Miscellaneous active electrical nonlinear devices – circuits – and – Specific identifiable device – circuit – or system – With specific source of supply or bias voltage
Reexamination Certificate
2000-02-28
2001-11-13
Cunningham, Terry D. (Department: 2816)
Miscellaneous active electrical nonlinear devices, circuits, and
Specific identifiable device, circuit, or system
With specific source of supply or bias voltage
C327S543000, C327S541000, C323S283000
Reexamination Certificate
active
06316988
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to the field of electronic devices, and more particularly, but not by way of limitation, to an embedded programmable voltage source that facilitates voltage margin testing in an integrated circuit device.
BACKGROUND OF THE INVENTION
Electrical devices permeate almost every aspect of modern society. Continued advancements in circuit integration has made possible numerous consumer products that were, for the most part, unimaginable even a few years ago.
Yet irrespective of complexity, electronic circuitry continues to require the supply of electrical power, usually in the form of source voltage in order to operate properly. At a basic level, the source voltage originates from an external source, either from an alternating current (AC) line voltage that is transformed and rectified, or a direct current (DC) voltage source device such as a battery pack.
Common source voltages used in electronic devices, such as computers and computer peripheral devices such as disc drives, include nominal voltage levels such as +5.0 volts or +3.3 volts. It is important to ensure that the source voltage or voltages supplied to electronic circuitry remain within specified tolerances to ensure proper operation of (and prevent damage to) the electronic circuitry. Voltage regulators have thus for many years been incorporated into the electronic circuitry of electronic devices to provide regulation of the source voltages to desired levels.
With increases in device complexity, system designers have increasingly employed voltage margin testing as a way to evaluate the robustness of new circuit designs. By adjusting the magnitude of the source voltage, the effects of various environmental conditions likely to be encountered by the device during normal consumer use can be evaluated. Moreover, some devices have been designed with some level of programmability so that, depending upon the requirements of a given application, an optimum magnitude of source voltage can be selected for use by the circuitry. Such adjustable voltage regulators are discussed, for example, by U.S. Pat. No. 5,770,939 and U.S. Pat. No. 5,774,734.
While operable, these and other devices fail to support real-time programmability and level detection, especially for circuits that are integrated into a single device. That is, while external voltage source levels supplied to the device can be readily adjusted up or down to simulate a range of real world voltage supply conditions, and the circuitry adjacent discrete voltage regulators can be manually manipulated to provide different voltage regulator outputs, at present there is no easy way to efficiently perform voltage margin testing in an integrated circuit device that internally incorporates voltage regulation circuitry.
SUMMARY OF THE INVENTION
The present invention provides an apparatus and method for performing voltage margin testing in an integrated circuit device, such as an application specific integrated circuit (ASIC) used in a disc drive.
In accordance with preferred embodiments, an ASIC device is provided with an embedded voltage source having a voltage regulator which outputs a regulated analog voltage at a nominal magnitude, such as +3.3 volts. A voltage monitor provides an indication when the regulated analog voltage varies from the nominal magnitude by an output tolerance range determined as a first selected percentage of the nominal magnitude, such as −10% of +3.3 volts.
An adjustment circuit applies a voltage regulator adjustment signal to the voltage regulator to adjust the regulated analog voltage by a second selected percentage of the nominal magnitude (such as −5% of +3.3 volts). The adjustment circuit further provides a voltage monitor adjustment signal to the voltage monitor to concurrently adjust the output tolerance range to a third selected percentage of the nominal magnitude different from the first selected percentage (such as −40% of +3.3 volts).
In this way, voltage margin testing can be readily performed on remaining circuitry internal to the device without inadvertently resetting the voltage source because of a detected undervoltage (or overvoltage) condition. Moreover, the realtime programmability of the voltage source allows the disc drive to adjust the analog voltage source to optimum levels in response to changing environmental conditions, such as changes in operational temperature.
These and various other features and advantages which characterize the present invention will be apparent from a reading of the following detailed description and a review of the associated drawings.
REFERENCES:
patent: 5285151 (1994-02-01), Akama et al.
patent: 5552696 (1996-09-01), Trainor et al.
patent: 5631547 (1997-05-01), Fujioka et al.
patent: 5696729 (1997-12-01), Kitamura
patent: 5744944 (1998-04-01), Danstrom
patent: 5770939 (1998-06-01), Edwards et al.
patent: 5774734 (1998-06-01), Kikinis et al.
patent: 5856740 (1999-01-01), Rau et al.
patent: 5907237 (1999-05-01), Sekimoto
patent: 5919262 (1999-07-01), Kikinis et al.
patent: 5936388 (1999-08-01), Casper
patent: 5951665 (1999-09-01), Crane, Jr. et al.
patent: 6094367 (2000-07-01), Hsu et al.
patent: 6144606 (2000-11-01), Pan
Forehand Monty A.
Street David R.
Crowe & Dunlevy
Cunningham Terry D.
Seagate Technology LLC
Tra Quan
LandOfFree
Voltage margin testing using an embedded programmable... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Voltage margin testing using an embedded programmable..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Voltage margin testing using an embedded programmable... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2611258