MAX5015EVKIT

19-2053; Rev 3; 2/07 MAX5015 Evaluation Kit The MAX5015 evaluation kit (EV kit) is a fully assembled and tested printed circuit board (PCB) that contains a 50W forward converter in the industry-standard halfbrick footprint. The circuit is configured for a +5.0V output voltage and provides up to 10A of current. Power for the circuit can be provided from either a +36V to +72V or -36V to -72V DC source. High efficiency of 86% is achieved at 5A using a single transistor, forward converter topology providing output power up to 50W. The surface-mount transformer provides galvanic isolation and has a reset winding to recover magnetic energy. Galvanic isolation up to 1500V is achieved by an optocoupler and surfacemount transformer. Operation at 280kHz allows the use of small magnetics and output capacitors. Warning: The MAX5015 EV kit is designed to operate with high voltages. Dangerous voltages are present on this EV kit and on equipment connected to it. Users who power up this EV kit or power the sources connected to it must be careful to follow safety procedures appropriate to working with high-voltage electrical equipment. Under severe fault or failure conditions, this EV kit may dissipate large amounts of power, which could result in the mechanical ejection of a component or of component debris at high velocity. Operate this kit with care to avoid possible personal injury. Features ♦ +36V to +72V or -36V to -72V Input Range ♦ +5V Output at 10A ♦ VOUT Regulation better than 0.1% over Line and Load ♦ 86% Efficiency at 48V Input and 5V/5A Output ♦ Half-Brick Module Footprint and Pinout ♦ Short-Circuit Protection ♦ 275kHz Switching Frequency ♦ Designed for 1500V Isolation ♦ Soft-Start ♦ Fully Assembled and Tested ♦ Remote ON/OFF ♦ Remote Sense Ordering Information PART TEMP RANGE MAX5015EVKIT 0°C to +70°C MAX5015EVKIT+ 0°C to +70°C 8 SO +Denotes a lead-free package and RoHS-compliant EV kit. Component List DESIGNATION QTY C1, C15 2 0.1µF ±10%, 50V X7R ceramic capacitors (0805) Taiyo Yuden UMK212BJ104KG C2 1 0.01µF ±10%, 50V X7R ceramic capacitor (0805) Component Suppliers SUPPLIER PHONE WEBSITE IC PACKAGE 8 SO DESCRIPTION Central Semiconductor 631-435-1110 Coiltronics 561-752-5000 www.cooperet.com Dale/Vishay 402-564-3131 www.vishay.com C3 0 Not installed (0805) General Semiconductor/ Vishay 760-804-9258 www.vishay.com C4, C5, C6 3 0.68µF, 100V X7R ceramic capacitors (1812) TDK C4532X7R2A684K International Rectifier 310-322-3331 www.irf.com C7, C13, C14 3 560µF, 6.3V electrolytic capacitors (8 x 11.5) Sanyo 6MV560WX Murata Mfg. Co., Ltd. 770-436-1300 www.murata.com C8 1 0.047µF ±10%, 50V X7R ceramic capacitor (0805) Taiyo Yuden UMK212BJ473KG C9 1 10µF ±20%, 16V X5R ceramic capacitor (1210) Taiyo Yuden EMK325BJ106MN www.centralsemi.com Sanyo North America Corp. 619-661-6835 www.sanyodevice.com Taiyo Yuden 800-348-2496 www.t-yuden.com TDK Corp. 847-803-6100 www.component.tdk.com Note: Indicate that you are using the MAX5015 when contacting these component suppliers. ________________________________________________________________ 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 Evaluates: MAX5015 General Description Evaluates: MAX5015 MAX5015 Evaluation Kit Component List (continued) DESIGNATION QTY C10 1 C11 C12 C16 1 1 0.1µF ±10%, 16V X7R ceramic capacitor (0603) Taiyo Yuden EMK107BJ104KA 0.33µF ±10%, 35V X7R ceramic capacitor (0805) Taiyo Yuden GMK212BJ334KG 0.001µF, 200V X7R ceramic capacitor (0603) Murata GRM39-X7R102K200 0.0047µF, 250VAC X7R ceramic capacitor (2220) Murata GA355DR7GC472KY02L DESIGNATION QTY DESCRIPTION R5 1 240kΩ ±5% resistor (0805) R6 1 0.1Ω ±1% power resistor (1206) Dale Electronics, Inc. WSL1206 R1000FEA R7 1 1Ω ±5% resistor (0805) R8 1 499Ω ±1% resistor (0805) R9 1 150Ω ±5% resistor (0805) R11 1 25.5kΩ ±1% resistor (0805) R12 1 8.25kΩ ±1% resistor (0805) R13 1 4.75kΩ ±1% resistor (0805) R15 1 3.32kΩ ±1% resistor (0805) R16, R17 2 51Ω ±5% resistors (0805) C17 1 0.022µF ±10%, 25V X7R ceramic capacitor (0603) T1 1 D1 0 Not installed 15V, 150mW zener diode (S-mini) 170µH 1:0.857: 0.357:0.357 turn transformer (12-pin Gull Wing) Coiltronics CTX03-14856 U1 1 MAX5015ESA+ (8-pin SO) D2 0 Not installed 3V, 150mW zener diode (S-mini) U2 1 D3 1 80V, 100mA Schottky diode (S-mini) 70V ±100% to 200% CTR phototransistor (8-pin SO) Fairchild M0C207M U3 1 1 40V, 20A Schottky diode (TO-220AB) General Semiconductor SBL2040CT 1.24V precision shunt regulator (SOT23) Texas Instruments TLV431AIDBV — 1 Aluminum heatsink plate Vista Industrial Products 5015 — 2 Nylon spacers, 1/4 x 5/8 nylon — 2 Nylon screws, 4-40 x 1/4 — 2 Nylon screws, 4-40 x 1/2 — 2 Nylon screws, 6-32 x 3/8 — 2 TO-220AB Mica thermal insulating pads — 1 PCB: MAX5015 Evaluation Kit D4 1 250V, 250mA high-voltage switching diode (SOD-123) Central Semiconductor CMHD2003 1 4.7µH, 21.5A inductor Coiltronics, HC2-4R7-R N1 1 200V, 18A n-channel MOSFET (TO-220AB) International Rectifier IRF640NP6F Q1 0 Not installed npn transistor (SOT23) R1, R10 0 Not installed (0805) R3 1 20Ω ±5% resistor (1206) D5 L1 2 1 DESCRIPTION _______________________________________________________________________________________ MAX5015 Evaluation Kit Shutdown The MAX5015 EV kit is fully assembled and tested. Follow these steps to verify board operation. Do not turn on the power supply until all connections are completed. Shutdown Mode (Remote Control Method) The MAX5015 EV kit features a pin to remotely shutdown the forward converter. An open-collector/drain transistor or relay contact must be connected to the SHDN and VIN- pins of the EV kit. Table 1 lists the options. Output 1) Connect a jumper wire from the VOUT pin to the +SENSE pin. 2) Connect a jumper wire from the SGND pin to the -SENSE pin. 3) Connect a voltmeter to the VOUT pin and SGND. 4) Connect a +36V to +72V power supply to the VIN+ pin. Do not exceed 100V input voltage. Connect the power supply’s ground to the VIN- pin. Table 1. Shutdown Pin Function (Remote Control) SHDN PIN Open Pull low MAX5015 OUTPUT MAX5015 enabled, VOUT = +5.0V Shutdown mode, VOUT = 0V 5) Turn on the power supply above +36V and verify that VOUT provides +5V at the voltmeter. For instructions on selecting the feedback resistors for other output voltages, refer to the Evaluating other Output Voltages section in this document. Detailed Description The MAX5015 EV kit is a 50W forward converter which provides +5.0V and up to 10A at the output. The circuit can be powered from a +36V to +72V or a -36V to -72V DC source. The user must supply at least 220µF of bulk storage capacitor at the input terminals (VIN+, VIN-). The capacitor should be rated for 100V and be able to carry 1.5A of ripple current. The 50W forward converter achieves high efficiency by using a single transistor topology. Current limiting protects the converter against short circuits at the output. A current sense resistor (R6) senses the current through the primary of the transformer (T1) and the switching transistor (N1) and turns off the transistor when the trip level of 500mV is reached. The surfacemount transformer features a reset winding that, along with diode (D5), recovers the magnetic energy stored in the core and feeds it back to the input (VIN+). The transformer provides galvanic isolation up to 1500V. Shunt regulator (U3) along with feedback resistors (R11, R12) provide voltage feedback to the primary side through optocoupler (U2). Remote output voltage sensing is provided by the +SENSE and -SENSE for accurate output voltage regulation across the load. The softstart allows the output voltage to slowly ramp up in a controlled manner within 20ms. The MAX5015 controller switches at a fixed 275kHz frequency, and the duty cycle is varied to control energy transfer to the output. Evaluating