摘要:
In a communication arrangement (1) provided for transmitting data (DA) to a transponder (2) which arrangement includes a data source (5) for delivering data (DA) and includes a carrier signal generator (6) for generating a carrier signal (CS) and includes modulation means (7) to which can be applied the data (DA) and the carrier signal (CS) and which modulation means are provided for modulating a carrier signal (CS) in accordance with the data (DA) and for delivering a modulated carrier signal (CSM) to transmitting means (8) having an input resistance (9), the modulation means (7) have a changeable output resistance (10) which forms a resistance network together with the input resistance (9) of the transmitting means (8), and resistance change means (25) for changing the output resistance (10) in accordance with the data (DA).
摘要:
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.
摘要:
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.
摘要:
A data carrier (1), or a circuit (2) for such a data carrier (1), which is arranged to receive a carrier signal (CSM) amplitude modulated in conformity with data (DA), is provided with data regenerating means (12) for regenerating data (DA) modulated on the amplitude modulated carrier signal (CSM), and with data processing means (28) for processing data (DA), the data regenerating means (12) additionally including receiving storage means (20) for temporarily storing a predetermined quantity of data (DA), and also detection means (22) for detecting the fact that the predetermined quantity of data (DA) has been buffered in the receiving storage means (20), the detection means (22) being capable of generating control information (CI1) whereby the data processing means (28) can be switched over from a power saving operating mode to a normal operating mode.
摘要:
A data carrier receives an amplitude-modulated carrier signal that is amplitude modulated in dependence on data to be received. The modulated carrier signal has a high interval of high amplitude and a pause interval of reduced amplitude. The data carrier has a data processor for processing received data. The data carrier generates d.c. power from the received carrier signal and stores the d.c. power, and detects the pause interval. Upon detecting the pause interval, the data carrier generates an identification signal from the received carrier signal. The identification signal is a logic gating signal. In dependence of the identification signal, a controller causes the application of a clock signal to data processor to be inhibited.
摘要:
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).
摘要:
In a data carrier with a data processing device in which there is provided an external as well as an internal power supply, it is proposed to provide at least one switching means in which is accommodated in the data carrier in order to realize temporary decoupling of the external power supply, thus making the retrieval of sensitive data impossible.
摘要:
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.
摘要:
A data carrier processing system is provided for receiving an amplitude-modulated carrier signal. The system includes rectifiers and a voltage limiter that limits the d.c. supply voltage that is provided by the rectifiers. The voltage limiter provides a delayed response to amplitude variations in the carrier signal, so as to avoid adverse effects on the modulation of the carrier signal, while also providing an un-delayed response to excess amplitude values, so as to avoid excessive d.c. supply voltage for circuit elements of the data carrier system.