19-2849; Rev 0; 4/03 Smallest, Most Reliable, 12V, InfinibandCompliant Hot-Swap Controller Features 12V Hot-Swap Controller for 25W or 50W Infiniband Ports Programmable Overcurrent Protection Regulation Level EN and LPEN Inputs for Flexible Sequencing Power-Good Signal 16V Absolute Maximum Rating Withstands Inductive Kickbacks Soft-Start Overcurrent Protection During Turn-On Timed Current Regulation Period (Adjustable) 100ns IC Response Time to Output Dead Short Adjustable Overvoltage Protection Undervoltage Lockout Adjustable Turn-On Ramp Ordering Information PART MAX8533EUB TEMP RANGE PIN-PACKAGE -40C to +85C 10 MAX Typical Operating Circuit Applications VB_OUT 12V Hot-Swap Infiniband Bulk Power Hot-Swap/Plug/Dock Power Management BACKPLANE VB_IN Blade Servers INFINIBAND MODULE 10V TO 14V RAID IN Network Routers and Switches VBxEN LPEN GATE OUT OVP LPEN VB_RET Pin Configuration appears at end of data sheet. Infiniband is a trademark of InfinibandSM Trade Association. ISET EN VIN MAX8533 CTIM RET POK ________________________________________________________________ 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 MAX8533 General Description The MAX8533 is a single-port, 12V, InfinibandTM-compliant (IB) versatile hot-swap controller. The device can be implemented in both IB Class I (nonisolated) and Class II (isolated) power-topology applications. Additionally, the MAX8533 can be used as a reliable power controller on hot-swappable blade servers, RAID cards, and network switches or routers that are powered from a 12V bus. The MAX8533 integrates several features that allow reliable insertion and removal of the circuit card, as well as real-time monitoring of abnormal occurrences. The MAX8533 allows for an adjustable soft-start ramp during turn-on of the input voltage, while providing overcurrent protection. It also provides accurate and consistent current-regulated outputs for a programmable period of time to latch off and soft-start in the presence of overcurrent conditions (OC). Additionally, it provides a second level of severe overcurrent (SOC) protection by responding to a dead short in 100ns. The MAX8533 also includes adjustable overvoltage protection. The MAX8533 incorporates undervoltage lockout (UVLO) and a power-good (POK) signal to the DC-toDC converters to confirm the status of output voltage rails during operation. Two enable inputs EN (logic enable) and LPEN (local power enable) provide flexible sequencing. The MAX8533 is specified across the extended temperature range and has an absolute maximum rating of 16V to withstand inductive kickback during board removal. The MAX8533 is available in the space-saving 10-pin MAX package. MAX8533 Smallest, Most Reliable, 12V, InfinibandCompliant Hot-Swap Controller ABSOLUTE MAXIMUM RATINGS IN, POK to RET .......................................................-0.3V to +16V GATE to RET ...................................................-0.3V to (VIN + 7V) OUT, ISET, CTIM to RET ..............................-0.3V to (VIN + 0.3V) EN, LPEN, OVP to RET .............................................