MAXIM MAX5954 Technical data
General Description
The MAX5954 hot-plug controller is designed for PCI
Express™ applications. The device provides hot-plug
control for 12V, 3.3V, and 3.3V auxiliary supplies of a single PCI Express (PCI-E) slot. The MAX5954’s logic
inputs/outputs allow interfacing directly with the system
hot-plug management controller or through an SMBus™
with an external I/O expander. Integrated debounced
attention switch and present-detect signals are included
to simplify system design.
The MAX5954 drives two external n-channel MOSFETs
to control the 12V and 3.3V main outputs. The 3.3V auxiliary output is controlled through an internal 0.3Ω
n-channel MOSFET. An internal charge pump provides
gate drive for the 12V output while the gate drive of the
3.3V output is driven by the 12V input supply. The 3.3V
auxiliary output is completely independent from the
main outputs with its own charge pump.
At power-up, the MAX5954 keeps all of the external
MOSFETs off until the supplies rise above their respective undervoltage-lockout (UVLO) thresholds. The
device keeps the internal MOSFET off only until the auxiliary input supply rises above its UVLO threshold. Upon
a turn-on command, the MAX5954 enhances the external and internal MOSFETs slowly with a constant gate
current to limit the power-supply inrush current. The
MAX5954 actively limits the current of all outputs at all
times and shuts down if an overcurrent condition persists for longer than a programmable overcurrent timeout. Thermal-protection circuitry also shuts down all
outputs if the die temperature exceeds +150°C. After an
overcurrent or overtemperature fault condition, the
MAX5954L latches off while the MAX5954A automatically restarts after a restart time delay. The device is available in a 36-pin (6mm × 6mm) thin QFN package and
operates over the -40°C to +85°C temperature range.
Applications
Servers
Desktop Mobile Server Platforms
Workstations
Embedded Devices
Features
♦ PCI Express Compliant
♦ Hot Swaps 12V, 3.3V, and 3.3V Auxiliary for a
Single PCI-E Slot
♦ Integrated Power MOSFET for Auxiliary Supply
Rail
♦ Controls dI/dt and dV/dt
♦ Active Current Limiting Protects Against
Overcurrent/Short-Circuit Conditions
♦ Programmable Current-Limit Timeout
♦ PWRGD Signal Output with Programmable
Power-On Reset (POR) (160ms Default)
♦ Latched FAULT Signal Output after Overcurrent
or Overtemperature Fault
♦ Attention Switch Input/Output with 4.4ms
Debounce
♦ Present-Detect Input
♦ Forced-On Input Facilitates Testing
♦ Thermal Shutdown
♦ Allows Control through SMBus with an I/O
Expander
MAX5954
Single PCI Express, Hot-Plug
Controller
________________________________________________________________ Maxim Integrated Products 1
19-3914; Rev 1; 1/06
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
EVALUATION KIT
AVAILABLE
N.C.
N.C.
3.3VAUXIN
PWRGD
FAULT
3.3G
N.C.
28
29
30
31
32
33
34
35
36
18
17
16
15
14
13
12
11
10
THIN QFN
MAX5954
TOP VIEW
+
3.3VAUXO
N.C.
T2T1N.C.
N.C.
N.C.
N.C.
N.C.
N.C.
N.C.
N.C.
OUTPUT
INPUT
GND
PGND
PORADJ
TIM
12VIN
N.C.
ON
AUXON
12S+
12G
3.3S+
3.3S-
PRES-DET
12S-
FON
27 26 25 24 23 22
21 20 19
123
456789
Pin Configuration
Ordering Information
PART
TEMP RANGE
PIN-
PKG
CODE
MAX5954AETX+
T3666-3
MAX5954LETX+
T3666-3
Typical Application Circuit appears at end of data sheet.
SMBus is a trademark of Intel Corp.
PCI Express is a trademark of PCI-SIG Corp.
+Denotes lead free package.
PACKAGE
-40°C to +85°C
-40°C to +85°C
36 Thin QFN
36 Thin QFN
MAX5954
Single PCI Express, Hot-Plug
Controller
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
(All voltages referenced to GND, unless otherwise noted.)
