MAX5955/MAX5956 19-3813 Rev 0 9/05 Low-Voltage, Dual Hot-Swap Controllers with Independent On/Off Control General Description Features The MAX5955 and MAX5956 are +1V to +13.2V dual Safe Hot Swap for +1V to +13.2V Power Supplies with V or V 2.7V hot-swap controllers with independent on/off control for IN1 IN2 complete protection of dual-supply systems. They allow Independent On/Off Control for Each Channel the safe insertion and removal of circuit cards into live Internal Charge Pumps Generate n-Channel backplanes. The MAX5955 and MAX5956 operate MOSFET Gate Drives down to 1V provided one of the inputs is above 2.7V. Inrush Current Regulated at Startup The discharged filter capacitors of the circuit card pro- Circuit-Breaker Function vide low impedance to the live backplane. High inrush currents from the backplane to the circuit card can burn Adjustable Circuit Breaker/Current-Limit up connectors and components, or momentarily collapse Threshold from 25mV to 100mV the backplane power supply leading to a system reset. VariableSpeed/BiLevel Circuit Breaker Response The MAX5955 and MAX5956 hot-swap controllers pre- Autoretry or Latched Fault Management vent such problems by gradually ramping up the output voltage and regulating the current to a preset limit when Status Outputs Indicate Fault/Safe Condition the board is plugged in, allowing the system to stabilize Output Undervoltage and Overvoltage Monitoring safely. After the startup cycle is completed, two on-chip or Protection comparators provide VariableSpeed/BiLevel protection against short-circuit and overcurrent faults, as well as Ordering Information immunity against system noise and load transients. In the event of a fault condition, the load is disconnected. The PART TEMP RANGE PIN-PACKAGE MAX5955B and MAX5956B must be unlatched after a MAX5955AEEE -40C to +85C 16 QSOP fault, and the MAX5955A and MAX5956A automatically restart after a fault. MAX5955AEEE+ -40C to +85C 16 QSOP MAX5955AUEE 0C to +85C 16 QSOP The MAX5955 and MAX5956 integrate an on-board charge pump to drive the gates of low-cost, external n- MAX5955AUEE+ 0C to +85C 16 QSOP channel MOSFETs. The devices offer integrated fea- MAX5955BEEE -40C to +85C 16 QSOP tures like startup current regulation and current glitch MAX5955BEEE+ -40C to +85C 16 QSOP protection to eliminate external timing resistors and MAX5955BUEE 0C to +85C 16 QSOP capacitors. These devices provide open-drain status outputs, an adjustable startup timer, and adjustable MAX5955BUEE+ 0C to +85C 16 QSOP current limits. The MAX5955 provides output undervolt- +Denotes lead-free package. age/overvoltage protection for each channel, while the Ordering Information continued at end of data sheet. MAX5956 provides undervoltage/overvoltage monitor- Selector Guide and Typical Operating Circuit appear at end ing for each channel. of data sheet. The MAX5955 and MAX5956 are available in a space- Pin Configuration saving 16-pin QSOP package. TOP VIEW Applications PGOOD1 1 16 PGOOD2 Base Station Line Cards Power-Supply Sequencing TIM 2 15 ON2 IN1 3 14 IN2 Network Switches, Hot Plug-In Daughter Routers, Hubs Cards SENSE1 4 MAX5955 13 SENSE2 MAX5956 Solid-State Circuit Portable Computer Device GATE1 12 GATE2 5 Breakers Bays (Docking Stations) GND 6 11 ON1 RAID LIM1 7 10 LIM2 MON1 8 9 MON2 Variable Speed/BiLevel is a trademark of Maxim Integrated QSOP Products, Inc. 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 AVAILABLELow-Voltage, Dual Hot-Swap Controllers with Independent On/Off Control ABSOLUTE MAXIMUM RATINGS IN to GND...........................................................................+14V Continuous Power Dissipation (T = +70C) A GATE to GND ...........................................-0.3V to (V + 6.2V) 16-Pin QSOP (derate 8.3mW/C above +70C)...........667mW IN ON , PGOOD , TIM to GND.......................-0.3V to the higher of Operating Temperature Range (V + 0.3V) and (V + 0.3V) MAX59 U ...................................................0C to +85C IN1 IN2 SENSE , MON , LIM to GND ...................-0.3V to (V + 0.3V) MAX59 E ................................................-40C to +85C IN Current into Any Pin .........................................................50mA 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 (V = +1V to +13.2V provided at least one supply is higher than +2.7V, V = V = +2.7V, T = T to T , unless otherwise IN ON1 ON2 A MIN MAX noted. Typical values are at V = +5V, V = +3.3V, and T = +25C.) (Note 1) IN1 IN2 A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS POWER SUPPLIES IN Input Voltage Range V Other V +2.7V 1.0 13.2 V IN IN Supply Current I I + I , V = +5V, V = +3.3V 1.2 2.3 mA IN IN1 IN2 IN1 IN2 CURRENT CONTROL T = +25C 22.5 25 27.5 A LIM = GND Slow-Comparator Threshold V T = -40C to +85C 20.5 27.5 mV SC,TH A (V - V ) (Note 2) IN SENSE R = 300k 80 100 130 LIM 1mV overdrive 3 ms Slow-Comparator Response Time t SCD (Note 3) 10mV overdrive 110 s V During startup 2 x V , Fast-Comparator Threshold SU,TH SC TH mV (V - V ) IN SENSE V V - V normal operation 4 x V , FC,TH IN SENSE SC TH Fast-Comparator Response Time t 10mV overdrive, from overload condition 260 ns FCD (V - V ) IN SENSE SENSE Input Bias Current I V = V 0.03 1 A B SENSE SENSE IN MOSFET DRIVER R = 100k 610.816 TIM Startup Period (Note 4) t ms START R = 4k (minimum value) 0.31 0.45 0.58 TIM TIM floating 4 9 17 C harg i ng, V = + 5V, V = + 10V ( N ote 5) 65 100 130 A GATE IN Average Gate Current I GATE Discharging, triggered by a fault or when 3mA V < 0.875V ON V = 3V to 13.2V 4.8 5.4 6.0 V - V , IN GATE IN Gate-Drive Voltage V V DRIVE I < 1A GATE V = 2.7V to 3.0V 4.1 5.0 6.0 IN ON COMPARATOR Low to high 0.85 0.875 0.90 V ON Threshold V , ON TH Hysteresis 25 mV ON Propagation Delay 10mV overdrive 50 s 2 MAX5955/MAX5956