View MAX5954_612969.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

19-3914; Rev 1; 1/06
KIT ATION EVALU E AILABL AV
Single PCI Express, Hot-Plug Controller
General Description 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
The MAX5954 hot-plug controller is designed for PCI ExpressTM 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 SMBusTM 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 0.3 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 +150C. 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 x 6mm) thin QFN package and operates over the -40C to +85C temperature range.
Ordering Information
PART TEMP RANGE PINPACKAGE 36 Thin QFN 36 Thin QFN PKG CODE T3666-3 T3666-3
MAX5954AETX+ -40C to +85C MAX5954LETX+ -40C to +85C
+Denotes lead free package.
Pin Configuration
N.C. N.C. T2 T1 N.C. N.C. N.C. N.C. N.C. TOP VIEW
27 26 25 24 23 22 21 20 19
Applications
Servers Desktop Mobile Server Platforms Workstations Embedded Devices
TIM 28 N.C. 29 N.C. OUTPUT INPUT 12VIN GND PGND PORADJ
30 31 32 33 34 35 36 18 17 16 15
N.C. N.C. N.C. N.C. 3.3VAUXIN 3.3VAUXO PWRGD FAULT 3.3G
MAX5954
14 13 12 11 10
+
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.
1
2
3
4
5
6
7
8
9
PRES-DET FON
________________________________________________________________ Maxim Integrated Products
ON AUXON 12S+
THIN QFN
12S12G 3.3S+ 3.3S-
1
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.
Single PCI Express, Hot-Plug Controller MAX5954
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND, unless otherwise noted.) 12VIN......................................................................-0.3V to +14V 12G............................................................-0.3V to (V12VIN + 6V) 12S, 12S-, 3.3G ......................................-0.3V to (V12VIN + 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 (V3.3VAUXIN + 0.3V) Continuous Power Dissipation (TA = +70C) 36-Pin Thin QFN (derate 26.3mW/C above +70C).....2.105W Operating Temperature Range ...........................-40C to +85C Junction Temperature ......................................................+150C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C
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.
ELECTRICAL CHARACTERISTICS
(V12VIN = V12S- = V12S+ = 12V, V3.3S+ = V3.3S- = V3.3VAUXIN = VON = VAUXON = VFON = 3.3V, PWRGD = FAULT = PORADJ = TIM = OUTPUT = 12G = 3.3G = OPEN, INPUT = PRES-DET = PGND = GND, TA = -40C to +85C, unless otherwise noted. Typical values are at TA = +25C.) (Note 1)
PARAMETER 12V SUPPLY 12V Supply Voltage Range 12VIN Undervoltage Lockout 12VIN Supply Current 12VIN CONTROL 12VIN Current-Limit Threshold (V12S+ - V12S-) 12G Gate Charge Current 12G Gate Discharge Current 12G Gate High Voltage (V12G - V12VIN) 12G Threshold Voltage For PWRGD Assertion 12S- Input Bias Current 12S+ Input Bias Current 3.3V SUPPLY 3.3V Supply Voltage Range Undervoltage Lockout (Note 3) V3.3S+ 3.3S+ rising Hysteresis 3.0 2.52 3.3 2.65 30 3.6 2.78 V V mV 20 V12ILIM I12G_CHG I12G_DIS V12G = GND Normal turn-off, ON = GND, V12G = 2V Output short-circuit condition, strong gate pulldown to regulation, V12VIN - V12S_ 1V, V12G_= 5V I12G = 1A Referred to V12VIN, I12G_ = 1A (Note 2) 49 4 50 50 4.8 3.0 54 5 150 120 5.3 4 59 6 250 180 5.8 4.8 1 60 mV A A mA V V A A V12VIN V12UVLO I12VIN 10.8 12 10 0.1 0.5 1 13.2 10.5 V V mA SYMBOL CONDITIONS MIN TYP MAX UNITS
V12VIN rising
Hysteresis V12VIN = 13.2V
9.5
V12GH VPGTH12
2
_______________________________________________________________________________________
Single PCI Express, Hot-Plug Controller
ELECTRICAL CHARACTERISTICS (continued)
(V12VIN = V12S- = V12S+ = 12V, V3.3S+ = V3.3S- = V3.3VAUXIN = VON = VAUXON = VFON = 3.3V, PWRGD = FAULT = PORADJ = TIM = OUTPUT = 12G = 3.3G = OPEN, INPUT = PRES-DET = PGND = GND, TA = -40C to +85C, unless otherwise noted. Typical values are at TA = +25C.) (Note 1)
PARAMETER 3.3V CONTROL 3.3V Current-Limit Threshold (V3.3S+ - V3.3S-) 3.3G Gate Charge Current 3.3G Gate Discharge Current 3.3G Gate High Voltage (V3.3G - V3.3S+) 3.3G Threshold Voltage For PWRGD Assertion 3.3S- Input Bias Current 3.3S+ Input Bias Current 3.3V AUXILIARY SUPPLY 3.3VAUXIN Supply Voltage Range 3.3VAUXIN Undervoltage Lockout 3.3VAUXIN Supply Current 3.3VAUXIN to 3.3VAUXO Maximum Dropout 3.3VAUXO Current-Limit Threshold 3.3VAUXO Threshold For PWRGD Assertion (V3.3VAUXIN - V3.3VAUXO) LOGIC SIGNALS Input-Logic Threshold (ON, FON, AUXON, PRES-DET, INPUT) Input Bias Current (ON, AUXON, INPUT) FON, PRES-DET Internal Pullup ON, AUXON High-to-Low Deglitch Time 25 50 4 Rising edge Hysteresis 1.0 25 1 75 2.0 V mV A k s V3.3VAUXIN V3.3VAUXUVLO 3.3VAUXIN rising Hysteresis V3.3VAUXIN = 3.6V I3.3VAUXO = 375mA 3.3VAUXO shorted to GND 376 470 3.0 2.52 3.3 2.65 30 1.5 3 225 564 3.6 2.78 V V mV mA mV mA 20 V3.3ILIM I3.3G CHG I3.3G_DIS V3.3G = GND ON = GND, V3.3G = 2V Output short-circuit condition, strong gate pulldown to regulation, V3.3S+ - V3.3S 1V, V3.3G = 5V Sourcing 1A Referred to V3.3VAUXIN, I3.3G = 1A (Note 2) 17 4 50 100 4.5 -3.0 20 5 150 150 5.5 +4 23 6 250 220 6.8 +4.5 1 60 mV A A mA V V A A SYMBOL CONDITIONS MIN TYP MAX UNITS