-0.3V to +6V Continuous Power Dissipation (TA = +70C) 10-Pin Max (derate 5.6 mW/C above +70C) .......444.4 mW 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 (VIN = +12V, VEN = 0, TA = 0C to +85C, unless otherwise noted. Typical values are at TA = +25C.) PARAMETER CONDITIONS MIN TYP MAX UNITS 10 12 14 V 18.5 20 21.5 A -4 0 +4 mV 6 12 A VB BULK SUPPLY CONTROL IN Supply Voltage Range ISET Current Source Current-Limit Offset Voltage VISET - VIN OUT Input Current VOUT = 12V Severe Overcurrent Threshold With respect to current regulation threshold 25W OUT Current Regulation RISET = 3.09k 1%, RSENSE = 20m 1% 2.6 150 3.1 3.6 mV A 50W OUT Current Regulation RISET = 3.09k 1%, RSENSE = 10m 1% 5.2 6.2 7.2 A GATE PARAMETERS Gate Response Time to Severe Overcurrent VRSENSE (150mV + current regulation threshold + 50mV) until VGATE begins to slew low (Note 1) 100 ns Gate Response Time to Overcurrent VRSENSE current regulation threshold + 50mV until VGATE begins to slew low (Note 1) 600 ns Gate Turn-On Current Gate Pulldown Current 8.4 10 Overcurrent, VRSENSE (current regulation threshold + 100mV) (Note 1) 2.7 Severe overcurrent 350 Gate High Voltage 11.6 A mA VIN + 4 VIN + 5 V IN PARAMETERS Quiescent Supply Current IN UVLO Threshold Hysteresis = 300mV 7.5 1.5 3 mA 8.4 9.0 V POK Undervoltage Threshold Measured at OUT, rising edge, hysteresis = 300mV 9.2 9.6 10.0 V POK Delay VPOK rising 100 220 350 s POK Output Voltage VOUT < 9.2V, IPOK = 1.6mA 0.1 0.25 V POK Leakage Current VOUT > 10V, VPOK = 14V 0.1 1 A EN Rising Threshold Hysteresis = 120mV 1.3 1.65 2.0 EN Pullup Voltage EN unconnected 4.5 5.5 12 20 EN Pullup Current 2 _______________________________________________________________________________________ V V 28 A Smallest, Most Reliable, 12V, InfinibandCompliant Hot-Swap Controller (VIN = +12V, VEN = 0, TA = 0C to +85C, unless otherwise noted. Typical values are at TA = +25C.) PARAMETER CONDITIONS MIN TYP MAX 2.0 LPEN Rising Threshold Hysteresis = 120mV 1.3 1.65 LPEN Pullup Voltage LPEN unconnected 4.5 5.5 12 20 28 1.96 2.00 2.04 LPEN Pullup Current OVP Threshold Voltage Hysteresis = 10mV, VOVP rising OVP Fault Timeout UNITS V V 1.5 A V ms CTIM PARAMETERS CTIM Charging Current VCTIM < 1.5V 16 20 24 A CTIM Fault Pullup Current VCTIM = 6V 6 8 12 mA 1.5 1.8 2.1 V MIN TYP MAX UNITS Current-Limit Timeout Threshold Voltage ELECTRICAL CHARACTERISTICS (VIN = +12V, VEN = 0, TA = -40C to +85C, unless otherwise noted.) (Note 2) PARAMETER CONDITIONS VB BULK SUPPLY CONTROL IN Supply Voltage Range 10 14 V ISET Current Source Current regulation threshold = ISET x RISET 18 22 A Current-Limit Offset Voltage VISET - VIN -4 +4 mV OUT Input Current VOUT = 12V 12 A 25W OUT Current Regulation RISET = 3.09k 1%, RSENSE = 20m 1% 2.5 3.7 A 50W OUT Current Regulation RISET = 3.09k 1%, RSENSE = 10m 1% 5.0 7.4 A 8 12 A GATE PARAMETERS Gate Turn-On Current Gate High Voltage VIN + 4 V IN PARAMETERS Quiescent Supply Current 3 mA IN UVLO Threshold Hysteresis = 300mV 7.5 9.0 V POK Undervoltage Threshold Measured at OUT, rising edge, hysteresis = 300mV 9.0 10.2 V POK Delay VPOK rising 100 350 s POK Output Voltage VOUT < 9.2V, IPOK = 1.6mA POK Leakage Current VOUT > 10V, VPOK = 14V EN Rising Threshold Hysteresis = 120mV 1.3 EN Pullup Voltage EN unconnected 4.5 EN Pullup Current 12 0.25 V 1 A 2.0 V V 28 A _______________________________________________________________________________________ 3 MAX8533 ELECTRICAL CHARACTERISTICS (continued) MAX8533 Smallest, Most Reliable, 12V, InfinibandCompliant Hot-Swap Controller ELECTRICAL CHARACTERISTICS (continued) (VIN = +12V, VEN = 0, TA = -40C to +85C, unless otherwise noted.) (Note 2) PARAMETER CONDITIONS MIN LPEN Rising Threshold Hysteresis = 120mV 1.3 LPEN Pullup Voltage LPEN unconnected 4.5 LPEN Pullup Current OVP Threshold Voltage Hysteresis = 10mV, VOVP rising TYP MAX UNITS 2.0 V V 12 28 A 1.96 2.04 V CTIM PARAMETERS CTIM