19-2244; Rev 2; 11/02 +48V Quad Hot-Swap Controllers For Power-Over-LAN TEMP RANGE PIN-PACKAGE MAX5913EMH PART -40°C to +85°C 44 MQFP MAX5914EMH -40°C to +85°C 44 MQFP 34 ON1 RLYON1 DC 36 35 ON2 RLYON2 37 38 39 RLYON4 ON3 RLYON3 40 41 33 2 32 3 31 4 30 5 29 MAX5913 MAX5914 6 7 28 27 23 RTRYEN STATOUT OCEN DGND VCC CSP1 DRAIN1 GATE1 OUT1 CSP2 DRAIN2 AGND OUT2 GATE2 22 24 11 21 25 10 20 26 9 19 8 OUT3 GATE3 Typical Operating Circiut appears at end of data sheet. 42 1 18 FAULT STAT1 STAT2 STAT3 STAT4 CSP4 DRAIN4 OUT4 GATE4 CSP3 DRAIN3 43 TOP VIEW VDD RTIM ON4 Pin Configuration 12 Mid-Span Power-Over-MDI Ordering Information 17 Network Switches/Routers ♦ On-Chip +12V, 100mA Voltage Relay Drivers DGND RLYD1 RLYD2 Telecom Line Cards ♦ +32V Input Undervoltage Lockout 16 IP Phone Switches/Routers ♦ Foldback Current Limiting 15 Power-Over-MDI ♦ On-Board Charge Pumps to Drive External N-Channel FETs ♦ Current Sense with External Resistor 14 Power-Over-LAN ♦ Open-Circuit Detector VRLY RLYD3 RLYD4 Applications ♦ Four Independent Power Switch Controllers 44 The MAX5913/MAX5914 are available in a 44-pin MQFP package and are specified for the extended -40°C to +85°C operating temperature range. ♦ Wide Operating Input Voltage Range +35V to +72V ♦ IEEE 802.3AF Compatible 13 The MAX5913/MAX5914 feature an internal undervoltage lockout (UVLO) function that prevents the FET from turning on, if VCC does not exceed the default value of +32V. The devices also feature a +12V relay driver with 100mA current drive capable of driving low-voltage +3.3V relays. The MAX5913 features an active-low relay driver that sinks current when the relay output is enabled. The MAX5914 features an active-high relay driver output that sources 1mA to drive an external FET relay driver when the relay output is enabled. Control circuitry ensures the relays and the FETs are off until V CC reaches the UVLO threshold. The MAX5913/ MAX5914 use an external sense resistor to enable all the internal current-sense functions. The MAX5913/MAX5914 feature a programmable analog current-limit circuit. If the switch remains in current limit for more than a programmable time, the N-channel FET latches off and the supply can be restarted either by autoretry or by an external command after the preset off-time has elapsed. Features MQFP ________________________________________________________________ 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 MAX5913/MAX5914 General Description The MAX5913/MAX5914 are quadruple hot-swap controllers. The MAX5913/MAX5914 independently control four external N-channel switches to hot-swap system loads from a single VCC supply line. The devices allow the safe insertion and removal of power devices from live network ports. Operating supply voltage range is between +35V and +72V. The devices are intended for applications in Power-Over-Media-Dependent Interface (MDI), but are not limited to such usage. MAX5913/MAX5914 +48V Quad Hot-Swap Controllers For Power-Over-LAN ABSOLUTE MAXIMUM RATINGS VCC to AGND or DGND..........................................-0.6V to +76V DRAIN_, OUT_ to AGND or DGND................-0.6V to VCC +0.3V CSP_ to VCC ..........................................................-0.3V to +0.3V GATE_ to OUT_ .....................................................-0.3V to +13V VRLY to DGND ........................................................-0.3V to +18V RLYD_ to DGND........................................-0.3V to (VRLY + 0.3V) ON_, RLYON_, OCEN, RTRYEN, STATOUT, DC to DGND........................................................-0.3V to +12V FAULT to DGND .....................................................-0.3V to +12V STAT_, RTIM to DGND ...............................-0.3V to (VDD + 0.3V) VDD to DGND ...........................................................-0.3V to +7V DGND to AGND...........................................................-5V to +5V Current into RLYD_ .........................................-50mA to +150mA Current into Any Other Pin................................................±50mA Continuous Power Dissipation (TA = +70°C) 44-Pin MQFP (derate 12.7mW/°C above +70°C)......... 1.013W Operating Temperature Range ...........................