RADIATION-HARDENED PROGRAMMABLE DEVICE

• US 20080014531A1
• Filed: 07/06/2007
• Published: 01/17/2008
• Est. Priority Date: 10/23/2001
• Status: Active Grant

• Current Assignee: Aeroflex Colorado Springs Incorporated (Cobham PLC)
• Original Assignee: Aeroflex Colorado Springs Incorporated (Cobham PLC)
• Inventors: Gardner, Harry, Kerwin, David
• Granted Patent: US 7,656,699 B2
• Time in Patent Office: Days
• US Class Current: 430/270.11
• CPC Class Codes: G11C 11/4125 Cells incorporating circuit means for protecting against loss of information
• CPC Class Codes: H10B 10/12 comprising a MOSFET load element

Abstract

A method of programming a radiation-hardened integrated circuit includes the steps of supplying a prototype device including an SRAM memory circuit or programmable key circuit to a customer, having the customer develop working data patterns in the field in the same manner as a reading and writing to a normal RAM memory, having the customer save the final debugged data pattern, delivering the data pattern to the factory, loading the customer-developed data pattern into memory, programming the customer-developed data pattern into a number of production circuits, irradiating the production circuits at a total dosage of between 300K and 1 Meg RAD to burn the data pattern into memory, and shipping the irradiated and programmed parts to the customer.

Claims

1. A method of converting a soft SRAM memory into a radiation hardened read-only memory, the method comprising:

programming a data pattern into an SRAM memory;

irradiating the SRAM memory at a total dosage of between 300K and 1 Meg RAD in order to burn the data pattern into memory.

2. The method of claim 1 further comprising shipping the irradiated and programmed parts to the customer.

3. A method of using a radiation-hardened integrated circuit comprising:

receiving soft prototype memory devices;

developing a final, debugged, data pattern using the soft prototype memory devices;

shipping the final data pattern to the factory;

receiving irradiated pin-compatible production memory devices including a read-only version of the final data pattern from the factory.

4. The method of claim 3 in which receiving soft prototype memory devices comprises receiving prototype memory devices including at least one SRAM memory cell.

5. The method of claim 3 in which receiving irradiated pin-compatible production memory devices comprises receiving production memory devices including at least one SRAM memory cell.

6. The method of claim 3 in which receiving irradiated pin-compatible production memory devices comprises receiving production memory devices that have been exposed to a total dose radiation of at least 300K Rads.

7. A programmable key method comprising:

providing a plurality of key circuits;

writing a data pattern into a plurality of key circuits; and

irradiating the key circuits at a total dosage of between 300K and 1 Meg RAD in order to burn the data pattern into memory.

8. The method of claim 7 in which providing a plurality of key circuits comprises providing a plurality of circuits each including an N-channel transistor and a resistor coupled together in a source-follower amplifier configuration.

9. The method of claim 7 in which providing a plurality of key circuits comprises providing a plurality of circuits each including an N-channel transistor and a resistor coupled together in a common-source amplifier configuration.

10. The method of claim 7 in which providing a plurality of key circuits comprises providing a plurality of circuits each including an N-channel transistor and a P-channel transistor coupled together in a common-source amplifier configuration.