19-3914; Rev 1; 1/06 KIT ATION EVALU LE B A IL A AV Single PCI Express, Hot-Plug Controller ♦ 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 Ordering Information PINPACKAGE PKG CODE MAX5954AETX+ -40°C to +85°C 36 Thin QFN T3666-3 MAX5954LETX+ -40°C to +85°C 36 Thin QFN T3666-3 PART TEMP RANGE +Denotes lead free package. N.C. N.C. N.C. TOP VIEW T2 T1 N.C. N.C. Pin Configuration N.C. N.C. 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. Features 27 26 25 24 23 22 21 20 19 Applications TIM 28 N.C. 29 Embedded Devices N.C. OUTPUT INPUT 12VIN 30 16 31 15 33 13 GND PGND PORADJ 34 12 35 11 32 10 36 + 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. 14 MAX5954 1 2 3 4 5 6 7 8 N.C. N.C. N.C. N.C. 3.3VAUXIN 3.3VAUXO PWRGD FAULT 3.3G 9 12S12G 3.3S+ 3.3S- Workstations 17 ON AUXON 12S+ Desktop Mobile Server Platforms 18 PRES-DET FON Servers THIN QFN ________________________________________________________________ Maxim Integrated Products 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. 1 MAX5954 General Description MAX5954 Single PCI Express, Hot-Plug Controller 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 = +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 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 = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS V 12V SUPPLY 12V Supply Voltage Range 12VIN Undervoltage Lockout 12VIN Supply Current V12VIN V12UVLO I12VIN V12VIN rising 10.8 12 13.2 9.5 10 10.5 V Hysteresis 0.1 V12VIN = 13.2V 0.5 1 mA 54 59 mV 12VIN CONTROL 12VIN Current-Limit Threshold (V12S+ - V12S-) V12ILIM 12G Gate Charge Current I12G_CHG 12G Gate Discharge Current 12G Gate High Voltage (V12G - V12VIN) 12G Threshold Voltage For PWRGD Assertion I12G_DIS V12GH VPGTH12 49 V12G = GND 4 5 6 µA Normal turn-off, ON = GND, V12G = 2V 50 150 250 µA Output short-circuit condition, strong gate pulldown to regulation, V12VIN - V12S_ ≥ 1V, V12G_= 5V 50 120 180 mA I12G = 1µA 4.8 5.3 5.8 V Referred to V12VIN, I12G_ = 1µA (Note 2) 3.0 4 4.8 V 1 µA 20 60 µA 12S- Input Bias Current 12S+ Input Bias Current 3.3V SUPPLY 3.3V Supply Voltage Range Undervoltage Lockout (Note 3) 2 V3.3S+ 3.3S+ rising Hysteresis 3.0 3.3 3.6 V 2.52 2.65 2.78 V 30 _______________________________________________________________________________________ mV Single PCI Express, Hot-Plug Controller (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 = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 17 20 23 mV 3.3V CONTROL 3.3V Current-Limit Threshold (V3.3S+ - V3.3S-) 3.3G Gate Charge Current V3.3ILIM I3.3G CHG V3.3G = GND 4 5 6 µA ON = GND, V3.3G = 2V 50 150 250 µA 3.3G Gate Discharge Current I3.3G_DIS Output short-circuit condition, strong gate pulldown to regulation, V3.3S+ - V3.3S ≥ 1V, V3.3G = 5V 100 150 220 mA 3.3G Gate High Voltage (V3.3G - V3.3S+) V3.3G_H Sourcing 1µA 4.5 5.5 6.8 V Referred to V3.3VAUXIN, I3.3G = 1µA (Note 2) -3.0 +4 +4.5 V 1 µA 20 60 µA 3.0 3.3 3.6 V 2.52 2.65 2.78 V 3.3G Threshold Voltage For PWRGD