-40°C to +85°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 (VCC = VCSP_ = +48V, AGND = DGND = 0, VDD = +3.3V, VRLY = +12V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VCC = VCSP_ = +48V and TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 72 V POWER SUPPLIES Analog Supply Voltage VCC Measured with respect to AGND VCC = VCSP_ = 72V IS = ICC + ICSP Analog Supply Current IS Digital Supply Voltage VDD Measured with respect to DGND Digital Supply Current IDD All logic outputs high, RTIM floating Analog Supply Undervoltage Lockout VUVLO UVLO Hysteresis VUVLO,H UVLO Deglitch Delay tD,UVLO 35 0°C to +85°C 2.7 -40°C to 0°C VCC rising, circuits enabled 4 5 1.8 3.3 3.7 V 1.1 3 mA 29 32 35 V 12.8 25.6 38.4 ms 14 V 4 V 2 µA 3 VON = 3.3V, VRLYON = 3.3V (Figure 1) Relay Driver Supply VRLY Measured with respect to DGND Ground Potential Difference VGG Voltage difference between DGND and AGND mA -4 V FEEDBACK INPUT AND CURRENT SENSE OUT Sense Bias Current IFP Initial Feedback Voltage VFB_S Voltage under which the foldback circuit starts reducing the current-limit value (Note 1) VSC Maximum ∆V across RSENSE at VOUT > VFB_S 125 142.5 160 mV Maximum ∆V across RSENSE at VOUT = 0 42 48 54 mV 360 420 480 mV 1.2 1.5 1.8 V Current-Limit Threshold Voltage Foldback Voltage Fast Discharge Threshold Switch-On Threshold Switch-On Comparator Hysteresis VFLBK VOUT_ = VCC VFC VSWON Maximum VCC - VOUT at which the switch is defined as fully on, VOUT increasing 18 VSWON_H V 160 mV MOSFET DRIVERS Gate Overdrive Voltage Gate Charge Current 2 VGS IGATE VGATE - VCC when switch is fully on 0°C to +85°C 7 9 11 -40°C to 0°C 7 9 12 VGATE = 0 7 10 13 _______________________________________________________________________________________ V µA +48V Quad Hot-Swap Controllers For Power-Over-LAN (VCC = VCSP_ = +48V, AGND = DGND = 0, VDD = +3.3V, VRLY = +12V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VCC = VCSP_ = +48V and TA = +25°C.) (Note 3) PARAMETER Gate Discharge Current Source-Gate Clamp Voltage SYMBOL IGATE,DIS CONDITIONS MIN TYP MAX UNITS During current regulation 8 µA VON = 0 1 mA (VCSP_ - VDRAIN_) > VFC 15 mA VSGZ VOUT_ = 0, force 30mA into GATE_, measure VGATE - VOUT 14 16.5 18 V VOC Minimum ∆V across RSENSE to detect an open circuit 1.5 3 4.5 mV tOC (Figure 2) 450 900 1350 ms (VCSP_ - VDRAIN__) < VOC (Figure 2) 106 204 302 ms 0.5 V 0.3 0.8 1.3 mA 2 V OPEN-CIRCUIT DETECTOR Open-Circuit Current-Threshold Voltage Delay to Open-Circuit Detect Deglitch Delay tLPFD RELAY DRIVERS Maximum Low Voltage (MAX5913) VRLOW RLYON = high, IRLYD_ = 100mA Relay Pullup Current (MAX5914) IRPLUP RLYON = high, VRLYD_ = 0 Clamp Diode Voltage VRCLAMP Relay Output Leakage Force 100mA into RLYD, measure VRLYD VRLY RLYON_ = low, VRLYD_ = VRLY 1 µA TIMING Short-Circuit and Startup Timer (Note 2) tO RRTIM = 2kΩ On time for continuous RRTIM = 40kΩ overcurrent conditions RRTIM = ∞ 4.8 6.4 8.0 76 128 180 3.2 6.4 9.6 DC = logic low Auto-Retry Duty Cycle ms 1 DC = logic high 2 DC = floating 4 % Port Turn-ON Delay tON_DEL VON = 3.3V (Figure 3) 12.8 25.6 38.4 ms Relay Turn-OFF Delay tOFF_DEL After RLYON_ goes low (Figure 3) 1.6 3.2 4.8 ms DIGITAL INTERFACE VIH_DC +1.8V ≤ VDD ≤ +3.7V DC Pin Input Voltage Low VIL_DC +1.8V ≤ VDD ≤ +3.7V DC Pin Input Impedance RIN_DC DC Pin Input Voltage High 0.7 x VDD 0.3 x VDD 1 Logic Input High VIH +1.8V ≤ VDD ≤ +3.7V Logic Input Low VIL +1.8V ≤ VDD ≤ +3.7V VFL ISINK = 4mA Logic Output Voltage High VOH STAT_ outputs sourcing 0.5mA Logic Output Voltage Low VOL STAT_ outputs sinking 0.5mA V 0.3 x VDD FAULT High Input Leakage V kΩ 0.8 x VDD Logic Input Leakage FAULT Output Voltage Low V V 1 µA 0.4 V 1 VDD - 0.4 µA mV 0.4 V Note 1: See Typical Operating Characteristics for Current-Limit Foldback, and refer to Current Sensing and Regulation section. Note 2: The resistor at RTIM can range from 2kΩ to 40kΩ. Note 3: Limits are 100% tested at TA = +25°C and TA = +85°C. Limits at -40°C are guaranteed by design and characterization, but are not production tested. _______________________________________________________________________________________ 3 MAX5913/MAX5914 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (VCSP_ = VCC = +48V, VDD = +3.3V, VRLY = +12V, AGND = DGND = 0, RTIM = open, TA = +25°C, unless otherwise specified.) 3.2 3.0 2.8 2.6 2.4 3.1 VCC = +48V 3.0 VCC = +57V 2.9 VCC FALLING 29 28 VCC = +36V 27 2.5 -40 -15 10 35 60 85 -40 -15 10 35 60 INPUT VOLTAGE (V) TEMPERATURE (°C) TEMPERATURE (°C) GATE OVERDRIVE VOLTAGE vs. INPUT VOLTAGE GATE OVERDRIVE VOLTAGE vs. TEMPERATURE STARTUP WAVEFORMS TA = -40°C 9.00 VCC = +72V VCC = +57V GATE OVERDRIVE (V) TA = +25°C 85 MAX5913/4 toc06 9.5 MAX5913/4 toc04 9.50 8.75 30 2.8 33 36 39 42 45 48 51 54 57 60 63 66 69 72 9.25 MAX5913/4 toc02 VCC RISING 2.6 2.0 31 3.2 2.7 TA = -40°C 2.2 32 UVLO (V) TA = +25°C VCC = +72V 3.3 MAX5913/4 toc05 SUPPLY CURRENT (mA) TA = +85°C 3.4 SUPPLY CURRENT (mA) 3.8 3.4 3.5 MAX5913/4 toc01 4.0 3.6 UNDERVOLTAGE LOCKOUT vs. TEMPERATURE SUPPLY CURRENT vs. TEMPERATURE MAX5913/4 toc03 SUPPLY CURRENT vs. INPUT VOLTAGE GATE OVERDRIVE (V) MAX5913/MAX5914 +48V Quad Hot-Swap Controllers For Power-Over-LAN A 0 0 B 0 C 0 D 9.0 VCC = +48V VCC = +36V 8.5 TA = +85°C 8.0 8.50 33 36 39 42 45 48 51 54 57 60 63 66 69 72 -40 -15 10 35 60 85 4ms/div TEMPERATURE (°C) INPUT VOLTAGE (V) TURN-OFF WAVEFORMS A: VON = VRLYON, 5V/div B: VRLYD, 20V/div C: VOUT, 20V/div D: VGATE, 20V/div GATE TURN-OFF WAVEFORM MAX5913/4 toc07 UVLO TURN-ON DELAY MAX5913/4 toc08 MAX5913/4 toc09 A A B 0 A 0 0 0 B B 0 C 0 0 C 0 D D 0 4ms/div A: VON = VRLYON, 5V/div B: VRLYD, 20V/div C: VOUT, 20V/div D: VGATE, 20V/div 4 0 C 0 D 0 