IP Library Granted Patent US 7,020,019
Granted Patent B2
US 7,020,019 · App. 10/912,114 · Granted Mar 28, 2006

System and method for destructive purge of memory device

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Quick Facts
Patent No.
US 7,020,019
App. No.
10/912,114
Granted
Mar 28, 2006
Kind
B2
Abstract

A memory purge system destructively purges the memory circuits of a memory device. The system includes a power supply for supplying a selectable voltage and current. Switching circuits electrically connect the power supply to the memory circuits of the memory device. A controller selects a voltage and current supplied by the power supply and activates the switching circuit to apply the voltage and current to the memory circuits. The controller determines whether the memory circuits have been destroyed by monitoring current flow into the memory circuits.

Claims (25)

1. A memory purge system for destructively purging a memory device, the memory purge system comprising:

a power supply for supplying a selectable voltage and current;

a switching circuit for electrically connecting said power supply to a memory circuit of the memory device;

a controller for selecting a first voltage and current supplied by said power supply and activating said switching circuit to apply the selected first voltage and current to the memory circuit in response to a purge command; and

a current detector for detecting current between said power supply and the memory circuit, wherein, if the detected current drops below a threshold, said controller deactivates said switching circuit to stop the application of the selected voltage and current to the memory circuit.

2. The memory purge system according to claim 1 , wherein the voltage and current are applied to the memory circuit for a predetermined period of time.

3. The memory purge system according to claim 2 , wherein, if the detected current does not drop below the threshold within the predetermined period of time, said controller selects a second voltage, higher than the first voltage, to be supplied by said power supply and reactivates said switching circuit to apply the selected second voltage and current to the memory circuit for the predetermined period of time.

4. The memory purge system according to claim 1 , wherein said switching circuit comprises a transistor.

5. The memory purge system according to claim 4 , wherein said switching circuit further comprises a diode for blocking current flowing from the memory circuit.

6. The memory purge system according to claim 1 , wherein said power supply comprises a converter for converting input power into the selected voltage and current.

7. The memory purge system according to claim 6 , wherein the input power is supplied by the power source external to the memory device.

8. The memory purge system according to claim 1 , wherein the memory device includes a plurality of memory circuits, and the memory purge system further comprises a respective plurality of switching circuits.

9. The memory purge system according to claim 8 , wherein said controller applies the selected voltage and current to each of the plurality of memory circuits by activating each respective switching circuit independently in series.

10. A method for destructively purging a memory device, the method comprising the steps of:

selecting a voltage and current supplied by a power supply;

activating a switching circuit connecting the power supply to a memory circuit of the memory device to apply the selected voltage and current to the memory circuit;

detecting current between the power supply and the memory circuit; and

deactivating the switching circuit if the detected current drops below a threshold,

wherein the switching circuit is activated in response to a purge command.

11. The method according to claim 10 , wherein the voltage and current are applied to the memory circuit of the memory device for a predetermined period of time.

12. The method according to claim 11 , further comprising the steps of:

increasing the supplied voltage by a predetermined period of time; and

reactivating the switching circuit for the predetermined period of time to apply the increased voltage and current to the memory circuit.

13. The method according to claim 12 , further comprising the step of repeating said increasing step and said reactivating step until the current detected in said detecting step drops below the threshold.

14. A method for destructively purging a memory device including a plurality of memory circuits, each memory circuit having a respective switching circuit, the method comprising the step of repeating the steps of the method according to any one of claims 10 and 11 – 13 for each memory circuit.

Assignments (12)
PATENT COLLATERAL AGREEMENT Recorded Aug 23, 2024
From: SANDISK TECHNOLOGIES, INC.
To: JPMORGAN CHASE BANK, N.A., AS THE AGENT
Reel/Frame 068762/0494 →
CHANGE OF NAME Recorded Jun 27, 2024
From: SANDISK TECHNOLOGIES, INC.
To: SANDISK TECHNOLOGIES, INC.
Reel/Frame 067982/0032 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 29, 2024
From: WESTERN DIGITAL TECHNOLOGIES, INC.
To: SANDISK TECHNOLOGIES, INC.
Reel/Frame 067567/0682 →
PATENT COLLATERAL AGREEMENT - A&R LOAN AGREEMENT Recorded Aug 21, 2023
From: WESTERN DIGITAL TECHNOLOGIES, INC.
To: JPMORGAN CHASE BANK, N.A.
Reel/Frame 064715/0001 →
PATENT COLLATERAL AGREEMENT - DDTL LOAN AGREEMENT Recorded Aug 21, 2023
From: WESTERN DIGITAL TECHNOLOGIES, INC.
To: JPMORGAN CHASE BANK, N.A.
Reel/Frame 067045/0156 →
RELEASE OF SECURITY INTEREST AT REEL 052915 FRAME 0566 Recorded Feb 8, 2022
From: JPMORGAN CHASE BANK, N.A.
To: WESTERN DIGITAL TECHNOLOGIES, INC.
Reel/Frame 059127/0001 →
SECURITY INTEREST Recorded Feb 6, 2020
From: WESTERN DIGITAL TECHNOLOGIES, INC.
To: JPMORGAN CHASE BANK, N.A., AS AGENT
Reel/Frame 052915/0566 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 16, 2018
From: HGST TECHNOLOGIES SANTA ANA, INC.
To: WESTERN DIGITAL TECHNOLOGIES, INC.
Reel/Frame 046174/0446 →
CORRECTIVE ASSIGNMENT TO CORRECT THE TYPOGRAPHICAL ERROR IN THE SUPPORTING LEGAL DOCUMENTATION PREVIOUSLY RECORDED ON REEL 015668 FRAME 0099. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT. Recorded Aug 23, 2016
From: SALESSI, NADER; GAZERI, HOSEIN
To: SIMPLETECH, INC.
Reel/Frame 039787/0442 →
CHANGE OF NAME Recorded Jul 1, 2015
From: STEC, INC.
To: HGST TECHNOLOGIES SANTA ANA, INC.
Reel/Frame 036042/0390 →
MERGER AND CHANGE OF NAME Recorded Jun 12, 2007
From: SIMPLETECH, INC.
To: STEC, INC.
Reel/Frame 019440/0517 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 6, 2004
From: SALESSI, NADER; GAZERI, HOSEIN
To: SIMPLETECH, INC.
Reel/Frame 015668/0099 →