MIC2593
Micrel
MIC2593
Dual-Slot PCI Hot Plug Controller
General Description
The MIC2593 is a power controller supporting power distribu-
tion requirements for Peripheral Component Interconnect hot
plug systems compliant to PCI v2.3 and PCI-X 1.0b. The
MIC2593 provides complete power control support for two
PCI slots, including the 3.3V
AUX
defined by the PCI v2.3
specification. Support for +5V, +3.3V, +12V, and –12V sup-
plies is provided and includes programmable current limit,
voltage supervision, fault reporting, and circuit breaker func-
tions which provide fault isolation. The MIC2593 also incor-
porates an SMBus interface that provides complete status
and control of power within each slot.
Features
• Supports two completely independent PCI slots:
- Compliant to PCI v2.3 and PCI-X 1.0b power control
requirements
- Provides all major power control functions for two
independent PCI-X 2.0 slots
• Five voltage supplies supported: +12V, -12V, +5V,
+3.3V, and +3.3V
AUX
- Integrated gate driver circuits, current sense,
and power MOSFETs for 3.3V
AUX
, +12V, and –12V
- High-side +5V and +3.3V gate driver circuits for
external N-Channel MOSFETs
• Overcurrent protection with adjustable timeout elimi-
nates false tripping of circuit breakers
• Dual-level, dual-speed overcurrent detection circuitry for
quick fault response without nuisance tripping
• Slot power control with “Power-is-Good” and Fault
status reporting
- Via software over an SMBus interface or
- Via dedicated hardware input/output lines: Hot Plug
Interface (HPI)
• Complete thermal isolation between circuitry for Slot A
and Slot B
• One General Purpose Input (GPI) pin per slot for
mechanical switch or plug-in card retention/removal
input
Applications
• PCI hot plug power distribution
Ideal Applications:
• Mid- and High-end Server Applications compliant to
PCI v2.3, PCI-X 1.0b, and PCI-X 2.0
Ordering Information
Part Number
MIC2593-2BTQ
MIC2593-5BTQ
5V & 3V Fast-trip
Threshold
100mV
Disabled*
+12V & –12V Fast-trip
Threshold
1.5A/0.4A
1.5A/0.4A
Operating Temp. Range
0°C to +70°C
0°C to +70°C
Package
48-Pin TQFP
48-Pin TQFP
*Contact factory for availability.
LITTLE FOOT is a registered trademark of Siliconix Incorporated
.
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
April 2004
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M9999-042204
MIC2593
Micrel
Typical Application
Power
Supply
+12V
–12V
+5.0V
+3.3V
0.1µF
0.1µF
VSTBY
0.1µF
5
32
17
18
0.1µF
#
Schottky Diode
(Clamp)
PCI Connector
12VINA 12VINB
VSTBYA
12MVINA 12MVINB
VAUXA
15
PCI Bus
0.1µF
6
11
5VINA
0.1µF
26
VSTBYB
5VSENSEA
7
R
SENSE
0.008Ω
*R
12VGATEA
15Ω
0.01µF
Si4420DY
3.3AUXA
375mA
3
34
12VSLEWA
12VSLEWB
5VGATEA
8
**C3
**C4
5VOUTA
3VINA
2
35
9
5V, 5A
12
0.1µF
CFILTERA
CFILTERB
3VSENSEA
3VGATEA
100k
GPIA
GPIB
V
STBY
5VINB
10k
×
4
AUXENA
AUXENB
ONA
ONB
Hot Plug
Controller
V
STBY
45
42
44
43
13
R
SENSE
0.005Ω
V
STBY
**C1
**C2
14
16
10
19
*R
3VGATEA
15Ω
Si4420DY
3.3V, 7.6A
12V, 0.5A
–12V, 0.1A
100k
4
38
GPIA
GPIB
MIC2593
3VOUTA
12VOUTA
12MVOUTA
C
GATE
0.01µF
31
0.1µF
5VSENSEB
AUXENA
AUXENB
ONA
ONB
30
R
SENSE
0.008Ω
*R
12VGATEB
15Ω
Si4420DY
5V, 5A
0.1µF
5VGATEB
29
0.01µF
5VOUTB
28
10k
×
2
/FAULTA
/FAULTB
1
36
3VINB
/FAULTA
/FAULTB
3VSENSEB
3VGATEB
A0
3VOUTB
A1
A2
/INT
SCL
SDA
12VOUTB
12MVOUTB
VAUXB
GND
GND
25
24
R
SENSE
0.005Ω
*R
3VGATEB
41
23
21
27
20
22
33
46
Si4420DY
3.3V, 7.6A
12V, 0.5A
–12V, 0.1A
3.3AUXB
15Ω
SMBus
Base
Address
40
39
37
V
STBY
47
48
C
GATE
0.01µF
PCI Bus
10k
×
3
SDA
SMBus I/O
SCL
/INT
SDA
SCL
/INT
Management
Controller
PCI Connector
* Values for R
5VGATE[A/B]
and R
3VGATE[A/B]
may vary depending upon the C
GS
of the external MOSFETs.
