Interface for shunt voltage regulator in a contactless smartcard

The present invention provides a shunt voltage regulator using a rectifier (M1 - M4) to rectify the incoming signal and a current quenching means (M5 M6) to divide the current from the output (0) of the rectifier in such a way that the output voltage remains at an appropriate level. level and modulation level do not rise above an acceptable range. This is achieved by having two feedback mechanisms for the control of said current extinguishing agent. A first feedback mechanism (G) utilizes a voltage splitting means (R6 - R7) to generate a control voltage signal which will cause the average output voltage of the rectifier to be equal to a reference voltage. A second feedback mechanism utilizes a nonlinear processing means (NLP; Figure 7) and the capacitors (C3 - C4) to transmit portions of the modulation frequency to the control (M7 - M14, R2 - R5) of the power quenching means thereby maintaining modulation at the output of rectifier time. continuously at an appropriate level.