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 pre-
vents 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 capaci-
tive 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.
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
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Applications
• PCI hot-plug systems
• CompactPCI™ hot-swap systems
Typical Application
10mΩ
1µF
10mΩ
IRF7413
Platform
Adapter
IRF7413
MIC2580A
+12V
+5V
+3.3V
GND
–12V
1µF
5VIN
12VIN
12VOUT
5VSENSE
5VGATE
5VOUT
3VSENSE
3VGATE
3VIN
1µF
1.2k
/PCIRST
/ON
CSLEW
3VOUT
VPCHG
/POR
CRST
/LPCIRST
Overcurrent
Fault
V
IO
V
PCH
= +1V
±20%
(PRECHARGE SUPPLY)
+12V/1A
+5V/8A
+3.3V/8A
GND
–12V/1A
+12V
+5V
VIO
V
IO
+3.3V
/PCI_RST
/BD_SEL
/PCIRST
/ON
/HEALTHY
/PGD
/FAULT
/EPWRGD CSTART
GND
/PWRGD
M12VIN M12VOUT
1µF
–12V
/LPCIRST
/ENUM
D0
D0
PCI
D1 Controller D1
D2
D2
Dn
Dn
Data Bus
CompactPCI™ Adapter with Early Power
CompactPCI is a trademark of the PCI Industrial Computer Manufacturer’s Group.
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
February 2005
1
Data Bus
MIC2580A
MICREL [ MICREL SEMICONDUCTOR ]