** Values determined by design requirements. See “Functional Description” section for detailed information.
# MBRS140T3 or equivalent is recommended.
Bold
lines indicate high current paths
M9999-042204
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April 2004
MIC2593
Micrel
Pin Configuration
Hot Plug
Control
Interface
SDA
SCL
GND
AUXENA
ONA
ONB
AUXENB
A0
A1
A2
GPIB
/INT
48 47 46 45 44 43 42 41 40 39 38 37
/FAULTA
CFILTERA
12VSLEWA
GPIA
12VINA
5VINA
5VSENSEA
5VGATEA
5VOUTA
12VOUTA
VSTBYA
3VINA
1
2
3
4
5
6
7
8
9
10
11
12
13 14 15 16 17 18 19 20 21 22 23 24
3VSENSEA
3VGATEA
VAUXA
3VOUTA
12MVINA
12MVINB
12MVOUTA
12MVOUTB
3VOUTB
VAUXB
3VGATEB
3VSENSEB
36
35
34
33
32
31
30
29
28
27
26
25
/FAULTB
CFILTERB
12VSLEWB
GND
12VINB
5VINB
5VSENSEB
5VGATEB
5VOUTB
12VOUTB
VSTBYB
3VINB
Slot A
Interface
Slot B
Interface
48-Pin TQFP
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MIC2593
Micrel
Pin Description
Pin Number
5
32
Pin Name
12VINA
12VINB
Pin Function
+12V Supply Power [A/B]: Pin 5 is the input to the drain side of the internal
MOSFET switch for +12V Slot A. Pin 32 is the input to the drain side of the
internal MOSFET switch for +12V Slot B. These two pins must ultimately
connect to each other within 10 cm of the MIC2593. An undervoltage lockout
circuit (UVLO) prevents the switches from turning on while this input is less
than its lockout threshold.
+12V Output [A/B]: Pin 10 is connected to the source terminal of the internal
MOSFET switch for +12V Slot A and pin 27 is connected similarly for Slot B.
–12V Supply Power [A/B]: Pin 17 is the input to the drain side of the internal
MOSFET switch for +12V Slot A. Pin 18 is the input to the drain side of the
internal MOSFET switch for –12V Slot B. These two pins must ultimately
connect to each other within 10 cm of the MIC2593. An undervoltage lockout
circuit (UVLO) prevents the switches from turning on while this input is less
than its lockout threshold.
–12V Output [A/B]: Pin 19 is connected to the source terminal of the internal
MOSFET switch for –12V Slot A and pin 20 is connected similarly for Slot B.
12V Slew Rate Control [A/B]: Connect capacitors between these pins and
ground to set the output slew rates of the +12V and –12V supplies. See the
“Functional Description” section for more details.
5V Supply Power and Sense Input [A/B]: Pin 6 is the (+) Kelvin-sense
connection to the supply side of the sense resistor for 5V Slot A. Pin 31 is
the (+) Kelvin sense connection to the supply side of the sense resistor for
5V Slot B. These two pins must ultimately connect to each other within
10 cm of the MIC2593. An undervoltage lockout circuit (UVLO) prevents the
switches from turning on while this input is less than its lockout threshold.
5V Circuit Breaker Sense Input [A/B]: The current limit thresholds are set
by connecting sense resistors between these pins and 5VIN[A/B]. When
the current limit threshold of IR = 50mV is reached, the 5VGATE[A/B] pin
is modulated to maintain a constant voltage across the sense resistor and
therefore a constant current into the load. If the 50mV threshold is exceeded
for t
FLT
(see CFILTER[A/B] pin description), the circuit breaker is tripped and
the GATE pin for the affected supply’s external MOSFET is immediately
pulled low.
5V Power-Good Sense Inputs: Connect to 5V[A/B] outputs. Used to
monitor the 5V output voltages for Power-is-Good status.
5V Gate Drive Output [A/B]: Each pin connects to the gate of an external
N-Channel MOSFET. During power-up, the C
GATE
and the C
GS
of the
MOSFETs are charged by a 25µA current source. This controls the value of
dv/dt seen at the source of the MOSFETs, and hence the current flowing into
the load capacitance.
During current-limit events, the voltage at the pin is adjusted to maintain
constant current through the switch for a period of t
FLT
. Whenever an
overcurrent, thermal shutdown, or input undervoltage fault condition occurs,
the GATE pin for the affected slot is immediately brought low.
During power-down, these pins are discharged by an internal current source.