Charging Current VCTIM < 1.5V 15 25 A CTIM Fault Pullup Current VCTIM = 6V 6 12 mA 1.4 2.2 V Current-Limit Timeout Threshold Voltage Note 1: The current regulation threshold is set by R3 (Figure 2). It is equal to 20A x R3. Note 2: Specifications to -40C are guaranteed by design and not production tested. Typical Operating Characteristics (TA = +25C, unless otherwise noted.) HOT PLUG WITH 10V INPUT INTO 50W LOAD HOT PLUG WITH 14V INPUT INTO 65W LOAD MAX8533 toc01 10V/div VIN 10V/div VIN VOUT 0V 5A/div 0A IIN 10V/div VIN 0V 0V 10V/div VPOK 0V VPOK 10V/div VOUT 0V 10V/div MAX8533 toc03 10V/div 0V VPOK HOT PLUG INTO SHORT CIRCUIT MAX8533 toc02 VOUT 0V 5A/div 0A IIN 0V 5A/div 0A IIN 20ms/div 20ms/div 0V 20ms/div ON/OFF CONTROL WITH EN TOGGLED ON/OFF CONTROL WITH LPEN TOGGLED MAX8533 toc04 MAX8533 toc05 10V/div VEN 0V 10V/div VPOK 5V/div VLPEN 0V 10V/div VPOK 0V VOUT 0V 10V/div 10V/div VOUT 0V 5A/div 0A IIN 200ms/div 4 0V 5A/div 0A IIN 200ms/div _______________________________________________________________________________________ Smallest, Most Reliable, 12V, InfinibandCompliant Hot-Swap Controller INPUT OVERVOLTAGE PROTECTION FAULT CONDITION HOT PLUG INTO INPUT OVERVOLTAGE CONDITION MAX8533 toc07 MAX8533 toc06 10V/div VIN 10V/div VOUT 0V 0V 10V/div VGATE 10V/div VGATE 0V 0V IIN 5V/div 10V/div VOUT 0V 0A 2ms/div 40ms/div OUTPUT-VOLTAGE RISE TIME AS A FUNCTION OF GATE CAPACITOR (C2) SHORT-CIRCUIT CURRENT PROTECTION MAX8533 toc08 MAX8533 toc09 0.047F 0.1F 10V/div VOUT 0.22F 0.47F 0.022F 0V VIN 12V 10V/div VGATE 5V/div VOUT 0V 0V 2A/div IIN 0A 10s/div 40ms/div INPUT-CURRENT RISE TIME AS A FUNCTION OF GATE CAPACITOR (C2) HOT UNPLUG MAX8533 toc11 MAX8533 toc10 0.047F 0.1F 0.022F 0.22F 0.47F 10V/div VIN 0V 2A/div IIN 10V/div VOUT 0V 0A 2A/div IIN 0A 40ms/div 4ms/div _______________________________________________________________________________________ 5 MAX8533 Typical Operating Characteristics (continued) (TA = +25C, unless otherwise noted.) Smallest, Most Reliable, 12V, InfinibandCompliant Hot-Swap Controller MAX8533 Pin Description PIN NAME 1 ISET 2 IN FUNCTION Current-Limit Threshold Programming Input. Connect to the low side of the current-limit threshold programming resistor. Bulk Power Supply. Connect to the input power supply and positive terminal of the current-sense resistor. 3 GATE External MOSFET-Gate-Drive Output. Connect to the gate of the external N-channel MOSFET. A series resistor and capacitor connected from GATE to RET sets the turn-on ramp rate. At turn-on, this capacitor is charged to VIN + 5V (typ) by an internal current source. GATE is pulled to RET when EN is high and/or LPEN is low. GATE is pulled to RET during a fault condition. 4 CTIM Current Regulation Time Programming Input. Connect a capacitor from CTIM to RET. The capacitance at CTIM determines the time delay between an overcurrent event and chip output shutdown (current-limit timeout). CTIM is pulled low, resetting the fault latch when either EN is high or LPEN is low. 5 RET Bulk Power Ground 6 OVP Overvoltage Protection Input. Connect to common point of a resistor-divider from OUT to RET. GATE pulls low when VOVP exceeds the 2V threshold for at least 1.5ms and the IC is latched off. 7 OUT Output Voltage. Connect to the output of the circuit. 8 POK Power-Good Output. POK is an open-drain output that becomes high impedance when VOUT reaches 9.6V. Pull POK up to the supply rail using an external pullup resistor. POK is pulled to RET until the MAX8533 is enabled. 