Method and apparatus providing final test and trimming for a power supply controller

• US 20060053319A1
• Filed: 08/19/2005
• Published: 03/09/2006
• Est. Priority Date: 09/28/1999
• Status: Active Grant

• Current Assignee: Alex B. Dlenguerian, Balu Balakrishnan, Erdem Bircan
• Original Assignee: Alex B. Dlenguerian, Balu Balakrishnan, Erdem Bircan
• Inventors: Balakrishnan, Balu, Bircan, Erdem, Dlenguerian, Alex B.
• Granted Patent: US 7,227,733 B2
• Time in Patent Office: Days
• US Class Current: 713/300
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G11C 29/02 Detection or location of defective auxiliary circuits, e.g. defective refresh counters
• CPC Class Codes: G11C 29/021 in voltage or current generators
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 1/36 Means for starting or stopping converters
• CPC Class Codes: H02M 3/00 Conversion of dc power input into dc power output
• CPC Class Codes: H02M 3/157 with digital control

Abstract

A power supply controller having final test and trim circuitry. In one embodiment, a power supply controller for switched mode power supply includes a selector circuit, a trim circuit, a shutdown circuit and a disable circuit. The trim circuit includes a programmable circuit connection that can be selected by the selector circuit by toggling a voltage on an external terminal such as for example a power supply terminal, a control terminal or a function terminal of the power supply controller. The programmable circuit connection in the trim circuit can be programmed by applying a programming voltage to the external terminal. The shutdown circuit shuts down the power supply controller if the temperature rises above an over temperature threshold voltage. The shutdown circuit includes adjustment circuitry that can be used to test the shutdown circuit. The adjustment circuitry can adjust and reduce the over temperature threshold of the power supply controller. Thus, the power supply controller can be tested without having to actually heat the part. The disable circuit includes a programmable circuit connection, which when programmed prevents further trimming of power supply controller and prevents adjustment of the shutdown circuit over temperature threshold.

Claims

1-47. -47. (canceled)

48. A method for providing a power supply controller circuit, comprising:

selecting through an external terminal of the power supply controller circuit an adjustment circuit of an over temperature shutdown circuit of the power supply controller circuit, the external terminal one of a power supply terminal, a control terminal and a function terminal of the power supply controller circuit, an over temperature shutdown temperature of the over temperature shutdown circuit to be adjusted from a second threshold temperature to a third temperature in response to the adjustment circuit being selected; and

deselecting through the external terminal the adjustment circuit, the over temperature shutdown temperature to be adjusted from the third threshold temperature to the second threshold temperature in response to the adjustment circuit being deselected.

49. The method for providing the power supply controller circuit of claim 48 further comprising:

selecting through the external terminal a trim circuit of the power supply controller circuit; and

applying a programming voltage to the external terminal after selecting the trim circuit to program a first programmable circuit connection of the first trim circuit.

50. The method for providing the power supply controller circuit of claim 48 further comprising:

selecting through the external terminal a disable circuit of the power supply controller circuit; and

applying a programming voltage to the external terminal after selecting the disable circuit to program a second programmable circuit connection of the disable circuit to disable permanently the adjustment circuit from adjusting the over temperature shutdown temperature.

51. The method for providing the power supply controller circuit of claim 50 wherein the over temperature shutdown temperature is adjusted to a first threshold temperature in response to the second programmable circuit being programmed.

52. A method for providing a power supply controller, comprising:

providing a power supply controller circuit including an over temperature shutdown circuit having an over temperature shutdown temperature; and

electrically adjusting the over temperature shutdown temperature of the over temperature shutdown circuit.

53. The method for providing the power supply controller of claim 52 further comprising packaging an integrated circuit die including the power supply controller circuit before electrically adjusting the over temperature shutdown temperature of the over temperature shutdown circuit.

54. The method for providing the power supply controller of claim 52 further comprising:

selecting a disable circuit of the power supply controller with an external terminal of the power supply controller, the external terminal one of a power supply terminal, a control terminal and a function terminal of the power supply controller circuit; and

applying a programming voltage to the external terminal after selecting the disable circuit to disable the over temperature shutdown temperature of the over temperature shutdown circuit from being adjusted.

55. The method for providing the power supply controller of claim 54 wherein applying the programming voltage to the external terminal after selecting the disable circuit adjusts the over temperature shutdown temperature of the over temperature shutdown circuit to a first over temperature threshold.

56. The method for providing the power supply controller of claim 54 wherein electrically adjusting the over temperature shutdown temperature of the over temperature shutdown circuit includes adjusting over temperature shutdown temperature of the over temperature shutdown circuit between a second over temperature threshold and a third over temperature threshold.