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.

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 method for calibrating gain in a multi-path subsystem having a first processing path, a second processing path, and a mixed signal return path, may include low-pass filtering an input signal and a mixed signal return path signal generated from the input signal at subsonic frequencies to generate a filtered input signal and a filtered mixed signal return path signal and tracking and correcting for a gain difference between the first processing path and the second processing path based on the filtered input signal and the filtered mixed signal return path 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.

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 method for calibrating gain in a multi-path subsystem having a first processing path, a second processing path, and a mixed signal return path, may include low-pass filtering an input signal and a mixed signal return path signal generated from the input signal at subsonic frequencies to generate a filtered input signal and a filtered mixed signal return path signal and tracking and correcting for a gain difference between the first processing path and the second processing path based on the filtered input signal and the filtered mixed signal return path signal.

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.

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.

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.