Assertion VPGTH3.3 3.3S- Input Bias Current 3.3S+ Input Bias Current 3.3V AUXILIARY SUPPLY 3.3VAUXIN Supply Voltage Range 3.3VAUXIN Undervoltage Lockout V3.3VAUXIN V3.3VAUXUVLO 3.3VAUXIN rising Hysteresis 30 3.3VAUXIN Supply Current V3.3VAUXIN = 3.6V 1.5 3.3VAUXIN to 3.3VAUXO Maximum Dropout I3.3VAUXO = 375mA 3.3VAUXO Current-Limit Threshold 3.3VAUXO shorted to GND 3.3VAUXO Threshold For PWRGD Assertion (V3.3VAUXIN - V3.3VAUXO) 376 470 VPGTH3.3AUX (Note 3) mV 3 mA 225 mV 564 mA 400 mV 2.0 V LOGIC SIGNALS Input-Logic Threshold (ON, FON, AUXON, PRES-DET, INPUT) Rising edge 1.0 Hysteresis 25 Input Bias Current (ON, AUXON, INPUT) FON, PRES-DET Internal Pullup ON, AUXON High-to-Low Deglitch Time 25 50 4 mV 1 µA 75 kΩ µs _______________________________________________________________________________________ 3 MAX5954 ELECTRICAL CHARACTERISTICS (continued) MAX5954 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 = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER PRES-DET High-to-Low Deglitch Time PWRGD Power-On Reset Time (Note 2) SYMBOL CONDITIONS MIN TYP MAX UNITS 3 5 7 ms PORADJ = open 90 160 250 RPORADJ = 20kΩ 35 55 75 RPORADJ = 100kΩ 145 265 380 tDEG tPOR_HL RPORADJ = 200kΩ PWRGD Low-to-High Deglitch Time PWRGD, FAULT Output-High Leakage Current FAULT Timeout 570 4 tPOR_LH PWRGD, FAULT Output Low Voltage µs Sinking 2mA 0.1 Sinking 30mA 0.7 VPWRGD = VFAULT = 5.5V tFAULT ms 1 TIM = open 5.5 11 17.0 RTIM = 15kΩ 1.4 2.6 3.8 RTIM = 120kΩ 12 22 32 RTIM = 300kΩ V µA ms 59 FAULT Timeout During Startup tSU 2 x tFAULT ms Autorestart Delay Time tRESTART 64 x tFAULT ms Fault Reset Minimum Pulse Width Thermal-Shutdown Threshold tRESET (Note 4) 100 µs TSD TJ rising +150 °C 20 °C Thermal-Shutdown Threshold Hysteresis OUTPUT Debounce Time tDBC 2.6 OUTPUT High Voltage Sourcing 2mA OUTPUT Low Voltage Sinking 2mA Note 1: Note 2: Note 3: Note 4: 4 4.4 6.2 V3.3VAUXIN V3.3VAUXIN - 0.3 100% production tested at TA = +25°C. 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. _______________________________________________________________________________________ 0.4 ms V V Single PCI Express, Hot-Plug Controller (V12VIN = V12S+ = 12V, V3.3VAUXIN = V3.3S+ = VON = VAUXON = VINPUT = 3.3V, PRES-DET = GND, FON = PORADJ = TIM = float, FAULT = 10kΩ to 3.3VAUXIN, PWRGD = 10kΩ to 3.3VAUXO, TA = +25°C, unless otherwise noted, see the Typical Application Circuit.) 3.3VAUXIN SUPPLY CURRENT vs. TEMPERATURE 1.9 THRESHOLD VOLTAGE (V) 1.6 1.4 1.2 1.0 0.8 0.6 10 35 60 1.8 1.7 1.6 1.5 1.4 1.3 0.4 1.2 0.2 1.1 1.0 -40 85 MAX5954 toc03 2.0 MAX5954 toc02 1.8 SUPPLY CURRENT (mA) -15 -15 10 35 60 85 -40 -15 10 35 60 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) 3.3VAUXO OUTPUT VOLTAGE vs. CURRENT 12G AND 3.3G GATE CHARGE CURRENT vs. TEMPERATURE 12G AND 3.3G GATE DISCHARGE CURRENT vs. TEMPERATURE 2.5 2.0 1.5 1.0 0.5 5.25 12G 5.20 5.15 5.10 5.05 5.00 3.3G 4.95 170 85 MAX5954 toc06 5.30 GATE DISCHARGE CURRENT (µA) 3.0 5.35 MAX5954 toc05 MAX5954 toc04 3.5 