MAX5941B Evaluation MAX5941B evaluation kit) fully assembled test
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MAX5941B Evaluation
MAX5941B evaluation kit) fully assembled tested surface-mount circuit board featuring Ethernet port, network powered device (PD) interface DC-DC controller circuit -48V systems. MAX5941B used power-over-LAN applications requiring DC-DC, fixed-frequency, isolated power supply from Ethernet network port such phones, wireless access nodes, security cameras. MAX5941B receives power from IEEE 802.3af-compliant power sourcing equipment (PSE). Refer MAX5922 MAX5935 data sheets controllers. provides required -44V -57V power over unshielded, twisted-pair Ethernet network cable kit. features 10/100BASE-TX voice over (VoIP) magnetic module separate diode bridges separating power from module provided endspan/endpoint midspan Ethernet system. MAX5941B demonstrates interface DC-DC features. also demonstrates full functionality MAX5941B. Features such detection signature, configurable classification signature, programmable inrush current, programmable undervoltage lockout (UVLO) evaluated. these features configurable kit. MAX5941B also features galvanically isolated, 13.2W, 275kHz switching frequency DC-DC converter, which uses MAX5941B current-mode controller section Power forward DC-DC converter circuit provided from MAX5941B's -48V output, from local input supply, such wall cube. DC-DC converter configured output voltage +3.3V provides High efficiency 85%) achieved using single transistor, forward DC-DC converter topology primary side, synchronous rectifiers secondary side. surfacemount transformer provides 1500VRMS galvanic isolation output. UVLO, soft-start, current limit provide robust 13.2W isolated power supply. Warning: MAX5941B designed operate with high voltages. Dangerous voltages present this equipment connected Users power this kit, power sources connected must follow safety procedures appropriate working with high-voltage electrical equipment. Under severe fault failure conditions, this dissipate large amounts power, which could result mechanical ejection component component debris high velocity. Operate this with care avoid possible personal injury.
Features
IEEE 802.3af-Compliant Interface Circuit Detection Configurable Classification Signatures Programmable Inrush Current Limit Programmable UVLO Isolated 13.2W Forward DC-DC Converter -36V -60V Input Range Isolated +3.3V Output Receives Power from Endspan Midspan Ethernet Systems -48V Power Interface External DC-DC Converter Local Power Inputs (Wall Cube) Fully Assembled Tested
Evaluates: MAX5941B
Ordering Information
PART MAX5941BEVKIT TEMP RANGE +70°C PACKAGE
Maxim Integrated Products
pricing, delivery, ordering information, please contact Maxim/Dallas Direct! 1-888-629-4642, visit Maxim's website www.maxim-ic.com.
MAX5941B Evaluation Evaluates: MAX5941B
Component List
DESIGNATION DESCRIPTION 0.068µF ±10%, 100V ceramic capacitor (1210) Murata GRM32NR72A683K 6800pF ±10%, 100V ceramic capacitor (0805) Murata GRM219R72A682K 1000pF ±10%, 250VAC ceramic capacitor (2010) Murata GA352QR7GF102KW01L 0.01µF ±10%, 100V ceramic capacitors (0805) Murata GRM21BR72A103K 680pF ±10%, ceramic capacitor (0603) C1608X7R1H681K 4700pF, 250VAC ceramic capacitor (2220) Murata GA355DR7GC472KY02 ±10%, 100V ceramic capacitor (1210) 1210C105KAT9A ±10%, ceramic capacitor (0805) C2012X7R1C105K 100pF ±10%, ceramic capacitor (0603) Murata GRM188I5C1H101J 180µF ±20%, aluminum organic capacitor Panasonic EEFUE0G181R 0.033µF ±10%, ceramic capacitor (0603) Murata GRM188R71E333K 0.1µF, ceramic capacitor (0603) Murata GRM188R71E104K 0.22µF ±10%, ceramic capacitor (0805) Murata GRM21BR71C224K ±10%, ceramic capacitor (0805) Murata GRM21BR71A105K DESIGNATION DESCRIPTION installed, ceramic capacitor (0603) 10µF, electrolytic capacitor (6.3mm 6.0mm) Sanyo 50CV10AX 1.0µF ±10%, ceramic capacitor (1206) C3216X7R1H105K 47µF ±20%, 100V electrolytic capacitor (12.5mm 13.5mm) Sanyo 100CV47FS 1000pF ±10%, ceramic capacitor (0603) Murata GRM188R71H102K 56.7V, 600W transient voltage suppressor (SMB) Vishay SMBJ51A installed, 100V standardrecovery power rectifier (SMA) Diodes Incorporated recommended 100V standard-recovery power rectifier (SMA) Diodes Incorporated 200V standard-recovery power rectifiers (DFS-case) Vishay DF02SA 100mA, switching diodes (SOD323) Diodes Incorporated 1N4148WS 30V, 250mW zener diode (SOD323) Central Semiconductor CMDZ5256B 200mA, 200V power diodes (SMINI2) Panasonic MA115 Schottky diode (SMA) Diodes Incorporated B330A 30V, 500mW zener diode (SOD-123) Diodes Inc. BZT52C30 RJ-45 black through hole connector, 8P-8C
D6-D9, D11, D15, D12, D13,
MAX5941B Evaluation
Component List (continued)
DESIGNATION DESCRIPTION 3-pin header 5-pin header 12µH, 5.2A inductor Coilcraft DO5010P-123HC 3.3mH, 24mA inductor Coilcraft DS1608-335 200V, 9.4A n-channel MOSFET (D-PAK) International Rectifier IRFR9N20D 30V, n-channel MOSFET (D-PAK) Fairchild FDD6630A 20V, n-channel MOSFET (D-PAK) International Rectifier IRLR3714Z 30V, 1.4A n-channel MOSFET (SOT23) Fairchild NDS351AN 60V, 200mA transistors (SOT23) Central Semiconductor CMPT3904 60V, 600mA transistor (SOT23) Central Semiconductor CMPT2907A installed, resistor (1206) installed, resistor (0805) 25.5k resistor (1206) ±1%, 100ppm thick film resistor (0805) Panasonic ERJ6ENF1002V ±1%, 100ppm thick film resistor (1206) Panasonic ERJ8ENF7320V ±1%, 100ppm thick film resistor (1206) Panasonic ERJ8ENF3920V ±1%, 100ppm thick film resistor (1206) Panasonic ERJ8ENF2550V ±1%, 100ppm thick film resistor (1812) Panasonic ERJ12NF1780U 2.0k resistor (0805) 100k resistor (0805) resistor (0805) resistors (0805) 0.56 resistors (1206) Panasonic ERJ8BQFR56V DESIGNATION R20, R21, DESCRIPTION 160k resistor (0603) 4.12k resistor (0603) resistor (0603) 2.49k resistor (0603) resistors (0603) resistor (0603) 3.65k resistor (0603) resistor (0603) resistor (0603) resistor (0603) 180k resistor (0603) installed, resistor (0603) resistor (0603) resistor (0805) 4.99k resistor (0805) resistor (0805) 24.9k resistor (0603) resistor (1206) installed, resistor (0805) 10/100BASE-TX VoIP magnetic module Pulse Engineering H2005A 15W, 225µH transformer (12-pin gull wing) Cooper Electronic Technologies CTX01-16741 Coilcraft B0863-A test point (black) test points (red) MAX5941BCSE (16-pin 30V, ±100% 200% optically isolated error amplifier (8-pin Fairchild Semiconductor FOD2712 2.5V, precision shunt regulator (SOT23-5L) Texas Instruments TL431AIDBVT High-isolation voltage photocoupler (SOP-4) CEL/NEC PS2701A-1 Shunts (JU1, JU2) Rubber bumpers MAX5941B board
Evaluates: MAX5941B
R12, R14,
TP1, TP2,
None None None
MAX5941B Evaluation Evaluates: MAX5941B
Component Suppliers
SUPPLIER CEL/NEC; California Eastern Laboratories Central Semiconductor Coilcraft Cooper-Coiltronics Diodes Incorporated Fairchild International Rectifier Murata Panasonic Pulse Engineering Sanyo Vishay PHONE 843-946-0238 800-997-5227 631-435-1110 847-639-6400 561-752-5000 805-446-4800 888-522-5372 310-322-3331 770-436-1300 714-373-7366 858-674-8100 619-661-6835 847-803-6100 402-563-6866 843-626-3123 408-588-2213 631-435-1824 847-639-1469 561-742-1178 805-446-4850 972-910-8036 310-726-8721 770-436-3030 714-737-7323 858-674-8262 619-661-1055 847-390-4405 402-563-6296 WEBSITE www.avxcorp.com www.cel.com www.centralsemi.com www.coilcraft.com www.cooperet.com www.diodes.com www.fairchildsemi.com www.irf.com www.murata.com www.panasonic.com www.pulseeng.com www.sanyo.com www.component.tdk.com www.vishay.com
Note: Indicate that using MAX5941B when contacting these manufacturers.