MAX5954
V3.3G_H VPGTH3.3
VPGTH3.3AUX (Note 3)
400
mV
_______________________________________________________________________________________
3
Single PCI Express, Hot-Plug Controller MAX5954
ELECTRICAL CHARACTERISTICS (continued)
(V12VIN = V12S- = V12S+ = 12V, V3.3S+ = V3.3S- = V3.3VAUXIN = VON = VAUXON = VFON = 3.3V, PWRGD = FAULT = PORADJ = TIM = OUTPUT = 12G = 3.3G = OPEN, INPUT = PRES-DET = PGND = GND, TA = -40C to +85C, unless otherwise noted. Typical values are at TA = +25C.) (Note 1)
PARAMETER PRES-DET High-to-Low Deglitch Time PWRGD Power-On Reset Time (Note 2) PWRGD Low-to-High Deglitch Time PWRGD, FAULT Output Low Voltage PWRGD, FAULT Output-High Leakage Current SYMBOL tDEG PORADJ = open tPOR_HL RPORADJ = 20k RPORADJ = 100k RPORADJ = 200k tPOR_LH Sinking 2mA Sinking 30mA VPWRGD = VFAULT = 5.5V TIM = open FAULT Timeout tFAULT RTIM = 15k RTIM = 120k RTIM = 300k FAULT Timeout During Startup Autorestart Delay Time Fault Reset Minimum Pulse Width Thermal-Shutdown Threshold Thermal-Shutdown Threshold Hysteresis OUTPUT Debounce Time OUTPUT High Voltage OUTPUT Low Voltage tDBC Sourcing 2mA Sinking 2mA 2.6 tSU tRESTART tRESET TSD (Note 4) TJ rising 5.5 1.4 12 11 2.6 22 59 2 x tFAULT 64 x tFAULT 100 +150 20 4.4 6.2 ms ms s C C ms V V CONDITIONS MIN 3 90 35 145 TYP 5 160 55 265 570 4 0.1 0.7 1 17.0 3.8 32 ms s V A MAX 7 250 75 380 ms UNITS ms
V3.3VAUXIN V3.3VAUXIN - 0.3 0.4
Note 1: Note 2: Note 3: Note 4:
100% production tested at TA = +25C. Parameters over temperature are guaranteed by design. PWRGD asserts a time tPOR_HL after VPGTH12, VPGTH3.3, and VPGTH3.3AUX conditions are met. The UVLO for the 3.3V supply is sensed at 3.3S+. This is the time that ON or AUXON must stay low when resetting a fault condition.
4
_______________________________________________________________________________________
Single PCI Express, Hot-Plug Controller
Typical Operating Characteristics
(V12VIN = V12S+ = 12V, V3.3VAUXIN = V3.3S+ = VON = VAUXON = VINPUT = 3.3V, PRES-DET = GND, FON = PORADJ = TIM = float, FAULT = 10k to 3.3VAUXIN, PWRGD = 10k to 3.3VAUXO, TA = +25C, unless otherwise noted, see the Typical Application Circuit.)
12VIN INPUT SUPPLY CURRENT vs. TEMPERATURE
0.505 0.504 0.503 0.502 0.501 0.500 0.499 0.498 0.497 0.496 0.495 0.494 0.493 0.492 0.491 0.490 -40 -15 10 35 60 TEMPERATURE (C)
MAX5954 toc01
MAX5954
3.3VAUXIN SUPPLY CURRENT vs. TEMPERATURE
1.8 1.6 SUPPLY CURRENT (mA) 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 85 -40 -15 10 35 60 85 TEMPERATURE (C)
MAX5954 toc02
ON AND AUXON LOW-TO-HIGH THRESHOLD VOLTAGE vs. TEMPERATURE
1.9 THRESHOLD VOLTAGE (V) 1.8 1.7 1.6 1.5 1.4 1.3 1.2 1.1 1.0 -40 -15 10 35 60 85 TEMPERATURE (C)
MAX5954 toc03
2.0
2.0
SUPPLY CURRENT (mA)
3.3VAUXO OUTPUT VOLTAGE vs. CURRENT
MAX5954 toc04
12G AND 3.3G GATE CHARGE CURRENT vs. TEMPERATURE
MAX5954 toc05
12G AND 3.3G GATE DISCHARGE CURRENT vs. TEMPERATURE
MAX5954 toc06
3.5 3.0 OUTPUT VOLTAGE (V) 2.5 2.0 1.5 1.0 0.5 0 0 0.1 0.2 0.3 0.4 0.5
5.35 5.30 GATE CHARGE CURRENT (A) 5.25 5.20 5.15 5.10 5.05 5.00 4.95 4.90 4.85 3.3G 12G
170 GATE DISCHARGE CURRENT (A)
165 3.3G 160
155 12G 150
145 -40 -15 10 35 60 85 -40 -15 10 35 60 85 TEMPERATURE (C) TEMPERATURE (C)
0.6
OUTPUT CURRENT (A)
3.3VAUX INTERNAL SWITCH MAXIMUM DROPOUT vs. TEMPERATURE
MAX5954 toc07
12V AND 3.3V CURRENT-LIMIT THRESHOLD VOLTAGE vs. TEMPERATURE
MAX5954 toc08
AUXILIARY CURRENT LIMIT vs. TEMPERATURE
0.495 AUXILIARY CURRENT LIMIT (A) 0.490 0.485 0.480 0.475 0.470 0.465 0.460 0.455
MAX5954 toc09
0.20 0.18 0.16 DROPOUT VOLTAGE (V) 0.14 0.12 0.10 0.08 0.06 0.04 0.02 0 -40 -15 10 35 60 AUXILIARY OUTPUT CURRENT = 375mA
60 CURRENT-LIMIT THRESHOLD VOLTAGE (mV) 50 40 30 20 10 0 12V CURRENT-SENSE THRESHOLD
0.500
3.3V CURRENT-SENSE THRESHOLD
0.450 -40 -15 10 35 60 85 -40 -15 10 35 60 85 TEMPERATURE (C) TEMPERATURE (C)
85
TEMPERATURE (C)
_______________________________________________________________________________________
5
Single PCI Express, Hot-Plug Controller MAX5954
Typical Operating Characteristics (continued)
(V12VIN = V12S+ = 12V, V3.3VAUXIN = V3.3S+ = VON = VAUXON = VINPUT = 3.3V, PRES-DET = GND, FON = PORADJ = TIM = float, FAULT = 10k to 3.3VAUXIN, PWRGD = 10k to 3.3VAUXO, TA = +25C, unless otherwise noted, see the Typical Application Circuit.)