165 3.3G 160 155 12G 150 4.90 0 4.85 0 0.1 0.2 0.3 0.4 0.5 0.6 145 -40 -15 10 35 60 85 -40 -15 10 35 60 TEMPERATURE (°C) TEMPERATURE (°C) 3.3VAUX INTERNAL SWITCH MAXIMUM DROPOUT vs. TEMPERATURE 12V AND 3.3V CURRENT-LIMIT THRESHOLD VOLTAGE vs. TEMPERATURE AUXILIARY CURRENT LIMIT vs. TEMPERATURE 0.12 0.10 0.08 0.06 0.04 0.02 0 12V CURRENT-SENSE THRESHOLD 40 3.3V CURRENT-SENSE THRESHOLD 30 20 10 -15 10 35 TEMPERATURE (°C) 60 85 0.495 0.490 0.485 0.480 0.475 0.470 0.465 0.460 0.455 0 -40 85 MAX5954 toc09 50 0.500 AUXILIARY CURRENT LIMIT (A) 0.14 MAX5954 toc08 0.16 60 CURRENT-LIMIT THRESHOLD VOLTAGE (mV) AUXILIARY OUTPUT CURRENT = 375mA 0.18 MAX5954 toc07 OUTPUT CURRENT (A) 0.20 DROPOUT VOLTAGE (V) ON AND AUXON LOW-TO-HIGH THRESHOLD VOLTAGE vs. TEMPERATURE 0 -40 OUTPUT VOLTAGE (V) 2.0 MAX5954 toc01 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 GATE CHARGE CURRENT (µA) SUPPLY CURRENT (mA) 12VIN INPUT SUPPLY CURRENT vs. TEMPERATURE 0.450 -40 -15 10 35 TEMPERATURE (°C) 60 85 -40 -15 10 35 60 85 TEMPERATURE (°C) _______________________________________________________________________________________ 5 MAX5954 Typical Operating Characteristics Typical Operating Characteristics (continued) (V12VIN = V12S+ = 12V, V3.3VAUXIN = V3.3S+ = VON = VAUXON = VINPUT = 3.3V, PRES-DET = GND, FON = PORADJ = TIM = float, FAULT = 10kΩ to 3.3VAUXIN, PWRGD = 10kΩ to 3.3VAUXO, TA = +25°C, unless otherwise noted, see the Typical Application Circuit.) 3.3VAUXIN UNDERVOLTAGE-LOCKOUT THRESHOLD vs. TEMPERATURE 12VIN UNDERVOLTAGE-LOCKOUT THRESHOLD vs. TEMPERATURE 10.15 MAX5954 toc11 2.70 MAX5954 toc10 10.20 2.68 10.10 UVLO THRESHOLD (V) UVLO THRESHOLD (V) MAX5954 Single PCI Express, Hot-Plug Controller 10.05 10.00 9.95 9.90 2.66 2.64 2.62 9.85 2.60 9.80 -40 -15 10 35 60 -40 85 -15 10 35 60 85 TEMPERATURE (°C) TEMPERATURE (°C) 12V TURN-ON/OFF TIME 3.3V TURN-ON/OFF TIME MAX5954 toc12 MAX5954 toc13 3.3V OUTPUT 5V/div 12V OUTPUT 10V/div 3.3G 10V/div 12G 20V/div ON 5V/div ON 5V/div PWRGD 5V/div PWRGD 5V/div 40ms/div 40ms/div 3.3V AUXILIARY TURN-ON/OFF TIME 12V POWER-UP MAX5954 toc15 MAX5954 toc14 3.3AUXO OUTPUT VOLTAGE 2V/div 12G 20V/div 12V OUTPUT 10V/div PWRGD 2V/div 12VIN, 12V INPUT 10V/div AUXON 2V/div 40ms/div 6 PWRGD 5V/div 40ms/div _______________________________________________________________________________________ Single PCI Express, Hot-Plug Controller TURN-ON DELAY 3.3V OUTPUT AND 3.3V AUXILIARY OUTPUT 3.3V INPUT/3.3V AUXILIARY INPUT POWER-UP MAX5954 toc17 MAX5954 toc16 3.3G 10V/div 5V/div 3.3VAUXO OUTPUT VOLTAGE 3.3V OUTPUT 5V/div 5V/div 3.3 INPUT, 3.3VAUXIN 3.3S+ 5V/div 5V/div 3.3 VOLTAGE 3.3VAUXO 5V/div 5V/div PWRGD 3.3G 10V/div PWRGD 5V/div 4ms/div 100ms/div FAULT CONDITION ON 12V OUTPUT (AUTORESTART OPTION MAX5954A) FAULT CONDITION ON 3.3V OUTPUT (AUTORESTART OPTION MAX5954A) MAX5954 toc18 RLOAD STEP TO 1.5Ω MAX5954 toc19 12V OUTPUT CURRENT 5A/div RLOAD STEP TO 0.5Ω 12G 20V/div 3.3G 10V/div 12V OUTPUT VOLTAGE 10V/div tRESTART FAULT 5V/div 