A pipelined successive approximation register analog-to-digital converter (2), SAR ADC, comprises a first SAR ADC stage (4); an inter-stage amplifier (6) for amplifying an analog residue from the first SAR ADC stage; and a second SAR ADC stage (8) input from the inter-stage amplifier, wherein the inter-stage amplifier (6) comprises one or more MOS transistors (16, 18), wherein the source and drain terminals of each of the one or more MOS transistors (16, 18) are connected to each other and may be toggled between ground and a supply voltage.

Devices and methods for improving voltage handling and/or bi-directionality of stacks of elements when connected between terminals are described. Such devices and method include use of symmetrical compensation capacitances, symmetrical series capacitors, or symmetrical sizing of the elements of the stack.

A digital-to-analog conversion circuit (60) for converting a digital input sequence to an analog representation is disclosed. It comprises a first DAC, (100) wherein the first DAC (100) is of a capacitive voltage division type having a capacitive load (110). Furthermore, it comprises a second DAC (120) having a resistive load (130). An output (104) of the first DAC (100) and an output (124) of the second DAC (120) are connected, such that said capacitive load (110) and said resistive load (130) are connected in parallel.

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.

Disclosed is a SAR ADC (Ai) having an input for receiving an input voltage, a comparator, a first switch network configured to be controlled by the SAR state machine and connected to the input of the SAR ADC and to reference voltage nodes, and a first capacitor network. The first capacitor network has a first node connected to an input of the comparator, a second node, and a bridge capacitor (Cb) connected between the first node and the second node. Furthermore, the first capacitor network comprises a first set of capacitors having a first and a second terminal, wherein the first terminal of each capacitor in the first set is connected to the first node and the second terminal of each capacitor in the first set is connected to the switch network. Moreover, the first capacitor network comprises a second set of capacitors having a first and a second terminal, wherein the first terminal of each capacitor in the second set is connected to the second node and the second terminal of each capacitor in the first set is connected to the switch network. The SAR ADC further comprises a second capacitor network configured to control a gain of the SAR ADC.

This application relates to driver circuitry (200) for receiving a digital input signal (D) and outputting, at first and second output nodes (203p, 203n), first and second analogue driving signals respectively for driving a transducer (101), e.g. loudspeaker, in a bridge-tied-load configuration. The driver circuitry may particularly be suitable for driving low-impedance transducers. The driver circuitry has first and second digital-to-analogue converters (201p, 201n) configured to receive the digital input signal and the outputs of the first and second digital-to-analogue converters are coupled to the first and second output nodes respectively. A differential-output amplifier circuit (202) has outputs connected to the first and second output nodes and is configured to regulate the outputs of the digital-to-analogue converters at output nodes to provide the analogue driving signals.

A stage, suitable for use in an analog to digital converter or a digital to analog converter, can have a plurality of slices that can be operated together to form a composite output. The stage can have reduced thermal noise, while each slice on its own has sufficiently small capacitance to respond quickly to changes in digital codes applied to the slice. This feature allows a fast conversion to be achieved without loss of noise performance.

An analog to digital converter (ADC) is disclosed. The ADC includes a DAC which generates a first signal based on an analog input and a digital input word, and a comparator which generates a comparator output having a value corresponding with a sign of a difference between first and second signals. During a first time period, the second signal is equal to a reference signal, the first signal is equal to an analog input, and the comparator generates a first comparator output. During a second time period, the second signal is equal to the reference signal, the first signal is equal to a the analog input plus a predetermined signal, and the comparator generates a second comparator output. A SAR logic circuit generates the digital input word for the DAC based on the first and second comparator outputs.

A successive approximation ADC includes: a comparator generating a judge signal related to an input analog and a reference signals; a SAR successively generating a register signal including a first and a second bit signals based on the judge signal and generating an AD conversion value of the input analog signal; a thermometer decoder switching different thermometer code conversion rules and converting the first bit signal to thermometer codes corresponding to the different thermometer code conversion rules in one AD conversion cycle; a first and a second DA converters respectively converting the thermometer codes to a first analog signal and the second bit signal to a second analog signal; an average value calculator averaging the AD conversion values by the thermometer codes. Two of the different thermometer codes have values that a high-order bit and a low-order bit groups by dividing total bits of the thermometer code equally are exchanged.

A charge sharing circuit includes a charge source having an accumulated first charge and a charge load having an accumulated second charge, where during a charge sharing interval the second charge is less than the first charge. A charge sharing regulator selectively couples between the charge source and the charge load along a charge sharing path. The charge sharing regulator regulates transfer of a shared amount of charge from the charge source to the charge load during the charge sharing interval.