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
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
MIC2580A
Micrel, Inc.
Ordering Information
Standard
Part Number
Pb-Free
MIC2580A-1.0YTS
MIC2580A-1.6YTS
Precharge
Voltage
1V
1.6V
Temperature
Range
–40°C to +85°C
–40°C to +85°C
Package
24-lead TSSOP
24-lead TSSOP
MIC2580A-1.0BTS
MIC2580A-1.6BTS
Pin Configuration
12VOUT 1
3VGATE 2
3VOUT 3
3VSENSE 4
3VIN 5
/PCIRST 6
/LPCIRST 7
/EPWRGD 8
/PWRGD 9
VPCHG 10
GND 11
M12VIN 12
24 12VIN
23 5VGATE
22 5VOUT
21 5VSENSE
20 5VIN
19 /FAULT
18 CSTART
17 CSLEW
16 /POR
15 CRST
14 /ON
13 M12VOUT
24-lead TSSOP (TS)
Pin Description
Pin Number
1
2
Pin Name
12VOUT
3VGATE
Pin Function
+12V Switched Supply (Output): Load carrying output.
3.3V Gate Drive (Output): Drives gate of external N-channel MOSFET +3V
switch. Adding capacitance will slow the slew rate of the external MOSFET
switch turn-on. (The external MOSFET’s gate is charged by an internal
current source.)
+3.3V Output Voltage Sense (Input): Connect to source of external
N-channel MOSFET (+3V switched output) to monitor for output undervolt-
age conditions.
+3.3V Current Sense (Input): Measures voltage drop across an external
sense resistor with respect to 3VIN for overcurrent detection through the
+3.3V switch.
3V Supply (Input): +3.3V-supply input for current monitoring (reference input
for 3VSENSE). Not a load-current carrying input.
PCI-Bus Reset (Input): Input from PCI bus that resets the internal logic.
3
3VOUT
4
3VSENSE
5
6
3VIN
/PCIRST
MIC2580A
2
February 2005
MIC2580A
Pin Number
7
8
Pin Name
/LPCIRST
/EPWRGD
Pin Function
Micrel, Inc.
Local PCI Reset (Open-Drain Output): Local PCI reset output to PCI
controller. Compliant to CompactPCI specification for LOCAL_PCI_RESET.
Early Power Good (Open-Drain Output): This signal goes active should
/FAULT or /PWRGD go active. No deglitch filtering is provided. This signal
satisfies PCI /RST timing for T
FAIL
per PCI Local Bus Specification, ver-
sion 2.1.
Power Good (Open-Drain Output): Active-low output goes active when all
supplies are within tolerance. (A 20µs delay is inserted prior to activation to
reduce nuisance tripping.)
Precharge Supply (Output): (MIC2580A-1.0) +1V
±20%
supply used for
precharge bias for I/O terminations (CompactPCI only).
Ground
–12V Supply (Input): Input for internal –12V switch.
–12V Switched Supply (Output): Switched –12V supply to PCI Hot Plug
compliant socket. Load carrying output.
On-Off Control (Input): Logic low turns on all switches; logic high turns off all
switches. Also used to reset the device from a circuit breaker condition. The
/ON pin is edge-triggered and requires a high-to-low transition once all four
supplies are above their respective thresholds.
Reset Delay (External Component): Connect to external capactior (C
RST
) to
increase power-on reset delay.
Reset (Open-Drain Output): Active-low signal remains active for a time
determined by C
RST
after all supplies are within tolerance; i.e., /PWRGD is
active. This signal may be used as a reset for logic controllers.
Slew (External Component): Connect to external capacitor (C
SLEW
) to
program the output slew rate of 3VGATE, 5VGATE, 12VGATE (internal) and
M12VGATE (internal).
Start-Up Timer (External Component): Connect to external capacitor
(C
START
) to increase the filter delay used to gate the /FAULT output upon
start-up. Used to prevent nuisance tripping during turn-on of supplies.
