19-1914; Rev 1; 1/01 MAX5003 Evaluation Kit Features ♦ 5V at 1A Output The MAX5003 EV kit is a fully assembled and tested surface-mount printed circuit (PC) board. It comes with the output voltage set to 5V. This EV kit is configured as a flyback converter, and can easily be configured for either isolated or nonisolated operation by selecting the state of a mechanical switch. Additionally, for systems in which the input and output ground references are not at the same potential and for which isolation is not desired, the user has the option to install a level-shifter (not supplied) in the controller feedback loop. WARNING: 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. ♦ 300kHz Switching Frequency 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. *With air flow. ♦ +36V to +72V Input Voltage Range ♦ Can be Configured for -48V Input and +5V Output ♦ Selectable Isolated or Nonisolated Operation ♦ Proven PC Board Layout ♦ Fully Assembled and Tested Surface-Mount Board Ordering Information PART TEMP. RANGE MAX5003EVKIT 0°C to +70°C* IC PACKAGE 16 QSOP Component List DESIGNATION QTY DESCRIPTION DESIGNATION QTY DESCRIPTION 1 33µF, 100V electrolytic capacitor Sanyo 100MV33CZ Q2 1 C2, C3 2 22µF, 10V ceramic capacitors Taiyo Yuden LMK432BJ226MM 2N3904-type NPN transistor Central Semiconductor CMPT3904 or equivalent R1 1 41.2kΩ ±1% resistor C5 C6 C7 1 1 1 2200pF ±10% ceramic capacitor 3900pF ±10% ceramic capacitor 0.01µF ceramic capacitor R2 1 17.4kΩ ±1% resistor R3 1 68kΩ ±5% resistor R4, R22, R23 3 1MΩ ±5% resistors C8 1 10µF, 16V ceramic capacitor Taiyo Yuden EMK325BJ106MN R5 1 39kΩ ±5% resistor R6 1 51kΩ ±5% resistor R7 R8, R15 1 2 200kΩ ±5% resistor 43Ω ±5% resistors DESIGNATION C1 C9 1 100pF ±10% ceramic capacitor C10 1 0.47µF ceramic capacitor C11, C13, C17 3 0.1µF ceramic capacitors C12 1 390pF ±10% ceramic capacitor R9 1 0.11Ω ±1%, 1/4W resistor Dale WSL-1206/0.11Ω/1% C16 1 4.7µF, 25V tantalum capacitor AVX TAJB475M025 D1 1 30V, 1A Schottky diode Fairchild MBRS130L 1 1 1 1 100Ω ±5% resistor 100kΩ ±5% resistor 20kΩ ±5% resistor 1.3kΩ ±5% resistor D2 1 Small-signal switching diode Central Semiconductor CMSD4448 R10 R11 R12 R13 N1 1 200V, 5.2A N-channel MOSFET International Rectifier IRF620S Q1 0 Not installed R14 1 240kΩ ±5% resistor R16, R17 2 24.9kΩ ±1% resistors R18 0 Not installed ________________________________________________________________ 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: MAX5003 General Description The MAX5003 evaluation kit (EV kit) provides a regulated 5V output voltage up to 1A while operating from a +36V to +72V input voltage. Evaluates: MAX5003 MAX5003 Evaluation Kit Component List (continued) DESIGNATION QTY DESCRIPTION R19 0 Not installed R20 1 680Ω ±5% resistor R21 1 15Ω ±5% resistor SW1 SW2 1 1 DPDT switch SPDT switch T1 1 65µH, 8:1:2.5 transformer Coiltronics CTX03-14502 U1 1 MAX5003EEE (16-pin QSOP) U2 1 2.5V voltage reference Motorola TL431BCD U3 1 Low-current optocoupler QT Opto MOC217 None None None 1 1 1 MAX5003 PC board MAX5003 data sheet MAX5003 EV kit data sheet Table 1. Switch/Jumper Functions FUNCTION Nonisolated, Non-level-shifted Feedback Mode (e.g., +48V input and +5V output) Nonisolated, Level-Shifted Feedback Mode (e.g., -48V input and +5V output) Isolated Feedback Mode (input and output supplies isolated from one another) SWITCH/ JUMPER POSITION SW1 NON SW2 DIR JU1 Closed* (default trace) SW1 NON SW2 LVL JU1 Open (Cut) SW1 ISO SW2 LVL JU1 Open (Cut) *Default setting Component Suppliers PHONE FAX AVX 803-946-0690 803-626-3123 3) Verify that switch SW1 is set to the NON position and SW2 is set to the DIR position. See Table 1 for a description of the switch settings. Central Semiconductor 516-435-1110 516-435-1824 4) Turn on the power and verify that the output voltage is +5V. Coiltronics 561-241-7876 561-241-9339 Dale-Vishay 402-564-3131 402-563-6418 Fairchild 408-822-2000 408-822-2102 International Rectifier 310-322-3331 310-322-3332 Motorola 303-675-2140 303-675-2150 QT Optoelectronics 408-720-1440 408-720-0848 SUPPLIER Sanyo 619-661-6835 619-661-1055 Taiyo Yuden 408-573-4150 408-573-4159 Note: Please indicate that you are using the MAX5003 when contacting the above component suppliers. Quick Start The MAX5003 EV kit is fully assembled and tested. Follow these steps to verify board operation in nonisolated mode. Do not turn on the power supply until all connections are completed. 1) Connect a +36V to +72V power supply to the pad labeled VIN. Do not exceed 100V input voltage. The ground connects to the GND pad (-48V). 