Methods and systems for aligning amplification gains in a plurality of interconnected devices are disclosed. The method includes receiving by each device limiter gain attenuations and brownout gain attenuations broadcasted by the plurality of devices and selecting the maximum brownout gain attenuation and the maximum limiter gain attenuation. The method includes determining a total attenuation as a sum of the maximum brownout attenuation gain and the maximum limiter attenuation gain. The method includes receiving a frame synchronization signal and adjusting the amplification gain by applying the total attenuation responsive to the frame synchronization signal.

A transmission unit includes a first transistor that amplifies power of a first signal and outputs a second signal, a power supply circuit that supplies to the first transistor a power supply voltage that changes in accordance with an amplitude level of the first signal, and an attenuator that attenuates the first signal in such a manner that an amount of attenuation of the first signal increases with a decrease in the power supply voltage when the power supply voltage is less than a first level.

A power output circuit supplies an audio power output signal that is adjusted to prevent clipping when needed based on an estimate of available energy from the power supply supplying the power output circuit. The power output circuit may be an audio power output circuit that generates an audio power output signal from samples of an audio program that are stored in a buffer. A processing block determines an energy requirement for producing the audio power output signal from the audio program and adjusts an amplitude of the audio power output signal in conformity with the determined energy requirement and an available energy determined for the power supply so that the audio power output signal is reproduced without clipping of the audio power output signal.

An amplifier unit for operating a piezoelectric loudspeaker or microphone includes an audio amplifier and a detection unit, which is configured to detect whether a sound transducer coupled to the amplifier unit is a piezoelectric sound transducer or a dynamic sound transducer. The amplifier unit is configured in such a way that, after a sound transducer has been coupled, the amplifier unit sends a test signal to the coupled sound transducer. Moreover, a sound-generation unit includes a sound transducer and an amplifier unit, which amplifies an audio signal and feeds it to the sound transducer.

A signal receiving circuit includes a first amplifier, a switch circuit, a second amplifier and a mixer. The first amplifier is configured to amplify a radio frequency (RF) signal to generate a first amplified RF signal. The switch circuit is configured to receive the first amplified RF signal. The second amplifier is configured to receive and amplify the first amplified RF signal to generate a second amplified RF signal. The mixer is configured to modulate one of the first amplified RF signal and the second amplified RF signal to generate a mixed signal, wherein the switch circuit is configured to determine whether the first amplified RF signal is amplified by the second amplifier.

A signal receiving circuit includes a first amplifier, a switch circuit, a second amplifier and a mixer. The first amplifier is configured to amplify a radio frequency (RF) signal to generate a first amplified RF signal. The switch circuit is configured to receive the first amplified RF signal. The second amplifier is configured to receive and amplify the first amplified RF signal to generate a second amplified RF signal. The mixer is configured to modulate one of the first amplified RF signal and the second amplified RF signal to generate a mixed signal, wherein the switch circuit is configured to determine whether the first amplified RF signal is amplified by the second amplifier.

An instrumentation amplifier configured for providing high common mode rejection is described and includes an input differential stage configured to receive a differential input voltage and a folded cascode amplifying stage configured to receive output current mode signals provided from the input differential pair. A plurality of feedback networks is provided to improve the input stage. The amplifier may operate to provide an enhanced common mode rejection ratio of a single gain block in the instrumentation amplifier. In some examples, the circuitry may have a differential folded cascode amplifying stage which permits high precision and low distortion of amplified signals without degrading the common mode rejection ratio.

A power converter may include an input for receiving an input signal and output for generating an intermediate signal that is a power converted signal from the input signal wherein the intermediate signal is determined based on various parameters of a signal path that utilizes the intermediate signal, wherein the various parameters comprise one or more of the following: a peak output signal of the signal path, energy requested over a period of time by the signal path, available energy from an energy source to the power converter, stored energy at an output of the power converter, and stored energy of a battery for providing electrical energy at the input.

Biasing circuitry for RF and microwave integrated circuits keeps the quiescent current of a power amplifier integrated circuit constant when operated with a time-varying DC supply voltage. A dynamic gate bias circuit includes an on-chip sense transistor and control circuitry to keep current of the sense transistor substantially constant by varying sense transistor bias voltage to compensate for variation in the time-varying supply voltage signal. The varying bias voltage is then applied to the amplifying transistors of the power amplifier, resulting in their quiescent current being substantially independent of the time-varying supply voltage.

Described herein are systems and methods that can adjust the performance of a transimpedance amplifier (TIA) in order to compensate for changing environmental and/or manufacturing conditions. In some embodiments, the changing environmental and/or manufacturing conditions may cause a reduction in beta of a bipolar junction transistor (BJT) in the TIA. A low beta may result in a high base current for the BJT causing the output voltage of the TIA to be formatted as an unusable signal output. To compensate for the low beta, the TIA generates an intermediate signal voltage, based on the base current and beta that is compared with the PN junction bias voltage on another BJT. Based on the comparison, the state of a digital state machine may be incremented, and a threshold base current is determined. This threshold base current may decide whether to compensate the operation of the TIA, or discard the chip.