Fault (Open-Drain Output/Input): This active-low output signal activated
upon overcurrent or thermal shutdown. Includes 20µs deglitch filter. Fault is
reset using /ON.
Forcing pin low turns off all switches but does not activate the circuit breaker
function.
5V Supply (Input): +5V-supply input for current monitoring (reference
voltage for 5VSENSE). Not a load-current carrying input.
+5V Current Sense (Input): Measures voltage drop across an external
sense resistor with respect to 5VIN for overcurrent detection through the +5V
switch.
+5V Output Voltage Sense (Input): Connect to source of external N-channel
MOSFET (+5V switched output) to monitor for output undervoltage condi-
tions.
5V Gate Drive (Output): Drives gate of external N-channel MOSFET +5V
switch. Adding capacitance will slow the slew rate of the external MOSFET
switch turn-on. (The external MOSFET’s gate is charged by an internal
current source.)
12V Supply (Input): MIC2580A power supply and input for internal +12
switch. Supplies power for internal circuitry.
9
/PWRGD
10
11
12
13
14
VPCHG
GND
M12VIN
M12VOUT
/ON
15
16
CRST
/POR
17
CSLEW
18
CSTART
19
/FAULT
20
21
5VIN
5VSENSE
22
5VOUT
23
5VGATE
24
12VIN
February 2005
3
MIC2580A
MIC2580A
Micrel, Inc.
Absolute Maximum Ratings
(Note 1)
Supply Voltages
+12V Input (V
12VIN
) ................................................. +14V
+5V Input (V
5VIN
) ....................................................... +7V
+3.3V Input (V
3VIN
) .................................................... +7V
–12V Input (V
M12VIN
) ............................................... –14V
/PWRGD, /FAULT, /POR, /EPWRGD, and /PCIRST
Output Current ........................................................... 10mA
Lead Temperature (Soldering)
Standard Package (-x.xBTS)
IR Reflow ......................................... 240°C + 0ºC/-5ºC
Lead-free Package (-x.xYTS)
IR Reflow ......................................... 260ºC + 0ºC/-5ºC
ESD Rating,
Note 3
Human body model ................................................... 2kV
Operating Ratings
(Note 2)
Supply Voltages
+12V Input (V
12VIN
) ............................. +11.4V to +12.6V
–12V Input (V
M12VIN
) ........................... –11.4V to –12.6V
+5V Input (V
5VIN
) ................................... +4.75V to +5.25
+3.3V Input (V
3VIN
) .............................. +3.125V to +3.5V
Temperature Range (T
A
) ........................... –40°C to +85°C
Junction Temperature (T
J
) ........................................ 150°C
Package Thermal Resistance
(θ
JA
)
24-Lead TSSOP .................................................. 83°C/W
Electrical Characteristics
V
12VIN
= 12V, V
5VIN
= 5V, V
3VIN
= 3.3V, V
M12VIN
= –12V; T
A
= 25°C,
bold
values indicate –40°C
≤
T
A
≤
+85°C; unless noted
Symbol
I
12IN
I
5IN
I
3IN
I
12MIN
V
UVLO
Undervoltage Lockout
V
12VIN
increasing
V
12VIN
UVLO hysteresis
V
M12VIN
decreasing
V
M12VIN
UVLO hysteresis
V
5VIN
increasing