12VIN UNDERVOLTAGE-LOCKOUT THRESHOLD vs. TEMPERATURE
10.15 UVLO THRESHOLD (V) 10.10 10.05 10.00 9.95 9.90 9.85 9.80 -40 -15 10 35 60 85 TEMPERATURE (C) 2.60 -40 -15 10 35 60 85 TEMPERATURE (C)
MAX5954 toc10
3.3VAUXIN UNDERVOLTAGE-LOCKOUT THRESHOLD vs. TEMPERATURE
MAX5954 toc11
10.20
2.70
2.68 UVLO THRESHOLD (V)
2.66
2.64
2.62
12V TURN-ON/OFF TIME
MAX5954 toc12
3.3V TURN-ON/OFF TIME
MAX5954 toc13
12V OUTPUT 10V/div
3.3V OUTPUT 5V/div 3.3G 10V/div
12G 20V/div ON 5V/div
ON 5V/div
PWRGD 5V/div 40ms/div 40ms/div
PWRGD 5V/div
3.3V AUXILIARY TURN-ON/OFF TIME
MAX5954 toc14
12V POWER-UP
MAX5954 toc15
3.3AUXO OUTPUT VOLTAGE 2V/div
12G 20V/div 12V OUTPUT 10V/div
PWRGD 2V/div
12VIN, 12V INPUT 10V/div
AUXON 2V/div
PWRGD 5V/div 40ms/div
40ms/div
6
_______________________________________________________________________________________
Single PCI Express, Hot-Plug Controller MAX5954
Typical Operating Characteristics (continued)
(V12VIN = V12S+ = 12V, V3.3VAUXIN = V3.3S+ = VON = VAUXON = VINPUT = 3.3V, PRES-DET = GND, FON = PORADJ = TIM = float, FAULT = 10k to 3.3VAUXIN, PWRGD = 10k to 3.3VAUXO, TA = +25C, unless otherwise noted, see the Typical Application Circuit.)
3.3V INPUT/3.3V AUXILIARY INPUT POWER-UP
MAX5954 toc16
TURN-ON DELAY 3.3V OUTPUT AND 3.3V AUXILIARY OUTPUT
MAX5954 toc17
3.3G 10V/div 3.3V OUTPUT 5V/div 3.3S+ 5V/div 3.3VAUXO 5V/div PWRGD 5V/div 100ms/div
5V/div
3.3VAUXO OUTPUT VOLTAGE 3.3 INPUT, 3.3VAUXIN 3.3 VOLTAGE PWRGD 3.3G
5V/div 5V/div 5V/div 10V/div
4ms/div
FAULT CONDITION ON 12V OUTPUT (AUTORESTART OPTION MAX5954A)
MAX5954 toc18
FAULT CONDITION ON 3.3V OUTPUT (AUTORESTART OPTION MAX5954A)
MAX5954 toc19
RLOAD STEP TO 1.5
12V OUTPUT CURRENT 5A/div 12G 20V/div 12V OUTPUT VOLTAGE 10V/div
RLOAD STEP TO 0.5
3.3V MAIN OUTPUT CURRENT 2A/div
3.3G 10V/div 3.3V OUTPUT VOLTAGE 5V/div tRESTART 100ms/div FAULT 5V/div
tRESTART 100ms/div
FAULT 5V/div
FAULT CONDITION ON AUXILIARY OUTPUT (AUTORESTART OPTION MAX5954A)
MAX5954 toc20
FAULT CONDITION ON 12V OUTPUT (LATCH OPTION MAX5954L)
MAX5954 toc21
RLOAD STEP TO 4
3.3VAUXO OUTPUT CURRENT 500mA/div
RLOAD STEP TO 1.5
12V OUTPUT CURRENT 5A/div 12G 20V/div
3.3VAUXO OUTPUT VOLTAGE 2V/div
12V OUTPUT VOLTAGE 10V/div
tRESTART 100ms/div
FAULT 2V/div 100ms/div
FAULT 5V/div
_______________________________________________________________________________________
7
Single PCI Express, Hot-Plug Controller MAX5954
Typical Operating Characteristics (continued)
(V12VIN = V12S+ = 12V, V3.3VAUXIN = V3.3S+ = VON = VAUXON = VINPUT = 3.3V, PRES-DET = GND, FON = PORADJ = TIM = float, FAULT = 10k to 3.3VAUXIN, PWRGD = 10k to 3.3VAUXO, TA = +25C, unless otherwise noted, see the Typical Application Circuit.)
FAULT CONDITION ON 3.3V OUTPUT (LATCH OPTION MAX5954)
MAX5954 toc23
FAULT CONDITION ON 12V OUTPUT
MAX5954 toc22
tFAULT
RLOAD STEP TO 1.5
12V OUTPUT CURRENT 5A/div 12G 20V/div 12V OUTPUT VOLTAGE 10V/div
RLOAD STEP TO 0.5
3.3V OUTPUT CURRENT 2A/div
3.3G 10V/div
3.3V OUTPUT VOLTAGE 5V/div FAULT 5V/div 100ms/div
FAULT 5V/div 4ms/div
FAULT CONDITION ON 3.3V MAIN OUTPUT
MAX5954 toc24
FAULT CONDITION ON AUXILIARY OUTPUT (LATCH OPTION MAX5954)
MAX5954 toc25
tFAULT
RLOAD STEP TO 0.5
3.3V OUTPUT CURRENT 2A/div
RLOAD STEP TO 4
3.3VAUXO OUTPUT CURRENT 500mA/div
3.3G 10V/div 3.3V OUTPUT VOLTAGE 5V/div FAULT 5V/div 4ms/div 100ms/div
3.3VAUXO OUTPUT VOLTAGE 2V/div
FAULT 2V/div
FAULT CONDITION ON AUXILIARY OUTPUT
MAX5954 toc26
SHORT CIRCUIT ON 12V OUTPUT
MAX5954 toc27
tFAULT
RLOAD STEP TO 4
3.3VAUXO OUTPUT CURRENT 500mA/div
12V OUTPUT CURRENT 5A/div 12G 20V/div
3.3VAUXO OUTPUT VOLTAGE 2V/div
12V OUTPUT VOLTAGE 10V/div
FAULT 2V/div 4ms/div 2ms/div
FAULT 5V/div
8
_______________________________________________________________________________________
Single PCI Express, Hot-Plug Controller MAX5954
Typical Operating Characteristics (continued)
(V12VIN = V12S+ = 12V, V3.3VAUXIN = V3.3S+ = VON = VAUXON = VINPUT = 3.3V, PRES-DET = GND, FON = PORADJ = TIM = float, FAULT = 10k to 3.3VAUXIN, PWRGDA = 10k to 3.3VAUXO, TA = +25C, unless otherwise noted, see the Typical Application Circuit.)