9 LPEN Local Power-Enable Input. LPEN is a positive-assertion enable input to turn on the IC. Pull LPEN low to disable the output. LPEN has an internal pullup to 5V. 10 EN Chip-Enable Input. EN is an active-low input that enables the IC. Detailed Description The MAX8533 is a single-port, 12V, IB-compliant versatile hot-swap controller IC designed for applications where a line card is inserted into a live backplane. The MAX8533 can be implemented in both IB Class I (nonisolated) and Class II (isolated) power-topology applications. Normally, when a line card is plugged into a live backplane, the low impedance of the card's discharged filter capacitors can momentarily collapse the input supply voltage. The MAX8533 is designed to reside on the line card and to provide inrush currentlimiting and short-circuit protection. This is achieved using an external N-channel MOSFET, current-sense resistor, and current-limit set resistor, along with two on-chip comparators (Figure 1). UVLO and Startup The MAX8533 has an undervoltage lockout protection circuit. The circuit is disabled when VIN is below 8.4V (typ). The gate of the MOSFET, CTIM, LPEN, and POK is pulled to RET until VIN exceeds the UVLO threshold. 6 Once VIN exceeds the UVLO threshold and LPEN and EN are enabled, the capacitor on the gate of the external MOSFET is charged and the MOSFET turns on. The charging of this capacitor provides soft-start to prevent high inrush currents. On/Off Control The MAX8533 is enabled/disabled using LPEN and EN. Drive EN low and LPEN high to enable the device. LPEN can also be left unconnected as it is internally connected to 5V. Drive LPEN low or EN high to disable the output. Table 1 is the truth table for these inputs. Table 1. Truth Table EN LPEN OUTPUT 0 0 OFF 0 1 ON 1 0 OFF 1 1 OFF Zero is a logic-low input, 1 is a logic-high input or unconnected input. _______________________________________________________________________________________ Smallest, Most Reliable, 12V, InfinibandCompliant Hot-Swap Controller IN GATE IREG CURRENT-REGULATION CONTROL LOGIC 5V LINEAR REGULATOR 100F 5V CLAMP LPEN 5V CLAMP IN LPEN CTIM C3 0.01F OUT 2V MAX8533 20A POK IN N Figure 1. MAX8533 Functional Diagram N1 VVB_OUT R2 20 C1 470F C2 0.1F ISET GATE R5 31.6k OUT VIN EN C4 0.22F CTIM OVP 2V POK COMPARATOR VBxEN VB_RET OVP COMPARATOR 20A R3 3.09k LPEN CURRENTREGULATION TIMER EN R1 10m 10F 20A IN RET 7.5k BIAS UVLO COMPARATOR External Power MOSFET Selection VIN IN IN SEVERE OVERCURRENT COMPARATOR 2V REFERENCE (REF) Setting the Turn-On Ramp Rate INFINIBAND MODULE 10V TO 14V I0A OVERCURRENT COMPARATOR The MOSFET turn-on ramp rate is determined by the capacitor (C2) at GATE (Figure 2). An internal 10A current source charges C2 to bring GATE high. The soft-start rate is determined as follows: tSS = C2 x (VIN + 5)/(10 x 10-6) tSS may be longer than expected in the application depending on the gate capacitance of the external MOSFET. The necessary gate voltage is provided by an on-board charge pump that boosts the voltage at GATE to (VIN + 5V). BACKPLANE ISET CHARGE PUMP Applications Information Select the N-channel MOSFET according to the application's current requirements. Table 2 lists some recommended components. The MOSFET's on-resistance (RDS(ON)) should be chosen low enough to have a minimal voltage drop at full load to limit the MOSFET power dissipation. High RDS(ON) can cause high output ripple if the board has pulsing loads, or trigger an external MAX8533 Startup Into Load The