Thermal shutdown control for multi-channel integrated...

Details Thermal shutdown control for multi-channel integrated... Thermal shutdown control for multi-channel integrated...

2001-10-03

2003-12-23

Sircus, Brian (Department: 2836)

Electricity: electrical systems and devices

Safety and protection of systems and devices

Circuit interruption by thermal sensing

C361S114000

Reexamination Certificate

active

06667868

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to thermal shutdown control on computer boards and more particularly to thermal shutdown control for motherboards having a number of channels receptive to daughterboards.
BACKGROUND OF THE INVENTION
Motherboards in modem electronic systems can carry one or more daughterboards, each of which can plug into the motherboard. These daughterboards receive power from and exchange signals with the motherboard. During operation, various conditions can occur that can damage the daughterboards, including overly high operating temperatures and over-current conditions. To replace the damaged daughterboards, the entire power supply for the motherboard often needs to be turned off to prevent damage to the motherboard.
In the past, circuits were developed to monitor temperature and over-current conditions in an attempt to prevent damage from occurring to the daughterboards. For example, when an over-temperature and/or over-current condition occurred, the power to that daughterboard could be turned off. While these circuits may successfully protect the daughterboards from damage, it required increasing the motherboard size and component count. This resulted in increased costs because each daughterboard required its own chip to monitor for temperature and current and to provide power shutdown abilities. Additionally, when a fault condition occurred (due to a defective daughterboard), the power to the entire motherboard had to be shut off to allow the replacement of the defective daughterboard. Unfortunately, this also shutoff power to all of the daughterboards carried by the motherboard. Replacing a daughterboard with power still applied could potentially cause a short circuit and overload the main power supply.
Accordingly, what is needed is a way to monitor for over-temperature and overcurrent conditions to daughterboards while minimizing additional board space and component count. Also, the ability to replace individual daughterboards while the main power supply is on is also needed (also referred to as ‘hot-swapping’).
SUMMARY OF THE INVENTION
The present invention provides an improved circuit and method for shutting down power to individual channels on an electronics board, without greatly increasing board size and component count.
A multi-channel power shut-down circuit in accordance with the present invention includes a plurality of channel disabler circuits formed on a common substrate. Each of the channel disabler circuits includes a first combinational logic and a second combinational logic having an input coupled to an output of the first combinational logic. A channel disable output and a channel overcurrent detector are coupled to an input of the first combinational logic. A thermal warning detector is formed on the common substrate and is coupled to the inputs of the first combinational logic of the plurality of channel disabler circuits. A thermal shutdown detector formed on the common substrate and is coupled to the inputs of the second combinational logic of the plurality of channel disabler circuits.
A method in accordance with the present invention for powering down multiple channels including individually monitoring each of a plurality of channels for an overcurrent condition. A thermal warning signal is developed at a first temperature and a thermal shutdown signal is developed at a second temperature greater than the first temperature. A channel is shutdown upon an occurrence of an overcurrent condition for that channel and upon an occurrence of a thermal warning signal. All channels are shutdown upon an occurrence of the thermal shutdown signal.
The present invention therefore provides an improved circuit and method for shutting down power to individual channels on an electronics board. The present invention provides less expensive, more compact and more reliable electronics to be built and maintained. Furthermore, the present invention allows for all of the channels to be shutdown simultaneously if a sufficiently adverse operating condition is detected.
These and other advantages of the invention will become apparent upon a reading of the following descriptions and a study of the various figures of the drawings.