SHORT CIRCUIT ON 12V OUTPUT
MAX5954 toc28
SHORT CIRCUIT ON 3.3V OUTPUT
MAX5954 toc29
12V OUTPUT CURRENT 25A/div 12G 20V/div 0V 12V OUTPUT VOLTAGE 10V/div 0V FAULT 5V/div 0V 4s/div 2ms/div
3.3V OUTPUT CURRENT 2A/div
3.3G 5V/div 3.3V OUTPUT VOLTAGE 5V/div FAULT 5V/div
SHORT CIRCUIT ON 3.3V OUTPUT
MAX5954 toc30
SHORT CIRCUIT ON 3.3AUXO_
MAX5954 toc31
3.3V OUTPUT CURRENT 10A/div
3.3VAUXO OUTPUT CURRENT 500mA/div
3.3G 5V/div 3.3V OUTPUT VOLTAGE 5V/div FAULT 5V/div 0V 2s/div 2ms/div
3.3VAUXO OUTPUT VOLTAGE 2V/div
FAULT 5V/div
SHORT CIRCUIT ON 3.3VAUXO_
MAX5954 toc32
POWER-UP INTO FAULT (AUXILIARY SUPPLY)
MAX5954 toc33
RLOAD = 4 3.3VAUXO OUTPUT CURRENT 5A/div tSU 3.3VAUXO OUTPUT CURRENT 500mA/div 3.3VAUXO OUTPUT VOLTAGE 2V/div
3.3VAUXO OUTPUT VOLTAGE 2V/div
AUXON 5V/div FAULT 5V/div 2s/div FAULT 5V/div 4ms/div
_______________________________________________________________________________________
9
Single PCI Express, Hot-Plug Controller MAX5954
Typical Operating Characteristics (continued)
(V12VIN = V12S+ = 12V, V3.3VAUXIN = V3.3S+ = VON = VAUXON = VINPUT = 3.3V, PRES-DET = GND, FON = PORADJ = TIM = float, FAULT = 10k to 3.3VAUXIN, PWRGDA = 10k to 3.3VAUXO, TA = +25C, unless otherwise noted, see the Typical Application Circuit.)
POWER-UP INTO FAULT (3.3V MAIN)
MAX5954 toc34
POWER-UP INTO FAULT (12V OUTPUT)
MAX5954 toc35
RLOAD = 0.5 tSU 3.3V OUTPUT CURRENT 4A/div 3.3G 5V/div 3.3V OUTPUT VOLTAGE 2V/div ON, AUXON 5V/div FAULT 5V/div 4ms/div 4ms/div tSU 12V OUTPUT CURRENT 5A/div 12G 10V/div 12V OUTPUT VOLTAGE 10V/div ON, AUXON 5V/div FAULT 5V/div
PRESENT-DETECT (ON/OFF) OPERATION
MAX5954 toc36
PRESENT-DETECT (ON/OFF) OPERATION
MAX5954 toc37
10V/div
12V OUTPUT VOLTAGE
10V/div
12V OUTPUT VOLTAGE
5V/div 5V/div
3.3VAUXO OUTPUT VOLTAGE PWRGD
5V/div 5V/div
3.3VAUXO OUTPUT VOLTAGE PWRGD
5V/div
PRES-DET
5V/div
PRES-DET
40ms/div
4ms/div
FORCED-ON (ON/OFF) OPERATION
MAX5954 toc38
FORCED-ON (ON/OFF) OPERATION
MAX5954 toc39
10V/div
12V OUTPUT VOLTAGE
10V/div
12V OUTPUT VOLTAGE
5V/div 5V/div
3.3VAUXO OUTPUT VOLTAGE PWRGD
5V/div 5V/div
3.3VAUXO OUTPUT VOLTAGE PWRGD
5V/div
FON
5V/div
FON
40ms/div
4ms/div
10
______________________________________________________________________________________
Single PCI Express, Hot-Plug Controller MAX5954
Typical Operating Characteristics (continued)
(V12VIN = V12S+ = 12V, V3.3VAUXIN = V3.3S+ = VON = VAUXON = VINPUT = 3.3V, PRES-DET = GND, FON = PORADJ = TIM = float, FAULT = 10k to 3.3VAUXIN, PWRGDA = 10k to 3.3VAUXO, TA = +25C, unless otherwise noted, see the Typical Application Circuit.)
