Infineon Technologies Ag

Markus Auer

Walter Kargl

Albert Missoni

Guenter Hofer

Christian Klapf

A demodulator is provided for demodulating a phase-modulated data signal. The demodulator includes a phase frequency detector to output a voltage representing a phase difference between a received phase-modulated data signal and a reference clock signal. The voltage is input to first and second phase change detectors, which are provided to measure the phase difference of the phase-modulated data signal during first and second time periods, respectively.

Circuit for demodulating a phase modulated signal

A circuit having a first input and a second input configured to apply an alternating voltage, a first output and a second output configured to supply a rectified and regulated voltage, a rectifier bridge circuit having a current return circuit, a third transistor and a fourth transistor, and a controller configured to regulate the voltage between the first and the second output to a constant value. The current return circuit is connected to the first input, the second input and to the second output. The third transistor is configured as a series voltage regulator and is connected to the first input and the first output. The fourth transistor is configured as a series voltage regulator and is connected to the second input and the first output. The controller is coupled to a control input of the third transistor and to a control input of the fourth transistor. Further, a method for rectifying and regulating voltages of a circuit is provided. The circuit and the method can be used in a contactless chip card.

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Graz, Austria

Markus Auer