Antifuse programming, protection, and sensing device

• US 20070085593A1
• Filed: 10/17/2005
• Published: 04/19/2007
• Est. Priority Date: 10/17/2005
• Status: Active Grant

• Current Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Original Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Inventors: Gosmain, Vincent, Wich, Mathew
• Granted Patent: US 7,236,043 B2
• Time in Patent Office: Days
• US Class Current: 327/525
• CPC Class Codes: G11C 17/18 Auxiliary circuits, e.g. for writing into memory

Abstract

An antifuse programming, protection, and sensing device incorporates a control circuit to program and protect an antifuse. The antifuse, which is initially constructed as a low conductivity path, is programmable to a high conductivity path by application of an elevated voltage across terminals of the antifuse. Application of 0 volts to the V_DD node of a conduction control portion of the antifuse programming, protection, and sensing device allows an elevated voltage for programming to be applied to the antifuse. Upon application of a nominal working voltage to the V_DD node of the conduction control circuitry, the antifuse and an adjoining sense amplifier circuit are protected from overvoltage and tampering. The sense amplifier supplies a sense current to the antifuse, measures a voltage at an input to the antifuse, and determines a programmed state if a measured voltage level is low.

Claims

1. An electrical conduction control and sensing device comprising:

a control circuit;

an electrically configurable conduction device coupled to the control circuit and capable of being configured to have a high conductivity;

a sense amplifier coupled to the electrically configurable conduction device and capable of producing a sense current, detecting a magnitude of voltage produced by the sense current, and producing a blown signal; and

a coupling circuit coupled to the electrically configurable conduction device and the sense amplifier, the coupling circuit having means for electrically communicating the sense current to the electrically configurable conduction device and for electrically protecting the sense amplifier.

2. The electrical conduction control and sensing device of claim 1, wherein the control circuit has means for programming the electrically configurable conduction device and electrical protection from overvoltage on the electrically configurable conduction device.

3. The electrical conduction control and sensing device of claim 2, wherein the control circuit provides tampering prevention by preventing an excessive voltage that is applied to an input pad from raising a voltage across the electrically configurable conduction device and causing an erroneous measurement by the sense amplifier, the preventing of excessive voltage is activated while a nominal voltage is applied to a supply node of the electrical conduction control and sensing device.

4. The electrical conduction control and sensing device of claim 1, further defined by a gating logic device coupled to the sense amplifier and capable of communicating a control signal.

5. The electrical conduction control and sensing device of claim 1, wherein the means for electrically protecting the sense amplifier comprises an electrical isolation element.

6. The electrical conduction control and sensing device of claim 1, wherein the sense amplifier has means for measuring a voltage across the electrically configurable conduction device due to the sense current applied and for determining a programmed or non-programmed state of the electrically configurable conduction device.

7. An electrical conduction control and sensing device comprising:

a control circuit;

an electrically configurable conduction device coupled to the control circuit and capable of being configured to have a high conductivity;

a bias circuit coupled to the electrically configurable conduction device and capable of producing a sense current;

a level sensing device coupled to the bias circuit and capable of detecting a voltage level produced by the sense current and producing a blown signal; and

a coupling circuit coupled between the electrically configurable conduction device, the level sensing device, and the bias circuit, the coupling circuit having means for electrically communicating the sense current to the electrically configurable conduction device and for electrically protecting the level sensing device.

8. The electrical conduction control and sensing device of claim 7, wherein the control circuit is configured to have a first plurality of configuring voltages applied and further has means for providing electrical protection of the electrically configurable conduction device.

9. The electrical conduction control and sensing device of claim 8, wherein the control circuit provides tampering prevention by preventing an excessive voltage that is applied to an input pad from raising a voltage across the electrically configurable conduction device and causing an erroneous measurement by the sense amplifier, the preventing of excessive voltage is activated while the first plurality of configuring voltages is applied.

10. The electrical conduction control and sensing device of claim 7, wherein the control circuit is configured to have a second plurality of configuring voltages applied and further has means for providing programming of the electrically configurable conduction device.

11. The electrical conduction control and sensing device of claim 7, further defined by a gating logic device coupled to the level sensing device and capable of communicating a control signal.

12. The electrical conduction control and sensing device of claim 7, wherein the means for electrically protecting the level sensing device comprises an electrical isolation element.

13. The electrical conduction control and sensing device of claim 7, further comprises a means for associating the voltage level produced by the sense current applied to the electrically configurable conduction device to determine either a non-programmed state or a programmed state with a resultant blown signal.

14. An antifuse programming, protection, and sensing device comprising:

a programming device;

an antifuse coupled to the programming device and capable of being configured to have a high conductivity;

a bias circuit coupled to the antifuse and capable of producing a sense current;

a voltage sensing circuit coupled to the bias circuit and capable of detecting a voltage level produced by the sense current and producing a blown signal;

a coupling circuit coupled between the antifuse and the voltage sensing circuit, the coupling circuit capable of electrically communicating the sense current to the antifuse and electrically protecting the voltage sensing circuit; and

a logic gating device coupled to the voltage sensing circuit and capable of communicating a control signal.

15. The antifuse programming, protection, and sensing device of claim 14, wherein the voltage sensing circuit is further capable of determining a programmed or non-programmed state from the detected voltage level across the antifuse and further producing the blown signal upon determination of a programmed state.

16. An electrical conduction control and sensing device comprising:

a control means for configuring and protecting a programmable electronic storage device;

an electrostatic discharge means for protecting an electronic circuit;

an amplification means for sensing a condition of electrical conductivity;

an electrical coupling means for providing electrical isolation of the amplification means; and

a logic inversion means for gating a sense voltage across the programmable electronic storage device.

17. The electrical conduction control and sensing device of claim 16, wherein a first plurality of voltages applied to the control means programs the programmable electronic storage device and a second plurality of voltages applied to the control means protects the programmable electronic storage device.

18. The electrical conduction control and sensing device of claim 17, wherein tampering prevention is provided by the control means preventing an excessive voltage that is applied to an input pad from raising a voltage across the electrically configurable conduction device and causing an erroneous measurement by the sense amplifier, the preventing of excessive voltage is activated while the second plurality of voltages is applied.

19. The electrical conduction control and sensing device of claim 16, wherein the amplification means further applies a current to the programmable electronic storage device and senses a resultant voltage across the programmable electronic storage device to determine a programmed state.