Tire pressure detector having reduced power consumption mechanism

• US 20080297337A1
• Filed: 05/31/2007
• Published: 12/04/2008
• Est. Priority Date: 05/31/2007
• Status: Active Grant

• Current Assignee: Schrader Electronics Limited (Sensata Technologies Holding Plc)
• Original Assignee: Schrader Electronics Limited (Sensata Technologies Holding Plc)
• Inventors: Strahan, Samuel, Marguet, Emmanuel, Bilcliff, Neil, Henriet, Nicholas
• Granted Patent: US 7,741,964 B2
• Time in Patent Office: Days
• US Class Current: 340/447
• 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 23/0433 Radio signals
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

Abstract

A tire pressure detector employs a reduced power consumption mechanism comprising a PLL circuit including a VCO, that is operated in response to the logic states of an input data stream and a power amplifier configured to be externally located to an integrated circuit. The input data stream includes tire pressure information and is configured to be encoded to have multiple logic states. A micro-controller is employed to control the VCO, turning the VCO, and/or the amplifier, on and off for a certain period, according to the pattern of each data bit of the input data stream thus providing reduced current consumption. This tire pressure detector thus embodies an optimized circuit arrangement in terms of power efficiency.

Claims

1. A tire pressure detector, comprising:

a pressure sensor that measures pressure of a tire;

a data processing circuit that receives the tire pressure from said pressure sensor and generates an input data stream, said input data stream configured to be encoded to represent a first logic state and a second logic state, wherein said data processing circuit modulates said input data stream for radio frequency transmission;

a phase-locked loop circuit that includes a voltage controlled oscillator, said voltage controlled oscillator configured to be powered on according to said first logic state and powered off according to said second logic state; and

an RF antenna transmitting the modulated input data stream.

2. The tire pressure detector of claim 1, further comprising a power amplifier disposed between said phase-locked loop circuit and said RF antenna, wherein said power amplifier is powered on according to said first logic state and powered off according to said second logic state.

3. The tire pressure detector of claim 2, wherein said data processing circuit and said phase-locked loop circuit are implemented with an integrated circuit and said power amplifier is external to said integrated circuit.

4. The tire pressure detector of claim 2, wherein said power amplifier comprises one of a Class A type amplifier and a Class B type amplifier.

5. The tire pressure detector of claim 1, wherein said input data stream is encoded to experience transition from high to low or from low to high at half of a bit width of each data bit.

6. The tire pressure detector of claim 1, wherein said voltage controlled oscillator is powered on when said input data stream transitions from high to low and powered off when said input data stream transitions from low to high.

7. A tire pressure detector, comprising:

a pressure sensor that measures pressure in a tire;

an integrated circuit that receives tire pressure information from said pressure sensor and processes it as an RF signal for transmission;

a power amplifier that receives said RF signal from said integrated circuit and amplifies said RF signal, said power amplifier configured to be externally disposed to said integrated circuit; and

an RF antenna connected to said power amplifier and transmitting said RF signal.

8. The tire pressure detector of claim 7, wherein said integrated circuit comprises a phase-locked loop circuit formed thereon.

9. The tire pressure detector of claim 8, wherein said phase-locked loop circuit comprises a voltage controlled oscillator that operates to be turned on and turned off according to a pattern of an input data stream of said integrated circuit.

10. The tire pressure detector of claim 9, wherein said power amplifier operates to be turned on and turned off according to said pattern of said input data stream of said integrated circuit.

11. The tire pressure detector of claim 9, wherein said input data stream is encoded to experience transition from high to low or from low to high at half of a bit width of each data bit.

12. The tire pressure detector of claim 11, wherein said voltage controlled oscillator is turned on when said input data stream transitions from high to low and turns off when said input data stream transitions from low to high.

13. The tire pressure detector of claim 8, wherein said power amplifier comprises one of a Class A type amplifier and a Class B type amplifier.

14. A reduced power consumption mechanism of a tire pressure detector, wherein said tire pressure detector is configured to detect and process tire pressure information, said mechanism comprising:

an input data stream including said tire pressure information and configured to be encoded to have multiple logic states; and

a phase-locked loop circuit including a voltage controlled oscillator that is operated in response to the logic states of said input data stream, wherein said phase-locked loop circuit is implemented with an integrated circuit.

15. The reduced power consumption mechanism of claim 14 wherein said voltage controlled oscillator operates to be turned on and turned off according to a pattern of said input data stream.

16. The reduced power consumption mechanism of claim 15, wherein said input data stream is encoded to experience transition from high to low or from low to high at half of a bit width of each data bit.

17. The reduced power consumption mechanism of claim 14, wherein said voltage controlled oscillator is powered on when said input data stream transitions from high to low and powered off when said input data stream transitions from low to high.

18. The reduced power consumption mechanism of claim 14, further comprising a power amplifier configured to be located external to said integrated circuit.

19. A method comprising:

collecting data at each tire of a plurality of tires of a vehicle representative of at least one tire characteristic;

generating an input data stream employing a data processing circuit at each respective tire, including data responsive to said data representative of said at least one tire characteristic;

encoding said input data stream to comprise a plurality of bits such that each bit of data may contain a plurality of logic states;

powering a voltage controlled oscillator included in a phase-locked loop circuit in response to said logic states within said data bits included in said input data stream;

presenting a signal representative of said input data stream using said voltage controlled oscillator to a power amplifier; and

transmitting said output signal from said power amplifier to a central control unit using additional circuitry contained in said tire pressure detector

20. The method of claim 19 wherein said data comprises data indicative of pressure in said tire.

21. The method of claim 19, wherein said powering a voltage controlled oscillator comprises turning said voltage controlled oscillator on and off according to a-pattern of said input data stream.

22. The method of claim 19, wherein said operating an amplifier comprises turning said amplifier on and off according to said pattern of said input data stream.

23. The method of claim 19, wherein said encoding comprises encoding said input data stream to experience a transition from high to low or from low to high at half of a bit width of each data bit to provide said plurality of bits such that each bit of data contains a plurality of logic states.

24. The method of claim 23, wherein said powering a voltage controlled oscillator comprises powering on said voltage controlled oscillator when said input data stream transitions from high to low and powering off said voltage controlled oscillator when said input data stream transitions from low to high.

25. The method of claim 19, further comprising:

operating said amplifier in response to said logic states within said data bits included in said input data stream.

26. The method of claim 19, further comprising:

locating amplifier external to said integrated circuit