POWER-ON RESET TIME vs. PORADJ RESISTOR
1400 INPUT 2V/div tPOR_HL (MS) 1200 1000 800 600 400 200 0 10ms/div 0 50 100 150 200 250 300 350 400 450 500 RPORADJ (K)
MAX5954 toc41 MAX5954 toc42
DEBOUNCED ON/OFF OPERATION
MAX5954 toc40
1600
OUTPUT 2V/div
tFAULT TIME DELAY vs. TIM RESISTOR
120 100 80 60 40 20 0 0 50 100 150 200 250 300 350 400 450 500 RTIM (k)
______________________________________________________________________________________
tFAULT (ms)
11
Single PCI Express, Hot-Plug Controller MAX5954
Pin Description
PIN NAME FUNCTION Present-Detect Input. PRES-DET accepts inputs from the PRSNT#2 pin on a PCI-E connector. PRES-DET has an internal pullup to 3.3VAUXIN. When PRES-DET is low, the outputs follow the command from ON and AUXON after a 4ms debounced time. When PRES-DET goes from low to high, all outputs of the respective slot shut down with no delay (see Table 2). Forced-On Input. FON has a 50k internal pullup to 3.3VAUXIN. A logic-low on FON turns on all PCI-E outputs as long as the power inputs are within their operating range, regardless of the status of the other input signals. Leave FON open for normal operation (see Table 2). 12V and 3.3V Outputs Enable. A logic-high at ON turns on the 12V and 3.3V outputs (see Table 2). 3.3V Auxiliary Output Enable. A logic-high at AUXON turns on the auxiliary output (3.3VAUXO) (see Table 2). 12V Positive Current-Sense Input. Connect the positive terminal of the current-sense resistor to 12S+ using the Kelvin-sensing technique to assure accurate current sensing. 12V Negative Current-Sense Input. Connect 12S- to the negative side of the current-sense resistor using the Kelvin-sensing technique to assure accurate current sensing. 12V Gate-Drive Output. Connect 12G to the gate of the 12V MOSFET. At power-up, V12G is raised to the internal charge-pump voltage level by a constant current. 3.3V Positive Current-Sense Input. Connect the positive side of the current-sense resistor to 3.3S+ using the Kelvin-sensing technique to assure accurate current sensing. This input is also used for the 3.3V supply's UVLO function. 3.3V Negative Current-Sense Input. Connect to the negative side of the sense resistor using the Kelvinsensing technique to assure accurate current sensing. 3.3V Gate-Drive Output. Connect 3.3G to the gate of the 3.3V MOSFET. At power-up, V3.3G is charged to 5.5V above the 3.3V supply by a constant current derived from V12VIN. Open-Drain Fault Output Signal. FAULT latches active low whenever the outputs are shut down due to a fault. A fault is either of: * An overcurrent condition lasting longer than the overcurrent timeout. * A device over temperature condition. If the fault is detected in the main outputs, FAULT must be reset by toggling the ON input. If the fault is in the auxiliary output, FAULT must be reset by toggling both ON and AUXON. For the auto-restart version, FAULT is reset when the part initiates the next power-on cycle. Open-Drain Power-Good Output. PWRGD goes low tPOR_HL after all outputs reach their final value and the power MOSFETs are fully enhanced. 3.3V Auxiliary Power-Supply Output 3.3V Auxiliary Supply Input. 3.3VAUXIN is the input to a charge pump that drives the internal MOSFET connecting 3.3VAUXIN to 3.3VAUXO. V3.3VAUXIN is also used to power the internal control logic and analog references of the MAX5954. No Connection. Not internally connected. Test Input. Connect T1 to GND.
1
PRES-DET
2 3 4 5 6 7
FON ON AUXON 12S+ 12S12G
8
3.3S+
9 10
3.3S3.3G
11
FAULT
12 13 14 15-23, 26, 27, 29, 30 24
PWRGD 3.3VAUXO 3.3VAUXIN
N.C. T1
12
______________________________________________________________________________________
Single PCI Express, Hot-Plug Controller
Pin Description (continued)
PIN 25 28 31 32 33 34 35 36 NAME T2 TIM OUTPUT INPUT 12VIN GND PGND PORADJ Test Input. Connect T2 to GND. Overcurrent Timeout Programming Input. Connect a resistor between 500 and 500k from TIM to GND to program tFAULT. Leave TIM floating for a default timeout of 11ms. Digital Output. 4ms debounced digital output of INPUT. Digital Logic Gate Input 12V Supply Input. V12VIN drives the gate of the MOSFET connected to 3.3G. 12VIN powers an internal charge pump that drives the gate of the MOSFET connected to 12G. Ground Power Ground. Connect externally to GND. Power-On-Reset Programming Input. Connect a resistor between 500 and 500k from PORADJ to GND to program the POR timing. Leave floating for a default value of 160ms. FUNCTION
MAX5954
Detailed 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 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. An 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 0.3 n-channel MOSFET. An internal charge pumps provides a 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 all supplies rise above their respective UVLO thresholds. The device keeps the internal MOSFET off only until the 3.3VAUXIN 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. Thermalprotection circuitry also shuts down all outputs if the die temperature exceeds +150C. After an overcurrent or overtemperature fault condition, the MAX5954L latches
off while the MAX5954A automatically restarts after a restart time delay. The power requirement for PCI Express connectors is defined by the PCI Express card specification and summarized in Table 1.
Startup
The main supply outputs can become active only after all the following events have occurred: * V3.3VAUXIN is above its UVLO threshold * * * V 12VIN and V 3.3S+ are both above their UVLO threshold ON is driven high PRES-DET is low for more than 5ms
The auxiliary supply output is made available only after the following events have occurred: * V3.3VAUXIN is above its UVLO threshold * * AUXON is driven high PRES-DET is low for more than 5ms
The FON input overrides all other control signals and turns on the PCI Express slot when driven low, as long as the UVLO thresholds have been reached. Table 2 summarizes the logic conditions required for startup. The auxiliary supply input powers the internal control logic and analog references of the MAX5954, so the main supplies cannot be enabled if V3.3VAUXIN is not present. When an output is enabled, a programmable startup timer (tSU) begins to count the startup time duration. The value of tSU is set to 2x the fault timeout period
______________________________________________________________________________________
13
Single PCI Express, Hot-Plug Controller MAX5954
RTIM RPORADJ
IN TIM PORADJ
OUT
12VIN
PWRGD
FAULT
12S+ + + 54mV 12S5A A01 10A tFAULT OSCILLATOR DEBOUNCE
RSENSE12
108mV CHARGE PUMP
12G
tPOR OSCILLATOR
FAST OSCILLATOR
A001 100mA 150A
40mV + + -
3.3S+ RSENSE3.3 3.3S5A 3.3G A01 10A
20mV
BIAS, REFERENCES AND UVLO
CONTROL LOGIC MAIN-CHANNEL A051 150mA 150A
3.3V
AUXIN
MAX5954
VREF + CONTROL LOGIC AUX-CHANNEL UVLO CHARGE PUMP
INPUT COMPARATORS AND CHIP CONTROL LOGIC
3.3AUXO
ON
AUXON
FON
PRES-DET
PGND
GND
Figure 1. Functional Diagram 14 ______________________________________________________________________________________
Single PCI Express, Hot-Plug Controller MAX5954
Table 1. Power Requirements for PCI Express Connectors
POWER RAIL 3.3V Voltage Tolerance Supply Current Capacitive Load 12V Voltage Tolerance Supply Current Capacitive Load 3.3V AUXILIARY Voltage Tolerance Supply Current, Wake Enabled Supply Current, Non-Wake Enabled Capacitive Load 9% (max) 375mA (max) 20mA (max) 150F (max) 9% (max) 375mA (max) 20mA (max) 150F (max) 9% (max) 375mA (max) 20mA (max) 150F (max) 9% (max) 3.0A (max) 1000F (max) 8% (max) 0.5A (max) 300F (max) 9% (max) 3.0A (max) 1000F (max) 8% (max) 2.1A (max) 1000F (max) 9% (max) 3.0A (max) 1000F (max) 8% (max) 5.5A (max) 2000F (max) X1 CONNECTOR X4/8 CONNECTOR X16 CONNECTOR
Table 2. Control Logic Truth Table
ON X X Low High Low High AUXON X X Low Low High High FON Low High High High High High PRES-DET X High Low* Low* Low* Low* 12V AND 3.3V OUTPUTS On Off Off On Off On 3.3VAUXO AUXILIARY OUTPUT On Off Off Off On On
*PRES-DET high-to-low transition has a 5ms delay (tDEG).