10ms/div A: VRLYD, 20V/div B: VRLYON, 5V/div C: VON, 5V/div D: VGATE, 20V/div 4ms/div RLYON = VDD A: VON, 5V/div B: VCC, 10V/div C: VOUT, 50V/div D: VGATE, 50V/div _______________________________________________________________________________________ +48V Quad Hot-Swap Controllers For Power-Over-LAN MAX5913/4 toc12 MAX5913/4 toc11 MAX5913/4 toc10 A A 0 0 TURN-ON INTO CAPACITIVE LOAD (CL = 470µF) TURN-ON INTO CAPACITIVE LOAD (CL = 47µF) TURN-ON INTO CAPACITIVE LOAD (CL = 0.47µF) B B C C A 0 C 0 0 0 0 0 0 D 0 D 0 10ms/div RLYON = VDD, RRTIM = 40kΩ A: VON, 5V/div B: VGATE, 20V/div C: VOUT, 20V/div D: IOUT, 200mA/div RLYON = VDD, RRTIM = 2kΩ A: VON, 5V/div B: VGATE, 20V/div C: VOUT, 20V/div D: IOUT, 200mA/div CURRENT-LIMIT FOLDBACK (VCC = +48V) CURRENT-LIMIT FOLDBACK (VCC = +36V) 0 CURRENT-LIMIT FOLDBACK (VCC = +57V) MAX5913/4 toc14 MAX5913/4 toc13 A B 0 C 0 D 0 1ms/div 400µs/div RLYON = VDD A: VON, 5V/div B: VGATE, 20V/div C: VOUT, 20V/div D: IOUT, 100mA/div B MAX5913/4 toc15 A B A 0 B 0 C C 0 0 0 0 10ms/div RLYON = VDD, RL = 100Ω, RRTIM = 40kΩ, CLOAD = 470µF A: VON, 5V/div B: VOUT, 10V/div C: IOUT, 200mA/div 10ms/div RLYON = VDD, RL = 139Ω, RRTIM = 40kΩ, CLOAD = 470µF A: VON, 5V/div B: VOUT, 10V/div C: IOUT, 200mA/div 10ms/div RLYON = VDD, RL = 162Ω, RRTIM = 40kΩ, CLOAD = 470µF A: VON, 5V/div B: VOUT, 10V/div C: IOUT, 200mA/div _______________________________________________________________________________________ 5 MAX5913/MAX5914 Typical Operating Characteristics (continued) (VCSP_ = VCC = +48V, VDD = +3.3V, VRLY = +12V, AGND = DGND = 0, RTIM = open, TA = +25°C, unless otherwise specified.) MAX5913/MAX5914 +48V Quad Hot-Swap Controllers For Power-Over-LAN Typical Operating Characteristics (continued) (VCSP_ = VCC = +48V, VDD = +3.3V, VRLY = +12V, AGND = DGND = 0, RTIM = open, TA = +25°C, unless otherwise specified.) CURRENT-LIMIT FOLDBACK (VCC = +72V) CURRENT-LIMIT FOLDBACK (VCC = +57V) MAX5913/4 toc16 MAX5913/4 toc17 A 0 B 0 CURRENT-LIMIT FOLDBACK (VCC = +72V) MAX5913/4 toc18 A B A 0 B 0 0 C 0 0 0 10ms/div C RLYON = VDD, RL = 200Ω, RRTIM = 40kΩ A: VON, 5V/div B: VOUT, 10V/div C: IOUT, 200mA/div 20ms/div RLYON = VDD, RL = OPEN, RRTIM = 40kΩ, CLOAD = 470µF A: VON, 5V/div B: VOUT, 10V/div C. IOUT, 200mA/div RLYON = VDD, RL = OPEN, RRTIM = 40kΩ, CLOAD = 470µF A: VON, 5V/div B: VOUT, 20V/div C: IOUT, 200mA/div SHORT-CIRCUIT RESPONSE (VCC = +48V) OVERCURRENT DELAY (EXPANDED TIME SCALE) OVERCURRENT DELAY MAX5913/4 toc19 C 0 10ms/div MAX5913/4 toc21 MAX5913/4 toc20 A A A 0 0 0 B B 0 B 0 20ms/div RTRYEN = VDD, RLYON = ON = VDD, DC = 4%, RRTIM = 2kΩ, RL = 100Ω A: VGATE, 20V/div B: IOUT, 200mA/div 6 1ms/div RTRYEN = VDD, RLYON = ON = VDD, DC = DON'T CARE, RRTIM = 2kΩ, RL = 100Ω A: VGATE, 20V/div B: IOUT, 200mA/div 0 1ms/div ON = RLYON = VDD, RL = 1Ω, RRTIM = 2kΩ A: IOUT, 200mA/div B: VGATE, 20V/div _______________________________________________________________________________________ +48V Quad Hot-Swap Controllers For Power-Over-LAN SHORT-CIRCUIT RESPONSE (VCC = +48V EXPANDED TIME SCALE) SHORT-CIRCUIT RESPONSE (VCC = +57V) PEAK SHORT-CIRCUIT RESPONSE (VCC = +48V EXPANDED TIME SCALE) MAX5913/4 toc22 MAX5913/4 toc24 MAX5913/4 toc23 A A A 0 0 0 B B B 0 0 0 40µs/div 1ms/div 1µs/div ON = RLYON = VDD, RL = 1Ω, RRTIM = 2kΩ A: IOUT, 200mA/div B: VGATE, 20V/div ON = RLYON = VDD A: IOUT, 200mA/div B: VGATE, 20V/div ON = RLYON = VDD, RL = 1Ω, RRTIM = 2kΩ A: IOUT, 5A/div B: VGATE, 20V/div SHORT-CIRCUIT RESPONSE (VCC = +57V, EXPANDED TIME SCALE) SHORT-CIRCUIT RESPONSE (VCC = +72V) PEAK SHORT-CIRCUIT RESPONSE TIME (VCC = +57V, EXPANDED TIME SCALE) MAX5913/4 toc25 MAX5913/4 toc27 MAX5913/4 toc26 A A A 0 0 0 B B B 0 40µs/div ON = RLYON = VDD, RL = 1Ω, RRTIM = 2kΩ A: IOUT, 200mA/div B: VGATE, 20V/div 0 0 1ms/div 1µs/div ON = RLYON = VDD, RL = 1Ω, RRTIM = 2kΩ A: IOUT, 5A/div B: VGATE, 20V/div ON = RLYON = VDD A: IOUT, 200mA/div B: VGATE, 50V/div _______________________________________________________________________________________ 7 MAX5913/MAX5914 Typical Operating Characteristics (continued) (VCSP_ = VCC = +48V, VDD = +3.3V, VRLY = +12V, AGND = DGND = 0, RTIM = open, TA = +25°C, unless otherwise specified.) +48V Quad Hot-Swap Controllers For Power-Over-LAN MAX5913/MAX5914 Typical Operating Characteristics (continued) (VCSP_ = VCC = +48V, VDD = +3.3V, VRLY = +12V, AGND = DGND = 0, RTIM = open, TA = +25°C, unless otherwise specified.) PEAK SHORT-CIRCUIT RESPONSE TIME (VCC = +72V, EXPANDED TIME SCALE) OPEN-CIRCUIT THRESHOLD vs. INPUT VOLTAGE MAX5913/4 toc29 MAX5913/4 toc28 4.0 THRESHOLD VOLTAGE (mV) 3.8 A A 0 0 B B TA = +85°C 3.6 3.4 3.2 3.0 2.8 TA = +25°C 2.6 TA = -40°C 2.4 0 0 MAX5913/14 toc30 SHORT-CIRCUIT RESPONSE (VCC = +72V, EXPANDED TIME SCALE) 2.2 2.0 1µs/div 40µs/div OPEN-CIRCUIT THRESHOLD vs. TEMPERATURE tO vs RRTIM MAX5913/4 toc32 120 100 A 0 MAX5913/4 toc33 3.5 INPUT VOLTAGE (V) OPEN-CIRCUIT GLITCH DELAY MAX5913/14 toc31 TA = -40°C, +25°C, +85 °C 80 0 3.0 C 0 