Antifuse memory cell and antifuse memory cell array

• US 6,570,805 B2
• Filed: 12/20/2000
• Issued: 05/27/2003
• Est. Priority Date: 12/20/2000
• Status: Expired due to Fees

• Current Assignee: Actel Corporation (Microchip Technology Incorporated)
• Original Assignee: Actel Corporation (Microchip Technology Incorporated)
• Inventors: McCollum, John
• Primary Examiner(s): MAI, SON LUU
• Application Number:
  US09/742,550
• Publication Number:
  US 20020075744A1
• Time in Patent Office: 888 Days
• Field of Search: 326/37, 326/38, 326/21, 327/525, 257/530, 365/225.7, 365/96
• US Class Current: 365/225.7
• CPC Class Codes: G11C 17/16 using electrically-fusible links

Abstract

An antifuse memory cell comprises a first antifuse having a first electrode and a second electrode, a second antifuse having a first electrode and a second electrode, and an MOS transistor having a gate, a source and a drain, wherein the first electrode of the first antifuse is connected to the first electrode of the second antifuse, and the drain of the MOS transistor is connected to said first electrode of the first antifuse and the first electrode of the second antifuse.

Claims

1. The programmable circuit structure comprising;

a first circuit node and a second circuit node programmably coupled by a pass transistor having a control gate; and

an antifuse memory cell coupled to said control gate wherein said antifuse memory cell comprises;

a first antifuse having a first electrode coupled to said control gate through an output node and a second electrode coupled to a pull-up voltage source;

a second antifuse having a first electrode coupled to said control gate through said output node and a second electrode coupled to a pull-down voltage source.

2. The antifuse memory cell of claim 1 wherein said second electrode of said first antifuse is coupled to said pull-up voltage source through a first switch transistor, said second electrode of said second antifuse is coupled to said pull-down voltage source through a second switch transistor and said first and second antifuses are coupled to said control gate through a pass transistor.

3. The antifuse memory cell of claim 2 further comprising:

a pair of first addressing transistors, a first one of said pair of addressing transistors coupled between a first source programming potential and said second electrode of said first antifuse, a second one of said pair of addressing transistors coupled between a second programming source potential and said second electrode of said second antifuse; and

a second addressing transistor coupled between said output node and a ground potential.

4. The antifuse memory cell of claim 3 further comprising:

a programming transistor coupled between said output node and a ground potential;

a testing transistor coupled between said output node and a precharge Vpp source; and

a means for reading the voltage on the output node coupled to said antifuse node.