(tFAULT). RTIM externally connected from TIM to GND sets the duration of tFAULT.
12V and 3.3V Outputs Normal Operation
The MAX5954 monitors and actively limits the current of the 12V and 3.3V outputs after the startup period. Each output has its own overcurrent threshold. If any of the monitored output currents rise above the overcurrent threshold for a period tFAULT, FAULT asserts and the controller disengages both the 12V and 3.3V outputs (see the Fault Management section).
output current exceeds the overcurrent threshold for longer than tFAULT. A fault on an auxiliary channel causes all supplies to be disabled after a programmable time period tFAULT (see the Fault Management section).
P Power-Good (PWRGD)
Power-good (PWRGD) is an open-drain output that pulls low a time (tPOR_HL) after all of the outputs are fully on. All outputs are considered fully on when 3.3G has risen to VPGTH3.3, 12G has risen to VPGTH12, and V 3.3AUXO is less than V PGTH3.3AUX . t POR_HL is adjustable from 2.5ms to 1.5s by connecting a resistor from PORADJ to GND. See the Setting the Power-OnReset Timeout Period (tPOR) section.
3.3V Auxiliary Output Normal Operation
The auxiliary output current is internally monitored and actively limited to the maximum current-limit value. An overcurrent fault condition occurs when the
______________________________________________________________________________________
15
Single PCI Express, Hot-Plug Controller MAX5954
ON, AUXON VON_,TH VPGTH12 VPGTH3.3 12G, 3.3G VON_,TH ON
12VO, 3.3VO
V12ILIM,TH RSENSE
12G
12V OUTPUT CURRENT VPGTH3.3AUX 3.3VAUXO 3.3VAUXO PWRGD tPOR_HL PWRGD 3.3AUXIN RISING EDGE PWRGD IS PULLED UP TO 3.3. FAULT IS PULLED UP TO 3.3AUXIN. FAULT 3.3VAUXIN RISING EDGE 2 x tFAULT
FAULT PWRGD IS PULLED UP TO 3.3VAUXO. FAULT IS PULLED UP TO 3.3VAUXIN. A FAULT ON THE 3.3V OUTPUT OR 3.3VAUXO OUTPUT PRODUCES SIMILAR RESULTS.
Figure 2. Power-Up Timing, No Fault
Figure 3. 12V Power-Up Timing (Turn-On into Output Overcurrent/Short Circuit)
Fault Management
A fault occurs when an overcurrent lasts longer then tFAULT or when the device experiences an overtemperature condition. * A fault on a main output (12V or 3.3V) shuts down both main outputs. The 3.3V auxiliary is not affected. * A fault on the 3.3V auxiliary output shuts down all three outputs.
12G V12ILIM,TH RSENSE 12V OUTPUT CURRENT PWRGD
tFAULT
FAULT PWRGD IS PULLED UP TO 3.3VAUXO. FAULT IS PULLED UP TO 3.3VAUXIN. A FAULT ON THE 3.3V OUTPUT OR 3.3VAUXO OUTPUT PRODUCES SIMILAR RESULTS.
Figure 4. 12V Output Overcurrent/Short Circuit During Normal Operation
The MAX5954A automatically restarts from a fault shutdown after the tRESTART period, while the MAX5954L latches off. If an overcurrent fault occurred on a main output, bring ON low for at least tRESET (100s) and high again to reset the fault and restart the outputs. If the overcurrent fault occurred on an auxiliary output or an overtemperature fault occurred, bring both ON and AUXON low for a minimum of tRESET to reset the fault. Bring ON and/or AUXON high again to restart the respective outputs. As an extra protection, the MAX5954L waits a minimum of tRESTART before it can be restarted.
Thermal Shutdown
When the die temperature goes above +150C (TSD), an overtemperature fault occurs and the MAX5954 shuts down all outputs. The device waits for the junction temperature to decrease below TSD - Hysteresis before entering fault management (see the Fault Management section).
16
Debounced Logic Gate (Input and Output)
INPUT accepts an input from a mechanical switch. The corresponding output (OUTPUT) is debounced for 4.4ms. When INPUT goes from high to low, OUTPUT goes low right away and stays low for at least 4.4ms. After the debounce time OUTPUT follows INPUT. If INPUT goes from low to high, OUTPUT goes high right away and
______________________________________________________________________________________
Single PCI Express, Hot-Plug Controller
stays high for at least 4ms. After the debounce time, OUTPUT follows INPUT. Figure 5 shows the timing diagram describing the INPUT/OUTPUT debounced feature.
Undervoltage-Lockout Threshold
The UVLO thresholds prevent the internal auxiliary MOSFET and the external main channel MOSFETs (Q1 and Q2 in the Typical Application Circuit) from turning on if V12VIN, V3.3VIN, and V3.3VAUXIN are not present. Internal comparators monitor the main supplies and the auxiliary supply and keep the gate-drive outputs (12G and 3.3G) low until the supplies rise above their UVLO threshold. The 12V main supply is monitored at 12VIN and has a UVLO threshold of 10V. The 3.3V main supply is monitored at 3.3S+ and has a UVLO threshold of 2.65V. The auxiliary supply is monitored at 3.3VAUXIN and has a 2.65V UVLO threshold. For the main outputs to operate, V3.3VAUXIN must be above its UVLO threshold.
