Apparatus and method of use of radiofrequency identification tags

• US 5,583,819 A
• Filed: 01/27/1995
• Issued: 12/10/1996
• Est. Priority Date: 01/27/1995
• Status: Expired due to Term

• Current Assignee: Single Chip Holdings Incorporated
• Original Assignee: Single Chip Holdings Incorporated
• Inventors: Roesner, Bruce B., Ames, Ronald M.
• Primary Examiner(s): NGUYEN, TAN
• Application Number:
  US08/379,923
• Time in Patent Office: 683 Days
• Field of Search: 365/96, 365/225.7, 327/525, 340/825.34, 235/492, 235/380
• US Class Current: 340/10.51
• 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: G11C 17/18 Auxiliary circuits, e.g. for writing into memory

Abstract

A method of programming or writing to an RFID tag with a transient pulse at both high and low frequencies, i.e. in the GHz and KHz ranges is described. Programming an RFID tag using transient pulses rather than a long duration regulated signal allows for less control circuitry, less programming time, less energy, less cost and power requirements for the RFID tag.

Claims

1. A method of programming a radiofrequency identification device comprising:

providing an antifuse in a memory cell coupled to a bit line in said radiofrequency identification device;

charging a stray capacitance on said bit line; and

selectively discharging said antifuse to draw a high peak current through said antifuse from said charged stray capacitance to program said antifuse,

whereby said antifuse is programmed at high speed and low power.

2. The method of claim 1 where charging said stray capacitance comprises charging said capacitance to a voltage exceeding the antifuse programming voltage.

3. The method of claim 1 where charging said stray capacitance on said bit line charges said capacitance with approximately 60 microwatts of power or less.

4. The method of claim 1 where charging said stray capacitance on said bit line charges said capacitance with approximately less than 100 microwatts of power.

5. The method of claim 1 where selectively discharging said antifuse couples said antifuse through a gated transistor to ground, said gated transistor having a maximum saturation current capacity, said antifuse having a programming time defined for a predetermined time duration, said stray capacitance on said bit line being charged to a power level such that said saturation current is achieved through said antifuse and transistor during said programming time of said antifuse.

6. A method of programming an antifuse having a minimum programming time at high speed and low power comprising:

charging a bit line coupled to said antifuse to a predetermined voltage and thus stored predetermined power level, said bit line having a chargeable capacitance; and

discharging said bit line through said antifuse at high speed substantially equal to said minimum programming time required by said antifuse to generate a voltage and current spike through said antifuse sufficient to program said antifuse while utilizing low average power.