2) Connect a voltmeter and load (if any) to the +5V pad. 2 5) Refer to the Isolated Feedback section to modify the board for isolated operation. Refer to the Nonisolated Level-Shifted Feedback section to modify the board for operation with the input and output negative supplies at different potentials. Detailed Description Feedback Mode Selection Switch SW1 selects the feedback configuration (isolated or nonisolated). If SW1 is set to the NON position, switch SW2 selects either direct feedback (for the case in which the input and output share the same ground) or level-shifted feedback. Switch SW2 is only effective when nonisolated feedback is selected. Jumper JU1 determines whether the input and output ground references are connected. Table 1 summarizes switch and jumper functions. Do not operate switches SW1 and SW2 when power is applied to the EV kit because the controller can be damaged. Isolated Feedback To configure the MAX5003 EV kit for isolated operation, turn off the power supply and cut the JU1 PC board trace. Set the SW1 switch to the ISO position, and set the SW2 switch to the LVL position (setting SW2 to the _______________________________________________________________________________________ MAX5003 Evaluation Kit Nonisolated Level-Shifted Feedback To configure the MAX5003 EV kit for operation in a system in which the negative terminal of the input power supply is at a more negative potential than the negative terminal of the output power supply (for example, in a -48V input to +5V output application), first turn off the power supply and cut the JU1 PC board trace. Set the SW1 switch to the NON position, and set the SW2 switch to the LVL position. Locate parts R18, R19, and Q1 (directly above jumper JU1 on the PC board). Solder the following parts into the R18, R19, and Q1 locations: R18 = 36.5kΩ ±1% resistor (1206), R19 = 12.4kΩ ±1% resistor (1206), and Q1 = 60V 2N2907type PNP transistor (SOT23). Note that the initial DC output voltage accuracy and the temperature variation will be degraded in this configuration. Do not operate switches SW1 and SW2 when power is applied to the EV kit because the controller can be damaged. high signal to turn on transistor Q2. For normal operation, the SHDN pad can be connected to ground or left unconnected. Note that the logic-high signal used to drive the SHDN pad is referenced to the negative side of the input supply. For more details regarding undervoltage lockout, refer to the MAX5003 data sheet. Current Limiting The MAX5003 EV kit has a current-limiting feature implemented by current-sense resistor R9. The MAX5003 turns off switching FET N1 when the voltage at the CS pin reaches 100mV. Since R9 is a 0.11Ω resistor, this limits the current in the transformer primary to 0.91A peak, which corresponds to a typical output short-circuit current of 4.5A. R10, a 100Ω resistor, is connected between the current-sense resistor and the CS pin to enable current-sense blanking after N1 is turned on, as described in the MAX5003 data sheet. Layout Considerations The MAX5003 EV kit layout is optimized for fast switching and high currents. The input and output power and ground traces must both be as short and wide as possible to minimize unwanted parasitic inductance. This board was not designed per UL spacing specifications. Undervoltage Lockout and Shutdown The MAX5003 EV kit is configured to go into undervoltage lockout when VIN drops below 32V. The MAX5003 does not have a shutdown pin, but the undervoltage lockout state is equivalent to a shutdown state. The MAX5003 EV kit contains a shutdown function consisting of an NPN switching transistor (Q2) that can pull the VINDIV pin to ground. To place the MAX5003 in undervoltage lockout, drive the SHDN pad with a +5V logic- _______________________________________________________________________________________ 3 Evaluates: MAX5003 LVL position disconnects the R1-R2 resistor-divider from the MAX5003’s FB pin, as required for isolated operation). Turn the power supply back on and verify that the output voltage is still +5V. Note that for the isolated configuration, the output ground and the input ground may differ by as much as 500V. Do not operate switches SW1 and SW2 when power is applied to the EV kit because the controller can be damaged. 4 SHDN REF R11 100kΩ R23 1MΩ VIN GND (-48V) SW1-B 4 REF R12 20kΩ 1 Q2 2 3 ISO 6 NON 2 COMP R3 68kΩ C13 0.1µF 5 4 3 R5 39kΩ U1 C12 390pF FB 9 AGND CS PGND NDRV VCC VDD MAXTON MAX5003 COMP CON REF R7 200kΩ 8 7 6 SS FREQ ES V+ VINDIV 2 C10 0.47µF C11 0.1µF C9 100pF 1 R4 1MΩ 10 11 12 13 14 15 16 C1 33µF 100V R6 51kΩ 1 C8 10µF 16V R10 100Ω C17 0.1µF VDD 3 N1 2 VDD R22 1MΩ REF R9 0.11Ω 1/4W 1% D2 2 1 REF R18 OPEN C5 2200pF T1 R21 15Ω R13 1.3kΩ NOT INSTALLED R19 OPEN Q1 R8 43Ω 5 2 8 7 3 5 6 R14 240kΩ 11 12 9 10 1 U3 MOC217 7 2 2 1 2, 3 U2 TL431 1 C2 22µF 10V R15 43Ω VDD SW2 LVL DIR 3 D1 C16 4.7µF 25V 6, 7 8 C7 0.01µF R20 680Ω C6 3900pF JU1 CUT HERE R2 17.4kΩ 1% C3 22µF 10V R17 24.9kΩ 1% R16 24.9kΩ 1% R1 41.2kΩ 1% NON 1 3 5 GND ISO SW1-A +5V Evaluates: MAX5003 MAX5003 Evaluation Kit Figure 1. MAX5003 EV Kit Schematic _______________________________________________________________________________________ MAX5003 Evaluation Kit Figure 2. MAX5003 EV Kit Component Placement Guide— Component Side 1.0" 1.0" Figure 3. MAX5003 EV Kit PC Board Layout—Component Side Figure 4. MAX5003 EV Kit PC Board Layout—Solder Side 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. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 5 © 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. Evaluates: MAX5003 1.0"