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

• US 6,249,185 B1
• Filed: 09/14/1998
• Issued: 06/19/2001
• Est. Priority Date: 05/13/1996
• Status: Expired due to Term

• 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, Devereaux, Kevin M., Pax, George E., OʼToole, James E.
• Primary Examiner(s): Mottola, Steven J.
• Application Number:
  US09/152,662
• Time in Patent Office: 1,009 Days
• Field of Search: 330/69, 330/252, 330/253, 330/261, 330/302, 330/303, 330/9, 330/141, 330/281, 327/555, 327/559, 327/563
• US Class Current: 330/261
• 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 19/0716 at least one of the integrated circuit chips comprising a sensor or an interface to a sensor
• 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 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• 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: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• 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 powered by a selectively engageable voltage source, the amplifier comprising:

first and second electrodes for receiving an input signal to be amplified, the input first and second electrodes being adapted to be respectively connected to coupling capacitors;

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

selectively engageable resistances between the voltage source and respective inputs of the differential amplifier and defining, with the coupling capacitors, the high pass characteristics of the circuit; and

second selectively engageable resistances between the voltage source and respective inputs of the differential amplifier, the second resistances respectively having smaller values than the first mentioned 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 connected to the first and second electrodes.

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

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

5. An amplifier in accordance with claim 1 wherein the first mentioned 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 powered by a voltage source and including first and second electrodes for receiving an input signal to be amplified, the input electrodes being adapted to be respectively connected to coupling capacitors;

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.

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