Texas Instruments Incorporated Deutschland, Gmbh

Texas Instruments Corporation

Texas Instruments Holland B.v.

Herbert Meier

Andreas Hagl

Martin Sellmeir

Loek J D'Hont

Jim Childers

Anne A Tip

Jens Graul

Ruediger Ganz

Thomas J Flaxl

Konstantin O Aslanidis

Josef H Schurmann

An electronic device and method for half duplex data transmission in a long range keyless entry and go system, and more specifically to an RFID transponder, a corresponding read/write (R/W) unit and methods for operating the RFID transponder and the R/W-unit. There is a first coil, a second coil and a third coil, being arranged as a three-dimensional antenna, a first capacitor, a second capacitor and a third capacitor couplable in parallel to the first coil, the second coil and the third coil, respectively, for selectively forming a first, a second and a third parallel-resonant circuit for receiving radio signals, a series-resonant circuit for transmitting radio signals and a control stage configured to either use one of the first, second or third parallel-resonant circuits for receiving radio signals or the series-resonant circuit for transmitting signals.

Electronic device, method and system for half duplex data transmission

An electronic circuit includes a floating gate transistor with a floating gate capacitor. The floating gate transistor can be programmed to be in an ON or an OFF state by charging the floating gate capacitor. The circuit further includes a deactivation capacitor adapted to store a charge sufficient for deactivating the floating gate transistor temporarily. The deactivation capacitor is connectable in series to the floating gate capacitor. A method for deactivating a floating gate transistor temporarily is provided, wherein the floating gate transistor includes a floating gate capacitor. A deactivation capacitor is charged with a charge sufficient for changing the state of the floating gate transistor temporarily. The deactivation capacitor is connected in series to the floating gate capacitor for deactivating the floating gate transistor.

Electronic circuit with a floating gate transistor and a method for deactivating a floating gate transistor temporarily

An oscillation maintenance circuit for a half-duplex transponder that has an LC resonant circuit, a storage capacitor and a rectifier connected to charge the storage capacitor with a rectified oscillation signal, having an end-of-burst detector providing an end-of-burst signal when the amplitude of the oscillation signal has dropped below a predetermined threshold. A clock regenerator provides a clock signal derived from the oscillation signal. Switching means controlled by the clock signal in the presence of the end-of-burst signal connect the storage capacitor with LC resonant circuit through at least one current limiting resistor during part of the period of the clock signal, in such a manner that energy is fed into the LC resonant circuit.

Oscillation maintenance circuit for half duplex transponder

A power management circuit for a system that has combined power supplies from an inductively coupled circuit and from a battery comprises voltage sensing circuitry for sensing the voltage of each of the power supplies. A switching arrangement selectively connects one of the power supplies with a user or with plural users. The switching arrangement is controlled by appropriate control circuitry in response to outputs from the voltage sensing circuitry. The power management makes the best use of energy received over the inductive interface to preserve battery lifetime.

Method for selecting an inductive or battery power supply based on the voltage sensed therefrom for a transponder system

A vehicular tire pressure monitoring system, including a transponder unit () for each tire to be monitored, the transponder unit having an incorporated RF transmitter () and being physically associated with the tire to be monitored. A pressure sensor for each tire to be monitored is connected to circuitry in a corresponding transponder unit. An interrogator unit () is associated with each transponder unit and physically mounted on a vehicle in proximity to a wheel () whereon a tire to be monitored is mounted. A central RF receiver () for all transponder units is provided. Each transponder unit is inductively coupled with an associated interrogator unit and includes an electric charge accumulation element adapted to be charged by energy inductively supplied from the associated interrogator unit in a first mode of operation, and the charge accumulation element providing a power supply to the RF transmitter of the transponder unit in a second mode of operation.

Tire pressure monitoring system

A security system to prevent unauthorized starting of the engine of a vehicle has a remote control unit ( ) equipped with a transponder which, on reception of an interrogation signal using at least one reception aerial ( ), transmits an identification code group using a transmitter unit ( ). Located in the vehicle is a control unit ( ), which on actuation of a starter button ( ) within the vehicle, transmits the interrogation signal, and subsequently checks the identification code group transmitted by the remote control unit. Starting of the engine will only be possible when the identification code group coincides with the code group expected by it. Connected to the reception aerial ( ) is a signal detector ( ), which has a reaction threshold level that can be toggled between a high value and a low value. This signal detector will relay the interrogation signal to further processing stages only when the interrogation signal level exceeds the set reaction threshold.

