A driver for a circuit with a capacitive load is configured for coupling to a voltage source which provides a DC input voltage, and is configured to generate an output voltage at an output. The driver includes a bidirectional synchronous power converter with a first switch, a second switch, and an inductive device connected to the first and/or second switch. A controller is configured to control the first switch and the second switch. The bidirectional synchronous power converter generates a switching voltage from the input voltage at a switching node and generates the output voltage having an analog voltage waveform with a peak amplitude of at least twice the input voltage.

An analog to digital converter temperature compensation system comprising a comparator configured to compare an analog input signal to a compensated feedback signal and generate a comparator output. A SAR module processes the comparator output to generate a digital signal. A digital to analog converter, biased by a biasing signal having temperature change induced error, is configured to convert the digital signal to a feedback signal and a detector is configured to detect a signal that is proportional to temperature. A look-up table is configured to receive and convert the signal that is proportional to temperature to a compensation signal such that the compensation signal compensates for the temperature change induced error in the biasing signal. A summing node combines the feedback signal with the compensation signal to create a compensated feedback signal.

This disclosure describes systems, methods, and apparatus for a digital-to-analog (DAC) converter, that can be part of a variable capacitor and/or a match network. The DAC can include a digital input, an analog output, N contributors (e.g., switched capacitors), and an interconnect topology connecting the N contributors, generating a sum of their contributions (e.g., sum of capacitances), and providing the sum to the analog output. The N contributors can form a sub-binary sequence when their contributions to the sum are ordered by average contribution. Also, the gap size between a maximum contribution of one contributor, and a minimum contribution of a subsequent contributor, is less than D, where D is less than or equal to two time a maximum contribution of the first or smallest of the N contributors.

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.

Systems and methods for an asynchronous successive approximation register analog-to-digital converter (SAR ADC) with word completion algorithm may include a SAR ADC comprising a plurality of switched capacitors, a comparator, a metastability detector including a timer having a tunable time interval, and a successive approximation register. The SAR ADC may sample input signals at inputs of the switched capacitors and compare signals at outputs of the switched capacitors. The SAR ADC may also determine, based on a value of a tunable time interval, whether to set a metastability flag for a first bit to be evaluated and update the value of the tunable time interval based on whether the metastability flag was set.

A current cancellation circuit, a heart rate detection device and a wearable device. The current cancellation circuit includes: a current-voltage conversion circuit and a SAR ADC, where the SAR ADC includes a DAC, an SAR logic circuit and a comparator; the current-voltage conversion circuit is configured to receive an analog current output by the DAC and an interference current output by a photoelectric sensor, calculate a difference between the analog current and the interference current, and output an analog voltage; the comparator is configured to receive the analog voltage output by the current-voltage conversion circuit, and output a comparison result according to the analog voltage; and the DAC is configured to output the analog current according to a digital signal corresponding to the comparison result that is output by the SAR logic circuit, and the analog current is used to cancel the interference current output by the photoelectric sensor.

An analog-to-digital converter (ADC) circuit includes a signal input terminal, a sample-and-hold circuit, and a successive approximation register (SAR) ADC. The sample-and-hold circuit includes an input terminal coupled to the signal input terminal. The SAR ADC includes a comparator, a first capacitive digital-to-analog converter (CDAC), and a second CDAC. The first CDAC includes a first input terminal coupled to the signal input terminal, a second input terminal coupled to an output terminal of the sample-and-hold circuit, and an output terminal coupled to a first input terminal of the comparator. The second CDAC includes a first input terminal coupled to the signal input terminal, an output terminal coupled to a second input terminal of the comparator.

A low power high bandwidth analog to digital converter system is disclosed. A first analog signal input receives an input signal. A first programmable gain amplifier receives the input signal. An analog to digital converter (ADC) is coupled to the output of the first programmable gain amplifier and samples the input signal for conversion to a digital signal. A controller is coupled to the ADC and the first programmable gain amplifier. The controller selects and enables either a reduced power mode or a power up mode for the first programmable gain amplifier and the ADC. The power up mode is selected and enabled when the input signal is to be sampled to operate the first programmable gain amplifier and the ADC to sample the input signal.

A reference voltage controlling circuit and an analog-to-digital converter are disclosed. The reference voltage controlling circuit includes a reference voltage generating circuit, a plurality of groups of sampling switching units and a logic controlling circuit. The DAC capacitor array switches the sampling switching units to a second positive reference voltage and a second negative reference voltage before starting sampling or conversion, and is charged and discharged with the second positive reference voltage and the second negative reference voltage to raise a voltage to a preset voltage. The sampling switching unit is switched to a first positive reference voltage and a first negative reference voltage to charge and discharge the DAC capacitor array to a target voltage. The rising of the voltage from the preset voltage to the target voltage is completed by the first positive reference voltage and the first negative reference voltage.

A pipeline analog to digital converter includes converter circuitries. The converter circuitries are configured to sequentially convert an input signal to be digital codes. The converter circuitries includes a first converter circuitry and a second converter circuitry. The first converter circuitry is configured to a convert a first signal to be a first digital code in the digital codes, and generate a first residue signal according to the first signal and the first digital code. The second converter circuitry is configured to receive the first signal and the first digital code to quantize the first signal according to the first digital code, in order to generate a second digital code in the digital codes, and generate a second residue signal according to the first residue signal and the second digital code.