The resolution of a successive approximation analog-to-digital converter is varied in a wide range. Provided is a successive approximation analog-to-digital converter including a digital-to-analog converter that generates an analog voltage based on a digital code, a comparator to which the analog voltage as the output of the digital-to-analog converter is inputted, a DAC control circuit that generates the digital code of an input voltage sampled from an external clock signal by successively changing the digital code based on the output of the comparator, a delay circuit that starts the determination of the comparator by signal transition generated by delaying the signal state change of the output of the comparator, a clock generation circuit that generates a signal starting the determination of the comparator, and a selector circuit that selects a signal generated by the delay circuit or a signal generated by the clock generation circuit to feed the selected signal to the comparator.

According to one embodiment, an analog-to-digital converter includes a first digital-to-analog converter, a comparator configured to digitally output based on a first clock signal, a clock generator configured to generate the first clock signal from an input clock signal, and a controller configured to control the first digital-to-analog converter. The clock generator sets a cycle of the first clock signal to a first cycle if the input clock signal is at a first logic level, and sets the cycle of the first clock signal to a second cycle shorter than the first cycle if the input clock signal is at a second logic level.

A method of increasing SAR ADC conversion rate and reducing power consumption by employing a new timing scheme and minimizing timing delay for each bit-test during binary-search process. The high frequency clock input requirement is eliminated and higher speed rate can be achieved in SAR ADC.

A method of increasing SAR ADC conversion rate and reducing power consumption by employing a new timing scheme and minimizing timing delay for each bit-test during binary-search process. The high frequency clock input requirement is eliminated and higher speed rate can be achieved in SAR ADC.

A method and apparatus are disclosed for asynchronous clock generation in analog-to-digital converters (ADCs). For example, an ADC may comprise a comparator, a first logic gate, a second logic gate, a first memory element, a second memory element, and a digital-to-analog converter (DAC). The comparator may initiate an evaluation or precharge operation of comparator inputs. The first logic gate may generate, based on comparator outputs, a first output signal indicating validity of first logic gate output. The second logic gate may generate a second output signal indicating timing reference of bit conversion. The first memory element may generate a third output signal indicating a current state of a bit. The second memory element may generate a plurality of next state bits based on the second output signal and the comparator outputs. The second logic gate may generate the second output signal based on the first and third output signals.

A successive approximation register analog-to-digital converter capable of accelerating reset comprises: a sampling circuit generating at least one output signal(s) according to at least one input signal(s); a comparator generating at least one comparator output signal(s) according to the at least one output signal(s) and a reset signal; a control circuit controlling the operation of the sampling circuit according to the at least one comparator output signal(s) or the equivalent thereof, and generating the reset signal; a first reset wire circuit outputting the reset signal to the comparator so that a first circuit of the comparator is reset when the value of the reset signal is a first value; and a second reset wire circuit outputting the reset signal to the comparator so that a second circuit of the comparator is synchronously reset when the value of the reset signal is the first value.

An analog-to-digital conversion device is provided for converting an input signal pair to generate an output signal. The analog-to-digital conversion device includes switch groups, capacitors, a comparator, and a controller. The switch groups receive the input signal pair and reference voltages, and selects to output one of the input signal pair and the reference voltages according to a control signal to generate selection voltages respectively. The capacitors receive the selection voltages respectively and generate a first comparison voltage and a second comparison voltage. The comparator compares the first comparison voltage and the second comparison voltage to generate a comparison result signal. The controller sets conversion times for converting bits of the output signal according to the comparison result signal, wherein at least two of the conversion times are different.

An interface output for a capacitive sensor has a circuit to sample an input signal from the capacitive sensor, convert the sampled input signal to a digital signal and having an adjustable gain.

Provided is a successive approximation type analog/digital converter for generating a digital output signal corresponding to an analog input signal, including a capacitive digital/analog converter including a plurality of capacitors covering the most significant bit through the least significant bit, sampling an analog signal corresponding to the input signal, and generating an analog output signal corresponding to a digital input, a comparator performing successive approximation of the analog output signal for the most significant bit through the least significant bit with a comparison reference voltage, and a control circuit generating the digital input corresponding to a result of the successive approximation by the comparator and generating the digital output signal corresponding to the sampled analog signal corresponding to the result of the successive approximation by the comparator.

A successive-approximation analog-to-digital converter includes a sampling circuit for sampling an analog input signal to acquire a sampled voltage, and a regenerative comparator for comparing the sampled voltage with a succession of reference voltages to generate, for each reference voltage, a decision bit indicating the comparison result. The converter also includes a digital-to-analog converter which is adapted to generate the succession of reference voltages, in dependence on successive comparison results in the comparator, to progressively approximate the sampled voltage. The regenerative comparator comprises an integration circuit for generating output signals defining the decision bits, and a plurality of regeneration circuits for receiving these output signals. The regeneration circuits are operable, in response to respective control signals, to store respective decision bits defined by successive output signals from the integration circuit.