3.3V Supply Power and Sense Input [A/B]: Pin 12 is the (+) Kelvin-sense
connection to the supply side of the sense resistor for 3.3V Slot A. Pin 25 is
the (+) Kelvin-sense connection to the supply side of the sense resistor for
3.3V Slot B. These two pins must ultimately connect to each other within 10
cm of the MIC2593. An undervoltage lockout circuit (UVLO) prevents the
switches from turning on while this input is less than its lockout threshold.
10
27
17
18
12VOUTA
12VOUTB
12MVINA
12MVINB
19
20
3
34
6
31
12MVOUTA
12MVOUTB
12VSLEWA
12VSLEWB
5VINA
5VINB
7
30
5VSENSEA
5VSENSEB
9
28
8
29
5VOUTA
5VOUTB
5VGATEA
5VGATEB
12
25
3VINA
3VINB
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April 2004
MIC2593
Micrel
Pin Description (cont)
Pin Number
13
24
Pin Name
3VSENSEA
3VSENSEB
Pin Function
3V Circuit Breaker Sense Input [A/B]: The current limit thresholds are set by
connecting sense resistors between these pins and 3VIN[A/B]. When the
current limit threshold of IR = 50mV is reached, the 3VGATE[A/B] pin is
modulated to maintain a constant voltage across the sense resistor and
therefore a constant current into the load. If the 50mV threshold is exceeded
for t
FLT
(see CFILTER[A/B] pin description), the circuit breaker is tripped
and the GATE pin for the affected supply’s external MOSFET is immediately
pulled low.
3.3V Power-Good Sense Inputs: Connect to 3.3V[A/B] outputs. Used to
monitor the 3.3V output voltages for Power-is-Good status.
3V Gate Drive Output [A/B]: Each pin connects to the gate of an external
N-channel MOSFET. During power-up, the C
GATE
and the C
GS
of the
MOSFETs are connected to a 25µA current source. This controls the value
of dv/dt seen at the source of the MOSFETs, and hence the current flowing
into the load capacitance.
During current limit events, the voltage at this pin is adjusted to maintain
constant current through the switch for a period of t
FLT
. Whenever an
overcurrent, thermal shutdown, or input undervoltage fault condition occurs,
the GATE pin for the affected slot is immediately brought low. During power
down, these pins are discharged by an internal current source.
3.3V Standby Input Voltage: Required to support PCI VAUX output.
Additionally, the SMBus logic and internal registers run off of VSTBY[A/B]
to ensure that the MIC2593 is accessible during standby modes. A UVLO
circuit prevents turn-on of this supply until VSTBY[A/B] rises above its UVLO
threshold. Both pins must be connected together externally at the IC.
3.3VAUX[A/B] Output to PCI Card Slot: These outputs connect
the 3.3AUX pin of the PCI connectors to VSTBY[A/B] via internal
400mΩ MOSFETs. These outputs are current limited and protected against
short-circuit faults.
Enable Inputs: Rising-edge triggered. Used to enable or disable the MAINA
and MAINB (5V, 3.3V, +12V and –12V) outputs. Taking ON[A/B] low after a
fault resets the 5V, 3.3V, +12V and/or –12V fault latches for the affected slot.
Tie these pins to GND if using SMI power control. Also, see pin description
for /FAULTA and /FAULTB.
Enable Inputs: Rising-edge triggered. Used to enable or disable VAUXA and
VAUXB outputs. Taking AUXEN[A/B] low after a fault resets the respective
slot’s Aux Output Fault Latch. Tie these pins to GND if using SMI power
control. Also, see pin description for /FAULTA and /FAULTB.
Overcurrent Timer (Filter) Capacitor [A/B]: Capacitors connected between
these pins and GND set the duration of t
FLT
. t
FLT
is the amount of time for
which a slot remains in current limit before its circuit breaker is tripped.
/FAULT[A/B] Outputs: Open-drain, active-low. Asserted whenever the
circuit breaker trips due to a fault condition (overcurrent, input undervoltage,
overtemperature). Each pin requires an external pull-up resistor to VSTBY.
Bringing the slot’s ON[A/B] pin low resets /FAULT[A/B] if /FAULT[A/B]
was asserted in response to a fault condition on one of the slot’s MAIN
outputs (5V, 3.3V, +12V, or –12V).
/FAULT[A/B] is reset by bringing the slot’s AUXEN[A/B] pin low if
/FAULT[A/B] was asserted in response to a fault condition on the slot’s V
AUX
output. If a fault condition occurred on both the MAIN and VAUX[A/B]
outputs of the same slot, then both ON[A/B] and AUXEN[A/B] must be
brought low to de-assert the /FAULT[A/B] output.
16
21
14
23
3VOUTA
3VOUTB
3VGATEA
3VGATEB
11
26
VSTBYA
VSTBYB
15
22
VAUXA
VAUXB
44
43
ONA
ONB
45
42
AUXENA
AUXENB
2
35
1
36
CFILTERA
CFILTERB
/FAULTA
/FAULTB
April 2004
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M9999-042204
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