100ms/div 3.3V OUTPUT VOLTAGE 5V/div tRESTART FAULT 5V/div 100ms/div FAULT CONDITION ON 12V OUTPUT (LATCH OPTION MAX5954L) FAULT CONDITION ON AUXILIARY OUTPUT (AUTORESTART OPTION MAX5954A) MAX5954 toc21 MAX5954 toc20 RLOAD STEP TO 4Ω 3.3V MAIN OUTPUT CURRENT 2A/div 3.3VAUXO OUTPUT CURRENT 500mA/div RLOAD STEP TO 1.5Ω 12V OUTPUT CURRENT 5A/div 12G 20V/div tRESTART 100ms/div 3.3VAUXO OUTPUT VOLTAGE 2V/div 12V OUTPUT VOLTAGE 10V/div FAULT 2V/div FAULT 5V/div 100ms/div _______________________________________________________________________________________ 7 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 = 10kΩ to 3.3VAUXIN, PWRGD = 10kΩ to 3.3VAUXO, TA = +25°C, unless otherwise noted, see the Typical Application Circuit.) MAX5954 Single PCI Express, Hot-Plug Controller Typical Operating Characteristics (continued) (V12VIN = V12S+ = 12V, V3.3VAUXIN = V3.3S+ = VON = VAUXON = VINPUT = 3.3V, PRES-DET = GND, FON = PORADJ = TIM = float, FAULT = 10kΩ to 3.3VAUXIN, PWRGD = 10kΩ to 3.3VAUXO, TA = +25°C, unless otherwise noted, see the Typical Application Circuit.) FAULT CONDITION ON 3.3V OUTPUT (LATCH OPTION MAX5954) FAULT CONDITION ON 12V OUTPUT MAX5954 toc22 tFAULT RLOAD STEP TO 1.5Ω MAX5954 toc23 12V OUTPUT CURRENT 5A/div RLOAD STEP TO 0.5Ω 3.3V OUTPUT CURRENT 2A/div 12G 20V/div 3.3G 10V/div 12V OUTPUT VOLTAGE 10V/div 3.3V OUTPUT VOLTAGE 5V/div FAULT 5V/div 4ms/div 100ms/div FAULT CONDITION ON AUXILIARY OUTPUT (LATCH OPTION MAX5954) FAULT CONDITION ON 3.3V MAIN OUTPUT MAX5954 toc24 tFAULT FAULT 5V/div RLOAD STEP TO 0.5Ω MAX5954 toc25 3.3V OUTPUT CURRENT 2A/div RLOAD STEP TO 4Ω 3.3VAUXO OUTPUT CURRENT 500mA/div 3.3G 10V/div 3.3VAUXO OUTPUT VOLTAGE 2V/div 3.3V OUTPUT VOLTAGE 5V/div FAULT 2V/div FAULT 5V/div 4ms/div 100ms/div SHORT CIRCUIT ON 12V OUTPUT FAULT CONDITION ON AUXILIARY OUTPUT MAX5954 toc27 MAX5954 toc26 tFAULT RLOAD STEP TO 4Ω 12V OUTPUT CURRENT 5A/div 3.3VAUXO OUTPUT CURRENT 500mA/div 12G 20V/div 3.3VAUXO OUTPUT VOLTAGE 2V/div 12V OUTPUT VOLTAGE 10V/div FAULT 2V/div 4ms/div 8 FAULT 5V/div 2ms/div _______________________________________________________________________________________ Single PCI Express, Hot-Plug Controller SHORT CIRCUIT ON 12V OUTPUT SHORT CIRCUIT ON 3.3V OUTPUT MAX5954 toc28 MAX5954 toc29 3.3V OUTPUT CURRENT 2A/div 12V OUTPUT CURRENT 25A/div 12G 20V/div 0V 12V OUTPUT VOLTAGE 10V/div 0V 3.3G 5V/div 3.3V OUTPUT VOLTAGE 5V/div FAULT 5V/div 0V 4µs/div FAULT 5V/div 2ms/div SHORT CIRCUIT ON 3.3AUXO_ SHORT CIRCUIT ON 3.3V OUTPUT MAX5954 toc31 MAX5954 toc30 3.3VAUXO OUTPUT CURRENT 500mA/div 3.3V OUTPUT CURRENT 10A/div 3.3VAUXO OUTPUT VOLTAGE 2V/div 3.3G 5V/div 3.3V OUTPUT VOLTAGE 5V/div FAULT 5V/div FAULT 5V/div 0V 2ms/div 2µs/div POWER-UP INTO FAULT (AUXILIARY SUPPLY) SHORT CIRCUIT ON 3.3VAUXO_ MAX5954 toc32 MAX5954 toc33 RLOAD = 4Ω 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 2µs/div FAULT 5V/div 4ms/div _______________________________________________________________________________________ 9 