MAX5954
Present-Detect and Forced-On Inputs P (PRES-DET, FON)
PRES-DET input detects the PRSNT#2 pin on a PCI Express connector. When the card is plugged in, PRES-DET goes low and allows the turn-on of the output after a 4ms debounced time. When the card is removed, an internal 50k pullup forces PRES-DET high and the PCI Express slot is shut down with no delay. PRES-DET works in conjunction with ON and AUXON and only enables the device when ON and AUXON are high. A logic-low on FON forces the PCI Express slot (main supplies and auxiliary) to turn on regardless of the status of the other logic inputs provided the UVLO thresholds are exceeded on all of the inputs.
External MOSFET Gate Driver (12G and 3.3G)
The gate drive for the external MOSFETs is provided at 12G and 3.3G. 12G is the gate drive for the 12V main supply and is boosted to 5.3V above V12VIN by an internal charge pump. During turn-on, 12G sources 5A into the external gate capacitance to control the turn-on time of the external MOSFET. During turn-off, 12G sinks 150A from the external gate capacitance to quickly turn off the external MOSFET. During short-circuit events, an internal 120mA current activates to rapidly bring the load current into the regulation limits. 3.3G is the gate drive for the 3.3V main supply's MOSFET and is driven to 5.5V above the 3.3V main supply. The power for 3.3G is supplied from 12VIN and has no internal charge pump. During turn-on, 3.3G sources 5A into the external gate capacitance to control the turn-on time of the external MOSFET. During turn-off, 3.3G sinks 150A to quickly turn off the external MOSFET. During short-circuit events, an internal 150mA current activates to rapidly turn off the external MOSFET.
Active Current Limits
Active current limits are provided for all three outputs. Connect a current-sense resistor between 12S+ and 12S- to set the current limit for the 12V output. The current limit is set to 54mV/R SENSE12 . Connect a current-sense resistor between 3.3S+ and 3.3S- to set the current limit for the 3.3V main output to 20mV/RSENSE3.3. For the auxiliary output (3.3VAUXO) the current limit is fixed at 470mA. When the voltage across R SENSE12 or R SENSE3.3 reaches the current-limit threshold voltage, the MAX5954 regulates the gate voltage to maintain the current-limit threshold voltage across the sense resistor. If the current limit lasts for tFAULT, then an overcurrent fault occurs. The MAX5954 shuts down both the 12V and 3.3V outputs and asserts the FAULT output. When the auxiliary output reaches the current limit (470mA) for longer than tFAULT, a fault occurs and the device shuts down all outputs and asserts FAULT.
Auxiliary Supply (3.3VAUXIN)
3.3VAUXIN provides power to the auxiliary output as well as the internal logic and references. The drain of the internal auxiliary MOSFET connects to 3.3VAUXIN through internal sense resistor and the source connects to the auxiliary output 3.3VAUXO. The MOSFET's typical on-resistance is 0.3. An internal charge pump boosts the gate-drive voltage to fully turn on the internal n-channel MOSFET. The auxiliary supply has an internal current limit set to 470mA.
INPUT tDBC DEBOUNCED OUTPUT tDBC tDBC
Figure 5. INPUT and OUTPUT Debounced Feature
______________________________________________________________________________________
17
Single PCI Express, Hot-Plug Controller MAX5954
SHUT DOWN 12V AND 3.3V OUTPUTS. ASSERT FAULT STAY WAITING FOR tRESTART
Y
HAS tFAULT ELAPSED?
START COUNTING tFAULT
Y
WAS CURRENT LIMIT DETECTED ON ANY 12V OR 3.3V OUTPUT?
12V AND 3.3V OUTPUTS ARE ENABLED
N N
IS FAULT STILL PRESENT?
Y
N RESET tFAULT COUNTER Y LATCH-OFF OPTION? N
STAY WAITING FOR ON_ TRANSITION HIGH->LOW->HIGH
RESET FAULT AND RESTART 12V, 3.3V SUPPLIES N POWER-ON MAIN SUPPLIES FAULT AND PWRGD ARE HIGH IMPEDANCE ENABLE CHARGE ON 12G AND 3.3G PINS. START COUNTING tSU
3.3AUXIN IS ON AND ABOVE UVLO
HAS tSU ELAPSED?
Y
ARE PWRGD THRESHOLDS REACHED?
N
RESET PWRGD AFTER tPOR_LH DELAY
Y
STAY WAITING FOR BOTH ON AND AUXON TRANSITION HIGH->LOW->HIGH
RESET FAULT AND RESTART ALL SUPPLIES
ASSERT PWRGD AFTER tPOR_HL DELAY
N Y POWER-ON AUXILIARY SUPPLIES FAULT AND PWRGD ARE HIGH IMPEDANCE ENABLE CHARGE ON INTERNAL AUXILIARY MOSFET, BEGIN COUNTING tSU
HAS tSU ELAPSED?
Y
LATCH-OFF OPTION?
N
SHUT DOWN ALL OUTPUTS, ASSERT FAULT, STAY WAITING FOR tRESTART ELAPSED.
Y
IS tFAULT ELAPSED?
START COUNTING tFAULT
Y
WAS CURRENT LIMIT DETECTED ON AUXILIARY OUTPUT?
AUX SUPPLY OUTPUT IS ENABLED
N
N
IS FAULT STILL PRESENT?
Y
N RESET tFAULT COUNTER
Figure 6. Fault Management Flow Chart 18 ______________________________________________________________________________________
Single PCI Express, Hot-Plug Controller
Applications Information
Setting the Fault Timeout Period (tFAULT)
tFAULT is the time an overcurrent or overtemperature fault must remain for the MAX5954 to disable the main or auxiliary outputs. Program the fault timeout period (tFAULT) by connecting a resistor (RTIM) from TIM to GND. tFAULT can be calculated by the following equation: tFAULT = 166ns / x RTIM The tFAULT programmed time duration must be chosen according to the total capacitance load connected to 12G and 3.3G. To properly power-up the main supply outputs, the following constraints need to be taken: V x CLOAD t SU GATE ICHG where tSU = 2 x tFAULT and where: 1) ICHG = 5A. 2) VGATE = 18.4V for 12G and VGATE = 9.4V for 3.3G. 3) CLOAD is the total capacitance load at the gate. Maximum and minimum values for RTIM are 500k and 500, respectively. Leave TIM floating for a default tFAULT of 11ms. Maximum and minimum values for RPORADJ are 500k and 500, respectively. Leave PORADJ floating for a default tPOR of 160ms.
