An AD conversion circuit includes a comparison circuit, a first DA conversion circuit including a plurality of resistance elements, and a first voltage output circuit. A comparator of the comparison circuit outputs a signal that represents a result of comparing a first voltage of a first input terminal with a second voltage of a second input terminal. A first combined resistance value of the first DA conversion circuit and the first voltage output circuit seen from a second terminal of the first capacitance element is a first value when the first capacitance element holds a first signal. The first combined resistance value is a second value when the comparator compares the first voltage with the second voltage. The first value is less than the second value.

A signal processing circuit includes first and second resistors between an input end terminal and an output end terminal, a filter circuit that has a capacitive element that is connected to connection terminals of the first and second resistors, and an amplification circuit that is connected to the filter circuit. A cutoff frequency of the filter circuit is set by values of the first resistor and the capacitive element and a gain of the amplification circuit is set by values of the first and second resistors and a value of a feedback resistor.

The detection matrix for an Orthogonal Differential Vector Signaling code is typically embodied as a transistor circuit with multiple active signal inputs. An alternative detection matrix approach uses passive resistor networks to sum at least some of the input terms before active detection.

A digital-to-analog converter includes a resistor ladder, a first switch and a protection circuit. The first switch includes a first terminal and a second terminal that are respectively coupled to a rung of the resistor ladder and a reference voltage node. The protection circuit is coupled to the reference voltage node and to a reference voltage input terminal. The protection circuit includes a second switch, a third switch, and a fourth switch. First and second terminals of the second switch are respectively coupled to the reference voltage node and the reference voltage input terminal. First and second terminals of the third switch are respectively coupled to the reference voltage node and a reference voltage feedback terminal. The first and second terminals of the fourth switch are respectively coupled to the reference voltage input terminal and the reference voltage feedback terminal.

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.

A multiplying digital to analog converter (MDAC) includes a first resistor configured to be selectively connected to a current output node based on a first bit of a first portion of an input digital code and a second resistor configured to be selectively connected to the current output node based on a second bit of the first portion of the input digital code. A resistance of the second resistor is a resistance of the first resistor scaled by a factor. The MDAC further includes a first capacitor configured to be selectively connected to the current output node based on the first bit of the first portion and a second capacitor configured to be selectively connected to the current output node based on the second bit of the first portion. A capacitance of the second capacitor is a capacitance of the first capacitor scaled by an inverse of the factor.

A programmable resistance circuit provides a selected resistance by configuring a reference resistor to exhibit an effective resistance, in an operational sense, by achieving an average output voltage between a source line and a return line in the programmable resistance circuit. The average output voltage corresponds to the effective resistance. The effective resistance is achieved by utilizing a modulated voltage source to bias a transistor and intermittently draw current across the reference resistor according to the duty cycle of the modulated voltage source. A programmed resistance circuit can produce a selected resistance corresponding to button selection zones of a vehicle user interface when connected to a remote circuit that acts according to a user selection.

Differential circuitry including first and second current paths each including a succession of first and further load nodes, each successive further load node connected to its preceding load node via a divider impedance; and first switching circuitry connected to the further load node or nodes of the first current path, and second switching circuitry connected to the further load node or nodes of the second current path, the first and second switching circuitry controlling a magnitude of controllable current signals passing through the load nodes of the first current path and the second current path, respectively, wherein: the first load nodes of the first and second current paths include a first pair of load nodes, and the or each successive further load node of the first current path and its corresponding successive further load node of the second current path include a successive further pair of load nodes.

An analog signal processing module includes a processor and a comparator circuit module having a comparator circuit input and a comparator circuit output, the comparator circuit module being configured to receive a first analog signal at the comparator circuit input and generate a digital output, wherein the comparator circuit output is connected to the processor. A digital-to-analog converter (DAC) module is configured to receive a digital output from the processor and convert the digital output to a second analog signal. An operational amplifier (OpAmp) circuit module has an OpAmp circuit input and an OpAmp circuit output, the OpAmp circuit module being configured to receive the second analog signal at the OpAMp circuit input. A feedback loop is formed by the processor, the DAC module, and the OpAMp circuit module, and is configured to implement an amplification function or attenuation function performed by the OpAmp circuit module.

An analog-to-digital converter (ADC) includes a digital-to-analog converter (DAC) having a resistor network. The resistor network includes a first and second segments. The first segment includes a first switch coupled between a first supply voltage node and a first set of resistors. The second segment includes a second switch coupled between the first supply voltage node and a second set of resistors. The first segment includes a third switch coupled in series with a second resistor. The series-combination of the third switch and second resistor coupled in parallel with at least one resistor of the first set of resistors. The second segment includes a fourth switch coupled in series with a third resistor. The series-combination of the fourth switch and third resistor is coupled in parallel with at least one resistor of the second set of resistors.