MAX5946 19-3483 Rev 0 11/04 Dual PCI Express, Hot-Plug Controller General Description Features PCI Express Compliant The MAX5946 dual hot-plug controller is designed for PCI Express applications. The device provides hot- Hot Swaps 12V, 3.3V, and 3.3V Auxiliary for 2 plug control for 12V, 3.3V, and 3.3V auxiliary supplies of PCI-E Slots two PCI express slots. The MAX5946s logic inputs/out- Integrated Power MOSFET for Auxiliary Supply puts allow interfacing directly with the system hot-plug Rails management controller or through an SMBus with an Controls dI/dt and dV/dt external I/O expander. An integrated debounced atten- tion switch and present-detect signals are included to Active Current Limiting Protects Against simplify system design. Overcurrent/Short-Circuit Conditions The MAX5946 drives four external n-channel MOSFETs Programmable Current-Limit Timeout to control the 12V and 3.3V main outputs. The 3.3V aux- PWRGD Signal Outputs with Programmable iliary outputs are controlled through internal 0.3 Power-On Reset (POR) (160ms Default) n-channel MOSFETs. Internal charge pumps provide Latched FAULT Signal Output after Overcurrent gate drive for the 12V outputs while the gate drive of or Overtemperature Fault the 3.3V output is driven by the 12V input supply. The 3.3V auxiliary outputs are completely independent from Attention Switch Inputs/Outputs with 4ms Debounce the main outputs with their own charge pumps. Present-Detect Inputs At power-up, the MAX5946 keeps all of the external MOSFETs off until the supplies rise above their respec- Forced-On Inputs Facilitates Testing tive undervoltage lockout (UVLO) thresholds. The Thermal Shutdown device keeps the internal MOSFETs off only until the Allows Control through SMBus with an I/O auxiliary input supply rises above its UVLO threshold. Expander Upon a turn-on command, the MAX5946 enhances the external and internal MOSFETs slowly with a constant Ordering Information gate current to limit the power-supply inrush current. The MAX5946 actively limits the current of all outputs at PART TEMP RANGE PIN-PACKAGE all times and shuts down if an overcurrent condition persists for longer than a programmable overcurrent MAX5946AETX -40C to +85C 36 Thin QFN timeout. Thermal-protection circuitry also shuts down all MAX5946LETX -40C to +85C 36 Thin QFN outputs if the die temperature exceeds +150C. After an overcurrent or overtemperature fault condition, the Pin Configuration MAX5946L latches off while the MAX5946A automatical- ly restarts after a restart time delay. The device is avail- able in a 36-pin (6mm 6mm) thin QFN package and TOP VIEW operates over the -40C to +85C temperature range. 36 35 34 33 32 31 30 29 28 Applications PRES-DETA 1 27 PRES-DETB Servers 2 26 FONA FONB ONA 3 25 ONB Desktop Mobile Server Platforms AUXONA 4 24 AUXONB Workstations 12SA+ 5 MAX5946 23 12SB+ 12SA- 6 22 12SB- Embedded Devices 12GA 7 21 12GB 3.3SA+ 8 20 3.3SB+ 9 19 3.3SA- 3.3SB- 13 14 15 16 17 18 10 11 12 Typical Application Circuit appears at end of data sheet. SMBus is a trademark of Intel Corp. THIN QFN PCI Express is a trademark of PCI-SIG Corp. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLE 3.3GA PORADJ FAULTA PGND PWRGDA GND 3.3VAUXOA 12VIN 3.3VAUXIN INPUT1 3.3VAUXOB OUTPUT1 PWRGDB OUTPUT2 FAULTB INPUT2 TIM 3.3GBDual PCI Express, Hot-Plug Controller ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND, unless otherwise noted.) All Other Pins to GND......................-0.3V to (V + 0.3V) 3.3VAUXIN 12VIN......................................................................-0.3V to +14V Continuous Power Dissipation (T = +70C) A 12GA, 12GB ..............................................-0.3V to (V + 6V) 36-Pin Thin QFN (derate 26.3mW/C above +70C).....2.105W 12VIN 12SA+, 12SA-, 12SB+, 12SB-, Operating Temperature Range ...........................-40C to +85C 3.3GA, 3.3GB .....................................-0.3V to (V + 0.3V) Junction Temperature......................................................+150C 12VIN 3.3VAUXIN, ONA, ONB, FAULTA, FAULTB ............-0.3V to +6V Storage Temperature Range .............................-65C to +150C PWRGDA, PWRGDB ................................................-0.3V to +6V Lead Temperature (soldering, 10s) .................................+300C PGND ....................................................................-0.3V to +0.3V 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 (V = V = V = 12V, V = V = V = V = V = V = 3.3V, PWRGD = FAULT = PORADJ 12VIN 12S - 12S + 3.3S + 3.3S - 3.3VAUXIN ON AUXON FON = TIM = OUTPUT = 12G = 3.3G = OPEN, INPUT = PRES DET = PGND = GND, T = -40C to +85C, unless otherwise noted. A Typical values are at T = +25C.) (Note 1) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 12V SUPPLY 12V Supply Voltage Range V 10.8 12 13.2 V 12VIN 9.5 10 10.5 V rising 12VIN 12VIN Undervoltage Lockout V V 12UVLO Hysteresis 0.1 12VIN Supply Current I V = 13.2V 0.5 1mA 12VIN 12VIN 12VIN CONTROL 12VIN Current-Limit V 49 54 59 mV 12ILIM Threshold (V - V ) 12S + 12S - 12G Gate Charge Current I V = GND 4 5 6 A 12G CHG 12G Normal turn-off, ON = GND, V = 2V 50 150 250 A 12G 12G Gate Discharge Current I 12G DIS O utput short- ci r cui t cond i tion , strong g ate p ul l d ow n 50 120 180 mA to reg ul ation, V - V 1V , V = 5V 1 2VIN 1 2S 1 2G 12G Gate High Voltage V I = 1A 4.8 5.3 5.8 V 12G H 12G (V - V ) 12G 12VIN 12G Threshold Voltage For V Referred to V , I = 1A -3.0 -4 -4.8 V PGTH12 12VIN 12G PWRGD Assertion (Note 2) 12S - Input Bias Current 1A 12S + Input Bias Current 20 60 A 3.3V SUPPLY V , 3.3SA+ 3.3V Supply Voltage Range 3.0 3.3 3.6 V V 3.3SB+ 3.3SA+ rising 2.52 2.65 2.78 V Undervoltage Lockout (Note 3) Hysteresis 30 mV 2 MAX5946