MAX5954
Component Selection
Select the external n-channel MOSFET according to the applications current requirement. Limit the switch power dissipation by choosing a MOSFET with an RDS_ON low enough to have a minimum voltage drop at full load. High RDS_ON causes larger output ripple if there are pulsed loads. High RDS_ON can also trigger an external undervoltage fault at full load. Determine the MOSFET's power rating requirement to accommodate a short-circuit condition on the board during startup. Table 3 lists MOSFETs and sense-resistor manufacturers.
Additional External Gate Capacitance
External capacitance can be added from the gate of the external MOSFETs to GND to slow down the dV/dt of the 12V and 3.3V outputs.
Maximum Load Capacitance
Large capacitive loads at the 12V output, the 3.3V output, and the 3.3V auxiliary output can cause a problem when inserting discharged PCI cards into live backplanes. A fault occurs if the time needed to charge the capacitance of the board is greater than the typical startup time (2 x tFAULT). The MAX5954 can withstand large capacitive loads due to their adjustable startup times and adjustable current-limit thresholds. Calculate the maximum load capacitance as follows: t xI CLOAD < SU LIM VOUT VOUT is either the 3.3V output, the 12V output, or the 3.3V auxiliary output.
Setting the Power-On-Reset Timeout Period (tPOR_HL)
tPOR_HL is the time from when the gate voltages of all outputs reach their power-good threshold to when PWRGD pulls low. Program the power-on-reset timeout period (tPOR) by connecting a resistor (RPORADJ) from PORADJ to GND. tPOR_HL can be calculated by the following equation: tPOR_HL = 2.5s / x RPORADJ
Table 3. Component Manufacturers
COMPONENT Sense Resistor MANUFACTURER Vishay-Dale IRC Fairchild MOSFETs International Rectifier Motorola Vishay-Siliconix PHONE 402-564-3131 704-264-8861 888-522-5372 310-322-3331 602-244-3576 -- WEBSITE www.vishay.com www.irctt.com www.fairchildsemi.com www.irf.com www.mot-sps.com/ppd/ www.vishay.com
______________________________________________________________________________________
19
Single PCI Express, Hot-Plug Controller MAX5954
Input Transients
The 12V input (12VIN), the 3.3V input (3.3S+), and the 3.3V auxiliary (3.3VAUXIN) must be above their UVLO thresholds before startup can occur. Input transients can cause the input voltage to sag below the UVLO threshold. The MAX5454 rejects transients on the input supplies that are shorter than 4s (typ). PROCESS: BiCMOS
Chip Information
20
______________________________________________________________________________________
Single PCI Express, Hot-Plug Controller
Typical Application Circuit
V12VIN ADD-IN CARD PCI EXPRESS SLOT 1F PRSNT1# +12V Q1 SI7448DP-T1 R1 8m V3.3AUXIN IN5819
MAX5954
0.1F
GND
PWRGD# 10k 3.3VAUX
PWRGD TIM 3.3VAUX0
3.3AUXIN
12VIN
12S+
12S-
12G
RTIM = OPEN
MAX5954
PGND GND PRES-DET OUTPUT AUXON FAULT INPUT 3.3S+ 3.3SPORADJ
RPORADJ = OPEN
3.3G
FON
Q2 SI7448DP-T1 +3.3V
R2 5m V3.3VIN ATTENTION SWITCH 0.1F
V3.3AUXIN
10k
PRSNT2#
MRL
MAX7311 16-BIT I/O EXPANDER
LEDs 2 2 SMBUS 3 AO-2 INT
______________________________________________________________________________________
ON
21
Single PCI Express, Hot-Plug Controller MAX5954
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.)
E E/2
(NE-1) X e
k D/2
D
(ND-1) X e D2/2 e b E2/2 k
C L
C L
D2
L
E2
e L
C L C L
L1 L e e L
A1
A2
A
PACKAGE OUTLINE 36, 40, 48L THIN QFN, 6x6x0.8mm
21-0141
F
1
2
NOTES: 1. DIMENSIONING & TOLERANCING CONFORM TO ASME Y14.5M-1994. 2. ALL DIMENSIONS ARE IN MILLIMETERS. ANGLES ARE IN DEGREES. 3. N IS THE TOTAL NUMBER OF TERMINALS. 4. THE TERMINAL #1 IDENTIFIER AND TERMINAL NUMBERING CONVENTION SHALL CONFORM TO JESD 95-1 SPP-012. DETAILS OF TERMINAL #1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED WITHIN THE ZONE INDICATED. THE TERMINAL #1 IDENTIFIER MAY BE EITHER A MOLD OR MARKED FEATURE. 5. DIMENSION b APPLIES TO METALLIZED TERMINAL AND IS MEASURED BETWEEN 0.25 mm AND 0.30 mm FROM TERMINAL TIP. 6. ND AND NE REFER TO THE NUMBER OF TERMINALS ON EACH D AND E SIDE RESPECTIVELY. 7. DEPOPULATION IS POSSIBLE IN A SYMMETRICAL FASHION. 8. COPLANARITY APPLIES TO THE EXPOSED HEAT SINK SLUG AS WELL AS THE TERMINALS. 9. DRAWING CONFORMS TO JEDEC MO220, EXCEPT FOR 0.4mm LEAD PITCH PACKAGE T4866-1. 10. WARPAGE SHALL NOT EXCEED 0.10 mm. 11. MARKING IS FOR PACKAGE ORIENTATION REFERENCE ONLY. 12. NUMBER OF LEADS SHOWN FOR REFERENCE ONLY.
PACKAGE OUTLINE 36, 40, 48L THIN QFN, 6x6x0.8mm
21-0141
F
2
2
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
22 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2006 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.
QFN THIN.EPS

▲Up To Search▲

Price & Availability of MAX5954

	To Download MAX5954 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .