Abstract: User responses to prompts or queries are classified or scored using explainable artificial intelligence (XAI) according to levels of a defined proficiency scale for selected subject matter. Recommendations for improving user proficiency are generated using XAI based on the proficiency classifications or scores and underlying rationales leading to those classifications or scores. XAI can be employed for identifying user responses that are consistent with predetermined cheating patterns. Prompts and queries can be presented, user responses classified or scored, and recommendation generated in a single session, i.e., in near real time. Disclosed methods can be advantageously employed for assessing user proficiency, and providing recommendations for improving proficiency, in a wide variety of subject areas, including spoken, written, or signed human languages.

Abstract: A digital-to-analog converter has a reference value source, a reference value divider arrangement with a tap, a first switch arrangement which is designed to produce an electrical connection between the tap and a first output of the digital-to-analog converter, and a second switch arrangement which is designed to produce an electrical connection between the tap and a second output of the digital-to-analog converter.

Abstract: In a method for suppression of even-numbered harmonic distortion which occurs in a non-linear element 4, a signal x(n) is linked to a pseudo random noise sequence r(n), and is thus spread, before passing through the non-linear element 4. After passing through the non-linear element 4, the signal y*(n) is once again linked to the pseudo random noise sequence r(n). The signal y*(n) is thus despread while, in contrast, even-numbered order harmonic elements are once again spread, and remain as broadband noise.

Abstract: In one embodiment, an amplifier arrangement includes an amplifier having a first input, a second input and an output, a first resistor network, having a first parallel circuit formed by a first number N of resistors, and a second resistor network, having a first resistor or a second parallel circuit formed by a second number M of resistors. The resistors of the first and second resistor networks each have approximately the same nominal value, an approximately identical width W and an approximately identical length L of a resistive layer. The first and second resistor networks are coupled to the amplifier.

Abstract: Method and device for reducing the signal images at the output of a digital/analog converter. In a method for reducing the signal images at the output of a digital/analog converter, a frequency hopping clock generator provides a digital data signal whose data rate is varied according to a frequency hopping method. The digital data signal is converted into an analog signal by a digital/analog converter, the conversion clock being varied according to the frequency hopping method.

Abstract: A digital-to-analog converter has a reference value source, a reference value divider arrangement with a tap, a first switch arrangement which is designed to produce an electrical connection between the tap and a first output of the digital-to-analog converter, and a second switch arrangement which is designed to produce an electrical connection between the tap and a second output of the digital-to-analog converter.

Abstract: A shunt regulator for stepping down an input potential to an output potential, has an input for applying the input potential, an output for tapping off the output potential and a voltage drop circuit, across which the voltage difference between the input potential and the output potential drops. It is possible for the current flowing through the voltage drop circuit or its lower and/or upper limit value to be adjusted.

Abstract: The circuit arrangement includes a first and a second input to supply a first and a second supply voltage and also an output. The circuit arrangement includes a first transistor, which is connected between the first input and the output, and a second transistor, which is connected between the second input and the output. The first and second transistors include a respective substrate connection coupled to a supply connection. In addition, the circuit arrangement includes a third and a fourth transistor, which are connected between the first input or the second input and the supply connection, and also a control circuit, which is coupled to the first and second inputs and to control connections of the first and second transistors.

Abstract: A method for converting an analog input signal into a digital value with successive approximation. A first comparison operation is provided before a first approximation, which subdivides a predefined input voltage interval into five partial intervals according to four reference potentials. During the comparison operation, a partial voltage interval determined is used in the ensuing approximation for the selection of a new reference potential pair to be used. This method enables higher sampling rates. At the same time, the range of the input signal is increased.

Abstract: Method and device for reducing the signal images at the output of a digital/analogue converter. In a method for reducing the signal images at the output of a digital/analogue converter, a frequency hopping clock generator provides a digital data signal whose data rate is varied according to a frequency hopping method. The digital data signal is converted into an analogue signal by a digital/analogue converter, the conversion clock being varied according to the frequency hopping method.

Abstract: In a method for suppression of even-numbered harmonic distortion which occurs in a non-linear element 4, a signal x(n) is linked to a pseudo random noise sequence r(n), and is thus spread, before passing through the non-linear element 4. After passing through the non-linear element 4, the signal y*(n) is once again linked to the pseudo random noise sequence r(n). The signal y*(n) is thus despread while, in contrast, even-numbered order harmonic elements are once again spread, and remain as broadband noise.

Abstract: An analog-to-digital converter is presented, which comprises at least two quantization stages, wherein the final quantization stage comprises a sigma-delta modulator.

Abstract: The invention discloses a sigma-delta converter arrangement with a forward path including an amplifier and a quantizer with a clock input, and a feedback path with a D/A converter. The amplifier is coupled to an integrator which is in the form of a resonator with a tunable frequency and is actuated by a frequency synthesizer that also prescribes the clock rate of the quantizer. The synchronization between the quantizer and resonator results in highly accurate matching given inexpensive integratabiliy, which means that the sigma-delta converter is suitable for use in mobile radios, for example.

Abstract: The invention provides a clocked analog/digital converter for successive approximation which is designed using a jointly used amplifier and a dynamic range expansion facility by means of a special design for the comparison circuit in the first converter stage. The comparison circuits in the analog/digital converter allow decisions to be made for the further signal processing previously in a preceding time period. Two respective generator circuits in successive converter stages share one amplifier. This reduces the amount of space taken up and current drawn, increases the clock rate and simplifies signal processing for signals with high levels.

Abstract: The invention discloses a sigma-delta converter arrangement with a forward path including an amplifier and a quantizer with a clock input, and a feedback path with a D/A converter. The amplifier is coupled to an integrator which is in the form of a resonator with a tunable frequency and is actuated by a frequency synthesizer that also prescribes the clock rate of the quantizer. The synchronization between the quantizer and resonator results in highly accurate matching given inexpensive integratabiliy, which means that the sigma-delta converter is suitable for use in mobile radios, for example.