A method is provided for operating a radio frequency (RF) receiver including a transimpedance amplifier, a capacitor selectively connected in parallel with the transimpedance amplifier, a channel selection filter unit connected to an output terminal of the transimpedance amplifier, and a variable gain amplification unit selectively connected in parallel with the channel selection filter unit. The method includes measuring signal-to-noise ratio from an output of the RF receiver, and comparing the measured signal-to-noise ratio with a reference signal-to-noise ratio. When the measured signal-to-noise ratio is greater than the reference signal-to-noise ratio, the capacitor is electrically disconnected from being connected in parallel with the transimpedance amplifier and a variation in the measured signal-to-noise ratio is measured. When the measured variation is in tolerance, the channel selection filter is bypassed to select the variable gain amplification unit.

Provided herein are apparatus and methods for a multi-stage signal-processing circuit. The signal-processing circuit can include multiple configurable stages that can be cascaded and configured to process an input signal. Control circuitry can be used to select an output of the configurable stages. Serial data can be recovered with good signal integrity using a signal monitor with the configurable stages by virtually placing the signal monitor on a buffered output node.

A method is provided for operating a radio frequency (RF) receiver including a transimpedance amplifier, a capacitor selectively connected in parallel with the transimpedance amplifier, a channel selection filter unit connected to an output terminal of the transimpedance amplifier, and a variable gain amplification unit selectively connected in parallel with the channel selection filter unit. The method includes measuring signal-to-noise ratio from an output of the RF receiver, and comparing the measured signal-to-noise ratio with a reference signal-to-noise ratio. When the measured signal-to-noise ratio is greater than the reference signal-to-noise ratio, the capacitor is electrically disconnected from being connected in parallel with the transimpedance amplifier and a variation in the measured signal-to-noise ratio is measured. When the measured variation is in tolerance, the channel selection filter is bypassed to select the variable gain amplification unit.

An audio amplifier, including: at least a two stage amplifier configured to receive an input signal and output an amplified output signal, the at least a two stage amplifier including at least one stage amplifier and an output stage amplifier; and an auxiliary stage amplifier having an input coupled to an output of the at least one stage amplifier and an input of the output stage amplifier.

In some aspects, a programmable amplifier may comprise an n-channel metal-oxide-semiconductor (NMOS) amplification path and a complementary metal-oxide-semiconductor (CMOS) amplification path. In some aspects, the NMOS amplification path may include a first NMOS transistor and a second NMOS transistor that are connected in parallel between an input and an output. In some aspects, the CMOS amplification path may include a p-channel metal-oxide-semiconductor (PMOS) transistor connected in parallel with the first NMOS transistor between the input and the output. In some aspects, the programmable amplifier may further comprise a plurality of switches that are programmable to switch the PMOS transistor off in a first mode, such as an NMOS mode or a high linearity mode, and to switch the second NMOS transistor off in a second mode, such as a CMOS mode or a low current mode. Numerous other aspects are described.

An analog front-end architecture for a capacitive pressure sensor with a low-noise amplifier unit for amplification of sensor signals from the sensor. The amplifier unit includes first and second integrator units for integrating charges injected into input terminals of the amplifier unit and for outputting integrated charges to output terminals of the amplifier unit, a feedback unit, and a startup unit. The feedback unit reinjects integrated charges from the integrator unit into the input terminals of the amplifier unit. The startup unit is switchable between first and second switching states and is configured, in the first switching state, to route the charges injected into the input terminals past the first integrator unit into the second integrator unit and from the second integrator unit into the feedback unit, and, in the second switching state, to route charges injected into the input terminals directly into the first integrator unit.

A method for calibrating a fully-differential input system may include determining a first voltage of a first node of the fully-differential input system, wherein the first node is coupled at the first node to a plurality of first resistors in a first star configuration, determining a second voltage of a second node of the fully-differential input system, wherein the second node is coupled at the second node to a plurality of second resistors in a second star configuration, each resistor of the plurality of second resistors corresponding to a respective resistor of the plurality of first resistors, and trimming individual resistances of the plurality of first resistors and the plurality of second resistors in order to maintain a difference of a first voltage at the first node and a second voltage of the second node at approximately zero.