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 = 10kΩ to 3.3VAUXIN, PWRGDA = 10kΩ to 3.3VAUXO, TA = +25°C, unless otherwise noted, see the Typical Application Circuit.) MAX5954 Single PCI Express, Hot-Plug Controller Typical Operating Characteristics (continued) (V12VIN = V12S+ = 12V, V3.3VAUXIN = V3.3S+ = VON = VAUXON = VINPUT = 3.3V, PRES-DET = GND, FON = PORADJ = TIM = float, FAULT = 10kΩ to 3.3VAUXIN, PWRGDA = 10kΩ to 3.3VAUXO, TA = +25°C, unless otherwise noted, see the Typical Application Circuit.) POWER-UP INTO FAULT (3.3V MAIN) POWER-UP INTO FAULT (12V OUTPUT) MAX5954 toc34 MAX5954 toc35 RLOAD = 0.5Ω 3.3V OUTPUT CURRENT 4A/div tSU 12V OUTPUT CURRENT 5A/div tSU 3.3G 5V/div 12G 10V/div 3.3V OUTPUT VOLTAGE 2V/div 12V OUTPUT VOLTAGE 10V/div ON, AUXON 5V/div ON, AUXON 5V/div FAULT 5V/div FAULT 5V/div 4ms/div 4ms/div PRESENT-DETECT (ON/OFF) OPERATION PRESENT-DETECT (ON/OFF) OPERATION MAX5954 toc36 MAX5954 toc37 12V OUTPUT VOLTAGE 10V/div 12V OUTPUT VOLTAGE 10V/div 5V/div 3.3VAUXO OUTPUT VOLTAGE 5V/div 3.3VAUXO OUTPUT VOLTAGE 5V/div PWRGD 5V/div PWRGD 5V/div PRES-DET 5V/div PRES-DET 4ms/div 40ms/div FORCED-ON (ON/OFF) OPERATION FORCED-ON (ON/OFF) OPERATION MAX5954 toc38 12V OUTPUT VOLTAGE 10V/div 12V OUTPUT VOLTAGE 10V/div 5V/div 3.3VAUXO OUTPUT VOLTAGE 5V/div 3.3VAUXO OUTPUT VOLTAGE 5V/div PWRGD 5V/div PWRGD 5V/div FON 5V/div FON 40ms/div 10 MAX5954 toc39 4ms/div ______________________________________________________________________________________ Single PCI Express, Hot-Plug Controller POWER-ON RESET TIME vs. PORADJ RESISTOR DEBOUNCED ON/OFF OPERATION MAX5954 toc40 MAX5954 toc41 1600 1400 INPUT 2V/div tPOR_HL (MS) 1200 OUTPUT 2V/div 1000 800 600 400 200 0 0 10ms/div 50 100 150 200 250 300 350 400 450 500 RPORADJ (KΩ) tFAULT TIME DELAY vs. TIM RESISTOR MAX5954 toc42 120 tFAULT (ms) 100 80 60 40 20 0 0 50 100 150 200 250 300 350 400 450 500 RTIM (kΩ) ______________________________________________________________________________________ 11 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 = 10kΩ to 3.3VAUXIN, PWRGDA = 10kΩ to 3.3VAUXO, TA = +25°C, unless otherwise noted, see the Typical Application Circuit.) Single PCI Express, Hot-Plug Controller MAX5954 Pin Description PIN NAME FUNCTION 1 PRES-DET 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). 2 FON Forced-On Input. FON has a 50kΩ 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). 3 ON 4 AUXON 5 12S+ 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. 6 12S- 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. 7 12G 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. 8 3.3S+ 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. 9 3.3S- 3.3V Negative Current-Sense Input. Connect to the negative side of the sense resistor using the Kelvinsensing technique to assure accurate current sensing. 10 3.3G 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. 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). 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. 