Programmable trimmer for transponder

• US 6,922,134 B1
• Filed: 12/15/1999
• Issued: 07/26/2005
• Est. Priority Date: 04/14/1998
• Status: Expired due to Fees

• Current Assignee: Goodyear Tire & Rubber Company
• Original Assignee: Goodyear Tire & Rubber Company
• Inventors: Yones, Dale Lee
• Primary Examiner(s): Holloway, III, Edwin C.
• Application Number:
  US09/980,725
• Time in Patent Office: 2,050 Days
• Field of Search: 340/10.51, 340/10.5, 340/10.41, 340/10.34, 340/442, 340/447, 340/572.1, 365/192, 324/763, 318/439, 332/109
• US Class Current: 340/10.51
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
• CPC Class Codes: B60C 23/0462 Structure of transmission protocol

Abstract

Programmable trimming for a transponder (102, 200, 400) capable of measuring one or more parameters (e.g., temperature, pressure) in an object (e.g., a tire, 104) and transmitting a data stream (FIGS. 3C, 4B) to an external reader/interrogator (106). The transponder typically operates in a passive mode, deriving its power (Vxx, Vcc, Vdd) from an RF interrogation signal received by an antenna system (210, 410), but can also operate in a battery-powered active mode. The transponder includes memory (238, 438) for storing measurements, calibration data, programmable trim settings (436), transponder II) and the like. The trim settings can be programmed in each transponder'"'"'s EEPROM memory (436), and can be used to control operating characteristics of the transponder, such as modulation index, active/passive mode, current scaling for temperature, and current scaling for pressure. The programmable trim settings feature direct and continuous access (496) to the EEPROM cells containing the trim settings, with a dedicated line (485, 485.n) for each trimming bit, having a sensing circuit (498) powered independently of the EEPROM circuitry.

Claims

1. An RF transponder comprising an EEPROM memory, characterized by:

a trimming bits portion of the EEPROM memory comprising at least one trimming bit; and

at least one trimming bit circuit associated with the at least one trimming bit, wherein each one of the at least one trimming bit circuits comprises;

a trimming EEPROM cell comprising a pair of EEPROM transistors, wherein the pair of EEPROM transistors comprises a first EEPROM transistor and a second EEPROM transistor which cooperate to represent a single bit of trimming information;

a trim sensing circuit;

a reference voltage line connected to the pair of EEPROM transistors;

at least one sensing line connecting the trimming EEPROM cell to the trim sensing circuit; and

a trimming line for outputting the single bit of trimming information from the trim sensing circuit.

2. An RF transponder, according to claim 1, characterized in that:

the first and second EEPROM transistors in each trimming EEPROM cell are programmed to opposite states, wherein the first EEPROM transistor is programmed to the state of the single bit of trimming information.

3. An RF transponder, according to claim 1, characterized in that:

the trim sensing circuit comprises a push-pull amplifier.

4. An RF transponder, according to claim 1, characterized in that:

the trimming EEPROM cell further comprises elements for addressing individual ones of the EEPROM transistors and for including the programmed information in a data stream on a transponder data line, wherein the elements comprise;

a first row selection gate in series with the first EEPROM transistor, and a second row selection gate in series with the second EEPROM transistor;

a line for providing a first trimming row selection signal for controlling the first row selection gate;

a line for providing a second trimming row selection signal for controlling the second row selection gate; and

a column data line connected to the pair of EEPROM transistors.

5. An RF transponder, according to claim 4, characterized in that:

the trimming EEPROM cell further comprises elements for preventing simultaneous output of the programmed information on the trimming line and on the data line, in response to a read trim control signal, wherein the elements comprise;

a first gate transistor in series with the first EEPROM transistor;

a second gate transistor in series with the second EEPROM transistor; and

an enable trim circuit interposed between the trimming EEPROM cell and the trim sensing circuit.

6. An RF transponder, according to claim 1, characterized in that:

the trimming EEPROM cell further comprises elements for addressing and programming individual ones of the EEPROM transistors, wherein the elements comprise;

a first row selection gate in series with the first EEPROM transistor, and a second row selection gate in series with the second EEPROM transistor;

a line for providing a first trimming row selection signal for controlling the first row selection gate, and a line for providing a second trimming row selection signal for controlling the second row selection gate;

a column data line connected to the pair of EEPROM transistors; and

a line for providing a first programming voltage input to the first EEPROM transistor, and a line for providing a second programming voltage input to the second EEPROM transistor.

7. An RF transponder, according to claim 6, characterized by:

an enable trim circuit interposed between the trimming EEPROM cell and the trim sensing circuit for blocking EEPROM programming voltages from the trim sensing circuit and from the trimming line in response to a read trim control signal.

8. An RF transponder, according to claim 1, characterized in that:

the at least one trimming bit in the trimming bits portion of the EEPROM memory stores trimming information selected from the group consisting of modulation index, active/passive mode, current scaling for temperature, and current scaling for pressure.

9. Method of trimming operating characteristics of an RF transponder comprising an EEPROM memory, characterized by:

providing a trimming bits portion of the EEPROM memory comprising at least one trimming EEPROM transistor;

storing at least one trimming bit of programmed information in the at least one trimming EEPROM transistors;

directly sensing the programmed information of each one of the at least one trimming bits by using the gate threshold of each trimming EEPROM transistor for controlling a gate of at least one transistor in a trim sensing circuit which is associated with each one of the at least one trimming bits;

continuously outputting the programmed state of the at least one trimming bit on at least one associated trimming line dedicated to a single one of the at least one trimming bits;

powering the at least one trim sensing circuits and the at least one trimming lines independently of the EEPROM memory; and

using the at least one trimming lines for controlling any circuit in the transponder at any time.

10. Method, according to claim 9, characterized in that:

the operating characteristics represented by the at least one trimming bits in the trimming bits portion of the EEPROM memory are selected from the group consisting of modulation index, active/passive mode, current scaling for temperature, and current scaling for pressure.

11. Method, according to claim 9, characterized by:

powering the at least one trim sensing circuits and the at least one trimming lines with an analog power supply which is sufficient for controlling analog circuitry in the RF transponder so that the RF transponder can utilize the programmed information for analog control at times including times at very low passive power input levels.

12. Method, according to claim 9, characterized by:

addressing individual ones of the at least one trimming EEPROM transistors; and

including the programmed information in a data stream.

14. Method, according to claim 9, characterized by:

addressing and programming individual ones of the at least one trimming EEPROM transistors.

15. Method, according to claim 14, characterized by:

blocking EEPROM programming voltages from the at least one trim sensing circuits and the at least one trimming lines.

13. Method, according to claim 27, characterized by:

preventing simultaneous output of the programmed information on the at least one trimming lines and in the data stream.