MAX8533 is intended to be used in a circuit where no load is applied until the POK signal is enabled. In an application where the load is applied during the outputvoltage ramp up, the RDS(ON) of the MOSFET is higher and the power dissipated by the MOSFET is larger. Repeated, rapid hot-swaps into a load can create sufficient heat to exceed the power-dissipation limits of the package causing failure of the MOSFET. OVP MAX8533 RET POK R4 4.99k R6 100k POK Figure 2. Typical 50W Applications Circuit _______________________________________________________________________________________ 7 MAX8533 Smallest, Most Reliable, 12V, InfinibandCompliant Hot-Swap Controller Table 2. External Component List for 50W Output REF DESIGNATOR DESCRIPTION MANUFACTURER PART NO. C1 470F, 25V aluminum electrolytic capacitor Sanyo 25MV470HC C2 0.1F 10%, 25V X5R ceramic capacitor Taiyo Yuden TMK107BJ104KA C3 0.01F 20% X7R ceramic capacitor Kemet C0606C103M4RAC C4 0.22F 10%, 25V X5R TDK ceramic capacitor C1608X5R1A224K R1* 10m 1%, 0.5W current-sense resistor Dale LRF1206-01-R010-F R2 20 5% resistor Panasonic R3 3.09k 1% resistor Panasonic R4 4.99k 1% resistor Panasonic R5 31.6k 1% resistor Panasonic N1 N-channel MOSFET, 30V, 6m Siliconix Si4842DY *Use a 20m 1%, 0.25W current-sense resistor for 25W applications. undervoltage reset monitor at full load. The maximum gate voltage (VGS) rating must be at least 20V. Low MOSFET gate capacitance is not necessary for the inrush current limiting because it is achieved by limiting the GATE dV/dt. However, higher gate capacitance increases the turn-off time of the MOSFET under fault conditions. Current-Limit and Overload Protection The MAX8533 features a dual overcurrent protection circuit that turns off the MOSFET in overcurrent situations. When an overload event is sensed, the IC limits the current to a level set by ISET. Continuous overload for a period set by the user (t CTIM ) latches off the MOSFET. The severe overcurrent protection immediately shuts down the external MOSFET and latches it off. R3 sets the current-limit threshold voltage. This voltage is generated from an internal 20A source driven through R3. Therefore: VILIM = R3 x 20A The current-sense signal is sensed across resistor R1. With no load, the voltage at ISET is the input voltage 8 plus VILIM. As the load current increases, the voltage drop across R1 increases and reduces the voltage at ISET. Once VISET is lower than VIN, the overcurrent comparator (Figure 1) is tripped and the MAX8533 enters current regulation mode. During current regulation mode, the gate voltage of the MOSFET is decreased to limit the current to the output. The maximum time period for the current regulation mode is set by the external capacitor at CTIM (C3). This feature allows transient currents that exceed the current limit to pass without shutting down the circuit. The current regulation time period is determined as: tIREG = C3 x (1.8V/20A) If t IREG expires and the overcurrent condition still exists, the MOSFET is latched off. The severe overcurrent comparator (Figure 1) trips if the drop across the current-sense resistor (R1) is 150mV higher than the current-limit threshold (V IN exceeds VISET by 150mV). During a severe overcurrent event, the gate of the external MOSFET is pulled down with a 350mA current source and latched immediately. Toggle EN, LPEN, or input power to clear the latched fault condition. Overvoltage Protection The MAX8533 has an adjustable overvoltage protection