Abstract: In order to prevent the retrieval of data via the measurement of the power consumption in a data carrier provided with a data processing device, it is proposed to connect a load circuit to the power supply of the data carrier so as to influence the power consumption of the data carrier at least during security-relevant operations of the data processing device.

Abstract: A data carrier (1) which can be operated in a contact-bound mode and in a contactless mode and a circuit (1A) for such a data carrier (1) has supply voltage generating means (35), for deriving a supply voltage (VDD) for various circuit sections of the data carrier (1) and of the circuit (1A) from a received useful HF signal (HF), and additional switching means (91) by means of which the application of a potential (VDD), which appears as a result of the supply voltage generated by the supply voltage generating means (35), to at least one contact terminal (17A) can be inhibited.

Abstract: A transponder (1) for the contactless communication with a base station (2) comprises an antenna resonant circuit (10) for receiving a modulated HF signal (5), signal processing means (13) for processing the modulated HF signal and for supplying a data signal (DS) and a clock signal (CLK), and data processing means (23) arranged to receive the data signal (DS) and the clock signal (CLK) and to process the data signal (DS), the clock signal (CLK) defining the processing speed of the data processing means (23) and the data processing means (23) being arranged to receive reset information (RI) for terminating the processing of the data signal (DS), the transponder (1) further comprising a frequency detector (31) arranged to receive the clock signal (CLK) and adapted to compare the frequency of the clock signal (CLK) with at least one limit frequency (fG1) and to supply the reset information (RI) to the data processing means (23).

Abstract: In a data carrier (1), or a circuit (3) for such a data carrier (1), in which data processing means (20) are included which can be supplied with a supply voltage (V) and in which, during the processing of data while utilizing a characteristic value, a current peak pattern which is significant of the characteristic value occurs on its supply voltage drain terminals (27, 29, 31, 33 and 28, 30, 32 and 34), current peak pattern suppression means are associated with the data processing means (20;) these suppression means are preferably formed by filter means (36) which include a capacitor (37) which is arranged in the direct vicinity of the data processing means (20) and is connected to the data processing means (20) via low-ohmic connection segments (40, 41, 42, 43, 44, 45, 46, 47).

Abstract: A data carrier (1) which can be operated in a contact-bound mode and in a contactless mode and a circuit (1A) for such a data carrier (1) has a.c. detection means (69) for detecting the presence of a useful HF signal (HF) received via a transmission coil (31) and clock signal detection means (73) for detecting a clock signal (CLK1) received via a transmission contact (16), and has logic means (82) which cooperate with the a.c. detection means (69) and the clock signal detection means (73) and which enable the activation of the contact-bound mode (CONTACT) and the activation of the contactless mode (CONTACTLESS) to be initiated.

Abstract: A transponder has a memory, a data processor, a transmit memory and a transmission circuit. The memory stores data. In a transmit mode of the transponder, the data processor is operable in a normal-energy mode and an energy-saving mode. When the data processor is in the normal-energy mode, the data processor retrieves the data from the memory and processes the data, and the processed data is stored in the transmit memory. Thereafter, the data processor is controlled from the normal-energy mode to the energy-saving mode, and the transmission circuit reads out the stored processed data from said transmit memory and transmits the read out stored processed data to a base station. Transponder for transmitting processed data to a base station over large distances and at a high data transfer rate.

Abstract: A chip card is operable in a contactless and contact-coupled mode. For operation in the contactless mode, the chip card has an antenna coil and rectifier. In the contactless mode, the chip card receives an AC signal. The rectifier provides a rectified received AC signal. The rectified signal is used for powering internal circuitry of the chip card. The chip card further has a recognition circuit that recognizes whether an AC signal is actually received by the antenna coil. If the AC signal is recognized, the recognition circuit switches the chip card to the contactless mode. If no AC signal is recognized, the recognition circuit switches the chip card to the contact-coupled mode.

Abstract: A data carrier (1) which can be operated in a contact-bound mode and in a contactless mode and a circuit (1A) for such a data carrier (1) has supply voltage generating means (35) for deriving a supply voltage (VDD), for various circuit sections of the data carrier (1) and of the circuit (1A), from a received useful HF signal (HF), and, in addition, potential equalizing circuit (94) by which at least two contact terminals (17A, 19A) each connected to a respective transmission contact (17, 19) can be brought at the same potential (ground).

Abstract: A chip card includes a semiconductor chip that contains at least one memory. In order to supply energy to the chip and to provide for bi-directional data transmission from and to the chip, both contacts and a device for contactless data transmission are provided. A triggerable switch device which is provided on the chip connects the memory either to the contacts or to the device for contactless data transmission as a function of a state of an output signal of a logic circuit connected to at least a voltage supply contact. The switch device assumes a position of repose when it is not triggered and in that position it connects the memory to the device for contactless data transmission, while only upon application of a voltage to the supply voltage contact, triggered by the logic circuit, does it connect the contacts to the memory.

Abstract: A device for processing and storing data, in particular a chip card, includes a first interface with contacts and a second contactless interface for receiving energy or power from and for communication with a terminal device. A first controllable switching device connects either the first or the second interface to a non-volatile semiconductor memory through address, data and control lines. A logic circuit drives the first controllable switching device. A second controllable switching device disposed between the first controllable switching device and the memory can be driven at least by the logic circuit and an address signal present on the address lines.