11 FAULT 12 PWRGD 13 3.3VAUXO 3.3V Auxiliary Power-Supply Output 14 3.3VAUXIN 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. 15–23, 26, 27, 29, 30 N.C. 24 T1 12 Open-Drain Power-Good Output. PWRGD goes low tPOR_HL after all outputs reach their final value and the power MOSFETs are fully enhanced. No Connection. Not internally connected. Test Input. Connect T1 to GND. ______________________________________________________________________________________ Single PCI Express, Hot-Plug Controller PIN NAME 25 T2 Test Input. Connect T2 to GND. FUNCTION 28 TIM Overcurrent Timeout Programming Input. Connect a resistor between 500Ω and 500kΩ from TIM to GND to program tFAULT. Leave TIM floating for a default timeout of 11ms. 31 OUTPUT 32 INPUT Digital Logic Gate Input 33 12VIN 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. 34 GND Ground 35 PGND 36 PORADJ Digital Output. 4ms debounced digital output of INPUT. Power Ground. Connect externally to GND. Power-On-Reset Programming Input. Connect a resistor between 500Ω and 500kΩ from PORADJ to GND to program the POR timing. Leave floating for a default value of 160ms. 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 0.3Ω 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 +150°C. 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 MAX5954 Pin Description (continued) MAX5954 Single PCI Express, Hot-Plug Controller RTIM RPORADJ IN OUT 12VIN PWRGD FAULT PORADJ TIM 12S+ + - 108mV + - 54mV RSENSE12 12S- CHARGE PUMP 5µA 12G Aµ01 10µA tFAULT OSCILLATOR DEBOUNCE tPOR OSCILLATOR FAST OSCILLATOR Aµ001 100mA 150µA 40mV + - 3.3S+ + - RSENSE3.3 20mV 3.3S5µA 3.3G Aµ01 10µA BIAS, REFERENCES AND UVLO CONTROL LOGIC MAIN-CHANNEL Aµ051 150mA 150µA 3.3V VREF + - MAX5954 CHARGE PUMP CONTROL LOGIC AUX-CHANNEL UVLO 3.3AUXO INPUT COMPARATORS AND CHIP CONTROL LOGIC ON AUXON FON PRES-DET PGND GND Figure 1. Functional Diagram 14 ______________________________________________________________________________________ AUXIN Single PCI Express, Hot-Plug Controller MAX5954 Table 1. Power Requirements for PCI Express Connectors POWER RAIL X1 CONNECTOR X4/8 CONNECTOR X16 CONNECTOR Voltage Tolerance ±9% (max) ±9% (max) ±9% (max) Supply Current 3.0A (max) 3.0A (max) 3.0A (max) 1000µF (max) 1000µF (max) 1000µF (max) Voltage Tolerance ±8% (max) ±8% (max) ±8% (max) Supply Current 0.5A (max) 2.1A (max) 5.5A (max) 300µF (max) 1000µF (max) 2000µF (max) ±9% (max) ±9% (max) ±9% (max) Supply Current, Wake Enabled 375mA (max) 375mA (max) 375mA (max) Supply Current, Non-Wake Enabled 20mA (max) 20mA (max) 20mA (max) Capacitive Load 150µF (max) 150µF (max) 150µF (max) 3.3V Capacitive Load 12V Capacitive Load 3.3V AUXILIARY Voltage Tolerance Table 2. Control Logic Truth Table ON AUXON X X X X PRES-DET 12V AND 3.3V OUTPUTS 3.3VAUXO AUXILIARY OUTPUT Low X On On High High Off Off Off FON Low Low High Low* Off High Low High Low* On Off Low High High Low* Off On High High High Low* 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). 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 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). 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. ______________________________________________________________________________________ 15 MAX5954 Single PCI Express, Hot-Plug Controller ON ON, AUXON VON_,TH VPGTH12 VPGTH3.3 12G, 3.3G VON_,TH 12VO, 3.3VO V12ILIM,TH RSENSE 12G 12V OUTPUT CURRENT 3.3VAUXO 3.3VAUXO VPGTH3.3AUX PWRGD tPOR_HL PWRGD 3.3AUXIN RISING EDGE 3.3VAUXIN RISING EDGE FAULT 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. PWRGD IS PULLED UP TO 3.3. FAULT IS PULLED UP TO 3.3AUXIN. Figure 2. Power-Up Timing, No Fault Figure 3. 12V Power-Up Timing (Turn-On into Output Overcurrent/Short Circuit) Fault Management 12G V12ILIM,TH RSENSE 12V OUTPUT CURRENT • PWRGD 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 (100µs) 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. 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 Thermal Shutdown When the die temperature goes above +150°C (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 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. 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 Present-Detect and Forced-On Inputs (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 50kΩ 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. 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. INPUT tDBC tDBC tDBC DEBOUNCED OUTPUT 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. 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 5µA into the external gate capacitance to control the turn-on time of the external MOSFET. During turn-off, 12G sinks 150µA 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 5µA into the external gate capacitance to control the turn-on time of the external MOSFET. During turn-off, 3.3G sinks 150µA to quickly turn off the external MOSFET. During short-circuit events, an internal 150mA current activates to rapidly turn off the external MOSFET. 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 0.3Ω. 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. Figure 5. INPUT and OUTPUT Debounced Feature ______________________________________________________________________________________ 17 MAX5954 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. MAX5954 Single PCI Express, Hot-Plug Controller SHUT DOWN 12V AND 3.3V OUTPUTS. ASSERT FAULT STAY WAITING FOR tRESTART Y HAS tFAULT ELAPSED? WAS CURRENT LIMIT DETECTED ON ANY 12V OR 3.3V OUTPUT? Y START COUNTING tFAULT 12V AND 3.3V OUTPUTS ARE ENABLED N N IS FAULT STILL PRESENT? Y N RESET tFAULT COUNTER Y N LATCH-OFF OPTION? RESET FAULT AND RESTART 12V, 3.3V SUPPLIES STAY WAITING FOR ON_ TRANSITION HIGH->LOW->HIGH N ENABLE CHARGE ON 12G AND 3.3G PINS. START COUNTING tSU POWER-ON MAIN SUPPLIES FAULT AND PWRGD ARE HIGH IMPEDANCE 3.3AUXIN IS ON AND ABOVE UVLO Y HAS tSU ELAPSED? ARE PWRGD THRESHOLDS REACHED? RESET PWRGD AFTER tPOR_LH DELAY