Method of speeding power-up of an amplifier, and amplifier

• US 6,941,124 B1
• Filed: 02/11/2000
• Issued: 09/06/2005
• Est. Priority Date: 05/13/1996
• Status: Expired due to Fees

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Technology, Inc.
• Inventors: Ovard, David K., Tuttle, John R., Rotzoll, Robert R., Tuttle, Mark E., Lowrey, Tyler, Higgins, Brian P., Yu, Shu-Sun, O'Toole, James E., Devereaux, Kevin M., Pax, George E.
• Primary Examiner(s): Corsaro, Nick
• Assistant Examiner(s): SOBUTKA, PHILIP
• Application Number:
  US09/502,693
• Time in Patent Office: 2,034 Days
• Field of Search: 455/341, 455/342, 455/194.2, 455/231, 455/253.2, 455/241.1, 455/291, 455/293, 455/311, 455/312, 455/333, 330/64, 330252-253, 330/261, 330302-303, 330/9, 330/141, 330/281, 327/555, 327/557, 327/563, 342/28
• US Class Current: 455/341
• CPC Class Codes: G06K 19/0707 the arrangement being capable of collecting energy from external energy sources, e.g. thermocouples, vibration, electromagnetic radiation G06K19/0702 takes precedence
• CPC Class Codes: G06K 19/0712 the arrangement being capable of triggering distinct operating modes or functions dependent on the strength of an energy or interrogation field in the proximity of the record carrier active means for hindering electromagnetic reading or writing G06K19/07336
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 19/0726 the arrangement including a circuit for tuning the resonance frequency of an antenna on the record carrier
• CPC Class Codes: G06K 19/07758 arrangements for adhering the record carrier to further objects or living beings, functioning as an identification tag
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10059 transponder driven
• CPC Class Codes: H03L 7/0995 the oscillator comprising a ring oscillator
• CPC Class Codes: H03L 7/148 said digital means comprising a counter or a divider

Abstract

An amplifier powered by a selectively engageable voltage source and a method for operating the amplifier. The amplifier includes first and second electrodes for receiving an input signal to be amplified. The first and second electrodes are adapted to be respectively connected to coupling capacitors. The amplifier also includes a differential amplifier having inputs respectively connected to the first and second electrodes, and having an output. The amplifier additionally includes selectively engageable resistances coupled between the voltage source and respective inputs of the differential amplifier and defining, with the coupling capacitors, the high pass characteristics of the circuit. The amplifier further includes second selectively engageable resistances coupled between the voltage source and respective inputs of the differential amplifier. The second resistances respectively have smaller values than the first mentioned resistances, and are engaged and then disengaged in response to the voltage source being engaged.

Claims

1. An amplifier configured to be powered by a selectively engageable voltage source, the amplifier comprising:

a differential amplifier having first and second inputs for receiving an input signal to be amplified, and having an output;

first resistances between the voltage source and respective inputs of the differential amplifier; and

second, selectively engageable, resistances between the voltage source and respective inputs of the differential amplifier, the second resistances respectively having smaller resistance values than the first resistances, the second resistances being engaged then disengaged in response to the voltage source being engaged.

2. An amplifier in accordance with claim 1 and further comprising coupling capacitors respectively coupled to the first and second inputs.

3. An amplifier in accordance with claim 1 and further comprising a voltage divider, and wherein the first and second resistances are coupled to the voltage source via the voltage divider.

4. An amplifier in accordance with claim 1 wherein the first resistances comprise respective transistors.

5. An amplifier in accordance with claim 1 wherein the first resistances comprise respective p-type transistors.

6. An amplifier in accordance with claim 1 wherein the second resistances comprise respective transistors.

7. An amplifier in accordance with claim 1 wherein the second resistances comprise respective p-type transistors.

8. A method of speeding power up of an amplifier stage configured to be powered by a voltage source and including a differential amplifier having first and second inputs configured to receive an input signal to be amplified, and having an output;

and resistances between the voltage source and respective inputs of the differential amplifier, the method comprising;

shorting around the selectively resistances for an amount of time in response to the voltage source being engaged.

9. A method in accordance with claim 8 wherein the shorting comprises engaging selectively engageable second resistances respectively coupled in parallel with the first mentioned resistances and having respective resistance values lower than the first mentioned resistances.

10. A method of speeding power up of an amplifier stage configured to be powered by a voltage source and including first and second electrodes configured to receive an input signal to be amplified, the input electrodes being adapted to be respectively coupled to coupling capacitors;

a differential amplifier having inputs respectively connected to the first and second electrodes, and having an output; and

resistances between the voltage source and respective inputs of the differential amplifier, the method comprising;

shorting around the resistances for a predetermined amount of time in response to the voltage source being engaged, the shorting comprising engaging selectively engageable second resistances respectively coupled in parallel with the first mentioned resistances and having respective resistance values lower than the first mentioned resistances.

11. A receiver comprising:

a Schottky diode detector;

an amplifier coupled to the Schottky diode detector and configured to be powered by a selectively engageable voltage source, the amplifier including;

a differential amplifier having first and second inputs coupled to the Schottky diode detector to amplify a signal generated by the Schottky diode detector, and having an output;

first resistances between the voltage source and respective inputs of the differential amplifier; and

second, selectively engageable, resistances between the voltage source and respective inputs of the differential amplifier, the second resistances respectively having smaller resistance values than the first resistances, the second resistances being engaged then disengaged in response to the voltage source being engaged.

12. A receiver in accordance with claim 11 and further comprising coupling capacitors respectively coupled between the Schottky diode detector and the first and second inputs of the differential amplifier.

