Title of Invention

'A DATA CARRIER FOR BOTH CONTACTLESS AND WITH CONTACTS OPERATION SYSTEM'

Abstract

A data carrier, in particular a chip card, with a first logic circuit (1), with at least one coil (2) which is connected to the first logic circuit (1) via a contactless interface, the contactless interface obtaining from a signal induced in the coil (2) at least one DC supply voltage (VDD,VSS), a clock signal and a data signal corresponding to a modulation of the induced signal, with a number of contacts (3) connected to the first logic circuit (1) for receiving at least one supply voltage, a clock signal and a data signal, the supply - coltage contact (VCC) being connected to the first logic circuit (1) via a switching element (5).The switching element (5) is of a controllable design and is activated by a second logic circuit (4:40), which is coneected on the input side to the clock-signal contact (CLK). Figure 1

Full Text

Description Data carrier for both contactless and with-contacts operation The invention relates to a data carrier with a first circuit, with a coil which is connected to the first circuit via a contactless interface, the contactless interface obtaining from a signal induced in the coil at least one DC supply voltage, a clock signal and a data signal corresponding to a modulation of the induced signal, and with a number of contacts connected to the first circuit for receiving at least one suppl/ voltage, a clock signal and a data signal, the supply-voLtage contact being connected to the first circuit via a swiching element. Such a da:a carrier is known from WO 96/38814. It is designed there as chip card, to be more precise as a combination chip card. Data carriers according to the invention can, however, also be realized with different forms of housing. In the case of the knwn data carrier, a diode is arranged between the supply-voltage contact and a logic circuit with such polarity that it prevents the DC supply voltage present at the output of the rectifier of the contactless interface, likewise connected to the same supply voltage input of the logic circuit, from punching through to the contact. Such a diode, however, on the one hand requires a certain minimum voltage in order for it to conduct at all and on the other hand has in the forward mode a voltage drop which has a disruptive effect if a low supply voltage is desired. DE 195 31 372 Al discloses a chip card which is suitable for both contactless and with-contacts operation. A switch which makes it possible for a voltage at the supply contact to be switched through to a memory in a manner depending only on the state of a. control signal of a microprocessor, and otherwise connects it to means for contactless operation, is provided there. In the case of the chip card there, operation of the microprocessor from the contactless interface is also prevented by this switch. It is the object of the invention to develop a data carrier of the stated type in such a way that on the one hand a voltage induced in the coil is not present at the supply voltage contact and on the other hand there is no appreciable voltage drop in the forward mode- at a blocking element bringing this about. In addition, access to a microprocessor by the contactle3s means and by the with-contacts means with equal authoriza;ion in terms of the circuitry provided is to be ensured. The objec is achieved by the first circuit being a logic circuit, by the switching element being of a controllable design and by a second logic circuit being connected on the input side to the clock-signal contact and on the output side to the control input of the switching element. In integrated circuit technology, controllable switching elements are usually designed as transistors and have only a very low ::orward resistance, so that the voltage drop across such a switching element during operation of the data carrier via the contacts is negligible. In addition, the low voltage drop means; that lower supply voltages are also possible. In a way according to the invention, the presence of a clock signal is necessary for the conductivity switching of the switching element. second logic circuit is provided in order to establish the presence of the clock signal and activate the switching element correspondingly. In an advantageous development of the invention, the second logic circuit may be both autonomous, that is obtain its supply voltage itself from the clock signal, and connected to the suppl/ voltage. The use o. the clock signal as a criterion for the switching through o: the supply voltage to the first logic circuit has the advantage that the precondition of the presence of a clock signal is not a restrictive condition, since the first logic circuit would not operate without the clock signal even if the supply vo tage were present. Consequently, a signal that iB necessary in any case is used in an advantageous way as a switching condition. The contactless operation usually requires a supply voltage regulator since the operating voltage of the data carrier is obtained from the signal