MIC2580A Hot-Swap PCI Power Controller - Micrel - #1

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February 2005 1 MIC2580A MIC2580A Micrel, Inc. MIC2580A Hot-Swap PCI Power Controller General Description The MIC2580A is a hot-swap controller that provides for safe and orderly insertion and removal of PCI based adapter cards from a PCI hot-plug compliant system backplane or CompactPCI™ system. The MIC2580A incorporates a circuit breaker function that protects all four supplies (+12V, +5V, +3.3V, and –12V) upon an overcurrent fault condition. Current foldback limiting prevents large transient currents caused by plugging adapter cards into live backplanes, such as in a CompactPCI system. A programmable slew-rate control limits high inrush currents to all loads that occur when power is applied to large capacitive loads. Voltage supervisory functions for all four power supplies are provided by “power good” (/PWRGD) and “overcurrent fault” (/FAULT) diagnostic outputs. Power good and overcurrent fault include deglitch filters to prevent nuisance tripping. Power good is active when all four supplies are within tolerance. Fault (/FAULT) goes active upon overcurrent or overtemperature conditions. The on-off control input (/ON) is used to cycle power to the adapter card. Typical Application 12VOUT 5VGATE 3VGATE VPCHG 12VIN /FAULT GND CSTART /LPCIRST 5VIN 3VIN /PCIRST /EPWRGD /ON CSLEW MIC2580A 5VSENSE 3VSENSE 5VOUT 3VOUT /POR CRST IRF7413 IRF7413 +3.3V +5V +12V /PWRGD M12VIN M12VOUT +12V +5V +3.3V GND –12V –12V 10mÙ 10mÙ VPCH = +1V ±20% (PRECHARGE SUPPLY) Data Bus /HEALTHY /BD_SEL /PCI_RST VIO –12V/1A GND +3.3V/8A +5V/8A +12V/1A /ENUM Data Bus /ON /PCIRST /PGD Adapter Platform Overcurrent Fault VIO D0 D0 D1 D1 D2 D2 Dn Dn VIO PCI Controller /LPCIRST 1.2k 1ìF 1ìF 1ìF 1ìF CompactPCI™ Adapter with Early Power Features • PCI hot-plug and CompactPCI™ hot-swap support • +12V, +5V, +3.3V, and –12V power supply control • Circuit breaker function to protect system • Programmable slew rate control for all supplies • Foldback current-limiting • +5V and +3.3V programmable current-limit thresholds • Undervoltage and overcurrent diagnostic outputs • Deglitch filters on diagnostic fault outputs • Integrated +12V and –12V MOSFET switches • Integrated high-side drivers for 3.3V and 5V external switches • Precharge supply for CompatPCI™ I/O termination Applications • PCI hot-plug systems • CompactPCI™ hot-swap systems Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com CompactPCI is a trademark of the PCI Industrial Computer Manufacturer’s Group.