12VIN......................................................................-0.3V to +14V
12G............................................................-0.3V to (V
12VIN
+ 6V)
12S, 12S-, 3.3G ......................................-0.3V to (V
12VIN
+ 0.3V)
3.3VAUXIN, ON,
FAULT ..........................................-0.3V to +6V
PWRGD ....................................................................-0.3V to +6V
PGND ....................................................................-0.3V to +0.3V
All Other Pins to GND......................-0.3V to (V
3.3VAUXIN
+ 0.3V)
Continuous Power Dissipation (TA= +70°C)
36-Pin Thin QFN (derate 26.3mW/°C above +70°C).....2.105W
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
ELECTRICAL CHARACTERISTICS
(V
12VIN
= V
12S-
= V
12S+
= 12V, V
3.3S+
= V
3.3S-
= V
3.3VAUXIN
= VON= V
AUXON
= V
FON
= 3.3V, PWRGD = FAULT = PORADJ = TIM =
OUTPUT = 12G = 3.3G = OPEN, INPUT = PRES-DET = PGND = GND, T
A
= -40°C to +85°C, unless otherwise noted. Typical values
are at T
A
= +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
12V SUPPLY
12V Supply Voltage Range V
12VIN
V
V
12UVLO
Hysteresis
V
12VIN Supply Current I
12VIN
V
12VIN
= 13.2V
1mA
12VIN CONTROL
12VIN Current-Limit
Threshold (V
12S+
- V
12S-
)
V
12ILIM
mV
12G Gate Charge Current
V
12G
= GND 4 5 6 µA
Normal turn-off, ON = GND, V
12G
= 2V
µA
I
12G_DIS
O utp ut shor t- ci r cui t cond i ti on, str ong g ate p ul l d ow n
to r eg ul ati on, V
1 2V IN
- V
1 2S _
≥ 1V , V
1 2G_
= 5V
mA
12G Gate High Voltage
(V
12G
- V
12VIN
)
V
12GH
I
12G
= 1µA
V
12G Threshold Voltage For
PWRGD Assertion
V
PGTH12
Referred to V
12VIN
, I
12G_
= 1µA (Note 2)
4
V
12S- Input Bias Current 1µA
12S+ Input Bias Current
µA
3.3V SUPPLY
3.3V Supply Voltage Range V
3.3S+
V
3.3S+ rising
V
Undervoltage Lockout
(Note 3)
Hysteresis
mV
12VIN Undervoltage Lockout
V
12VIN
rising
10.8 12 13.2
9.5 10 10.5
0.1
0.5
49 54 59
I
12G_CHG
50 150 250
12G Gate Discharge Current
50 120 180
4.8 5.3 5.8
3.0
4.8
3.0 3.3 3.6
2.52 2.65 2.78
20 60
30
MAX5954
Single PCI Express, Hot-Plug
Controller
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(V
12VIN
= V
12S-
= V
12S+
= 12V, V
3.3S+
= V
3.3S-
= V
3.3VAUXIN
= VON= V
AUXON
= V
FON
= 3.3V, PWRGD = FAULT = PORADJ = TIM =
OUTPUT = 12G = 3.3G = OPEN, INPUT = PRES-DET = PGND = GND, T
A
= -40°C to +85°C, unless otherwise noted. Typical values
are at T
A
= +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
3.3V CONTROL
3.3V Current-Limit Threshold
(V
3.3S+
- V
3.3S-
)
V
3.3ILIM
mV
3.3G Gate Charge Current
V
3.3G
= GND 4 5 6 µA
ON = GND, V
3.3G
= 2V
µA
I
3.3G_DIS
O utp ut shor t- ci r cui t cond i ti on, str ong g ate p ul l d ow n