2.0 -40 -15 10 35 TEMPERATURE (°C) 60 40 VCC = +36V, +48V, +57V, AND +72V 2.5 8 B tO (ms) THRESHOLD VOLTAGE (mV) 4.0 33 36 39 42 45 48 51 54 57 60 63 66 69 72 ON = RLYON = VDD, RL = 1Ω, RRTIM = 2kΩ A: IOUT, 5A/div B: VGATE, 50V/div ON = RLYON = VDD, RL = 1Ω, RRTIM = 2kΩ A: IOUT, 200mA/div B: VGATE, 50V/div 60 85 40ms/div ON = RLYON = VDD, STATOUT = LOW A: IOUT, 20mA/div B: VSTAT, 5V/div C: VGATE, 20V/div 20 0 0 5 10 15 20 25 RRTIM (kΩ) _______________________________________________________________________________________ 30 35 40 +48V Quad Hot-Swap Controllers For Power-Over-LAN RETRY DUTY CYCLE vs. DC to vs. INPUT VOLTAGE CHANNEL-TO-CHANNEL CROSSTALK MAX5913/4 toc36 MAX5913/4 toc34 MAX5913/4 toc35 125 100 A RRTIM = 40kΩ tO (ms) 0 VTEST 5V/div 75 B 0 50 RRTIM = OPEN 25 C RRTIM = 2kΩ VOUT 10mV/div 0 0 1.8 2.1 2.4 2.7 3.0 3.3 3.6 VDD (V) 20µs/div 100ms/div VGATE = 20V/div, RRTIM = 2kΩ A: VGATE, 20V/div, DC = FLOATING (4%) B: VGATE, 20V/div, DC = VDD (2%) C: VGATE, 20V/div, DC = GND (1%) SEE FIGURE 4 FOR TEST CIRCUIT Pin Description PIN NAME FUNCTION FAULT Fault Output. FAULT is an open-drain output that goes low when a fault is detected on any of the four channels. FAULT is low when an OC (open circuit) is detected, or when the MAX5913/MAX5914 is in auto-retry caused by an overcurrent condition. When RTRYEN is low, and the channel switch is latched off due to overcurrent condition, FAULT remains low until ON_ is driven low. 2, 3, 4, 5 STAT1, STAT2, STAT3, STAT4 Status Outputs. STAT_ are push-pull outputs. Depending on the STATOUT pin status, STAT_ flags either the Power-OK_ or Port-OC_ status. Power-OK_ high indicates: a) ON_ input is high b) The switch port is fully on and startup is completed (VCSP_ - VOUT_) < VSWON c) Input voltage is above VUVLO d) Switch is not in current limit. Power-OK_ low indicates a fault with any of the above conditions. Port-OC_ output high indicates that the switch is latched off because the switch current is less than the open current threshold Port-OC is low otherwise. 6, 10, 24, 28 CSP4, CSP3, CSP2, CSP1 Current-Sense Positive Input. Connect to VCC and place a current-sense resistor from CSP_ to DRAIN_. Use Kelvin sense trace from current-sense resistor to CSP_ (see Figure 7). 7, 11, 23, 27 DRAIN4, DRAIN3, DRAIN2, DRAIN1 1 MOSFET Drain Current-Sense Negative Input. Connect to drain of power MOSFET and connect a current-sense resistor from CSP_ to DRAIN_. Use Kelvin sense trace from current-sense resistor to DRAIN_ (see Figure 7). _______________________________________________________________________________________ 9 MAX5913/MAX5914 Typical Operating Characteristics (continued) (VCSP_ = VCC = +48V, VDD = +3.3V, VRLY = +12V, AGND = DGND = 0, RTIM = open, TA = +25°C, unless otherwise specified.) MAX5913/MAX5914 +48V Quad Hot-Swap Controllers For Power-Over-LAN Pin Description (continued) PIN NAME 8, 12, 21, 25 OUT4, OUT3, OUT2, OUT1 9, 13, 22, 26 GATE4, GATE3, GATE2, GATE1 14 VRLY 15, 16, 18, 19 RLYD3, RLYD4, RLYD1, RLYD2 17, 30 DGND Digital Ground. All logic voltages are referred to DGND. The voltage difference between DGND and AGND can be up to ±4V. 20 AGND Analog Ground. All analog voltages are referred to AGND. 29 VCC Analog Power Supply. Connect VCC to +35V to +72V power supply. UVLO circutry turns off MOSFET switch and relay for VCC < VUVLO. Bypass VCC to AGND with a 1µF capacitor. 31 OCEN Open-Circuit Detector Enable Input. Drive OCEN high to enable open-circuit detector, or drive low to disable. When enabled, the open-circuit detector waits for a 900ms delay after Power-OK conditions are met before enabling the open-circuit detector function. 32 STATOUT Status Output Multiplexer (MUX) Control Input. Controls the signal MUX into the STAT_ outputs. Drive STATOUT high to route Power-OK_ status to STAT_ outputs, or drive STATOUT low to route Port-OC_ status to STAT_ outputs. 33 RTRYEN Auto-Retry Enable Input. Drive RTRYEN high to enable auto-retry. Drive RTRYEN low to enable switch latch-off mode. When switch is latched off, a high-to-low transition on the ON_ control input clears the latch. 10 FUNCTION MOSFET Source Output Voltage Sense. Connect to power MOSFET source through a 100Ω series resistor. MOSFET Gate Driver Output. The MAX5913/MAX5914 regulate the gate-drive voltage to (VCC + 9V) to fully turn on the power N-channel MOSFET. GATE_ sources 10µA during startup to slowly turn-on the MOSFET switch. GATE_ sinks 1mA to turn-off the MOSFET switch. Relay Supply Voltage Input. Referenced to DGND. Relay-Drive Output. For the MAX5913, RLYD_ sinks 100mA when the relay driver is enabled. For the MAX5914, RLYD_ sources 1mA when the relay driver is enabled. Duty-Cycle Programming Input. DC sets the minimum off-time after an overcurrent condition latches off the switch. When RTRYEN is high, DC sets the auto-retry duty cycle. Drive DC low for 1% duty cycle, drive DC high for 2%, or leave DC floating for 4% duty cycle. 34 DC 35, 37, 39, 41 RLYON1, RLYON2, RLYON3, RLYON4 36, 38, 40, 42 ON1, ON2, ON3, ON4 MOSFET Switch Control Input. Drive ON_ high to enable GATE_ to turn on MOSFET switch. RLYON_ must be high to enable the switch. Drive ON_ low to disable the switch. Pulling ON_ low also resets the latch when RTRYEN is low or if the switch is latched off due to open-circuit detection. 43 RTIM Timing Oscillator Frequency Set Input. Connect a 2kΩ to 40kΩ resistor from RTIM to DGND to set the maximum continuous overcurrent time, tO. Leave RTIM unconnected to set default 6.4ms tO. 44 VDD Digital Power Supply. Bypass VDD to DGND with a 1µF capacitor. Relay-Driver Control Input. Drive RLYON_ high to enable RLYD_, drive RLYON_ low to turn off MOSFET switch for the channel and disable RLYD_. ______________________________________________________________________________________ +48V Quad Hot-Swap Controllers For Power-Over-LAN Switch and Relay Control Inputs The MAX5913/MAX5914 ON_ inputs turn on the corresponding MOSFET switch. Driving ON_ high turns on the switch if the corresponding RLYON is driven high, and V CC > V UVLO for more than 25.6ms. Driving RLYON_ high immediately turns on the corresponding relay, and activates the 25.6ms delay after which the corresponding ON_ input is active. Driving RLYON_ low immediately turns off the switch and activates a 3.2ms delay after which the relay is turned off. These internal delays safely allow driving ON_ and RLYON_ simultaneously. The relay is turned on while the switch is off so that there is no voltage across the relay contacts. The relay is turned off while the switch is off so that there is no current flowing when the relay contacts are opened (see Figure 3). Input Voltage and UVLO The MAX5913/MAX5914 operate from +35V to +72V supply voltage. VCC powers the MAX5913/MAX5914 analog circuitry and is monitored continuously during startup and normal operation. The MAX5913/MAX5914 keep all MOSFET switches and relay drivers securely off before V CC rises above V UVLO . The MAX5913/ MAX5914 turn off all MOSFET switches and relay drivers after VCC falls below VUVLO - VUVLO,H. Startup When the turn-on condition is met (see Input Voltage and UVLO and Switch and Relay Control Inputs sections), the MAX5913/MAX5914 slowly turn on the external MOSFET switch by charging its gate using a constant current source, IGATE (10µA typ). The gate voltage slope is determined by the total gate capacitance CGATE connected to this node. Since the output voltage follows the gate voltage, thus the output rises with a slope determined by: ∆VOUT I = GATE ∆t CGATE If a capacitor load is connected to the output the total current through the FET is: I = IGATE CL CGATE + IL where CL is the load capacitance and IL is the current required by any load connected to the output during the startup phase. If the current through the FET reaches the programmed current-limit value: IMAX = VSC RSENSE the internal current-limit circuitry activates and regulates this FET current to be a value, ILIM, that depends on VOUT (IFLBK) (Figure 8). See the Current Sensing and Regulation section for more information. In this case the maximum rate of change of the output is determined by: ∆VOUT ILIM − IL = ∆t CL The formula shows the necessity for ILIM to be larger than IL in order to allow the output voltage to rise. The foldback function is active as long as the circuit is in overcurrent condition. Should the overcurrent condition persist for a period longer than the maximum time tO, the switch is latched off and GATE_ is discharged to ground with a 1mA pulldown current. If auto-retry is enabled, the switch turns on again after a waiting period, tOFF, which is determined by the programmed duty cycle. After the startup, the internal charge pumps provide (VCC + 9V) typical gate overdrive to fully turn on the switch. When the switch is fully on (voltage drop across the switch is ≤ 1.5V), and the switch is not in current limit, the Power-OK signal is asserted. Current Sensing and Regulation The MAX5913/MAX5914 control port current with using two voltage comparators (dual-level detection) that sense the voltage drop across an external currentsense resistor. Connect CSP_ to VCC and connect a current-sense resistor between CSP_ and DRAIN_. Kelvin sensing should be used as shown in Figure 7. ______________________________________________________________________________________ 11 MAX5913/MAX5914 Detailed Description The MAX5913/MAX5914 quadruple hot-swap controllers provide Power-Over-MDI, also known as Power-OverLAN systems (Figure 5). The MAX5913/MAX5914 enable control of four external N-channel MOSFET switches from a single VCC ranging from +35V to +72V, with timing control and current-limiting functions built in. Features include undervoltage lockout (UVLO), 100mA relay drivers, dual-level current sense, foldback current limit, programmable overcurrent time and auto-retry