Quick Start
MAX5941B fully assembled tested. Follow these steps verify board operation. turn power supply until connections completed. Required Equipment: IEEE 802.3af-compliant category Ethernet network cable, 48V, capable power supply MAX5941B voltmeter
MAX5941B kit. Connect power supply's most negative terminal -48V pad. Activate power supply turn external power supply. Using voltmeter, verify that provides +3.3V across VOUT PGND pads. PGND galvanically isolated from kit's input GND2 pads. Test point PGOOD pin), PGOOD), GATE), (-48V) pads provided throughout board observe desired signals with oscilloscope voltage meter.
Hardware Connections
Verify that shunt installed pins jumpers (class 1-4) (class following methods power MAX5941B kit: network connectivity required, connect category Ethernet network cable from MAX5941B input port RJ-45 (J1) connector corresponding Ethernet connection providing power kit. Test points TP4-TP9 provide ethernet data signals. network connectivity required, connect power supply -48V pads
Detailed Description Hardware
MAX5941B evaluation kit) features interface DC-DC controller circuit -48V supply rail systems. MAX5941B internal isolation switch that limits inrush current during startup. MAX5941B used receive power from unshielded, twisted-pair (UTP) Ethernet category network cable port, using midspan endspan Ethernet systems. MAX5941B receives power (12.95W, max) from IEEE 802.3af-compliant cable connected kit's RJ-45 connector 10/100BASE-TX VoIP magnetic module (T1)
MAX5941B Evaluation
diode bridge power rectifiers (D4, used separate -48V power sent PSE. Bridge diode provides midspan power bridge diode provides endspan power. Test points TP4-TP9 provided picking Ethernet data signals from 10/100BASE-TX VoIP magnetic module, Magnetic module dual module, however, only single module required. demonstrates full functionality MAX5941B, such detection signature, configurable classification signature, programmable inrush current, programmable UVLO. Resistor sets detection signature. smaller value resistor should used compensate diode bridges with higher resistance. classification signature determined resistors through appropriately configuring jumpers and/or JU2. single resistor only required determine actual classification. Gate capacitor sets inrush current drawn from MAX5941B. board pads provided install resistors utilizing UVLO feature MAX5941B. Resistors UVLO threshold voltage also determine detection signature. When reconfiguring UVLO operation, Programmable UVLO Configuration section this document. Also, proper operation, UVLO voltage across -48V pads must minimum 12V. MAX5941B kit's galvanically isolated 13.2W forward DC-DC converter uses MAX5941B's currentmode controller section Power DC-DC converter input circuit provided from MAX5941B VOUT pins (-32V -60V DC). forward DC-DC converter configured +3.3V output voltage provides output while achieving efficiency. Synchronous rectifiers secondary side contribute high efficiency. Transformer resets winding diode resets transformer when MOSFET turned off. Surfacemount transformer provides 1500VRMS galvanic isolation output. Minimal component count obtained using single-transistor (N1) forward DCDC converter topology. Parallel- connected resistors, R15, primary-side current-sense resistors. When peak voltage across current-sense resistors reaches 420mV, MAX5941B current-limit internal comparator immediately terminates drive pulse that switching cycle. This limits primaryside, pulse-by-pulse current 1.5A peak. Transformer primary bias winding secondary-side output winding turns ratio Inductor averages pulsating voltage across diodes cathodes. This causes primary-side bias winding voltage appearing across diode track output voltage. With output voltage 3.3V, bias voltage across diode 9.9V. bias voltage across goes low, DC-DC converter turns off. Capacitor then charges through resistor R34. Once voltage across exceeds 20.6V, MAX5941B begins switching primary-side MOSFET again. MAX5941B kit's output overloaded (>4.3A), MAX5941B stops switching Thus, during overload condition, DC-DC converter goes into hiccup mode operation limits overload current output. This limits power dissipation both secondary-side synchronous rectifier MOSFET's primary-side MOSFET Isolated voltage feedback achieved using optically isolated error amplifier (U2), which includes built-in shunt regulator optocoupler. Voltage feedback resistors output voltage 3.3V. MAX5941B OPTO receives voltage feedback signal primary side from biasing resistor compensation resistor/capacitor network R30/C14. Resistor capacitor form snubber network that suppresses transient-overvoltage ringing synchronous rectifier caused transformer leakage inductance capacitance transistor Transistor functions synchronous rectifier freewheeling diode D16. Both synchronous rectifier transistors driven secondary-side drive winding transformer secondary-side drive winding designed have better coupling primary-side drive winding than secondary-side power winding. MOSFET very gate charge very on-resistance. These features guarantee that MOSFET turned soon voltage diode cathode goes high. MOSFET turned secondary-side drive winding turned diode when primary-side MOSFET turned off. MAX5941B DC-DC controller operates 275kHz switching duty cycle limited maximum. Refer MAX5941B data sheet more information controller's DC-DC features. also reconfigured interfacing external DC-DC converter using provided -48VOUT GND2 board pads test points TP0, TP1, TP2. Additionally, also reconfigured stand-alone operation with external DC-DC converter rated 12.95W.
Evaluates: MAX5941B
MAX5941B Evaluation Evaluates: MAX5941B
Caution: -48VOUT isolated from power coming from RJ-45 jack, MAX5941B also provides circuit powering from wall adapter local input power source. local power source (36V 44V) applied LOCAL INPUT POWER LOCAL INPUT POWER board pads. Once local input voltage above 36V, optical coupler turns MAX5941B internal MOSFET pulling GATE voltage low. Transistor turns transistor which enables DC-DC converter run. Diode prevents supply from back driving local source. Local Input Power Source section more information using wall adapter local input power source. external DC-DC converter and/or local input power supply connected (especially when installing diode D2). stand-alone operation without kit's forward DC-DC converter, several components must removed. Capacitor must shorted disable kit's on-board converter. Additionally, gate capacitor must replaced dependent external DC-DC converter's total input capacitance, including kit's capacitors C19. Gate Capacitor Selection section details selecting capacitor maximum power available GND2 -48VOUT pads depends classification settings jumpers JU2. reconfigure MAX5941B either method operation, Table
Jumper Selection
MAX5941B features several jumpers reconfigure kit's classification various external DC-DC converter operations. Classification Signature Selection MAX5941B features jumpers desired classification signature provided connected kit's input port connector. 3-pin jumper 5-pin jumper used configure classification signature. Table lists jumper options.
Table External Converter StandAlone Operation
OPERATION MODIFICATIONS Calculate value using C19, external DC-DC converter total input capacitance. On-Board External interfacing with DC-DC Converter external DC-DC converter. GND2 -48VOUT pads power external converter. Calculate value, using external DC-DC converter total input capacitance with C19. Place short across capacitor C10. Stand Alone TP0, TP1, interfacing with external DC-DC converter. GND2 -48VOUT pads power external converter.
Table Classification Signature Selection
CLASS Class Class Class Class Class SHUNT SHUNT Don't Care
External DC-DC Converter Stand-Alone Operation MAX5941B features board pads test points interface directly with external DC-DC converter. GND2 -48VOUT board pads provide power external -48V DC-DC converter. (PGOOD) (PGOOD) provided interfacing with external converter. additional -48V test point connection. Gate capacitor must replaced dependent total input capacitance connected between GND2 -48VOUT. Local Input Power Source section MAX5941B kit's DC-DC converter used with
Local Input Power Source MAX5941B configured various configurations using local input power source with source. optical coupler transistors resistors R10, R11, diodes D18, D19, board pads diode enable these configurations. LOCAL INPUT POWER LOCAL
MAX5941B Evaluation
INPUT POWER board pads connect local input power supply. local-input power-supply operating voltage range must within kit. This voltage range changed with proper selection diode resistor When local input power source above 36V, always takes precedence over source. this case, optical coupler turns MAX5941B internal MOSFET pulling GATE voltage low, local power supplied directly GND2 -48VOUT pads. After taking over, local power source pollutes discovery classification signatures MAX5941B kit, prevents from powering until local power dropped zero. local input power source below power comes first, provides power through MAX5941B VOUT pin. Diode prevents from back-driving local input power source when local input power source below 30V. Optionally, when configuring MAX5941B local input power source, open board trace shorting diode D2's board pads install recommended diode. Diode prevents local input power source from polluting discovery classification signatures MAX5941B kit. this configuration, power source continuously detect provide power right away after local power source voltage dropped below 30V. UVLO Configuration, Gate Capacitor Selection, Ethernet Data Signal Interfacing Programmable UVLO Configuration MAX5941B features programmable UVLO circuit that prevents operation below programmed input-supply start voltage. Resistors input voltage turn-on turn-off UVLO MAX5941B. evaluate UVLO feature, remove resistor then install surface-mount resistors (1206 case) (0805 case). Using desired startup voltage, calculate resistor's using following equations: VREF 25.5k VINSTARTUP 25.5k
UVLO feature. proper operation, choose voltage MAX5941B UVLO does exceed 7.5V maximum input voltage. Gate Capacitor Selection MAX5941B gate capacitor value dependent upon total capacitance connected across -48VOUT GND2. Typically this DC-DC converter input capacitance (including C19) other connected bulk capacitance. Gate capacitor 0805 surface-mount board footprint chosen using following equation: 10µA typical values IINRUSH where ININRUSH desired inrush current (set 100mA this kit) total input capacitance connected across -48VOUT GND2. When reconfiguring powering external DCDC converter, External DC-DC Converter Stand-Alone Operation section removing certain components. Ethernet Data Signal Interfacing MAX5941B features several test points interface with Ethernet data signals. Test points TP4, TP5, provided interfacing with Ethernet data receive signals. Test points TP6, TP7, provided interfacing with Ethernet data transmit signals. trace lengths to/from module have been matched within mils length. data sheet module 10/100BASE-TX VoIP magnetic module, should consulted prior interfacing with kit's test-point Ethernet data signals. 10/100BASE-TX VoIP magnetic module (T1) replaced with module rated 1000BASE-TX evaluation Ethernet systems operating 1000Mp/s. MAX5941B been verified under actual network operating conditions. dual magnetic module used however, only single module required.
