Nxp B.v.

Erik Olieman

Alphons Litjes

Ibrahim Candan

Helmut Kranabenter

Mark Stoopman

Michael Todd Berens

Robert Van Veldhoven

Achal Venkatesh

Stephane Damien Thuriés

Peter Van Der Cammen

Leon Van Der Dussen

Rajesh Prabhakar Shamala

A SAR ADC includes a DAC, a comparator and SAR circuitry, where the DAC includes MSBs encoded with first capacitors; a mismatch error shaping capacitor coupled to the MSBs; LSBs encoded with second capacitors, where a first switch set couples bottom capacitor plates of the first capacitors and the mismatch error shaping capacitor to receive an analog input voltage, a high reference voltage, or a low reference voltage in response to first DAC feedback control signals, wherein a second switch set couples bottom capacitor plates of the second capacitors to receive the high reference voltage or the low reference voltage in response to second DAC feedback control signals, and wherein the SAR circuitry is configured to feedback a mismatch error value from a previous SAR conversion cycle to the LSBs sub-DAC during a current sampling cycle.

SAR ADC with bottom-plate sampling and mismatch error shaping

A device includes a filter circuit having both a transformer and a notch filter. The notch filter is formed via capacitive cross-coupling of windings of the transformer. The transformer includes a first winding with an input terminal and an output terminal and a second winding with an input terminal and an output terminal. The notch filter is formed by coupling a first capacitor between the input terminal of the first winding and the output terminal of the second winding, and by coupling a second capacitor between the output terminal of the first winding and the input terminal of the second winding.

Transformer filter with notch

An analog to digital converter including a digital to analog converter (DAC), a comparator, and a controller. The DAC includes a sample node and a capacitor array controlled by a digital control input. The comparator compares a voltage of the sample node with a reference voltage to generate a comparison value. The controller presets the digital control input, prompts the DAC to sample the input voltage onto the sample node, resets the digital control input, and performs a conversion by successively adjusting the digital control input based on the comparison value to determine a digital output. A preset value is subtracted from the digital output to provide an adjusted digital output. A sample predictor predicts the next sample to determine the preset value used to adjust the sample node within a full scale range after DAC reset.

System and method of extending input range of analog to digital converter

A calibration system comprises an actuator circuit comprising a first delay circuit that receives a plurality of data pulses and a second delay circuit that receives the pulses, wherein one of the first and second delay circuits delays the data pulses independently of the other of the first and second delay circuits; a data switch that receives an output of the actuator circuit including delay data signals of the data pulses from the first and second delay circuits and switches and outputs a plurality of local oscillator (LO) signals for output as a controlled LO signal according to control signals of the delay data signals and applied to the data switch. At least one calibration switch receives the output of the actuator circuit and the plurality of LO+ and LO&#x2212; signals, and outputs a second controlled LO signal output to a sense circuit.

Timing calibration technique for radio frequency digital-to-analog converter

A duty cycle correction (DCC) circuit for use in relation to differential signal communications, a method of providing duty cycle correction, and communications systems and methods employing same, are disclosed herein. In one example embodiment, the circuit includes a differential signal inverter circuit including first and second inverter circuits, each of which has a respective inverter and respective first and second transistor devices respectively coupled between the respective inverter and first and second voltages, respectively. The circuit also includes a feedback circuit coupled to respective output ports of the respective first and second inverter circuits and also to respective feedback input ports of the respective transistor devices. The feedback circuit operates to provide one or more feedback signals causing one or more of the transistor devices to perform current limiting. Respective duty cycles of output signals respectively are equal or substantially equal based on the current limiting.

Circuit to correct duty cycle and phase error of a differential signal with low added noise

A four-phase (or multi-phase) generation circuit, related method of operation, and transceivers or other systems utilizing such a circuit, are disclosed herein. In one example embodiment, the circuit includes two input ports respectively configured to receive positive and negative differential input signals, and four output ports respectively configured to output first, second, third and fourth output signals, respectively, the second, third, and fourth output signals being respectively phase-shifted relative to the first output signal by or substantially by 90, 180, and 270 degrees. Also, the circuit includes four SR latches respectively including output terminals that are respectively coupled to the respective output ports. Further, the circuit includes two tunable delay circuits respectively coupled at least indirectly between the input ports and latches, and two comparison circuits configured to output respective feedback signals. The latches receive two delayed input signals provided by the delay circuits based upon the feedback signals.

Negative-feedback four-phase generator with twenty-five percent duty cycle output

A capacitive sampling circuit comprises: a first-differential-input-terminal, configured to receive a first one of a pair of differential-input-signals; a second-differential-input-terminal, configured to receive the other one of the pair of differential-input-signals; a capacitive-circuit-output-terminal, configured to provide a sampled-output-signal; a plurality of first-sampling-capacitors, each having a first-plate and a second-plate; a plurality of reference-voltage-terminals, each configured to receive a respective reference-voltage; and a first-capacitor-first-plate-switching-block configured to selectively connect the first-plate of each of the plurality of first-sampling-capacitors to either: (i) the first-differential-input-terminal; or (ii) a respective one of the plurality of reference-voltage-terminals; and a first-capacitor-second-plate-switch, configured to selectively connect or disconnect the second-plate of each of the plurality of first-sampling-capacitors to the second-differential-input-terminal.

Capacitive sampling circuit

Embodiments of an analog-to-digital converter (ADC), resistive digital-to-analog converter (DAC) circuits, and methods of operating an ADC are disclosed. In an embodiment, an analog-to-digital converter includes a DAC unit configured to convert a digital code to a first voltage in response to an input voltage of the ADC, a comparator configured to compare the first voltage with a second voltage to generate a comparison output, and a logic circuit configured to generate the digital code, to control the DAC unit based on the comparison output, and to output the digital code as a digital output of the ADC. The DAC unit includes a capacitive DAC and multiple resistive DACs. Each of the resistive DACs is connected to the first voltage through a respective capacitor.

Analog-to-digital converter, resistive digital-to-analog converter circuit, and method of operating an analog-to-digital converter

An integrated charge redistribution successive approximate register (CR-SAR) analog-to-digital converter (ADC) includes a sample-and-hold switch, a digital-to-analog converter (DAC), a comparator and a logic circuit. The sample-and-hold switch obtains a sample input voltage (Vin). The DAC includes a plurality of digital multiplexers that selects between a superposition phase, which superimposes an analog offset voltage onto Vin, and a conversion phase which determines values for a digital output register which determines the input values to each control line. Each digital multiplexer presents input values to a control line. The comparator has two inputs coupled to the sample-and-hold switch and to the DAC such that the output of the converter determines a value of each successive bit in the digital output register. The logic circuit is coupled to the comparator and to digital multiplexers and includes the digital output register.

Analog signal generation by hardware re-use in sampled circuits

A low dropout (LDO) regulator system is provided. The LDO regulator system includes a first amplifier circuit, a second amplifier circuit, and a switch circuit. The first amplifier circuit has a first input coupled to receive a reference voltage and an output. The second amplifier circuit has a first input coupled to the output of the first amplifier and is configured to provide a predetermined voltage at a first output. The switch circuit is coupled between the first output of the second amplifier circuit and a second input of the first amplifier circuit and is configured to cause an open circuit in a first feedback path from the first output of the second amplifier circuit to the second input of the first amplifier circuit based on a control signal.

Dual loop low dropout regulator system

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.

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Waalre, Netherlands

Erik Olieman