Security system to prevent unauthorized starting of the engine of a vehicle

An assembly for generating a consecutive count includes an n-stage binary counter ( ) incrementable by counting pulses in successive cycles and an EEPROM ( ) in which an item of information representing the count achieved in each case is stored in the pauses between the cycles. The EEPROM ( ) comprises n&plus;1 memory cells. A control circuit ( ) is provided causing the contents of the n&minus;1 stages of the binary counter ( ) assigned to the most-significant bits to be stored in the n&minus;1 first memory cells of the EEPROM ( ) and the contents of the n or (n&plus;1) memory cell is changed in alternate cycles. On commencement of each cycle the contents of the n&minus;1 first memory cells of the EEPROM ( ) is transferred into the corresponding stages of the binary counter ( ) and a bit is written into the n stage of the binary counter ( ) formed by linking the contents of the n and (n&plus;1) memory cells of the EEPROM ( ) such that the count corresponds to the count attained in the previous cycle, whereby the counting pulse then increments the binary counter ( ) to the next count.

Assembly for generating a consecutive count

A road vehicle keyless entry system (,) having an in-vehicle communication processor (,) and a remote transponder (,) is provided. The communication processor (,) has a radio frequency receiver (,), a low frequency transmitter/receiver (,) and a controller (,) capable of encrypting and reading the signals sent and received by the low frequency transmitter/receiver (,). The transponder (,) has a radio frequency transmitter (,) that transmits a signal to the communication processor (,) upon receipt of a manual stimulus and a low frequency transmitter/receiver (,) capable of reading and responding to encrypted signals received from the communication processor (,).

Transponder for remote keyless entry systems

Novel means of achieving increased security while still obtaining a low cost, manufacturable device are disclosed and claimed. The first mode of operation is the learn mode which provides means for initial checkout with no security. In the learn mode of operation, the interrogator and transponder may be switched to a predetermined error detection algorithm, i.e. CCITT(Start Mask, CCITT Mask), and certain information is programmed into the transponder memory. During programming, all the bits received from the interrogator are shifted through the preintialized CRC generator. In addition, once the transponder response is sent back to the interrogator, the response is also shifted through a preinitialized CRC generator within the interrogator(which could be a software implementation). Because neither the Cypher Key nor the Function Key are directly readable once programmed, an encryption must be performed to verify the proper Cypher Key and Function Key were programmed into the transponder's memory. In the second and encryption mode of operation, after a special Command/Address is transmitted, a Random Number (which may vary in length but which has a minimum length) is transmitted from the interrogator to the transponder which in turn generates the Signature by shifting the Random Number through the CRC Encryption Generator (initialized with the Cypher and Function Key). The Signature along with data, status and address are transmitted back to the interrogator which in the meantime has predetermined the awaited Signature using the same Cypher and Function Key. If the received Signature and calculated Signature are equal validation is positive and then the programmed data must be locked(especially the Cypher Key and Function Key) to protect them against reprogramming in the future.

Low cost encryption transponder

Transponder signal collision avoidance system incudes a reader and wireless HDX or FDX type transponders (A, B) are disclosed, interrogated by the reader (R) by alternately powering and then reading through cycles corresponding to a number of possible transponders in the interrogation field. The cycles, which include reader power pulses, signify addresses of respective possible transponders, whether in or out of the field. The transponders for this purpose count reader power pulses by end-of-burst detection, increasing a stored count value with each reader power pulse. The transponder responds to the reader by transmission if and only if a stored count value in a read cycle matches a respective transponder address, preventing the transponders from transmitting telegrams interfering with each other. As a method of reader-transponder operation, the collision avoidance scheme thus cycles the reader interrogating through cycles having power pulses according to possible transponders in the field, not only calling the addresses of each of respective possible transponders but also shortening or lengthening read and power steps dependent upon responses received from the transponders.

