Method and apparatus for controlling a circuit with a high voltage sense device

• US 7,872,304 B2
• Filed: 01/15/2010
• Issued: 01/18/2011
• Est. Priority Date: 07/08/2004
• Status: Active Grant

• Current Assignee: Power Integrations Incorporated
• Original Assignee: Power Integrations Incorporated
• Inventors: Disney, Donald R.
• Primary Examiner(s): Lee; Calvin
• Application Number:
  US12/688,778
• Publication Number:
  US 20100117718A1
• Time in Patent Office: 368 Days
• Field of Search: 257/E29.021, 257/E29.262, 257/E29.318, 257329-340, 363 211- 212
• US Class Current: 257/329
• CPC Class Codes: H01L 21/823493 with a particular manufacturing method of the wells or tubs, e.g. twin tubs, high energy well implants, buried implanted layers for lateral isolation [BILLI]
• CPC Class Codes: H01L 27/088 the components being field-effect transistors with insulated gate
• CPC Class Codes: H01L 29/0634 Multiple reduced surface field (multi-RESURF) structures, e.g. double RESURF, charge compensation, cool, superjunction (SJ), 3D-RESURF, composite buffer (CB) structures
• CPC Class Codes: H01L 29/1066 Gate region of field-effect devices with PN junction gate
• CPC Class Codes: H01L 29/1075 of field-effect transistors
• CPC Class Codes: H01L 29/1087 characterised by the contact structure of the substrate region, e.g. for controlling or preventing bipolar effect
• CPC Class Codes: H01L 29/402 Field plates
• CPC Class Codes: H01L 29/7835 with asymmetrical source and drain regions, e.g. lateral high-voltage MISFETs with drain offset region, extended drain MISFETs
• CPC Class Codes: H01L 29/808 with a PN junction gate , e.g. PN homojunction gate H01L29/7725, H01L29/775, H01L29/778, H01L29/806 take precedence
• CPC Class Codes: H02M 1/36 Means for starting or stopping converters
• CPC Class Codes: H02M 3/33507 with automatic control of the output voltage or current, e.g. flyback converters H02M3/33561, H02M3/33569 take precedence
• CPC Class Codes: H03K 17/0822 in field-effect transistor switches

Abstract

A control circuit with a high voltage sense device. In one embodiment, a circuit includes a first transistor disposed in a first substrate having first, second and third terminals. A first terminal of the first transistor is coupled to an external voltage. A voltage provided at a third terminal of the first transistor is substantially proportional to a voltage between the first and second terminals of the first transistor when the voltage between the first and second terminals of the first transistor is less than a pinch-off voltage of the first transistor. The voltage provided at the third terminal of the first transistor is substantially constant and less than the voltage between the first and second terminals of the first transistor when the voltage between the first and second terminals of the first transistor is greater than the pinch-off voltage of the first transistor. The circuit also includes a control circuit disposed in the first substrate and coupled to the third terminal of the first transistor. The circuit further includes a second transistor disposed in a second substrate. A first terminal of the second transistor coupled to the external voltage.

Claims

1. A power supply, comprising:

an energy transfer element;

a first transistor disposed in a first substrate and coupled to an external voltage that is responsive to the energy transfer element, wherein the energy transfer element comprises a primary winding and an output winding, and wherein a control circuit is coupled to control the first transistor to transfer energy from the primary winding to the output winding; and

a high voltage sense element disposed in a second substrate to sense the external voltage received at the first transistor, wherein the high voltage sense element includes a first terminal coupled to receive the external voltage, wherein a voltage provided by the high voltage sense element is substantially proportional to a voltage between the first and a second terminal of the high voltage sense element when the voltage between the first and second terminals is less than a pinch-off voltage of the high voltage sense element, and wherein the voltage provided by the high voltage sense element is substantially constant and less than the voltage between the first and second terminals when the voltage between the first and second terminals is greater than the pinch-off voltage.

2. The power supply of claim 1, wherein the control circuit is disposed in the second substrate and is coupled to control the first transistor responsive to the voltage provided by the high voltage sense element to regulate a transfer of energy through the energy transfer element.

3. The power supply of claim 2, wherein the energy transfer element further comprises a bias winding coupled to provide feedback information representative of an output of the power supply to the control circuit.

4. The power supply of claim 1, further comprising a drive circuit disposed in the second substrate and coupled between the control circuit and the second terminal of the high voltage sense element to control operation of the high voltage sense element.

5. The power supply of claim 1, wherein the high voltage sense element includes a transistor.

6. The power supply of claim 1, wherein the high voltage sense element includes a junction field effect transistor (JFET).

7. The power supply of claim 6, wherein the high voltage sense element further includes a metal oxide field effect transistor (MOSFET).

8. The power supply of claim 1, wherein the first substrate having the first transistor and the second substrate having the high voltage sense element are packaged together as a hybrid package.