feature that latches the IC off in case of an overvoltage event. An external resistor-divider (R4 and R5, Figure 2) from OUT to RET with OVP connected to the center, sets the overvoltage threshold. Use 4.99k for R4. R5 is determined using the following equation: R5 = 4.99 x 103 x ((VOVT / VOVP) - 1) VOVT is the desired overvoltage threshold and VOVP is 2V (typ). OVP latches off the MAX8533 if an overvoltage condition exists for 1.5ms. Toggle EN, LPEN, or input power to clear the latched fault condition. Fault Reset Overcurrent, severe overcurrent, and overvoltage conditions result in the MAX8533 entering a latched fault condition. Toggle LPEN, EN, or input power to reset the latched fault condition and return to normal operation. Power-Good Output (POK) POK is an open-drain output used to enable the onboard DC-to-DC converter. The POK output turns high impedance when the output rail reaches 9.6V. POK must be pulled up to the user's logic level using a pullup resistor. _______________________________________________________________________________________ Smallest, Most Reliable, 12V, InfinibandCompliant Hot-Swap Controller Minimize the current-sense resistor trace length (<10mm), and ensure accurate current sensing with Kelvin connections. Place capacitor CTIM as close as possible to the IC. The traces from the current-sense resistor to IN and ISET should be as short as possible for accurate current sensing. Place the MAX8533 circuit as close as possible to the backplane connector. A sample PC board layout is available in the MAX8533 Evaluation Kit. Pin Configuration TOP VIEW ISET 1 IN 10 EN 2 MAX8533 9 LPEN GATE 3 8 POK CTIM 4 7 OUT RET 5 6 OVP MAX Chip Information TRANSISTOR COUNT: 2541 PROCESS: BiCMOS _______________________________________________________________________________________ 9 MAX8533 _______PC Board Layout Guidelines To take advantage of the switch response time to an output fault condition, keep all traces as short as possible and maximize the high-current trace width to reduce the effect of undesirable parasitic inductance. The MOSFET dissipates a fair amount of heat due to the high currents involved, especially during an overcurrent condition. In order to dissipate the heat generated by the MOSFET, make the power traces very wide with a large amount of copper area. A more efficient way to achieve good power dissipation on a surfacemount package is to lay out two copper pads directly under the MOSFET package on both sides of the board. Connect the two pads to the ground plane through vias, and use enlarged copper mounting pads on the top side of the board. 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 10LUMAX.EPS MAX8533 Smallest, Most Reliable, 12V, InfinibandCompliant Hot-Swap Controller 4X S 10 10 INCHES H y 0.500.1 0.60.1 1 1 0.60.1 BOTTOM VIEW TOP VIEW D2 MILLIMETERS MAX DIM MIN 0.043 A 0.006 A1 0.002 A2 0.030 0.037 0.120 D1 0.116 0.118 0.114 D2 0.116 0.120 E1 E2 0.114 0.118 H 0.187 0.199 L 0.0157 0.0275 L1 0.037 REF b 0.007 0.0106 e 0.0197 BSC c 0.0035 0.0078 0.0196 REF S 0 6 MAX MIN 1.10 0.15 0.05 0.75 0.95 3.05 2.95 3.00 2.89 3.05 2.95 2.89 3.00 4.75 5.05 0.40 0.70 0.940 REF 0.177 0.270 0.500 BSC 0.090 0.200 0.498 REF 0 6 E2 GAGE PLANE A2 c A b A1 E1 D1 L L1 FRONT VIEW SIDE VIEW PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE, 10L uMAX/uSOP APPROVAL DOCUMENT CONTROL NO. 21-0061 REV. I 1 1 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. 10 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.