periods, internal charge pumps to drive external MOSFET and soft-start, port status output indicating PowerOK or open-circuit conditions (Figure 6). MAX5913/MAX5914 +48V Quad Hot-Swap Controllers For Power-Over-LAN Test Circuits and Timing Diagrams VUVLO VCC (VCC - VOUT) ≤ 1.5V (POWER-OK IS GOOD) VCC OC DETECTOR ENABLED (INTERNAL SIGNAL) tOC VGATE +1V +1V tD, UVLO VGATE tLPFD Figure 2. Open-Circuit Detector Deglitch Delay Figure 1. UVLO Deglitch Delay 0.33Ω 470µF 270µF VIH RLYON 200Ω 100Ω VTEST VIL CSP1 DRAIN1 GATE1 OUT1 ON1 RLYON1 VGATE +42V +1V VCC 270µF MAX5913/MAX5914 270µF ON2 RLYON2 tON_DEL tOFF_DEL CSP2 DRAIN2 GATE2 OUT2 DGND 3.3V VRLY 100Ω RLYD (MAX5913) 0.33Ω VOUT 270µF Figure 3. Port Turn-On Delay, Relay Turn-Off Delay Figure 4. Channel-to-Channel Crosstalk Test Circuit The first comparator compares the sensed voltage against VSC threshold (typically 142.5mV). Choose a sense resistor as follows: drop across the sense resistor is lowered to a minimum value of 48mV (typ). This foldback feature helps reduce the power dissipation in the external power FET during output overload and output short-circuit conditions. If a load with very low activation voltage is permanently connected to the output, make the minimum limit current sufficiently larger than the load current. If the load current indeed exceeds the foldback-limit value the MAX5913/MAX5914 are not able to power-up the switch. RSENSE = VSC / IMAX where IMAX is the maximum current allowed through the switch. When IMAX is reached, foldback current-limit circuitry regulates the current limit as a function of VOUT (Figure 8). As VOUT approaches zero the maximum voltage 12 ______________________________________________________________________________________ +48V Quad Hot-Swap Controllers For Power-Over-LAN MAX5913/MAX5914 VCC = +35V TO +72V 1.0µF ON1 ON2 ON3 ON4 RLYON1 RLYON2 RLYON3 RLYON4 OCEN RTRYEN STATOUT DC DIGITAL INTERFACE INPUTS +12V +3.3V VCC CSP1 0.33Ω DRAIN1 FDT3612 N GATE1 NO PORT 1 NO PORT 4 OUT1 100Ω MAX5913 K1 VRLY VRLY VDD VCC 1µF 1kΩ CSP4 FAULT 0.33Ω STAT1 DIGITAL INTERFACE OUTPUTS STAT2 DRAIN4 STAT3 FDT3612 N GATE4 STAT4 OUT4 100Ω RTIM K4 2kΩ DGND AGND RLYD1 RLYD4 VRLY Figure 5. Typical Application Circuit A second comparator with a detection threshold of 3VSC activates a fast 15mA pulldown of the gate. The purpose of this comparator is to rapidly discharge the gate when a momentary current peak overstresses the external FET helping the regulation to act more rapidly. The sense resistor is also used to detect an open-circuit or low-current condition with a typical threshold of 3mV. Open-Circuit Detection after a 900ms delay. The open-circuit voltage threshold is set at 3mV across the current-sense resistor. Drive OCEN high to enable open-circuit detectors for all four ports. Drive OCEN low to disable the detectors. Each port has an open-circuit flag that can be read from STAT_ outputs when the STATOUT is low. STAT_ output high indicates that the switch is latched off due to an open-circuit condition on that port. To reset the latch pull ON_ low and then high to restart (Table 1). The MAX5913/MAX5914 detect when a port has low current or is open circuit, and turn off the switch to that port. After the switch is turned on and the Power-OK conditions are met, the open-circuit detector is enabled The MAX5913/MAX5914 sense the output voltage of the port at the source of the external MOSFET switch. Output Voltage Sense and Power-OK ______________________________________________________________________________________ 13 MAX5913/MAX5914 +48V Quad Hot-Swap Controllers For Power-Over-LAN RTRYEN DC RTIM CSP VCC 420mV 142.5mV 3mV FOLDBACK NL CONTROL DC COUNTER RESET LOGIC RSENSE DUAL LEVEL DETECTION FROM LOGIC CONTROLLER UVLO TIMING OSCILLATOR CHARGE PUMP DRAIN 10µA 1.236V CSP -1.5V POK COMPARATOR LOGIC CONTROLLER GATE VDD OUT VDD TO LOGIC OPEN-CIRCUIT CONTROLLER DETECTOR 1mA 8µA VRLY RELAY CONTROL 1mA DGND DELAY OCEN ON AGND RLYON RLYD DGND Figure 6. Functional Diagram Internally the circuit compares the output voltage with VCC to determine when the FET is completely on. A “Power-OK” condition is met when: (VCC - VOUT) ≤ 1.5V The internal circuit monitors V OUT to determine the value of the foldback current when the circuit goes into current-limit conditions. The value of the current limit decreases as the output voltage decreases in order to limit the power dissipation of the FET. The nonlinear relationship between V OUT and I LIM is depicted in Figure 8. The foldback circuit is active whenever the MAX5913/ MAX5914 is in current-limit mode after an overcurrent condition has been detected. 