to r eg ul ati on, V
3 .3 S +
- V
3 .3 S
≥ 1V , V
3 .3 G
= 5V
mA
3.3G Gate High Voltage
(V
3.3G
- V
3.3S+
)
V
3.3G_H
Sourcing 1µA
V
3.3G Threshold Voltage For
PWRGD Assertion
V
PGTH3.3
Referred to V
3.3VAUXIN
, I
3.3G
= 1µA (Note 2)
V
3.3S- Input Bias Current 1µA
3.3S+ Input Bias Current
µA
3.3V AUXILIARY SUPPLY
3.3VAUXIN Supply Voltage
Range
V
3.3VAUXIN rising
V
3.3VAUXIN Undervoltage
Lockout
Hysteresis
mV
3.3VAUXIN Supply Current V
3.3VAUXIN
= 3.6V
3mA
3.3VAUXIN to 3.3VAUXO
Maximum Dropout
I
3.3VAUXO
= 375mA
mV
3.3VAUXO Current-Limit
Threshold
3.3VAUXO shorted to GND
mA
3.3VAUXO Threshold For
PWRGD Assertion
(V
3.3VAUXIN
- V
3.3VAUXO
)
(Note 3)
mV
LOGIC SIGNALS
Rising edge
V
Input-Logic Threshold
(ON, FON, AUXON,
PRES-DET, INPUT)
Hysteresis
mV
Input Bias Current
(ON, AUXON, INPUT)
1µA
FON, PRES-DET Internal
Pullup
kΩ
ON, AUXON High-to-Low
Deglitch Time
4µs
3.3G Gate Discharge Current
I
3.3G CHG
V
3.3VAUXIN
V
3 .3 V A U X U V L O
V
PGTH3.3AUX
17 20 23
50 150 250
100 150 220
4.5 5.5 6.8
-3.0 +4 +4.5
20 60
30
1.5
3.0 3.3 3.6
2.52 2.65 2.78
225
376 470 564
400
1.0 2.0
25
25 50 75
MAX5954
Single PCI Express, Hot-Plug
Controller
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(V
12VIN
= V
12S-
= V
12S+
= 12V, V
3.3S+
= V
3.3S-
= V
3.3VAUXIN
= VON= V
AUXON
= V
FON
= 3.3V, PWRGD = FAULT = PORADJ = TIM =
OUTPUT = 12G = 3.3G = OPEN, INPUT = PRES-DET = PGND = GND, T
A
= -40°C to +85°C, unless otherwise noted. Typical values
are at T
A
= +25°C.) (Note 1)
PARAMETER
CONDITIONS
UNITS
PRES-DET High-to-Low
Deglitch Time
t
DEG
357ms
PORADJ = open
R
PORADJ
= 20kΩ
R
PORADJ
= 100kΩ
PWRGD Power-On Reset
Time (Note 2)
t
POR_HL
R
PORADJ
= 200kΩ
ms
PWRGD Low-to-High Deglitch
Time
t
POR_LH
4µs
Sinking 2mA
PWRGD, FAULT Output Low
Voltage
Sinking 30mA
V
PWRGD, FAULT Output-High
Leakage Current
V
PWRGD
= V
FAULT
= 5.5V 1 µA
TIM = open
R
TIM
= 15kΩ
R
TIM
= 120kΩ
FAULT Timeout t
FAULT
R
TIM
= 300kΩ
ms
FAULT Timeout During
Startup
t
SU
2 x t
FAULT
ms
Autorestart Delay Time t
RESTART
ms
Fault Reset Minimum Pulse
Width
t
RESET
(Note 4)
µs
Thermal-Shutdown Threshold
T
SD
TJ rising
°C
Thermal-Shutdown Threshold
Hysteresis
°C
OUTPUT Debounce Time t
DBC
ms
OUTPUT High Voltage Sourcing 2mA
V
3.3VAUXIN
- 0.3
V
OUTPUT Low Voltage Sinking 2mA
V
Note 1: 100% production tested at TA= +25°C. Parameters over temperature are guaranteed by design.
Note 2: PWRGD asserts a time t
POR_HL
after V
PGTH12
, V
PGTH3.3
, and V
PGTH3.3AUX
conditions are met.
Note 3: The UVLO for the 3.3V supply is sensed at 3.3S+.
Note 4: This is the time that ON or AUXON must stay low when resetting a fault condition.
