MIC2580A Datasheet, PDF (1/21 Pages) Micrel Semiconductor – Hot-Swap PCI Power Controller

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
Applications
• PCI hot-plug systems
• CompactPCI™ hot-swap systems
Typical Application
1µF
10mΩ _IRF7413
10mΩ IRF7413
+12V/1A
+5V/8A
+3.3V/8A
GND
–12V/1A
VIO
/PCI_RST
/BD_SEL
/HEALTHY
/ENUM
+12V
+5V
+3.3V
GND
–12V
MIC2580A
12VIN
5VIN
1µF
12VOUT
5VSENSE
5VGATE
5VOUT
3VSENSE
3VGATE
V_IO
3VIN
3VOUT
1µF
VPCHG
/PCIRST
/ON
1.2k
/POR
V_IO
/PCIRST
CRST
/ON
/LPCIRST
CSLEW
/FAULT
/PGD
/EPWRGD CSTART
/PWRGD
GND
M12VIN M12VOUT
1µF
+12V
+5V
V_PCH = +1V ±20%
(PRECHARGE SUPPLY)
+3.3V
Overcurrent
Fault
–12V
/LPCIRST
D0
D1
PCI
Controller
D0
D1
D2
D2
Dn
Dn
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 [phone] • fax + 1 [phone] • http://www.micrel.com
February 2005
1
MIC2580A