparatus can include an amplifier having a temperature dependency, a comparator configured to receive first and second currents and to provide an output voltage indicative of a hysteretic comparison of the first and second input voltages, wherein a range of hysteresis of the apparatus is controlled over a range of temperatures. In an example, the amplifier can be configured to receive first and second input voltages and to provide the first and second currents.

Abstract: Apparatus and methods for an integrated circuit, single ended-to-differential amplifier are provided. In an example, the amplifier can include an amplifier circuit having a first input configured to receive a single-ended signal, a second input, and a differential output configured to provide an amplified representation of the single-ended signal. The amplifier can include a filter circuit configured to balance a common-mode voltage between the first and second inputs of the amplifier circuit. The filter circuit can include a common-mode input configured to receive the common-mode voltage, a first impedance network coupled between the common-mode input and the first input of the amplifier circuit, and a second impedance network coupled between the common-mode input and the second input of the amplifier circuit. The filter circuit can provide a low frequency pole below 1 hertz.

Abstract: Apparatus and methods for an integrated circuit, high-impedance network are provided. In an example, the network can include an anti-parallel diode pair coupled between first and second nodes. The anti-parallel diode pair can include a first diode including a P+/NWELL junction and a second diode including N+/PWELL junction. In an example, the first diode and the second diode can include a common substrate.