SYMBOL
MIN TYP MAX
90 160 250
35 55 75
145 265 380
5.5 11 17.0
1.4 2.6 3.8
12 22 32
2.6 4.4 6.2
64 x t
+150
570
59
FAULT
100
20
V
0.1
0.7
3.3 V AU X IN
0.4
MAX5954
Single PCI Express, Hot-Plug
Controller
_______________________________________________________________________________________ 5
12VIN INPUT SUPPLY CURRENT
vs. TEMPERATURE
MAX5954 toc01
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
603510-15
0.491
0.492
0.493
0.494
0.495
0.496
0.497
0.498
0.499
0.500
0.501
0.502
0.503
0.504
0.505
0.490
-40 85
3.3VAUXIN SUPPLY CURRENT
vs. TEMPERATURE
MAX5954 toc02
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
603510-15
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
0
-40 85
ON AND AUXON LOW-TO-HIGH THRESHOLD
VOLTAGE vs. TEMPERATURE
MAX5954 toc03
TEMPERATURE (°C)
THRESHOLD VOLTAGE (V)
603510-15
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.0
1.0
-40 85
3.3VAUXO OUTPUT VOLTAGE vs. CURRENT
MAX5954 toc04
OUTPUT CURRENT (A)
OUTPUT VOLTAGE (V)
0.50.40.30.20.1
0.5
1.0
1.5
2.0
2.5
3.0
3.5
0
00.6
12G AND 3.3G GATE CHARGE
CURRENT vs. TEMPERATURE
MAX5954 toc05
TEMPERATURE (°C)
GATE CHARGE CURRENT (µA)
603510-15
4.90
4.95
5.00
5.05
5.10
5.15
5.20
5.25
5.30
5.35
4.85
-40 85
12G
3.3G
12G AND 3.3G GATE DISCHARGE
CURRENT vs. TEMPERATURE
MAX5954 toc06
TEMPERATURE (°C)
GATE DISCHARGE CURRENT (µA)
603510-15
150
155
160
165
170
145
-40 85
3.3G
12G
3.3VAUX INTERNAL SWITCH
MAXIMUM DROPOUT vs. TEMPERATURE
MAX5954 toc07
TEMPERATURE (°C)
DROPOUT VOLTAGE (V)
603510-15
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0.20
0
-40 85
AUXILIARY OUTPUT CURRENT = 375mA
12V AND 3.3V CURRENT-LIMIT THRESHOLD
VOLTAGE vs. TEMPERATURE
MAX5954 toc08
TEMPERATURE (°C)
CURRENT-LIMIT THRESHOLD VOLTAGE (mV)
603510-15
10
20
30
40
50
60
0
-40 85
12V CURRENT-SENSE
THRESHOLD
3.3V CURRENT-SENSE
THRESHOLD
AUXILIARY CURRENT LIMIT
vs. TEMPERATURE
MAX5954 toc09
TEMPERATURE (°C)
AUXILIARY CURRENT LIMIT (A)
603510-15
0.455
0.460
0.465
0.470
0.475
0.480
0.485
0.490
0.495
0.500
0.450
-40 85
Typical Operating Characteristics
(V
12VIN
= V
12S+
= 12V, V
3.3VAUXIN
= V
3.3S+
= VON= V
AUXON
= V
INPUT
= 3.3V, PRES-DET = GND, FON = PORADJ = TIM = float,
FAULT = 10kΩ to 3.3VAUXIN, PWRGD = 10kΩ to 3.3VAUXO, T
A
= +25°C, unless otherwise noted, see the Typical Application
Circuit.)
MAX5954
Single PCI Express, Hot-Plug
Controller
6 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(V
12VIN
= V
12S+
= 12V, V
3.3VAUXIN
= V
3.3S+
= VON= V
AUXON
= V
INPUT
= 3.3V, PRES-DET = GND, FON = PORADJ = TIM = float,
FAULT = 10kΩ to 3.3VAUXIN, PWRGD = 10kΩ to 3.3VAUXO, T
A
= +25°C, unless otherwise noted, see the Typical Application
Circuit.)
