An analog-to-digital converting device includes: a main analog-to-digital converter configured to convert an analog signal output from a sensor to a digital signal; and a monitoring unit configured to monitor the digital signal converted by the main analog-to-digital converter. The main analog-to-digital converter is provided by a special purpose IC arranged separately from a microcomputer for controlling the main analog-to-digital converter. The monitoring unit includes multiple sub analog-to-digital converters each of which having a conversion accuracy lower than that of the main analog-to-digital converter and converting the analog signal output from the sensor to a digital signal. The monitoring unit sets a predetermined threshold based on conversion values of the digital signals converted by the multiple sub analog-to-digital converters, and compares a conversion value of the digital signal converted by the main analog-to-digital converter with the predetermined threshold.

A delta sigma modulator includes a summation circuit, at least one integrator, a multi-bit quantizer and a negative feedback circuit. The summation circuit is configured to produce a difference signal between a unipolar or bipolar analog input signal and an analog feedback signal. The integrator is operatively coupled to the summation circuit to integrate the difference signal. The multi-bit quantizer is operatively coupled to the integrator to digitize the integrated signal to generate an N-bit digital output signal, N being an integer greater than 1. The negative feedback circuit operatively couples the multi-bit quantizer to the summation circuit. The negative feedback circuit includes a digital-to-analog converter arrangement for receiving the N-bit digital output signal and providing the analog feedback signal such that digital values of the N-bit digital output signal and values of the analog feedback encoded by the digital values have a non-linear relationship to one another.

A delta sigma modulator includes a summation circuit, at least one integrator, a multi-bit quantizer and a negative feedback circuit. The summation circuit is configured to produce a difference signal between a unipolar or bipolar analog input signal and an analog feedback signal. The integrator is operatively coupled to the summation circuit to integrate the difference signal. The multi-bit quantizer is operatively coupled to the integrator to digitize the integrated signal to generate an N-bit digital output signal, N being an integer greater than 1. The negative feedback circuit operatively couples the multi-bit quantizer to the summation circuit. The negative feedback circuit includes a digital-to-analog converter arrangement for receiving the N-bit digital output signal and providing the analog feedback signal such that digital values of the N-bit digital output signal and values of the analog feedback encoded by the digital values have a non-linear relationship to one another.

An analog-to-digital converting device includes: a main analog-to-digital converter configured to convert an analog signal output from a sensor to a digital signal; and a monitoring unit configured to monitor the digital signal converted by the main analog-to-digital converter. The main analog-to-digital converter is provided by a special purpose IC arranged separately from a microcomputer for controlling the main analog-to-digital converter. The monitoring unit includes multiple sub analog-to-digital converters each of which having a conversion accuracy lower than that of the main analog-to-digital converter and converting the analog signal output from the sensor to a digital signal. The monitoring unit sets a predetermined threshold based on conversion values of the digital signals converted by the multiple sub analog-to-digital converters, and compares a conversion value of the digital signal converted by the main analog-to-digital converter with the predetermined threshold.

A circuit includes a first current source configured to produce a first current in a first current line through a first diode-connected transistor having a voltage drop across the first diode-connected transistor, the first current being proportional to an absolute temperature via a first proportionality factor; a second current source configured to produce a second current in a second current line through a second diode-connected transistor having a voltage drop across the second diode-connected transistor, the second current being proportional to the absolute temperature via a second proportionality factor; a third current source configured to produce a third current in a third current line through a third diode-connected transistor having a voltage drop across the third diode-connected transistor; and a processing network including a sigma-delta analog-to-digital converter, the processing network being coupled to the, the second, and the third diode-connected transistors.

A digital-to-analog converter (DAC) capable of operating in radio frequency (RF) with linear output, low distortion, low power consumption, and input data independence. The DAC includes switch drivers and output switches driven by the switch drivers. The switch drivers include pairs of outputs, and positive feedback circuitries coupled between respective pairs of outputs. The output switches are arranged between a first current source configured to push current to the DAC's outputs and a second current source configured to pull current from the DAC's outputs. Different output switches are configured to push current to and pull current from the DAC's outputs in accordance with rising edges and falling edges, respectively.

A signal transmission device for pulse density modulated signals comprises a signal input for an input signal with a defined maximum signal value, a modulation stage for generating a pulse density modulated transmission signal out of the input signal, a locking device at the input for the pulse density modulated transmission signal to overwrite same with a static fault signal, a pulse reconstructing transmission path for the pulse density modulated transmission signal, a demodulation stage at the output, for reconstructing the input signal out of the transmitted pulse density modulated transmission signal, and a signal change monitoring device capturing the pulse density modulated transmission signal of the transmission path at the output, which has an error signal output for signaling the detection of a missing dynamic pulse density modulated transmission signal on the transmission path due to the static fault signal.

A digital-to-analog converter (DAC) capable of operating in radio frequency (RF) with linear output, low distortion, low power consumption, and input data independence. The DAC includes switch drivers and output switches driven by the switch drivers. The switch drivers include pairs of outputs, and positive feedback circuitries coupled between respective pairs of outputs. The output switches are arranged between a first current source configured to push current to the DAC's outputs and a second current source configured to pull current from the DAC's outputs. Different output switches are configured to push current to and pull current from the DAC's outputs in accordance with rising edges and falling edges, respectively.

A signal transmission device for pulse density modulated signals comprises a signal input for an input signal with a defined maximum signal value, a modulation stage for generating a pulse density modulated transmission signal out of the input signal, a locking device at the input for the pulse density modulated transmission signal to overwrite same with a static fault signal, a pulse reconstructing transmission path for the pulse density modulated transmission signal, a demodulation stage at the output, for reconstructing the input signal out of the transmitted pulse density modulated transmission signal, and a signal change monitoring device capturing the pulse density modulated transmission signal of the transmission path at the output, which has an error signal output for signaling the detection of a missing dynamic pulse density modulated transmission signal on the transmission path due to the static fault signal.

The present invention provides a fractional-N frequency synthesizer comprising a divider controller comprising a multistage noise Shaping (MASH) digital delta-sigma modulator comprising L stages, wherein the Lth stage is configured to receive as an input a high amplitude dither signal.