Other Output Voltages, Current Limits, and Soft-Starts VOUT Output Voltage The MAX5015 EV kit’s output (VOUT) is set to +5.0V by feedback resistors (R11, R12). To generate output voltages other than +5.0V (+3.2V to +5.0V), select different voltage-divider resistors (R11, R12). Resistor R11 is typically chosen to be less than 25kΩ. Using the desired output voltage, resistor R12 is then found by the following equation: R12 = [R11 / ((VOUT / VREF) - 1)] where VREF = 1.24V The maximum output current should be limited to less than 10A. The usable output voltage range for the EV kit is +3.2V to +5.0V. Additionally, ICs U2, U3, and resistor R9 limit the minimum output voltage (VOUT) to +3.2V. Current Limiting The EV kit features current limiting for the transformer primary current. The MAX5015 IC turns off the switching MOSFET (N1) when the voltage at the CS pin of the device reaches 465mV. A current sense resistor (R6, 0.1Ω) limits the peak primary current to 4.65A (465mV / 0.1Ω = 4.65A). This will limit short-circuit current on the secondary output (VOUT) to 13A typically. To evaluate lower current limits, the current sense resistor (R6) must _______________________________________________________________________________________ 3 Evaluates: MAX5015 Quick Start be replaced with a surface-mount resistor (1206 size) as determined by the following equation: R6 = VSENSE / ((NS / NP) x (1.2 x IOUTMAX)) where VSENSE = 0.5V, NS = 5, NP = 14, and IOUTMAX = maximum DC output current (10A as configured). Soft-Start The MAX5015 EV kit limits the ramp time to full current limit and duty cycle with a soft-start feature. Capacitor C2 (0.01µF), sets the ramp time to 20ms. To evaluate other soft-start ramp times replace capacitor C2 with another surface mount capacitor (0805 size) as determined by the following equation: 1V/div 0V 4ms/div C2 (µF) = soft-start time (s) / (0.45s/µF) Forward Converter Waveforms Figure 2. Output Voltage Transient at Power-Up. VIN+ = 48V, IOUT = 5A EFFICIENCY (%) vs. OUTPUT CURRENT (A) 90 80 70 EFFICIENCY (%) Evaluates: MAX5015 MAX5015 Evaluation Kit 60 50 40 20V/div 30 20 0V 10 0 0 2 4 6 8 10 12 14 1μs/div OUTPUT CURRENT (A) Figure 1. Efficiency vs. Output Current. VIN+ = 48V 4 Figure 3. MOSFET N1, Drain-Source Voltage Waveform, VIN+ = 48V _______________________________________________________________________________________ MAX5015 Evaluation Kit VDD VIN R1 OPEN 2 3 3 12T 4 5 C8 0.047μF 5T 6 1 VIN+ C4 0.68μF VIN- 1 8 C9 10μF C1 0.1μF VCC V+ NDRV VCC GND SS/SHDN 2 VDD C11 0.33μF VDD C6 0.68μF N1 1 3 C2 0.01μF CS 1 C12 0.001μF 200V 8, 9 D4 L1 4.7μH VOUT C7 560μF 6.3V C13 560μF 6.3V C14 560μF 6.3V C15 0.1μF SGND C16 0.0047μF 250VAC R8 499Ω 1% CS 4 U1 OPTO 5T 2 2 R7 1Ω 7 6 R3 20Ω 14T 2 SHDN R6 0.1Ω 1% MAX5015 3 5 C3 OPEN R16 51Ω CS VOUT R9 150Ω R13 4.75kΩ 1% R15 3.32kΩ 1% C5 0.68μF 3 11, 12 D3 SHORT COLLECTION TO EMITTER VIN T1 D5 1 Q1 Evaluates: MAX5015 D1 OPEN +SENSE 6 R10 SHORT D2 5 OPEN C17 0.022μF R5 240kΩ U2 7 1 C10 0.1μF 2 3 U3 4 5 R11 25.5kΩ 1% R17 51Ω R12 8.25kΩ 1% -SENSE Figure 4. MAX5015 EV Kit Schematic _______________________________________________________________________________________ 5 Evaluates: MAX5015 MAX5015 Evaluation Kit 1.0" Figure 5. MAX5015 EV Kit Component Placement Guide— Component Side 1.0" Figure 7. MAX5015 EV Kit PCB Layout—Inner Layer, Ground Plane 6 1.0" Figure 6. MAX5015 EV Kit PCB Layout—Component Side 1.0" Figure 8. MAX5015 EV Kit PCB Layout—Inner Layer, Power Plane _______________________________________________________________________________________ MAX5015 Evaluation Kit Evaluates: MAX5015 1.0" 1.0" Figure 9. MAX5015 EV Kit PCB Layout—Solder Side Figure 10. MAX5015 EV Kit Component Placement Guide— Solder Side Revision History Pages changed at Rev 3: 1, 2, 6, 7 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. 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