received from the coil and the amplitude of the Bignal can fluctuate considerably on account of the dependence on the distance of the data carrier from a transmitter. The regulated voltage is usually lower than the voltage supplied by the contacts, so that the regulator would be overloaded in contact operation. In a development according to the indention, the output signal of the second logic circuit, detecting the clock signal, is used for deactivating the regulator. The invent ion is explained in more detail below on the basis of exemplary embodiments with the aid of figures, in which: Figure 1 shows a first basic circuit diagram of a data carrier according to the invention, and Figure 2 shows a second basic circuit diagram of a data carrier according to the invention. Figure 1 shows a first logic circuit 1, which is preferably formed by a microprocessor and, in addition, is intended to have the circuits usually necessary and appropriate for the operation of a. microprocessor, "such as a RAM, a ROM or a nonvolatile memory. The first logic circuit 1 is connected to two supply vo.tage lines VDD and VSS. The supply voltage lines VDD and VSS a re connected on the one hand to a rectifier and smoothing network 7, which derives the operating voltage necessary for the contactless operation of the data carrier from a signal received from a coil 2. The supply voltage lines VDD, VSS are, in addition, connected to contacts VCC, VSS of a contact bank 3, in order to make the supply voltage available for the parts of the circuit in the with-contacts operation of the data carrier. The supply voltage line VDD is connected in a way according to the invention to the supply voltage contact VCC via a switching element 5 designed as a PMOS transistor. The switching element 5 is activated by a second logic circuit 4, which for its part is connected to the clock-signal contact CLK. The ;;econd logic circuit 4 detects the presence of a clock signal at the clock-signal contact CLK and, in the presence of a clock signal, activates the switching element 5, so that the supply volcage contact VCC is connected to the supply voltage line VDD and consequently the first logic circuit 1 is supplied with a supply voltage by the contacts 3. The butpu: of the second logic circuit 4, indicating the presence of a clock signal, is also connected directly to the first logic circuit 1, in order to indicate to the first logic circuit that the supply voltage ie coming from the contacts 3. The first logic circuit 1 can use this information to assume a certain operating state, in which for example certain access rights to the memory area are set. In the representation according to Figure 1, the second logic circuit 4 is also connected to a reset terminal RST and an input/outout terminal I/O and passes on the signals originati lg from there to the first logic circuit 1. The second logic circuit 4 may contain in an advantageous way protective structures and also filters. In the example according to Figure l, the second logic circuit 4 is connected to the supply voltage contacts VCC, VSS and can consequently process the incoming clock, reset and input/output signals only when a supply voltage is present. The data carrier according to Figure 1 also has a contactless interface circuit 6, which pre-processes the signal received from the coil 2, in particular obtains from it a clock signal and the data contained on account of a modulation of the signal, and passes this on to the first logic circuit l. The data-processing first logic circuit 1 of the data carrier according to Figure 1 is consequently always connected via the supply lines VDD, VSS to the coil 2 representing the contactlens receiving part, while a connection to the supply voltage contacts of the contact bank 3 takes place via a switching element 5 only if a clock signal is supplied by the contact bank 3. As a result, the switching element 5 on the one hand dffectively prevents the supply voltage supplied by the coil : via the rectifier and smoothing circuit 7 from also being present at the contact bank 3 and from being able to be shorted there, for example by means of a finger resting on it. On the other hand, the voltage drop across the controlled switching element 5 in with-contacts operation via the contacts is only very small and, what is more, the signal from the second logic circuit 4 activating the switching element 5 can also be used to indicate to the first logic circuit 1 that the supply voltage is coming from the contact bank 3. This is necessary because, by contrast with DE 195 31 3 72 Al, the microprocessor contained inr the first logic circuit 1 is connected with fully equal access authorization in terms of the circuitry provided both to the contactless interface and to the with-contacts interface and can consequen:ly also be activated via the coil 2. Represented in Figure 2 is a data carrier in which, by contrast rith the data carrier according to Figure 1, the second logic circuit 40 is of an autonomous design, that is to say is no: connected to the supply voltage contacts VCC, VSS. The