An improved analysis and determination of a relationship between a tone frequency and spurious frequencies is provided. A device under test is operated to generate signals based on multiple different tone frequencies. For each tone frequency a spectrum of the generated signal is measured and spurious frequencies in the generated signal are identified. Based on the measured spectrums a representation of the spurious frequencies versus the related tone frequencies is generated. Trajectories may be inserted into the representation for indicating relationships between the tone frequencies and the spurious frequencies. This representation provides a useful basis for a fast and reliable identification of relationships between spurious frequencies and tone frequencies.

An integrated circuit, including: at least three integrated circuit portions mutually spaced on a single electrically insulating die, the integrated circuit portions being mutually galvanically isolated; and signal coupling structures on the die to allow communication of signals between the integrated circuit portions while maintaining the galvanic isolation therebetween.

A reference buffer circuit for an analog-to-digital converter is provided. The reference buffer circuit includes a first input node configured to receive a first bias signal of a first polarity from a first signal line. Further, the reference buffer circuit includes a second input node configured to receive a second bias signal of a second polarity from a second signal line. Additionally, the reference buffer circuit includes a first output node configured to output a first reference signal of the first polarity. A first buffer amplifier is coupled between the first input node and the first output node. The reference buffer circuit includes in addition a second output node configured to output a second reference signal of the second polarity. A second buffer amplifier is coupled between the second input node and the second output node. Further, the reference buffer circuit includes a first coupling path comprising a first capacitive element. The first coupling path is coupled between the first output node and the second input node. In addition, the reference buffer circuit includes a second coupling path comprising a second capacitive element. The second coupling path is coupled between the second output node and the first input node.

Some disclosed embodiments relate, generally, to shaping a waveform of a reference signal used by a driver of a touch sensor to limit electromagnetic emissions (EME) emitted by a touch sensor during a sensing operation. Some disclosed embodiments relate, generally, to a DAC referenced touch sensor driver and controlling an amount of EME emitted at a touch sensor using shapes of reference signals used by a touch detector to detect touches at the touch sensor. Some disclosed embodiments relate, generally, to compensating for effects of foreign noise at a touch sensor. And more specifically, to changing a shape of a reference signal based on a change to a sampling rate made to compensate for foreign noise.

A device includes a voltage converter and an analog to digital converter (ADC). The voltage converter includes an input to receive a first voltage and an output to output a second voltage based on a switching signal having a first discrete converter frequency and a second discrete converter frequency. The ADC is coupled to and proximate to the voltage converter. The ADC includes a digital filter configured to substantially attenuate a first filter frequency and a second filter frequency. The voltage converter further includes a frequency control device configured to set the first discrete converter frequency and the second discrete converter frequency so that the first discrete converter frequency is approximately equal to the first filter frequency and the second discrete converter frequency is approximately equal to the second filter frequency.

The present invention involves driving multiple capacitors, including a shielding capacitance (Cin_sd), to minimize voltage fluctuations detected on the CDA signal line 200, thereby enhancing the resolution of the ADC. The additional capacitance (Cobj) generated between the CDA 100 and the object 20 due to the appearance of the object 20 is detected in the form of voltage. By analyzing with an ADC of improved resolution, it is possible to detect the presence of the object 20 more reliably.

Some disclosed embodiments relate, generally, to shaping a waveform of a reference signal used by a driver of a touch sensor to limit electromagnetic emissions (EME) emitted by a touch sensor during a sensing operation. Some disclosed embodiments relate, generally, to a DAC referenced touch sensor driver and controlling an amount of EME emitted at a touch sensor using shapes of reference signals used by a touch detector to detect touches at the touch sensor. Some disclosed embodiments relate, generally, to compensating for effects of foreign noise at a touch sensor. And more specifically, to changing a shape of a reference signal based on a change to a sampling rate made to compensate for foreign noise.

An improved analysis and determination of a relationship between a tone frequency and spurious frequencies is provided. A device under test is operated to generate signals based on multiple different tone frequencies. For each tone frequency a spectrum of the generated signal is measured and spurious frequencies in the generated signal are identified. Based on the measured spectrums a representation of the spurious frequencies versus the related tone frequencies is generated. Trajectories may be inserted into the representation for indicating relationships between the tone frequencies and the spurious frequencies. This representation provides a useful basis for a fast and reliable identification of relationships between spurious frequencies and tone frequencies.

Disclosed is a field device of automation technology, comprising: a housing having a wall; a data transmission means arranged on an outside of the housing wall; and an electronic operating circuit arranged in a housing chamber and is adapted to operate the data transmission means, wherein the data transmission means and the electronic operating circuit are connected via an electrical signal line having a plurality of electrical conductors, wherein a first electrical conductor is adapted to lead a data signal and wherein at least a second electrical conductor is adapted to shield the first electrical conductor, wherein the signal line has an isolation device adapted to isolate a first signal line section galvanically from a second signal line section, wherein the isolation device includes an electromagnetically transparent plate having a first lateral surface and a second lateral surface parallel to the first lateral surface.

An integrated circuit is provided that includes an output stage circuit. The output stage circuit includes an input node for receiving a digital input signal, a supply voltage node for receiving a supply voltage signal, a digital to analog convertor for converting the digital signal, an amplifier for amplifying the converted signal, a first/second and optionally third voltage regulator generating a first/second and optionally third voltage signal, and a greatest-voltage selector circuit for providing power to the amplifier. Two different voltages are provided to the DAC. The output signal can be a SENT signal. The circuit is highly robust against power-interruptions and EMI.