14 Connect a catch diode to analog ground and a 100Ω resistor in series with OUT_ to limit the current during negative inductive kicks that can bring OUT_ below the ground potential (Figure 5). Relay Drivers The MAX5913/MAX5914 include on-chip relay drivers, RYLD_, capable of sinking 100mA. When RLYON_ goes high the MAX5913/MAX5914 immediately enable the relay driver, and the corresponding ON_ switch control input is delayed 25.6ms to allow the relay to close under a zero-voltage condition. When RLYON_ goes low, the MAX5913/MAX5914 immediately turn off the corresponding switch, and then turn off the relay driver after a 3.2ms delay, ensuring the relay contacts open under a zero-current condition. The polarity of the ______________________________________________________________________________________ +48V Quad Hot-Swap Controllers For Power-Over-LAN However, the MAX5913/MAX5914 always waits a minimum time tOFF, before restarting the switch. Logic Interface and Status Outputs The MAX5913/MAX5914 logic interface controls the device functionality. All the basic control functions for the four switches are separated. ON_ enables individual on/off control of each MOSFET (the corresponding relay must be on to turn on the switch). RLYON_ enables individual on/off control of each relay. STAT_ indicates Power-OK or Port-OC (open circuit) status of each switch. The other logic pins are common to all four switches. A single FAULT output goes low when any of the four channels is latched off. Driving OCEN high enables the open-circuit detectors. Driving RTRYEN high enables the auto-retry function, RTRYEN low enables the switch latch-off function. DC, a three-level logic input, programs the duty cycle. The STATOUT input selects the signal multiplexed at STAT_ outputs (Table 1.). Driving STATOUT high routes Power-OK status to the STAT_ outputs. Driving STATOUT low routes Port-OC status to the STAT_ outputs. Programmable Timing, RTIM An external resistor from RTIM to DGND sets the frequency of the internal oscillator upon which tO and the auto-retry times are based. Use 2kΩ to 40kΩ resistors for RRTIM. tO = (RRTIM / 2kΩ) (6.4ms) If RTIM is unconnected (floating), an internal resistor sets tO to a nominal 6.4ms. Auto-Retry and Programmable Duty Cycle The MAX5913/MAX5914 feature auto-retry with adjustable duty cycle. Driving RTRYEN high enables the auto-retry function. When the switch encounters an overcurrent for a period greater than tO the switch is turned off, and remains off for a tOFF programmed by DC, a three-level input. After the tOFF period, the switch is automatically turned on again. When the port encounters a continuous overload or short-circuit condition, the switch turns on and off repeatedly with the on duty cycle of 1%, 2%, or 4% depending on the DC input state (Table 2). When RTRYEN is low, the autoretry is disabled, and a fault condition at the switch turns the switch off and the switch remains latched off. Driving the corresponding ON control input low resets the latch. Pulling ON high to turn on the switch. Fault Management UVLO and Power-OK The MAX5913/MAX5914 monitor the VCC input voltage and each switch’s current and voltage to determine Power-OK, overcurrent, or Port-OC status. When VCC falls below the UVLO threshold, FAULT goes low and all four switches and relays are turned off. When the volage across the switch is less than 1.5V, the switch is fully on, and if the switch is not in current limit or open circuit, Power-OK status is good (high). Open-Circuit Faults With the open circuit detector enabled, when any switch current falls below the open-circuit detector Table 1. Status Output PORT_ CONDITION OCEN STATOUT STAT_ Enabled. Switch fully on and not in current limit x H H (Power-OK_ is good) Enabled. Switch in current limit, or VDS > 1.5V x H L (Power-OK_ is not good) Enabled. Switch current is less than OC threshold, port is latched off H L H (Port-OC_ , Port current is low or zero) Enabled. Switch fully on and output current is greater than OC threshold H L L (Port-OC_ , Port current is good) Disabled L L L ______________________________________________________________________________________ 15 MAX5913/MAX5914 MAX5913 RLYD_ is opposite to that of the MAX5914. For the MAX5913, upon the assertion of the RLYON_ input RLYD_ sinks 100mA to DGND. For the MAX5914 when RLYON_ is high, an internal 1mA current source pulls up RLYD_ to VDD. A 100mA catch diode is internally connected between RYLD_ and VRLY to protect the MAX5913/MAX5914 from inductive kicks from the relay coil. VRLY must be connected to the high-side relay supply voltage. MAX5913/MAX5914 +48V Quad Hot-Swap Controllers For Power-Over-LAN threshold current, the open-circuit detector turns off the switch after a 25.6ms delay, FAULT goes low and the Port-OC flag is set for that switch. To clear the switch latched-off condition, FAULT and Port-OC flags drive the corresponding ON input low. Overcurrent Faults When an on switch current exceeds the current-limit threshold, foldback circuitry activates and regulates the switch current. When current limit lasts for longer than tO, the switch latches off. The Power-OK status flag is set low, and the FAULT flag is set. If