V
5VIN
UVLO hysteresis
V
3VIN
increasing
V
3VIN
UVLO hysteresis
V
5VGATE
V
3VGATE
I
5VGATE
I
3VGATE
V
PGTH
5VGATE Voltage
3VGATE Voltage
5VGATE Output Current
during start-up, V
5VGATE
= 5V
during turnoff; /FAULT = 0
3VGATE Output Current
during start-up, V
5VGATE
= 5V
during turnoff; /FAULT = 0
Power Good Threshold Voltage
V
12VOUT
increasing
V
12VOUT
Power-Good hysteresis
V
M12VOUT
decreasing
V
M12VOUT
Power-Good hysteresis
V
5VOUT
increasing
V
5VOUT
Power-Good hysteresis
V
3VOUT
increasing
V
3VOUT
Power-Good hysteresis
V
IL
V
IH
I
IL
Input Leakage Currnet (/ON)
Input Voltage Level (/ON)
logic low
logic high
2.0
–1
1
2.90
60
0.8
4.45
100
3.10
–11.2
50
4.7
11
200
–10
10.5
10.5
2.4
60
11
11
–40
6
–40
6
11.4
2.1
20
2.6
-10.5
100
3.1
8.9
300
-8.3
Parameter
Supply Current
Condition
/ON > V
IH
Min
Typ
2.2
4
0.23
3
Max
3
6
0.4
5
9.8
Units
mA
mA
mA
mA
V
mV
V
mV
V
mV
V
mV
V
V
µA
mA
µA
mA
V
mV
V
mV
V
mV
V
mV
V
V
µA
MIC2580A
4
February 2005
MIC2580A
Symbol
V
OL
Parameter
Output-Low Voltage
(/PWRGD, /FAULT, /POR,
EPWRGD, /LPCIRST)
Overtemperature Shutdown
Threshold
CRST Charge Current
CSTART Charge Current
CSLEW Charge Current
Output MOSFET Resistance
Condition
I
OL
= 2mA
Min
Typ
Micrel, Inc.
Max
0.4
Units
V
T
OV
I
CRST
I
CSTART
I
CSLEW
R
DS(on)12
R
DS(on)M12
T
J
increasing
T
J
decreasing
during turn-on
during turn-on
during turn-on
+12V internal MOSFET, I
DS
= 500mA
–12V internal MOSFET, I
DS
= 200mA
+12V internal MOSFET
–12V internal MOSFET
–100
0
45
45
1.0
–0.4
–9
–9
–30
170
160
–11.5
–11.5
–39
450
430
–45
600
600
100
300
56
55
1.3
–0.5
140
–170
2.4
67
67
1.5
–0.7
˚C
˚C
µA
µA
µA
mΩ
mΩ
µA
µA
mV
mV
A
A
mA
mA
V
1.2
1.92
V
V
V
Output MOSFET Leakage
V
CLTH
I
LIM12
I
LIM12M
Current Limit Threshold Voltage
V
5VIN
– V
5VSENSE
V
3VIN
– V
3VSENSE
+12V internal MOSFET, ramped load
–12V internal MOSFET, ramped load
+12V internal MOSFET, V
OUT
= 0V
–12V internal MOSFET, V
OUT
= 0V
MIC2580A-1.0, I
PCH
= 10mA
MIC2580A-1.6, I
PCH
= 10mA
Current-Limit
Threshold
Short-Circuit Current
V
POR(thr)
V
PCH
V
START
t
GOOD
t
/GOOD
Power-On Reset Threshold Voltage
Precharge Bias Supply
0.8
1.28
1.0
1.6
2.4
Start-up Threshold Voltage
AC Parameters
Early Power-Good
Response Low
Early Power-Good
Response High
Undervoltage to Power-Good Delay
Current-limit to Fault Delay
+5V Current-Limit-to-Off Delay
Note 4
+3.3V Current-Limit-to-Off Delay
Note 4
+12V Current-Limit-to-Off Delay
Note 4
–12V Current-Limit-to-Off Delay
Note 4
Note 1.
Note 2.
Note 3.
Note 4.
See
Figure 4
See
Figure 4
200
100
20
20
ns
ns
µs
µs
µs
µs
µs
µs
V
SENSE
= 10mΩ
V
SENSE
= 10mΩ
+12V
–12V
7
7
25
25
Exceeding the absolute maximum rating may damage the device.
The device is not guaranteed to function outside its operating rating.
Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF.
Off refers to the condition in which the circuit breaker turns all outputs off.
February 2005
5
MIC2580A
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