Evaluates: MAX5941B
where STARTUP desired startup voltage +12V which starts VREF 2.460V. Additionally, total series resistance must equate 25.5k. Resistors provide detection signature's resistive component when using
Evaluates: MAX5941B
MAX5941B Evaluation
Figure MAX5941B Schematic-PD DC-DC Converter Main Circuit
GND2 VOUT 180k 680pF -48VOUT OPEN OPEN 180µF VOUT 3.3mH 12µH 10µF -48VOUT VOUT OPTO SS_SHDN MAX5941B SS_SHDN SHORT GND2 TRACE) GND2 OPEN PGOOD -48V PGOOD SS_SHDN UVLO PGOOD SHORT TRACE) GATE 6800pF 100V -48VOUT -48VOUT PGOOD 0.22µF 100pF OPEN -48VOUT COMP U2P6 2.49k N.C. OPTO -48VOUT VR14 0.56 N.C. 0.56 NDRV 24.9k 1000pF -48VOUT 160k -48VOUT 3.65k PGND 4700pF 250VAC 4.99k OPTO U2P6 0.033µF 4.12k 0.1µF CLASS0 CLASS1 CLASS2 CLASS3 CLASS4 GATE
GND2
47µF 100V
-48VOUT
100V
25.5k
-48V
-48V
0.068µF 100V
SMALLER VALUE RESISTOR SHOULD USED COMPENSATE DIODE BRIDGES WITH HIGHER RESISTANCE.
MAX5941B Evaluation Evaluates: MAX5941B
GND2 LOCAL INPUT POWER 100k 2.0k RJ-45 8-PIN CONNECTOR RD1+ RD1TD1+ TD1RD2+ RD2TD2+ TD2RCT1 TCT1 TCT2 RCT2 H2005A RX1+ RX121 TX1+ TX123 -48V J1-3 J1-4 J1-6 J1-5 J1-1 J1-7 J1-2 J1-8 0.01µF 1000pF 250VAC CHASSIS_GND -48V GND2 SS_SHDN
PGOOD
GATE
-48V LOCAL INPUT -48VOUT POWER
RXCT1
0.01µF
TXCT1
RX2+ RX218 TX2+ TX2RXCT2 TXCT2
Figure MAX5941B Schematic-Local Input Power Ethernet Connection Circuit
MAX5941B Evaluation Evaluates: MAX5941B
Figure MAX5941B Component Placement Guide-Component Side Figure MAX5941B Board Layout-Component Side
MAX5941B Evaluation Evaluates: MAX5941B
Figure MAX5941B Board Layout-VCC Layer
Figure MAX5941B Board Layout-GND Layer
MAX5941B Evaluation Evaluates: MAX5941B
Figure MAX5941B Board Layout-Solder Side Figure MAX5941B Component Placement Guide-Solder Side
Maxim cannot assume responsibility circuitry other than circuitry entirely embodied Maxim product. circuit patent licenses implied. Maxim reserves right change circuitry specifications without notice time.
_Maxim Integrated Products, Gabriel Drive, Sunnyvale, 94086 408-737-7600 2005 Maxim Integrated Products Printed registered trademark Maxim Integrated Products.
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