auto-retry is enabled, the switch remains off for a period tOFF. If auto-retry is disabled, the switch remains latched off, and FAULT is low. Reset the latch and FAULT by driving corresponding ON_ low. Applications Information Considerations for circuit design include output capacitor requirements, current-limit requirements, setting the maximum on-time in current limit, and choosing a suitable MOSFET and on-time duty cycle in auto-retry. Output Capacitor Requirements The load capacitor requirements should be determined first, as this affects the required startup. Current-Limit Requirements (Choosing RSENSE) The current limit should be set to at least 20% higher than the expected full load current. If current limit is also used to control startup current, then set this limit high enough so that the output voltage can rise and settle before tO elapses (see Setting tO section below). Setting tO (Choosing RRTIM) Choose the tO time by connecting a 2kΩ to 40kΩ resistor from RTIM to DGND. The minimum 6.4ms tO is set with RRTIM = 2kΩ. The maximum 128ms tO is set with RRTIM = 40kΩ set according to the following equation: tO = (RRTIM / 2kΩ) (6.4ms). tO should be chosen appropriately, depending on the startup condition. There are two cases: 1) For startup without current limit, when I = IGATE CL VSC + IL < CGATE RSENSE on during large output load-current transients. The smaller the tO, the faster the MAX5913/MAX5914 turn off the external FET in case of output overload or short-circuit condition. 2) For startup with current limit, when CL VSC I = IGATE + IL ≥ CGATE RSENSE which is expected when CL CGATE is large, tO must be set to be long enough to allow the output voltage to rise and settle before tO elapses. In this case, tO must satisfy the following equation: t O = CL 18 V − 18V + CL CC 2 IMAX − IL IMAX − IL 3 where VCC is the input voltage and given that IL < ILIM. Choosing Power MOSFET The FET must withstand a short-circuit condition where its power dissipation is PDISS = VCC ✕ ILIM. The FET must have sufficient thermal capacitance to prevent thermal heating damage during the tO time. Choose Duty Cycle (setting DC) The duty cycle can be adjusted to allow time for heat to dissipate between tO cycles, allowing use of smaller MOSFETs with lower thermal capacitance. For smaller duty cycle, a smaller FET is sufficient. See Table 2 for setting the duty cycle. The auto-retry off-time should not be too long to keep system wait time during retry period to a reasonable value. For example, when tO is set to 128ms and duty cycle is set to 1%, the retry time is 99 ✕ 128ms = 12.7s. Application Circuits In a typical LAN system there are two ways to deliver power over the LAN cable. Power can be supplied to the unused cable pairs, or power can be supplied over the signal pairs (Figures 9 and 10). the startup current does not reach the maximum current-limit threshold and tO will not activate during startup condition. In this case, set t O to a small value, but large enough to allow the switch to remain 16 ______________________________________________________________________________________ +48V Quad Hot-Swap Controllers For Power-Over-LAN ILIM CSP_ DRAIN_ SENSE RESISTOR ∆ IMAX = VSC RSENSE IMAX /3 MAX5913 MAX5914 Figure 7. Recommended Layout for Kelvin-Sensing Current Through Sense Resistor 0 VOUT 18V Figure 8. Foldback Current-Limit Response Table 2. Duty Programming Cycle DC tOFF DUTY CYCLE 0 99 ✕ tO 1% 1 49 ✕ tO 2% Open 24 ✕ tO 4% ______________________________________________________________________________________ 17 MAX5913/MAX5914 HIGH-CURRENT PATH MAX5913/MAX5914 +48V Quad Hot-Swap Controllers For Power-Over-LAN LAN SWITCH N +48V POWER OVER SIGNAL PAIRS RJ45 RJ45 +48V PD +48V OUT MAX5913 MAX5914 CAT 5 DATA POWERED DEVICE (IP PHONE, ETC.) Figure 9. Power Sent Over Signal Pairs +48V POWER OVER SPARE PAIRS MIDSPAN HUB RJ45 RJ45 RJ45 RJ45 CAT 5 PD N +48V OUT CAT 5 POWERED DEVICE (IP PHONE, ETC.) +48V MAX5913 MAX5914 Figure 10. Power Sent Over Spare Pairs Chip Information TRANSISTOR COUNT: 14,622 PROCESS: BiCMOS 18 ______________________________________________________________________________________ +48V Quad Hot-Swap Controllers For Power-Over-LAN VCC = +35V TO +72V ON1 ON2 ON3 ON4 RLYON1 RLYON2 RLYON3 RLYON4 OCEN RTRYEN STATOUT DC DIGITAL INTERFACE INPUTS +12V +3.3V VCC CSP1 DRAIN1 GATE1 N PORT 1 OUT1 MAX5913 VRLY VRLY VDD VCC CSP4 FAULT DIGITAL INTERFACE OUTPUTS STAT1 STAT2 DRAIN4 STAT3 GATE4 STAT4 N PORT 4 OUT4 RTIM DGND AGND RLYD1 RLYD4 VRLY ______________________________________________________________________________________ 19 MAX5913/MAX5914 Typical Operating 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.) MQFP44.EPS MAX5913/MAX5914 +48V Quad Hot-Swap Controllers For Power-Over-LAN 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. 20 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2002 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.