12VIN UNDERVOLTAGE-LOCKOUT
THRESHOLD vs. TEMPERATURE
MAX5954 toc10
TEMPERATURE (°C)
UVLO THRESHOLD (V)
6035-15 10
9.85
9.90
9.95
10.00
10.05
10.10
10.15
10.20
9.80
-40 85
3.3VAUXIN UNDERVOLTAGE-LOCKOUT
THRESHOLD vs. TEMPERATURE
MAX5954 toc11
TEMPERATURE (°C)
UVLO THRESHOLD (V)
603510-15
2.62
2.64
2.66
2.68
2.70
2.60
-40 85
12V TURN-ON/OFF TIME
MAX5954 toc12
12G
20V/div
PWRGD
5V/div
ON
5V/div
12V OUTPUT
10V/div
40ms/div
3.3V TURN-ON/OFF TIME
MAX5954 toc13
3.3G
10V/div
PWRGD
5V/div
ON
5V/div
3.3V OUTPUT
5V/div
40ms/div
3.3V AUXILIARY TURN-ON/OFF TIME
MAX5954 toc14
40ms/div
3.3AUXO
OUTPUT VOLTAGE
2V/div
AUXON
2V/div
PWRGD
2V/div
12V POWER-UP
MAX5954 toc15
12V OUTPUT
10V/div
PWRGD
5V/div
12VIN, 12V INPUT
10V/div
12G
20V/div
40ms/div
MAX5954
Single PCI Express, Hot-Plug
Controller
_______________________________________________________________________________________ 7
Typical Operating Characteristics (continued)
(V
12VIN
= V
12S+
= 12V, V
3.3VAUXIN
= V
3.3S+
= VON= V
AUXON
= V
INPUT
= 3.3V, PRES-DET = GND, FON = PORADJ = TIM = float,
FAULT = 10kΩ to 3.3VAUXIN, PWRGD = 10kΩ to 3.3VAUXO, T
A
= +25°C, unless otherwise noted, see the Typical Application
Circuit.)
3.3V INPUT/3.3V AUXILIARY INPUT
POWER-UP
MAX5954 toc16
3.3V OUTPUT
5V/div
PWRGD
5V/div
3.3VAUXO
5V/div
3.3G
10V/div
100ms/div
3.3S+
5V/div
TURN-ON DELAY 3.3V OUTPUT AND
3.3V AUXILIARY OUTPUT
MAX5954 toc17
4ms/div
5V/div
5V/div
5V/div
5V/div
10V/div
3.3VAUXO
OUTPUT VOLTAGE
3.3 VOLTAGE
3.3 INPUT,
3.3VAUXIN
3.3G
PWRGD
FAULT CONDITION ON 12V OUTPUT
(AUTORESTART OPTION MAX5954A)
MAX5954 toc18
12G
20V/div
FAULT
5V/div
12V OUTPUT CURRENT
5A/div
100ms/div
12V OUTPUT VOLTAGE
10V/div
t
RESTART
R
LOAD
STEP TO 1.5Ω
FAULT CONDITION ON 3.3V OUTPUT
(AUTORESTART OPTION MAX5954A)
MAX5954 toc19
3.3G
10V/div
FAULT
5V/div
3.3V MAIN OUTPUT CURRENT
2A/div
100ms/div
3.3V OUTPUT VOLTAGE
5V/div
t
RESTART
R
LOAD
STEP TO 0.5Ω
FAULT CONDITION ON AUXILIARY OUTPUT
(AUTORESTART OPTION MAX5954A)
MAX5954 toc20
FAULT
2V/div
3.3VAUXO OUTPUT CURRENT
500mA/div
100ms/div
3.3VAUXO OUTPUT VOLTAGE
2V/div
t
RESTART
R
LOAD
STEP TO 4Ω
FAULT CONDITION ON 12V OUTPUT
(LATCH OPTION MAX5954L)
MAX5954 toc21
12G
20V/div
FAULT
5V/div
12V OUTPUT CURRENT
5A/div
100ms/div
12V OUTPUT VOLTAGE
10V/div
R
LOAD
STEP TO 1.5Ω
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