A method for testing an A/D converter with a built-in diagnostic circuit with a user supplied variable input voltage includes generating a charge by a binary-weighted capacitor array responsive to an external voltage and a user specified code. The method further includes applying the charge to a first input of a voltage comparator and applying a bias voltage to a second input of the voltage comparator, and generating, by the voltage comparator, a comparison voltage responsive to the applied charge and the bias voltage. The method also includes applying the comparison voltage to an input of a successive approximation register and generating, by the successive approximation register, an approximate digital code responsive to the comparison voltage. The method also includes determining if at least one bit of the approximate digital code fails to toggle independent of adjacent bits.

A baseline wander and offset correction system having inputs configured to receive input signals to be transmitted. Also part of the system is a driver circuit configured to receive and amplify the input signals. The driver circuit is configured with one or more transistors having an optional back bias terminal. A replica circuit receives the input signals and responsive thereto, generates back bias signals which are provided to the back bias terminal of the one or more transistors to change the back bias in response to the input signals having consecutive one values or consecutive zero values. This reduces the size of the one or more AC coupling capacitors located between the driver circuit and a channel. An embodiment may store back bias values in a memory. The back bias values are processed by DAC to generate the back bias signals for offset correction.

A method for testing an A/D converter with a built-in diagnostic circuit with a user supplied variable input voltage includes generating a charge by a binary-weighted capacitor array responsive to an external voltage and a user specified code. The method further includes applying the charge to a first input of a voltage comparator and applying a bias voltage to a second input of the voltage comparator, and generating, by the voltage comparator, a comparison voltage responsive to the applied charge and the bias voltage. The method also includes applying the comparison voltage to an input of a successive approximation register and generating, by the successive approximation register, an approximate digital code responsive to the comparison voltage. The method also includes determining if at least one bit of the approximate digital code fails to toggle independent of adjacent bits.

According to aspects of the disclosure, an apparatus is disclosed comprising: a controller; an analog-to-digital converter (ADC) coupled to the controller, the ADC including an input terminal for receiving a sensor signal from a transducer; and a diagnostic circuit coupled to the input terminal of the ADC and to the controller, the diagnostic circuit being configured to: generate a diagnostic signal that indicates whether a voltage at the input terminal of the ADC meets a first threshold, and provide the diagnostic signal to the controller, wherein the controller is configured to: receive a data sample from the ADC, detect whether the data sample meets a second threshold, and transition the apparatus into a safe state when: (i) the diagnostic signal indicates that the voltage at the input terminal does not meet the first threshold, and (ii) the data sample meets the second threshold

A switching circuit for checking an analog input circuit of an A/D converter is shown. The switching circuit comprises the analog circuit and a comparator circuit. The analog input circuit is configured to generate a first derived signal S1 and a second derived signal S2 from an analog input signal SE of the analog input circuit. The first derived signal S1 and the second derived signal S2 are input signals for the comparator circuit, but only the first derived signal S1 is an input signal for the A/D converter. The comparator circuit is configured to check whether a deviation of the derived signals S1, S2 from each other lies within a tolerance range TOL and to output an output signal SA depending on the check, which may be further evaluated.

An analog-to-digital conversion device includes: a switch connected to input units through signal lines to receive external voltages selecting and outputting one external voltage; an S/H circuit holding a voltage corresponding to an output of the switch; a converter performing AD conversion based on the voltage; and a controller determining the external voltage selected by the switch and performing a disconnection determination whether a disconnection occurs in the signal line. In the disconnection determination, the controller controls the switch to select a reference voltage different from the external voltage before controlling the switch to select the external voltage to be determined, and performs the disconnection determination based on a voltage difference between the reference voltage and the external voltage after controlling the switch to select the external voltage.

The fault diagnosis circuit includes a first line including a first resistor, having one end connected to the positive (+) terminal of a battery, and having the other end connected to a first input unit of an analog to digital converter (ADC); a second line including a second resistor, having one end connected to the positive (+) terminal of the battery, and having the other end connected to a first input unit of a comparator; and a third line including a third resistor, having one end connected to the negative (−) terminal of the battery, having a first other end connected to a second input unit of the ADC, and having a second other end connected to a second input unit of the comparator. A fault in a battery management system can be efficiently diagnosed using a smaller number of elements.

A sound source playback unit plays back sound data from a sound source and outputs a playback signal. An amplification unit amplifies the playback signal and outputs the playback signal as an output signal converted to sound in a speaker. A fault detection unit including a first conversion circuit compares the playback signal to a predetermined first threshold, converts a waveform of the playback signal, and outputs the converted waveform as a converted playback signal. A second conversion circuit compares the output signal to a predetermined second threshold, converts a waveform of the output signal, and outputs the converted waveform as a converted output signal. A comparison circuit compares the converted playback signal to the converted output signal, and a determination circuit determines an output of the comparison circuit. Based on the determination, the fault detection unit detects a fault in the amplification unit.

An analog input device, which converts an inputted analog signal to a digital signal and outputs the digital signal, includes a high resolution AD converter, a first low resolution AD converter, and a second low resolution AD converter. When a difference between a first digital signal converted by the high resolution AD converter and a second digital signal converted by the first low resolution AD converter is equal to or less than a predetermined first threshold, the analog input device outputs first digital signal. When the difference between the first digital signal and the second digital signal is larger than the predetermined first threshold, the analog input device stops an output of the first digital signal.

A circuit arrangement includes a microcontroller having a first analog-to-digital converter whose input is connected to the output of a first multiplexer whose output is connected to a first comparison device for comparing reference voltages, and a first serial interface circuit connected to the first comparison device. A voltage generating circuit includes a second analog-to-digital converter whose input is connected to the output of a second multiplexer whose output is connected to a number of registers, which are connected to a safety value generator and store digital values together with a respective safety value, and a second serial interface circuit connected to the registers. The first and second serial interface circuits are connected to each other for communication of the microcontroller with the voltage generating circuit, the first interface circuit being connected to a second comparison device for comparing supply voltages and/or currents with desired voltages and/or desired currents.