MAX5922 19-2708 Rev 0 4/03 +48V, Single-Port Network Power Switch For Power-Over-LAN General Description Features The MAX5922A/B/C is a single-port network power con- IEEE 802.3af Compliant troller with an integrated power MOSFET, operating from +32V to +60V Wide Operating Input Range a +32V to +60V supply rail. The device is specifically designed for power-sourcing equipment (PSE) in power- 0.45 Integrated Power Switch over-LAN applications and is fully compliant to the IEEE Power Device (PD) Detection and Classification 802.3af standard. The MAX5922 provides power devices 100A PD Leakage Detection Tolerant (PD) discovery, classification, current limit, and other nec- essary functions for an IEEE 802.3af compliant PSE. Programmable Current Limit The MAX5922 is suitable for PSE function in both Zero-Current Detection with Status Output switch/router systems where the power is delivered to the Detection Collision Avoidance Option for Midspan load through the signal pairs, and in midspan systems where the power is delivered to the load through the Application spare pairs. In midspan mode, a detection collision Input Logic Signals Compatible with 1.8V to 5V avoidance circuit (MAX5922A/C only) provides the nec- CMOS Logic essary back-off timing to prevent fault detections that happen when two different PSEs try to detect and Separate Analog and Digital Grounds with Up to power the same PD. The MAX5922B/C have a detec- 4V Offset tion disable input that can be connected high to disable Power-Good Status Output the detection/classification functions or connected low to enable them. Overcurrent and Overtemperature Protection with Status Outputs The MAX5922 features a programmable undervoltage lockout (UVLO) that keeps the device in shutdown until Current-Limit Foldback with Timeout and Duty- the input voltage exceeds a certain threshold, set to 38V Cycle Control (MAX5922A) or 28V (MAX5922B/C) internally. After suc- Latch or Autorestart Fault Management cessfully discovering and classifying a PD, the MAX5922 enters startup mode. During startup, the MAX5922 limits the output voltage and current slew rate to minimize EMI Ordering Information (electromagnetic interference). The MAX5922 has an inte- PART TEMP RANGE PIN-PACKAGE grated 0.45 N-channel power MOSFET that provides efficient operation and simplified system design. The MAX5922AEUI -40C to +85C 28 TSSOP MAX5922 monitors and provides current-limit protection MAX5922BEUI -40C to +85C 28 TSSOP to the load at all times. The current limit is programmable MAX5922CEUI -40C to +85C 28 TSSOP using an external current-sensing resistor. The MAX5922 features current-limit foldback and duty-cycle limit to Applications ensure robust operation during load-fault and short-circuit conditions. Fault management allows the part to either Power-Sourcing Equipment (PSE) latch-off or autorestart after a fault. Power-Over-LAN/Power-Over-MDI The MAX5922 provides POK, ZC, and FAULT status sig- (Media-Dependent Interface) nals to indicate output power is good, zero-current fault, and other faults (overcurrent, overtemperature), respec- Computer Telephony tively. The MAX5922 is available in a 28-pin TSSOP pack- Single-Port Power Injector/Adapter age and is rated over the extended -40C to +85C Midspan Power Injector temperature range. Switches/Routers with In-Line Power Typical Application Circuits, Selector Guide, and Pin Configuration appear at end of data sheet. 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.+48V, Single-Port Network Power Switch For Power-Over-LAN ABSOLUTE MAXIMUM RATINGS (All voltages with respect to AGND S, unless otherwise noted.) POK, ZC, CL0, CL1, CL2, and FAULT to DGND......-0.3V to +6V IN............................................................................-0.3V to +76V DGND..........................................................................-5V to +5V UVLO........................................................................-0.3V to +6V Maximum Current into Drain .................................................0.8A V to DGND ..........................................................-0.3V to +6V DIG Maximum Current into POK, ZC, CL0, CL1, CL2, FAULT...20mA OUT .......................................................-0.3V to (V + 0.3V) Continuous Power Dissipation (T = +70C) DRAIN A DRAIN..........................................................-0.3V to (V + 0.3V) IN 28-Pin TSSOP (Derate 12.8mW/C above +70C).....1026mW RDT.........................................................................-0.3V to +12V Operating Temperature Range ...........................-40C to +85C RCL to IN................................................................-10V to +0.3V Junction Temperature......................................................+150C EN, DET DIS, DCA, CLASS, ZC EN, Storage Temperature Range .............................-65C to +160C and LATCH to DGND ...........................................-0.3V to +6V 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 = 48V, V = 3.3V, AGND S = AGND = DGND = 0V, R = 0.5 1%, UVLO = open, EN = V , R = 150 1%, R IN DIG SENSE DIG RCL RDT = 18.2k 1%, T = -40C to +85C, unless otherwise noted. Typical values are at T = +25C.) (Note 1) A A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Analog Input Voltage Range V 32 60 V IN V = 60V, measured at AGND after OUT IN Analog Input Supply Current I 11.6 mA IN has stopped slewing Digital Input Voltage Range V 1.65 5.50 V DIG Digital Input Supply Current I V = 5V 0.05 0.1 mA DIG DIG DGND to AGND Operating -4 +4 V Voltage Range Current-Limit Response Time OUT shorted to AGND (Note 2) 1 s OUT Current-Limit Foldback V (Note 3) 18 V FBSTOP Voltage Maximum voltage across R at V > SENSE OUT 198 212 223 Current-Limit Sense Voltage V V FBSTOP mV ILIM (V - V ) (Note 4) IN DRS 0C to +70C 203 212 221 Current-Limit Sense Foldback V V = 0V 64 70 76 mV ILIM fb OUT Voltage (V - V ) IN DRS Overcurrent Timeout t OUT shorted to AGND (Note 5) 50 60 75 ms OC T = +25C0.45 A D On-Resistance R I = 100mA MOS DSON OUT T = +85C0.75 A Power-Off OUT Sink Current EN = DGND, V = 48V 15 A OUT Maximum Output Voltage Slew dV /dt V rising, no load 100 V/ms OUT OUT Rate Maximum Output Current Slew dI /dt V rising, C = 100F 35 A/ms OUT OUT LOAD Rate V rising, POK from low to high 650 750 850 mV OUT Power-OK Threshold (V - V )V IN OUT THPOK Hysteresis 10 % POK Output Low Voltage V I = 3mA 0.4 V POK LOW POK POK Output Leakage Current V = 3.3V 0.05 1 A POK 2 MAX5922