Processing circuitry comprising: a reference node for connection to a reference voltage source so as to establish a local reference voltage signal at the reference node; a signal processing unit connected to the reference node and operable to process an input signal using the local reference voltage signal, wherein the signal processing unit is configured to draw a current from the reference node at least a portion of which is dependent on the input signal; and a current-compensation unit connected to the reference node and operable to apply a compensation current to the reference node, wherein the current-compensation unit is configured, based on an indicator signal indicative of the input signal and/or of the operation of the signal processing unit, to control the compensation current to at least partly compensate for changes in the current drawn from the reference node by the signal processing unit due to the input signal.

A system can include an analog input port; a digital output port; and a successive approximation register (SAR) analog-to-digital converter (ADC). The SAR ADC can include a voltage comparator V.sub.d having a first input, a second input, and an output; a first plurality of capacitors C.sub.p[0:n] that are coupled with the analog input port and each have a top plate and a bottom plate; a second plurality of capacitors C.sub.n[0:n] that are coupled with the analog input port and each have a top plate and a bottom plate; and a SAR controller coupled between the output of the voltage comparator V.sub.d and the digital output port.

The present application relates to an EQ circuit, a method of operating it and a system comprising the EQ circuit and an ADC. The EQ circuit has a configurable load section, which is provided for selectively exposing one of a plurality of distinct loads to a reference source connected to a reference voltage signal input of the equalization circuit, and a logic section, which is arranged to accept a state signal from the ADC and to selectively connect one distinct load out of the plurality of distinct loads in response to the state signal. The state signal is indicative of an actual operation state of the ADC.

An ADC, including a DAC which receives an analog input voltage and a digital input word from SAR logic, and generates a first voltage based on the analog input voltage and the digital word. The ADC also includes a comparator, which receives the first voltage and a reference voltage, and generates a second voltage based on the first voltage and on the reference voltage. The second voltage has a value corresponding with a sign of the difference between the first voltage and the reference voltage. The ADC also includes the SAR logic circuit which receives the second voltage from the comparator. The SAR logic generates a digital output word based on a second voltages received from the comparator. A difference between the minimum input voltage on the maximum input voltage is substantially equal to two times a difference between reference voltage and the minimum input voltage.

The present application relates to an EQ circuit, a method of operating it and a system comprising the EQ circuit and an ADC. The EQ circuit has a configurable load section, which is provided for selectively exposing one of a plurality of distinct loads to a reference source connected to a reference voltage signal input of the equalization circuit, and a logic section, which is arranged to accept a state signal from the ADC and to selectively connect one distinct load out of the plurality of distinct loads in response to the state signal. The state signal is indicative of an actual operation state of the ADC.

In order to realize a circuit in a subsequent stage with a smaller circuit scale with respect to a single-ended input of a large signal, a double-sampling switched-capacitor input circuit includes a first switched-capacitor input circuit, which includes first capacitors for double sampling, and a second switched-capacitor input circuit, which includes second capacitors for double sampling, and which is configured to operate in opposite phase to the first switched-capacitor input circuit, the double-sampling switched-capacitor input circuit having a configuration in which the first capacitors and the second capacitors have different values, and in which the value of the second capacitors is adjusted so that a signal is attenuated.

Methods and systems for analog-to-digital conversion using two side branches that may be operated with overlapped timing such that a sampling phase may be overlapped with a previous conversion phase. Some embodiments provide a method of successive approximation A/D converting, comprising sampling a first signal onto a first capacitor that is configured to selectively couple to an analog input of a comparator, sampling a second signal onto capacitors that are coupled to a second analog input of the comparator and configured for charge redistribution successive approximation A/D conversion; carrying out, based on the first signal and the second signal, a charge redistribution successive approximation A/D conversion using the capacitors; and while carrying out the charge redistribution successive approximation A/D conversion based on the first and second signals, sampling a third signal onto a third capacitor that is configured to selectively couple to the analog input of a comparator.

An input sampling stage circuit includes, a precharge buffer, a precharge switch-capacitor circuit, and an input sampling capacitor. The precharge buffer is configured to buffer an input voltage. The precharge switch-capacitor circuit includes a plurality of switches, a first capacitor, and a second capacitor configured such that the first and second capacitors are connected in series during a coarse sampling time and in parallel during a fine sampling time and charge transfer time. The input sampling capacitor is configured to sample the input voltage through the precharge switch-capacitor circuit during the coarse sampling time and sample the input voltage directly during the fine sampling time.

A system can include an analog input port; a digital output port; and a successive approximation register (SAR) analog-to-digital converter (ADC). The SAR ADC can include a voltage comparator V.sub.d having a first input, a second input, and an output; a first plurality of capacitors C.sub.p[0:n] that are coupled with the analog input port and each have a top plate and a bottom plate; a second plurality of capacitors C.sub.n[0:n] that are coupled with the analog input port and each have a top plate and a bottom plate; and a SAR controller coupled between the output of the voltage comparator V.sub.d and the digital output port.

An interleaving successive approximation analog-to-digital converter (SAR ADC) with noise shaping having a first SAR block, a second SAR block, and a noise-shaping circuit is provided. The first and second SAR blocks take turns to sample an input voltage for successive approximation of the input voltage and observation of a digital representation of the input voltage. The noise-shaping circuit receives a first residue voltage from the first SAR block and receives a second residue voltage from the second SAR block alternately, and outputs a noise-shaping signal to be fed into the first SAR block and the second SAR block.