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

• US 8,120,097 B2
• Filed: 12/21/2010
• Issued: 02/21/2012
• 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:
  US12/975,224
• Publication Number:
  US 20110089482A1
• Time in Patent Office: 427 Days
• Field of Search: 257329-340, 257/E29.021, 257/E29.262, 257/E29.318, 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 control element for use in a power supply, the control element comprising:

a first transistor disposed in a first substrate;

a control circuit disposed in a second substrate and coupled to generate a drive signal to control switching of the first transistor to control a transfer of energy between a primary winding to an output winding of the power supply; and

means, disposed in the second substrate, for sensing a first voltage received at the first transistor and for providing a second voltage that is substantially proportional to the first voltage when the first voltage is less than a pinch-off voltage, wherein the second voltage is substantially constant and less than the first voltage when the first voltage is greater than the pinch-off voltage.

2. The control element of claim 1, further comprising means for limiting a current in the first transistor in response to the second voltage.

3. The control element of claim 1, further comprising means for powering the control circuit with current derived from the second voltage.

4. The control element of claim 1, further comprising means for sensing a line voltage condition of the power supply from the second voltage.