N 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 LATCH-OFF OPTION? POWER-ON AUXILIARY SUPPLIES FAULT AND PWRGD ARE HIGH IMPEDANCE N SHUT DOWN ALL OUTPUTS, ASSERT FAULT, STAY WAITING FOR tRESTART ELAPSED. Y ENABLE CHARGE ON INTERNAL AUXILIARY MOSFET, BEGIN COUNTING tSU IS tFAULT ELAPSED? START COUNTING tFAULT HAS tSU ELAPSED? Y AUX SUPPLY OUTPUT IS ENABLED N N IS FAULT STILL PRESENT? WAS CURRENT LIMIT DETECTED ON AUXILIARY OUTPUT? Y Y N RESET tFAULT COUNTER Figure 6. Fault Management Flow Chart 18 ______________________________________________________________________________________ Single PCI Express, Hot-Plug Controller 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 / Ω 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 × CLOAD t SU ≥ GATE ICHG Maximum and minimum values for RPORADJ are 500kΩ and 500Ω, respectively. Leave PORADJ floating for a default tPOR of 160ms. 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. where tSU = 2 x tFAULT and where: 1) ICHG = 5µA. 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 500kΩ and 500Ω, respectively. Leave TIM floating for a default tFAULT of 11ms. 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: 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 ×I CLOAD < SU LIM VOUT VOUT is either the 3.3V output, the 12V output, or the 3.3V auxiliary output. tPOR_HL = 2.5µs / Ω x RPORADJ Table 3. Component Manufacturers COMPONENT Sense Resistor MOSFETs MANUFACTURER PHONE WEBSITE Vishay-Dale 402-564-3131 www.vishay.com IRC 704-264-8861 www.irctt.com Fairchild 888-522-5372 www.fairchildsemi.com International Rectifier 310-322-3331 www.irf.com Motorola 602-244-3576 www.mot-sps.com/ppd/ Vishay-Siliconix — www.vishay.com ______________________________________________________________________________________ 19 MAX5954 Applications Information MAX5954 Single PCI Express, Hot-Plug Controller Chip Information 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 4µs (typ). 20 PROCESS: BiCMOS ______________________________________________________________________________________ Single PCI Express, Hot-Plug Controller V12VIN ADD-IN CARD PCI EXPRESS SLOT 1µF Q1 SI7448DP-T1 PRSNT1# IN5819 V3.3AUXIN R1 8mΩ +12V 12VIN 3.3AUXIN 12S- 12G GND 12S+ 0.1µF PWRGD PWRGD# RTIM = OPEN 10kΩ 3.3VAUX TIM MAX5954 3.3VAUX0 RPORADJ = OPEN PGND PORADJ Q2 SI7448DP-T1 OUTPUT INPUT ON AUXON FON FAULT PRES-DET 3.3S+ 3.3S- 3.3G GND R2 5mΩ V3.3VIN ATTENTION SWITCH +3.3V V3.3AUXIN 0.1µF 10kΩ PRSNT2# MRL MAX7311 16-BIT I/O EXPANDER LEDs 2 2 3 SMBUS AO-2 INT ______________________________________________________________________________________ 21 MAX5954 Typical Application Circuit 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.) QFN THIN.EPS MAX5954 Single PCI Express, Hot-Plug Controller (NE-1) X e E E/2 k D/2 CL (ND-1) X e D D2 D2/2 e b E2/2 L CL k E2 e L CL CL L1 L L e A1 A2 e 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 © 2006 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.