Transponder signal collision avoidance system

A method is described with the aid of which messages can be transmitted from batteryless transponders to interrogation devices. The interrogation devices are equipped with a receiving section and a transmitting section and as a request to transmit the message stored therein as reaction to an interrogation command rendered effective in the interrogation device said devices transmit an HF interrogation pulse with predetermined carrier frequency and predetermined carrier duration. In the transponder this HF interrogation pulse is utilized to generate a supply voltage. Each interrogation device checks as reaction to an interrogation command whether its receiving section (14) is receiving a signal with the carrier frequency. If no such signal is being received, the interrogation device transmits the HF interrogation pulse after expiry of a wait time of at least the predetermined message duration whereas, if it is receiving a signal with the carrier frequency, the HF interrogation pulse is not sent until the reception of said signal terminates and at least the wait time has expired or a delay time has passed which is longer than the sum of the predetermined carrier duration and the wait time.

Transponder/interrogator protocol in a multi-interrogator field

A transponder arrangement is described having an interrogator unit (10) which transmits at least one RF programming sequence and at least one RF interrogation pulse. The responder unit (12) includes a responder unit receiver (130) for receiving data transmitted by the RF programming sequence from the interrogator unit (10). The responder unit (12) then upon receipt of the RF interrogation pulse transmits data, which may have been modified by the programming sequence from the interrogator unit (10), back to the interrogator unit (10) in the form of a modulated RF carrier. The responder unit (12) further comprises a responder unit energy accumulator (136) which stores energy contained in the RF interrogation pulse and a responder unit end of burst detector (142) which upon detection of a decreasing power level of the RF interrogation pulse sends a RF threshold signal. Further contained within the responder unit (12) is a responder unit RF carrier wave generator (130) operating with the frequency contained in the RF interrogation pulse, which is excited upon receipt of a signal from the pluck circuit (196). The responder unit (12) further comprises a responder unit circuitry means (198,200) for providing from the output signal of the RF carrier wave generator a control signal which is utilized to maintain the RF carrier wave and to modulate the RF carrier to be sent back with the stored data.

Read/write transponder arrangement and method of communication

A Radio Frequency Identification (RFID) system having an interrogator (12) and a transponder (14). The interrogator has a first tuned circuit (28) of a powering frequency for sending a powering burst to a transponder (14), a filter/demodulator (64) for receiving an wireless, modulated RF response from a transponder (14). The interrogator (12) further has a second tuned circuit (29) in electrical communication with a modulator (48), the second tuned circuit (29) having a selected bandwidth about a communication frequency, the selected bandwidth not substantially overlapping the powering frequency and encompassing the bandwidth of the modulated carrier of the RF response. The interrogator also has a controller (16) in electrical communication with the filter/demodulator (64) and the tuned circuits (28,29) and capable of enabling the first tuned circuit (28) to send the powering burst during a first time period and of enabling the modulator (48) in electrical communication with the second tuned circuit (29) to receive the RF response during a second time period. The transponder has a tuned circuit (34), a tuning circuit (54,56) in electrical communication with the tuned circuit (34) for modifying the frequency characteristics of the tuned circuit (34) such that it is can be tuned during the powering burst to the powering frequency and to be tuned during the RF response to the communication frequency. The transponder (14) also includes a demodulator (66) in electrical communication with the tuned circuit (34) for receiving the RF interrogation therefrom and for demodulating data from the RF interrogation.

Transponders, Interrogators, systems and methods for elimination of

A method of communicating between an interrogator (10) and at least a first and second transponder (12). The transponders (12)are separately located within a first and a second vehicle (20) travelling within a first and a second traffic lane, respectively. The method has the steps of providing a first and a second LF antenna (16) associated with and proximity to a first and a second traffic lane, respectively. From each of the first and second LF antennas (16) a continuous LF subcarrier is transmitted to serve as a clock signal for each antenna's associated transponder (12). Initially, a wake-up signal is sent by each of the LF antennas (16) to its associated transponder (12). Following the wake-up signal, a unique lane code is sent by each of the LF antennas (16) to its associated transponder (12). The transponder (12) stores its unique lane code in its memory (70). The transponder then sends a UHF response in a pre-determined time period depending on the unique lane code stored in each of the transponders (12). The time period in which the transponder (12) sends its UHF response is unique to that transponder (12) so that interference between responding transponders (12) is avoided. Other devices, systems and methods are also disclosed.

Growing community of inventors

Moosburg, Germany

Herbert Meier