CDM simulator for testing electrical devices

• US 20010056340A1
• Filed: 06/18/2001
• Published: 12/27/2001
• Est. Priority Date: 06/26/2000
• Status: Abandoned Application

• Current Assignee: Integral Solutions International
• Original Assignee: Integral Solutions International
• Inventors: Gorin, Igor Anatoly, Moore, Christopher Thomas
• Application Number:
  US09/886,081
• Publication Number:
  US 20010056340A1
• Time in Patent Office: Days
• US Class Current: 703/14
• CPC Class Codes: G01R 31/002 where the device under test is an electronic circuit
• CPC Class Codes: G01R 31/129 of components or parts made of semiconducting materials; of LV components or parts G01R31/18 takes precedence
• CPC Class Codes: G11B 5/40 Protective measures on heads, e.g. against excessive temperature G11B5/31 takes precedence; protection against wear G11B5/255 ; protective structure of the head: see under structures, e.g. G11B5/3106
• CPC Class Codes: G11B 5/455 Arrangements for functional testing of heads; Measuring arrangements for heads

Abstract

A CDM simulator for a magnetic recording head can be used for the in situ testing of such heads and also for electrical and/or magnetic characterization. The recording head is disposed in the simulator adjacent a discharge plate of an electrically conductive material with a dielectric layer disposed therebetween. The recording head is resistively coupled to a ground potential. A stored charge is injected into the discharge plate. When the charge is injected, a current transient similar to electrostatic discharge, is developed through the magnetic recording head.

Claims

1. In a CDM simulator for providing a rapid discharge of an electrical current transient to test an electrical device under test, a test circuit comprising:

an electrically conductive material having a dielectric layer coextensively disposed thereon, said layer being adapted to receive said device when said device is under test;

a charge capacitor;

a normally open discharge switch electrically coupled in series between said electrically conductive material and said charge capacitor defining a first node between said charge capacitor and said discharge switch, said first node being adapted to have a power source resistively connected thereto to store a charge on said charge capacitor; and

a resistor adapted to be electrically connected in series between said charge capacitor and said device when said device is under test defining a second node between said resistor and said charge capacitor, said second node being normally grounded, whereby closing of said discharge switch subsequent to said charge being stored on said charge capacitor causes said current transient to be discharged through said device under test.

2. A test circuit as set forth in

claim 1

wherein said discharge switch is a wet relay switch.

3. A test circuit as set forth in

claim 1

wherein said discharge switch is a mercury switch.

4. A test circuit as set forth in

claim 1

further comprising a connection wire to be coupled electrically intermediate said resistor and said device under test.

5. A test circuit as set forth in

claim 4

wherein said connection wire has a predetermined inductance per unit length.

6. A test circuit as set forth in

claim 1

wherein said electrically conductive material is a charge plate having a first surface, said dielectric material being disposed on said first surface.

7. A test circuit as set forth in

claim 1

further comprising a decoupling resistor electrically connected to said first node, said power source being adapted to connect to said resistor.

8. A CDM simulator for providing a rapid discharge of an electrical current transient to a device under test comprising:

an electrically conductive material having a dielectric layer coextensively disposed thereon, said layer being adapted to receive said device when said device is under test;

a charge capacitor;

a normally open discharge switch electrically coupled in series between said electrically conductive material and said charge capacitor defining a first node between said charge capacitor and said discharge switch;

a power source resistively connected to said first node to store a charge on said charge capacitor; and

a resistor adapted to be electrically connected in series between said charge capacitor and said device when said device is under test defining a second node between said resistor and said charge capacitor, said second node being normally grounded, whereby closing of said discharge switch subsequent to said charge being stored on said charge capacitor causes said current transient to be discharged through said device under test.

9. A CDM simulator as set forth in

claim 8

wherein said discharge switch is a wet relay switch.

10. A CDM simulator as set forth in

claim 8

wherein said discharge switch is a mercury switch.

11. A CDM simulator as set forth in

claim 8

further comprising a connection wire to be coupled electrically intermediate said resistor and said device under test.

12. A CDM simulator as set forth in

claim 11

wherein said connection wire has a predetermined inductance per unit length.

13. A CDM simulator as set forth in

claim 8

wherein said electrically conductive material is a charge plate having a first surface, said dielectric material being disposed on said first surface.

14. A CDM simulator as set forth in

claim 8

further comprising a decoupling resistor electrically connected between said power source and said first node.

15. A method for providing a rapid discharge of an electrical current transient to test in situ an electrical device comprising:

spacing proximally said device from an electrically conductive material;

connecting resistively said device to ground potential; and

injecting an electrical charge into said electrically conductive material whereby said current transient is discharged through said device.

16. A method as set forth in

claim 15

wherein said spacing includes placing a dielectric material intermediate said electrically conductive material and said device.

17. A method as set forth in

claim 15

wherein said injecting includes:

charging a charge capacitor to store said charge thereon;

switching said charge to electrically conductive material.

18. A method as set forth in

claim 15

further comprising varying the inductance of a discharge path of said current transient.

19. A method as set forth in

claim 18

wherein said varying includes electrically connecting variable lengths of a connection wire having a predetermined inductance per unit length in series between said device and ground potential.

20. A method for providing a rapid discharge of an electrical current transient to test in situ an electrical device comprising:

placing a layer of a dielectric material on a first surface of a discharge plate of an electrically conductive material, said device being placed on said layer;

connecting a resistor in series between said device and ground potential;

connecting a normally open discharge switch and a charge capacitor in series between said resistor and said discharge plate wherein a first node is defined between said discharge switch and said discharge capacitor and a second node is defined between said resistor and discharge capacitor, said second node being coupled to ground potential; and

storing a charge on said charge capacitor, whereby closing of said discharge switch injects said charge into said electrically conductive material whereby said current transient is discharged through said device.

21. A method as set forth in

claim 20

wherein said storing includes connecting a power source through a decoupling resistor to said first node when said discharge switch is open.

22. A method as set forth in

claim 20

further comprising varying the inductance of a discharge path of said current transient.

23. A method as set forth in

claim 22

wherein said varying includes electrically connecting variable lengths of a connection wire having a predetermined inductance per unit length in series between said device and said resistor.