second logic circuit 4 0 obtains its supply energy directly from the clock signal and for this purpose may contain, for example, a rectifier. In the representation according to Figure 2, otherwise the same parti; are provided with the same reference numerals as in Figure 1. Unlike the data carrier according to Figure 1, a contactlesss interface circuit 12 is represented, containing both the rectifier and smoothing network and the data-pre-processinr parts of the circuit. For this purpose, data lines to the first logic circuit 1 are provided. The data carrier according to Figure 2 also has an AC-voltage limiting circuit 8 as well as a rectifier-voltage limiting circuit 9, in order to protect the first logic circuit 1 from overloading in contactless operation. On accoun: of the distance-dependent strong fluctuations in the amplcude of the operating voltages VDD, VSS, a voltage regulator 10 is provided, keeping the voltage across the first logic circuit 1 to a value of, for example, 2.1 volts by means of a capacitor CL. Since thi 3 regulator 10 would also regulate the supply voltage in with-contacts operation of the contact bank 3, but this voltage is usually higher then the supply voltage in contactless operation, it would be severely overloaded and possibly even destroyed. For this reason, in a development of the invention, it is either switched off by the output signal of the second logic circuit 40 in the presence of a clock Bignal at the contact bank 3 or is set to such a high regulating voltage that it cannot be overloaded. The voltage limiter circuits and the voltage regulator may of course al;;o be used in a data carrier according to Figure 1. All the parts of the circuit are usually realized as an integrated circuit on a single semiconductor chip. It is of course also possible to use a plurality of semiconductor chips for this. In some cases, it may be desired to have a greater energy store ava:lable for contactless operation than can be produced by integrated circuit technology. For this purpose, in a development of the invention, external terminals 11 may be led to the out side in order to connect an external capacitor there. 1. A dat 3. carrier, in particular a chip card, with a first circuit (l), with at least one coil (2) which is connected to the first circuit (l) via a contactless interface, the contactless interface obtaining from a signal induced in the coil (2) it least one DC supply voltage (VDD, VSS) , a clock signal and a data signal corresponding to a modulation of the induced s.gnal, with a number of contacts (3) for receiving at least one supply voltage, a clock signal and .a data signal, which are connected to the first circuit (1), the supply-voltage contact (VCC) being connected to the first circuit (1) via a switching element (5), characterized in that the first circuit () is a logic circuit, in that the switching element (5) is of a controllable design and in that a second logic circuit ( 40) is connected on the input side to the clock-signal contact (CLK) and on the output side to the control input of t.he switching element (5) , 2. The di.ta. carrier as claimed in claim 1, characterized in that the second logic circuit (40) has a rectifier element (7; 12) for obtaining a supply voltage from the clock signal. 3. The data carrier as claimed in claim 1, characterized in that the second logic circuit (4) is connected to the supply voltage contacts (VCC, VSS). 4. The data carrier as claimed in one of the preceding claims, characterized in that the output of the second logic circuit (4; 40) is connected to a control input of a voltage regulator (10) connected upstream of the first logic circuit Data carrier for both contactless and with-contacts operation A data carrier, in particular a chip card, with a first logic circuit (1), with at least one coil (2) which is connected to the first logic circuit (1) via a contactless interface, the contactless interface obtaining from a signal induced in the coil (2) at least one DC supply voltage (VDD, VSS), a clock signal and a data signal corresponding to a modulation of the induced signal, with a number of contacts (3) connected to the first logic circuit (1) for receiving at least one supply voltage, a clock signal and a data signal, the supply-voltage contact (7CC) being connected to the first logic circuit (1) via a switching element. (5). The switching element (5) is of a controllable design and is activated by a second logic circuit (4; 40), which is connected on the input side to the clock-signal contact (CLK).

Documents:

in-pct-2000-00312-kol-abstract.pdf

in-pct-2000-00312-kol-claims.pdf

in-pct-2000-00312-kol-correspondence others.pdf

in-pct-2000-00312-kol-description complete.pdf

in-pct-2000-00312-kol-drawings.pdf

in-pct-2000-00312-kol-form 1.pdf

in-pct-2000-00312-kol-form 18.pdf

in-pct-2000-00312-kol-form 2.pdf

in-pct-2000-00312-kol-form 3.pdf

in-pct-2000-00312-kol-form 5.pdf

in-pct-2000-00312-kol-letter patent.pdf

in-pct-2000-00312-kol-pa.pdf

in-pct-2000-00312-kol-priority document.pdf

in-pct-2000-00312-kol-reply f.e.r.pdf