A package for a current sense circuit may include a lead-frame having a shunt resistance configured to generate a shunt voltage, which can be used to measure a current through the lead-frame. The shunt resistance associated with the lead-frame may be highly variable with temperature, which can cause errors in the current measurement. Accordingly, a current sense circuit can include an amplifier with an input resistor having a composite temperature coefficient configured to match a lead-frame temperature coefficient so that an output of the amplifier is compensated to remove variations in the shunt resistance of the lead-frame due to temperature.

Example embodiments provide a process that includes one or more of receiving an audio signal at a feedback compressor circuit, multiplying the received audio signal with a power feedback signal to create a product audio signal, wherein the feedback signal comprises a low-pass filtered signal, applying a power amplifier to the product audio signal, and providing the amplified product audio signal as an output signal to a speaker.

Methods and apparatuses for signal attenuation is described. In an example, an attenuator can be configured to perform attenuation of signals for an integrated circuit. The attenuator can vary the attenuation with an ambient temperature. The attenuator can further adjust the attenuation based on a control signal applied to the attenuator. The control signal can be based on one or more of a temperature profile of the attenuator and a target gain variation of the integrated circuit.

A power amplifier includes a transistor, a temperature sensor and a filter. The transistor is used to receive a bias signal and amplify a radio frequency (RF) signal. The temperature sensor is arranged in proximity to the transistor, and is used to detect a temperature of the transistor to provide a voltage signal at a control node accordingly. The filter is coupled to the temperature sensor and is used to filter the voltage signal to generate a filtered voltage. The bias signal is adjusted according to the filtered voltage.

Measurement of signal power for variable or time varying signals. A log-linear VGA coupled in a feedback configuration to a difference detector and an integrator, includes a set of amplifier cells selectable by a sliding current generator, producing a sum of outputs. Outputs of the sliding current generator include a first control current provided using a sum of amplified currents, a sequence of intermediate control currents, and a final control current provided using a sum of amplified currents. Control currents to be summed can be differentially amplified or attenuated; attenuators include capacitors to compensate for capacitive loading. Selectable amplifier cells are differentially amplified or attenuated. Isolating switches and canceling stages reduce the effects of leakage between adjacent amplifier cells. The sliding current generator can have boosted current to first and last amplifier cells, providing a more linear-in-dB gain near a relative maximum or minimum.

A microphone device, an interface circuit and method are provided for managing a potential difference in sensitivity to a detected environmental stimulus associated with a sensor arrangement, where multiple electrical signals forming a differential signal can be produced, and the multiple electrical signals can be better balanced. Such an interface circuit, which can be used within a microphone device includes a bias voltage generator having one or more bias output voltage terminals, where a respective one of one or more DC bias voltages is produced at each of the bias output voltage terminals, for being coupled to a pair of transduction elements of a sensor. The interface circuit further includes an amplifier circuit having a first input terminal coupled to a first one of the pair of output terminals of the sensor and having a second input terminal coupled to a second one of the pair of output terminals of the sensor, the amplifier circuit producing a differential output signal. The interface circuit still further includes a compensation circuit coupled to the amplifier circuit for producing a balance signal based on an output signal being produced by the amplifier circuit, wherein the balance signal compensates for any difference in amplitude in the first and second electrical signals that are received by the amplifier circuit from the sensor.

To avoid damage from overheating, playback device operation can be modulated based on input from temperature sensors. An example method includes obtaining, via one or more temperature sensors carried by the playback device, temperature data. Based on the temperature data, a first temperature parameter is detected. In response to detecting the first temperature parameter, a gain of audio playback is decreased by a first amount. After decreasing the gain of audio playback by the first amount, a second temperature parameter is detected. In response to detecting the second temperature parameter, the gain of audio playback is decreased by a second amount different than the first amount.

A circuit comprises an amplifier network including a first amplifier and a second amplifier and a first transistor having a first base. The first transistor is thermally isolated from the second amplifier. The circuit further comprises a second transistor having a second base. The second transistor is thermally linked to the second amplifier. The circuit further comprises coupling circuitry configured to couple the first base to the second base.

To avoid damage from overheating, playback device operation can be modulated based on input from temperature sensors. An example method includes obtaining, via one or more temperature sensors carried by the playback device, temperature data. Based on the temperature data, a first temperature parameter is detected. In response to detecting the first temperature parameter, a gain of audio playback is decreased by a first amount. After decreasing the gain of audio playback by the first amount, a second temperature parameter is detected. In response to detecting the second temperature parameter, the gain of audio playback is decreased by a second amount different than the first amount.

In some implementations, a radiofrequency down converter comprises an input port to receive a radiofrequency input signal, and the down converter includes a first bandpass filter configured to filter the input signal. The down converter includes a mixer stage coupled to the bandpass filter, the mixer stage being configured to generate a mixer output signal by processing the filtered input signal using a gain adjustment device, one or more amplifiers, and a mixer. The down converter includes a signal adjustment stage coupled to receive the mixer output signal, the signal adjustment stage comprising: a temperature compensation device configured to compensate for changes in signal gain due to changes in temperature; a second bandpass filter; a gain adjustment device; one or more amplifiers; and a low pass filter. The down converter comprises an output port coupled to output an adjusted mixer output signal from the signal adjustment stage.