A multi-path subsystem may include a first processing path, a second processing path, a mixed signal return path, and a calibration engine configured to: estimate and cancel a direct current (DC) offset of the mixed signal return path, estimate and cancel a DC offset between the first processing path and the second processing path, estimate and cancel a phase difference between the first processing path and a sum of the second processing path and the mixed signal return path, estimate and cancel a return path gain of the mixed signal return path, and track and correct for a gain difference between the first processing path and the second processing path.

A charge pump controller for controlling a charge pump adapted to convert an input voltage into an output voltage with a conversion ratio is presented. The charge pump is operable in a plurality of modes corresponding to different conversion ratios. The controller includes a first selector for selecting a mode of operation of the charge pump. The first selector comprises a first input for coupling to a voltage supply; and a second input for coupling to a source signal. The first selector identifies a target value of the output voltage. The selector calculates a product of the conversion ratio and the input voltage. The selector compares the product with the target value and selects a mode of operation of the charge pump by increasing or decreasing the conversion ratio based on the comparison. The selector maintains the conversion ratio for a length of time before decreasing the conversion ratio.

A charge pump controller for controlling a charge pump adapted to convert an input voltage into an output voltage with a conversion ratio is presented. The charge pump is operable in a plurality of modes corresponding to different conversion ratios. The controller includes a first selector for selecting a mode of operation of the charge pump. The first selector comprises a first input for coupling to a voltage supply; and a second input for coupling to a source signal. The first selector identifies a target value of the output voltage. The selector calculates a product of the conversion ratio and the input voltage. The selector compares the product with the target value and selects a mode of operation of the charge pump by increasing or decreasing the conversion ratio based on the comparison. The selector maintains the conversion ratio for a length of time before decreasing the conversion ratio.

A circuit includes a plurality of first stage integrators. Each of the plurality of first stage integrators includes a first input, a second input, a third input and an output. The first input of each of the plurality of first stage integrators is coupled to a different one of circuit inputs, the second input is coupled to a first reference input, the third input is coupled to a second reference input and the output of each of the plurality of first stage integrators is coupled to the first input of such first stage integrator. The circuit includes a second stage integrator which includes a first input coupled to each of the first inputs of the plurality of first stage integrators, a second input coupled to the first reference input, and an output coupled to the first input of the second stage integrator.

An amplifying apparatus includes a variable gain amplifying circuit configured to operate in a gain mode selected from a plurality of gain modes in response to a first control signal during operation in an amplification mode, a variable attenuation circuit configured to have an attenuation value that is adjusted in response to a second control signal, and a phase compensation value which compensates for a phase distortion in the selected gain mode, and a control circuit configured to control the selecting of the gain mode, the adjusting of the attenuation value and the phase compensation value, based on the first and second control signals.

A multi-path subsystem may include a first processing path, a second processing path, a mixed signal return path, and a calibration engine configured to: estimate and cancel a direct current (DC) offset of the mixed signal return path, estimate and cancel a DC offset between the first processing path and the second processing path, estimate and cancel a phase difference between the first processing path and a sum of the second processing path and the mixed signal return path, estimate and cancel a return path gain of the mixed signal return path, and track and correct for a gain difference between the first processing path and the second processing path.

The present disclosure describes variable gain amplifiers with gain-based compensation. In some embodiments, a variable gain amplifier (VGA) includes a gain stage, an output stage, a compensation stage, and a capacitor coupled between respective outputs of the gain stage and compensation stage. A gain of the VGA is configured, based on a gain setting, to amplify signals received by the variable gain amplifier. A gain of the compensation stage is configured, based on the gain setting, to alter an effective capacitance of the capacitor, which is applied to the output of the gain stage for compensation of the VGA. By altering the effective capacitance based on the gain setting of the VGA, compensation capacitance is adjusted continuously with changes in the gain setting and at a similar resolution. In various embodiments, the continuous adjustment of the compensation capacitance across different gain levels prevents discontinuities in amplifier compensation.

An I-V conversion module includes: a current output type sensor, a pre-integral circuit, a charge transfer auxiliary circuit, and an I-V transformation circuit including an inverting amplifier. The current output type sensor is connected to an input end of the I-V transformation circuit through the pre-integral circuit. The charge transfer auxiliary circuit connects in parallel with the inverting amplifier. When both the pre-integral circuit and the charge transfer auxiliary circuit are open circuits, the pre-integral circuit pre-integrates the induction current output by the current output type sensor to store pre-integral charges. When both pre-integral circuit and the charge transfer auxiliary circuit are closed circuits, the pre-integral charges are transferred to the I-V transformation circuit. In these embodiments, both the time for establishing the I-V conversion module and power consumption can be reduced.

An energy-efficient consumer device audio power output stage with gain control provides improved battery life and reduced power dissipation without clipping the audio output signal. A control circuit controls a power supply that supplies the power supply rails to the power amplified output stage. The voltage of the power supply rails is controlled in conformity with an input audio signal level, which may be determined from a volume control setting of the device and/or from a signal level detector that determines the amplitude of the signal being amplified. The gain applied to the audio input signal is reduced for a predetermined time period when a higher output voltage of the power supply is selected, to avoid clipping the audio output signal.

A sub-ranging programmable gain amplifier resolves an incoming signal into one of multiple amplitude sub-ranges and dynamically steps down the PGA output according to the identified sub-range.