13. A receiver in accordance with claim 11 wherein the amplifier further comprises a voltage divider, and wherein the first mentioned and second resistances are coupled to the voltage source via the voltage divider.

14. A receiver in accordance with claim 11 wherein the first mentioned resistances of the amplifier comprise respective transistors.

15. A receiver in accordance with claim 11 wherein the first mentioned resistances of the amplifier comprise respective p-type transistors.

16. A receiver in accordance with claim 11 wherein the second resistances of the amplifier comprise respective transistors.

17. A receiver in accordance with claim 11 wherein the second resistances comprise respective p-type transistors.

18. A method of speeding power-up of an amplifier stage of a receiver having a Schottky diode detector, the amplifier stage being configured to be powered by a voltage source and including a differential amplifier having first and second inputs configured to receive an input signal to be amplified from the Schottky diode detector, and having an output;

and selectively resistances between the voltage source and respective inputs of the differential amplifier, the method comprising;

shorting around the resistances for an amount of time in response to the voltage source being engaged.

19. A method in accordance with claim 18 wherein the shorting comprises engaging selectively engageable second resistances respectively coupled in parallel with the first mentioned resistances and having respective resistance values lower than the first mentioned resistances.

20. A method of speeding power up of an amplifier stage of a receiver having a Schottky diode detector, the amplifier stage being configured to be powered by a voltage source and including first and second electrodes configured to receive an input signal to be amplified, the input electrodes being adapted to be respectively coupled to the Schottky diode detector by coupling capacitors to amplify a signal generated by the Schottky diode detector;

the amplifier stage further including a differential amplifier having inputs respectively connected to the first and second electrodes, and having an output; and

selectively engageable resistances between the voltage source and respective inputs of the differential amplifier, the method comprising;

shorting around the selectively engageable resistances for a predetermined amount of time in response to the voltage source being engaged, the shorting comprising engaging selectively engageable second resistances respectively coupled in parallel with the first mentioned resistances and having respective resistance values lower than the first mentioned resistances.

21. A receiver comprising:

an RF detector;

an amplifier coupled to the RF detector and configured to be powered by a selectively engageable voltage source, the amplifier including;

a differential amplifier having first and second inputs coupled to the Schottky diode detector to amplify a signal generated by the Schottky diode detector, and having an output;

first resistances between the voltage source and respective inputs of the differential amplifier; and

second, selectively engageable, resistances between the voltage source and respective inputs of the differential amplifier, the second resistances respectively having smaller resistance values than the first resistances, the second resistances being engaged then disengaged in response to the voltage source being engaged.

22. A receiver in accordance with claim 21 wherein the RF detector comprises a Schottky diode detector.

23. A receiver in accordance with claim 21 wherein the second resistances comprise transistors.

24. An amplifier configured to be powered by a selectively engageable voltage source, the amplifier comprising:

a differential amplifier having first and second inputs for receiving an input signal to be amplified, and having an output;

a first resistance between the voltage source and the first input of the differential amplifier;

a second resistance between the voltage source and the second input of the differential amplifier;

a third, selectively engageable, resistance between the voltage source and the first input of the differential amplifier, the third resistance having a smaller resistance value than the first resistance; and

a fourth, selectively engageable, resistance between the voltage source and the first input of the differential amplifier, the fourth resistance having a smaller resistance value than the first resistance, the third and fourth resistances being engaged then disengaged in response to the voltage source being engaged.

25. An amplifier in accordance with claim 24 wherein the third and fourth resistances are simultaneously engaged then disengaged in response to the voltage source being engaged.

26. An amplifier in accordance with claim 24 wherein the first resistance comprises a transistor.

27. An amplifier in accordance with claim 26 wherein the second resistance comprises a transistor.

28. An amplifier in accordance with claim 24 wherein the third resistance comprises a transistor.

29. An amplifier in accordance with claim 28 wherein the fourth resistance comprises a transistor.

30. A method of speeding power up of an amplifier stage configured to be powered by a voltage source and including a differential amplifier having first and second inputs configured to receive an input signal to be amplified, and having an output, a first resistance between the voltage source and the first input of the differential amplifier, and a second resistance between the voltage source and the second input of the differential amplifier, the method comprising:

simultaneously shorting around the first and second resistances for an amount of time in response to the voltage source being engaged.

31. An amplifier configured to be powered by a selectively engageable voltage source, the amplifier comprising:

a differential amplifier having first and second inputs for receiving an input signal to be amplified, and having an output;

a first resistance between the voltage source and the first input of the differential amplifier;

a second resistance between the voltage source and the second input of the differential amplifier;

circuitry configured to switch around the third and fourth resistances for a predetermined amount of time, to cause the inputs to the differential amplifier to come up to a bias voltage more quickly, in response to the voltage source being engaged.

32. An amplifier in accordance with claim 31 wherein the circuitry configured to switch around the third and fourth resistances comprises respective transistors.

33. An amplifier in accordance with claim 32 wherein the first resistance comprises a transistor.

34. An amplifier in accordance with claim 33 wherein the second resistance comprises a transistor.

35. A method of speeding power up of an amplifier stage configured to be powered by a voltage source and including a differential amplifier having first and second inputs configured to receive an input signal to be amplified, and having an output, a first resistance between the voltage source and the first input of the differential amplifier, and a second resistance between the voltage source and the second input of the differential amplifier, the method comprising:

simultaneously switching around the first and second resistances for a predetermined amount of time in response to the voltage source being engaged.