Abstract: A circuit arrangement comprises a first branch comprising a resistor of variable resistance and a diode-connected bipolar transistor and a second branch comprising a resistor of fixed resistance and another diode-connected bipolar transistor. A control loop reproduces a voltage drop at the resistor of variable resistance to a voltage drop at the resistor of fixed resistance. Output terminals are connected to the bipolar transistors to supply a differential voltage. The circuit arrangement may be used as an analog frontend circuit in a gas sensor or a temperature sensor arrangement.

Abstract: A circuit for measuring an unknown resistance of a resistive element comprises a sensor circuit to generate a differential voltage dependent on the resistance of the resistive element and a reference circuit to generate a differential reference voltage and a sigma-delta converter comprising a first stage, wherein a first capacitor is selectively coupled to one of the output terminals of the sensor circuit and a second capacitor is coupled to one of the output terminals of the reference circuit. The circuit generates logarithmically compressed values.

Abstract: In an embodiment an electro-thermal device includes a heater, a readout circuit, a digital controller having a first input coupled to a first output of the readout circuit and a digital sigma-delta modulator having a first input coupled to an output of the digital controller and an output coupled to the heater.

Abstract: A circuit arrangement comprises a first branch comprising a resistor of variable resistance and a diode-connected bipolar transistor and a second branch comprising a resistor of fixed resistance and another diode-connected bipolar transistor. A control loop reproduces a voltage drop at the resistor of variable resistance to a voltage drop at the resistor of fixed resistance. Output terminals are connected to the bipolar transistors to supply a differential voltage. The circuit arrangement may be used as an analog frontend circuit in a gas sensor or a temperature sensor arrangement.

Abstract: In an embodiment an electro-thermal device includes a heater, a readout circuit, a digital controller having a first input coupled to a first output of the readout circuit and a digital sigma-delta modulator having a first input coupled to an output of the digital controller and an output coupled to the heater.

Abstract: A circuit for measuring an unknown resistance of a resistive element comprises a sensor circuit to generate a differential voltage dependent on the resistance of the resistive element and a reference circuit to generate a differential reference voltage and a sigma-delta converter comprising a first stage, wherein a first capacitor is selectively coupled to one of the output terminals of the sensor circuit and a second capacitor is coupled to one of the output terminals of the reference circuit. The circuit generates logarithmically compressed values.

Abstract: The method of control according to the invention slaves a DC voltage generated by the alternator to a predetermined setpoint value by controlling an excitation current flowing in an excitation circuit comprising an excitation winding of a rotor of the alternator. The excitation current is controlled by means of a semiconductor switch, in turn controlled by a control signal having a predetermined period. The method comprises a detection of a failure of the excitation circuit. At least one short-circuit of the excitation winding is detected. According to another characteristic of the method, the control signal is generated on the basis of a combination of a setpoint signal formed by pulses of the predetermined period exhibiting a duty ratio representative of the setpoint value and of a detection signal indicative of the short-circuit.

Abstract: The method of control according to the invention slaves a DC voltage generated by the alternator to a predetermined setpoint value by controlling an excitation current flowing in an excitation circuit comprising an excitation winding of a rotor of the alternator. The excitation current is controlled by means of a semiconductor switch, in turn controlled by a control signal having a predetermined period. The method comprises a detection of a failure of the excitation circuit. At least one short-circuit of the excitation winding is detected. According to another characteristic of the method, the control signal is generated on the basis of a combination of a setpoint signal formed by pulses of the predetermined period exhibiting a duty ratio representative of the setpoint value and of a detection signal indicative of the short-circuit.