REFERENCES:
patent: 5099381 (1992-03-01), Wilcox
patent: 5119265 (1992-06-01), Qualich et al.
patent: 5206778 (1993-04-01), Flynn et al.
patent: 5239255 (1993-08-01), Shanin et al.
patent: 5267118 (1993-11-01), Marshall et al.
patent: 5285346 (1994-02-01), Davies et al.
patent: 5448174 (1995-09-01), Gose et al.
patent: 5600575 (1997-02-01), Anticole
patent: 5675297 (1997-10-01), Gose et al.
patent: 5710515 (1998-01-01), Teggatz et al.
patent: 5796280 (1998-08-01), Tuozzolo
patent: 5805403 (1998-09-01), Chemla
patent: 5838187 (1998-11-01), Embree
patent: 6098132 (2000-08-01), Olarig et al.
patent: 6199173 (2001-03-01), Johnson et al.
patent: WO98/49761 (1998-11-01), None
Abstract from European Application Publication No. 0797137, Lavaughn, “A Power Switch”, Sep. 24, 1997.
Abstract from European Patent Application Publication No. 00427085, Wilcox, “Enable Circuit With Embedded Thermal Turn-Off”, May 15, 1991.
Exemplary claim from European Patent No. 00398901/EP 81, DeVito, “Interface Circuit For Linear Variable Differential Transformer”, Aug. 4, 1993.
Abstract from Japanese Patent Application No. 09001059, Hara, “Thermal Shutdown Circuit”, Jul. 31, 1998.
Abstract from U.S. Patent No. 6,101,610, Beebe, “Computer System Having Sensing With Dual Voltage Sources For Sensor Stabilization”, Aug. 8, 2000.
Abstract from U.S. Patent No. 6,016,050, Brokaw, “Start-up And Bias Circuit”, Jan. 18, 2000.
Abstract from U.S. Patent No. 5,946,182, Gibson, “Thermal Shutdown And Method For Sensing Thermal Gradients To Extrapolate Hot Spot Temperature”, Aug. 31, 1999.
Abstract from U.S. Patent No. 5,907,233, Jabaji, “Voltage Regulator With Improved Field Coil Current Control System And Warning System”, May 25, 1999.
Abstract from U.S. Patent No. 5,881,251, Fung, “Hot Swap Control Circuit”, Oct. 10, 1996.
Abstract from U.S. Patent No. 5,862,394, Watts, “Electronic Apparatus Having A Software Controlled Power Switch”, Jan. 19, 1999.
Abstract from U.S. Patent No. 5,838,187, Embree, “Integrated Circuit Thermal Shutdown System Utilizing A Thermal Sensor”, Nov. 17, 1998.
Abstract from U.S. Patent No. 5,832,282, Pate, “Method and Apparatus For Implementing Protected Battery Hot Swapping in Portable Computers”, Nov. 3, 1998.
Abstract from U.S. Patent No. 5,805,403, Chemla, “Integrated Circuits Temperature Monitoring And Protection System”, Sep. 8, 1998.
Abstract from U.S. Patent No. 5,796,280, Tuozzolo, “Thermal Limit Circuit With Built-in Hysteresis”, Aug. 18, 1998.
Abstract from U.S. Patent No. 5,740,378, Rehl, “Hot Swap Bus Architecture”, Apr. 14, 1998.
Abstract from U.S. Patent No. 5,737,170, Moyer, “Thermal Shutdown Circuit Using A Pair Of Scaled Transistors”, Apr. 7, 1998.
Abstract from U.S. Patent No. 5,675,297, Gose, “Integrated Pulse-Width Modulation Circuit With Thermal Shutdown Circuit”, Oct. 7, 1997.
Abstract from U.S. Patent No. 5,664,119, Jeffries, “Local Proactive Hot Swap Request/Acknowledge System”, Sep. 2, 1997.
Abstract from U.S. Patent No. 5,640,059, Kammiller, “Power Supply System Including Thermal Current Limiting Protection”, Jun. 17, 1997.
Abstract from U.S. Patent No. 5,615,077, Takizawa, “Active Terminator The Shutdown Of Whick Can Be Detected”, Mar. 25, 1997.
Abstract from U.S. Patent No. 5,579,491, Jeffries, “Local Proactive Hot Swap Request/Acknowledge System”, Nov. 26, 1996.
Abstract from U.S. Patent No. 5,568,373, Small, “Tolerant Power Converter”, Oct. 22, 1996.
Abstract from U.S. Patent No. 5,448,174, Gose, “Protective Circuit Having Enhanced Thermal Shutdown”, Sep. 5, 1995.
Abstract from U.S. Patent No. 5,298,851, Denardis, “Multiple Application Voltage Regulator System and Method”, Mar. 29, 1994.
Abstract from U.S. Patent No. 5,285,346, Davies, “Current Driven Control for a Power Device”, Feb. 8, 1994.
Abstract from U.S. Patent No. 5,267,118, Marshall, “Method and Apparatus for Thermally Separating Devic

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