Input circuitry for an analog-to-digital converter (ADC) is provided. The input circuitry includes a calibration signal source configured to output a calibration signal for the ADC and an analog circuitry configured to receive and process an analog input signal for the ADC. The analog circuitry is further configured to generate a combined signal by combining the analog input signal and the calibration signal. The input circuitry further includes a buffer amplifier coupled to the analog circuitry and configured to supply a buffered signal to the ADC based on the combined signal. Further, the input circuitry includes neutralization circuitry configured to generate, based on the calibration signal, a neutralization signal for mitigating an unwanted signal component related to a limited reverse isolation of the analog circuitry. The neutralization circuitry is further configured to supply the neutralization signal to at least one of an input node and an intermediate node of the analog circuitry.

A system is disclosed herein. The system includes a splitter board. The splitter board includes a microprocessor, a converter, and a bypass relay. The converter includes analog-to-digital circuitry and digital-to-analog circuitry. The bypass relay is configurable between a first state and a second state. In the first state, the bypass relay is configured to direct an input signal to the converter. The converter converts the input signal to a converted input signal and splits the converted input signal into a first portion and a second portion. The first portion is directed to the microprocessor. The second portion is directed to an output port of the splitter board for downstream processes. In the second state, the bypass relay is configured to cause the input signal to bypass the converter. The bypass relay directs the input signal to the output port of the splitter board for the downstream processes.

A system is provided that includes electrodes configured to be implanted in a body, and a pulse generator (PG) circuitry to deliver a stimulus to one or more of the electrodes. The system also includes sensing circuitry configured to define a sensing channel between one or more of the electrodes to sense signals indicative of a physiologic activity of interest, and the sensing circuitry further configured to collect a calibration signal over the sensing channel. The sensing circuitry and PG circuitry are housed within an implantable medical device (IMD). The system also includes one or more processors configured to determine a signal characteristic of interest (COI) of the calibration signal. The one or more processors are also configured to compare a signal COI of the stimulus to the signal COI of the calibration signal, and adjust a parameter of the sensing circuitry or PG circuitry based on the comparison.

In an example, a system includes an input channel and a voltage to delay converter (V2D) coupled to the input channel. The system also includes a first multiplexer coupled to the V2D and an analog-to-digital converter (ADC) coupled to the first multiplexer. The system includes a second multiplexer coupled to the input channel and an auxiliary ADC coupled to the second multiplexer. The system includes calibration circuitry coupled to an output of the auxiliary ADC, where the calibration circuitry is configured to correct a non-linearity in a signal provided by the input channel. The calibration circuitry is also configured to determine the non-linearity of the signal provided to the ADC relative to the signal provided to the auxiliary ADC.

A digital signal processing (DSP) device includes a first fitter to equalize channel dispersion associated with signal transmission through a medium, a second filter to cancel channel reflections, and a third filter to at least reduce noise. The DSP device is a receiver DSP of the SERDES.

A memory device includes an array of memory cells, a diode having a threshold voltage that changes with temperature, an analog-to-digital converter (ADC), and a pulse generator. The ADC includes a voltage comparator having a positive terminal coupled with the diode. The ADC further includes a first capacitor coupled between a negative terminal of the voltage comparator and ground, and a second capacitor selectively coupled between the first capacitor and a voltage reference node. The second capacitor has a smaller capacitance than that of the first capacitor. The pulse generator is coupled with the ADC and generates pulses. The pulses cause the first capacitor to connect to the second capacitor and equalize charge between the first capacitor and the second capacitor. An inverted signal of the pulses causes the second capacitor to be coupled with the voltage reference node to pre-charge the first capacitor.

An analog-to-digital converter (ADC) includes a coarse ADC that receives an analog input voltage, generates a first digital signal based on the analog input voltage using a successive approximation register (SAR) method, and outputs a residual voltage remaining after the first digital signal is generated. The ADC further includes an amplifier that receives the residual voltage and a test voltage, generates a residual current by amplifying the residual voltage by a predetermined gain, and generates a test current by amplifying the test voltage by the gain. The ADC further includes a fine ADC that receives the residual current and generates a second digital signal based on the residual current using the SAR method, and an auxiliary path that receives the test current and generates a gain correction signal based on the test current. The gain of the amplifier is adjusted based on the gain correction signal.

An analog-to-digital converter (ADC) system includes a main ADC, a reference ADC, a sampling control circuit, and a calibration circuit. The main ADC obtains a first sampled input voltage by sampling an analog input according to a first sampling clock, and performs analog-to-digital conversion upon the first sampled voltage to generate a first sample value. The reference ADC obtains a second sampled voltage by sampling the analog input according to a second sampling clock, and performs analog-to-digital conversion upon the second sampled voltage to generate a second sample value. The sampling control circuit controls the second sampling clock to ensure that the second sampling clock and the first sampling clock have a same frequency but different phases, and adjusts the second sample value to generate a reference sample value. The calibration circuit applies calibration to the main ADC according to the first sample value and the reference sample value.

A system and method for calibrating a time-interleaved digital-to-analog converter (DAC). A calibration signal generator generates calibration data, and a time-interleaved DAC converts the calibration data to an analog calibration signal. An observation analog-to-digital converter (ADC) samples, and quantizes, the analog calibration signal filtered by an anti-alias filter. A mismatch estimation block estimates a frequency response mismatch between the sub-DACs and generates a sub-DAC mismatch correction factor based on an output of the observation ADC. The calibration signal generator applies the sub-DAC mismatch correction factor to the calibration data. The mismatch estimation block may estimate a DC offset mismatch between the sub-DACs based on the output of the observation ADC and generates a DC offset correction factor, and the calibration signal generator applies the DC offset correction factor to the calibration data.

An apparatus can include a digital-to-analog converter (DAC) and calibration circuitry including an oscillator. The calibration circuitry can be coupled to an output of the DAC, the calibration circuitry to sample and count DAC output pulses for at least two consecutive pulses using at least two separate counter circuits. The calibration circuitry can determine error between at least two consecutive pulses and provide a correction value based on the error. The apparatus can further include correction circuitry to provide a calibration signal to the DAC based on the correction value.