MAX8525EVKIT

19-3228; Rev 0; 3/04 MAX8525 Evaluation Kit The MAX8525 evaluation kit (EV kit) demonstrates the high-power, dynamically adjustable multiphase VRM 10.0 application circuit. This DC-DC converter steps down high-voltage input, generating a precision, lowvoltage CPU-core VCC rail. The MAX8525 EV kit meets the Intel VRM 10 CPU’s transient voltage specification and includes logic-to-interface with the CPU powergood signal. The MAX8525 EV kit consists of the MAX8525 current-mode, step-down controller and the MAX8523 high-speed, dual-phase MOSFET gate driver. The MAX8525 EV kit includes rapid-active average current sensing and voltage positioning, thereby reducing power dissipation and bulk output-capacitance requirements. Quad-phase operation reduces input-ripple-current requirements and output voltage ripple. The MAX8525 EV kit is a fully assembled and tested circuit board that provides a digitally adjustable 0.8375V to 1.5875V output voltage range (6-bit, on-board DAC, 12.5mV increments) from a 12V input source. Each phase delivers up to 25A output current for a total of 100A. The EV kit operates at a 210kHz switching frequency and has superior line- and load-transient responses. Two EV kits can be paralleled for true 8-phase interleaved operation up to 200A. The MAX8525 EV kit can easily be modified to meet Intel’s VRM 10.x requirements. Contact the factory for details. Features ♦ Quad-Phase Current-Mode EV Kit ♦ Parallel Operation for 200A Output ♦ VRM 10.0 Compatible (Easily Modified for VRM 10.x) ♦ Rapid-Active Average Current Sensing ♦ Fastest Voltage Positioning ♦ High-Speed Accuracy and Efficiency ♦ Low Bulk Output-Capacitor Count ♦ 12V Input Voltage ♦ 0.8375V to 1.5875V Output Voltage Range (6-Bit DAC) ♦ 100A Load-Current Capability (25A Each Phase) ♦ 210kHz Switching Frequency (Adjustable) ♦ Dynamic VID Change ♦ Differential Remote Voltage Sensing ♦ Power-Good Output ♦ 28-Pin QSOP Package (MAX8525) ♦ 16-Pin QSOP Package (MAX8523) ♦ Fully Assembled and Tested Ordering Information PART TEMP RANGE MAX8525EVKIT 0oC to +70oC IC PACKAGE 16 QSOP (MAX8523) 28 QSOP (MAX8525) Component List DESIGNATION C1, C2, C5, C6, C9, C10, C13, C14 QTY 8 DESCRIPTION 10µF, 25V X5R ceramic capacitors (1812) Taiyo Yuden TMK432BJ106KM or TDK C4532X5R1E106M C3, C7, C11, C15 0 Not installed (1812) C4 0 Not installed (1206) C8, C12, C32 3 470pF ±10%, 50V X7R ceramic capacitors (0603) Murata GRM188R71H471K or equivalent DESIGNATION QTY DESCRIPTION C16, C45 2 3300pF ±10%, X7R ceramic capacitors (0402) Murata GRP155R71H332K C17, C33–C41 10 680µF, 2.5V, 10mΩ low-ESR polymer capacitors (E-case) Sanyo 2R5TPD680M 4 10µF ±20%, 6.3V X5R ceramic capacitors (0805) Taiyo Yuden AMK212BJ106MG or TDK C2012X5R0J106M C18, C42, C43, C44 ________________________________________________________________ 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: MAX8523/MAX8525 General Description MAX8525 Evaluation Kit Evaluates: MAX8523/MAX8525 Component List (continued) DESIGNATION QTY C19, C20 2 2.2µF ±10%, 10V X5R ceramic capacitors (0612) TDK C1632X5R1A225K 1 2.2µF ±10%, 10V X7R ceramic capacitor (0805) Taiyo Yuden LMK212BJ225KG C21 C22 C23, C24, C25 C26–C30 C31 C46–C49 1 3 DESCRIPTION 2.2µF, 35V X7R ceramic capacitor (1206) Taiyo Yuden EMK316BJ225MD 1µF, 6.3V X5R ceramic capacitors (0603) Taiyo Yuden JMK107BJ105KA or TDK C1608X5R1A105K 5 0.22µF, 10V X7R ceramic capacitors (0603) Taiyo Yuden LMK107BJ224MA or TDK C1608X7R1C224M 1 820pF ±10%, 50V X7R ceramic capacitor (0402) Murata GRP155R71H821 4 0.033µF, 10V X7R ceramic capacitors (0402) Murata GRP155R71A333K DESIGNATION QTY DESCRIPTION R1–R4 4 0.001Ω ±1%, 1W resistors (2512) Panasonic ERJM1WTF1M0U R5 1 309Ω ±1% resistor (0603) R6 1 1.3kΩ ±1% resistor (0603) R7, R30, R34, R39, R40 5 0Ω ±1% resistors (0603) R8–R11 4 3.3Ω ±5% resistors (0603) R12, R14 2 10Ω ±5% resistors (0603) 10Ω ±5% resistor (0402) R13 1 R15, R17 2 15kΩ ±5% resistors (0603) R16 1 100kΩ ±5% resistor (0603) R18 0 Not installed (0603) R19, R20 2 50Ω ±5% resistors (0603) R21, R26 2 10kΩ ±1% resistors (0402) R22 1 2.67kΩ ±1% resistor (0402) R23 1 332kΩ ±1% resistor (0603) R24, R25 2 100Ω ±5% resistors (0603) R27, R33 2 27.4kΩ ±1% resistors (0402) R28, R29 2 1kΩ ±5% resistors (0603) R31 1 1.05kΩ ±1% resistor (0402) C50 0 Not installed (0402) R32 1 1.91kΩ ±1% resistor (0402) C51–C55 0 Not installed (D-case) R35–R38 4 24Ω ±5% resistors (0402) 7 1kΩ ±5% resistors (0402) 2 100mA, 30V dual Schottky diodes (SOT23) Central Semiconductor CMPSH-3A R41–R47 D1, D2 D3 1 R48, R49 2 0Ω ±1% resistors (0402) U1 1 MAX8525EEI (28-pin QSOP) 200mA dual silicon diode (SOT23) Central Semiconductor CMPD3003S U2, U3 2 MAX8523EEE (16-pin QSOP) D4 1 3.3V Zener diode (SOD-323) Central Semiconductor CMDZ5226B U4 1 Adjustable linear regulator (DPAK) Fairchild KA317MR or National Semiconductor LM317MDT L1–L4 4 0.6µH, 26A, 0.9mΩ power inductors (13mm x 13mm x 6mm) Panasonic ETQP1H0R6BFA None 1 Heatsink with mounting hardware Thermshield TS-54960-CW N1, N4, N7, N10, N13–N16 None 1 8 N-channel MOSFETs (8-pin SO) Fairchild FDS6694 or International Rectifier IRF7821 Heatsink insulation Bergquist GP-54960 None 2 N2, N3, N5, N6, N8, N9, N11, N12 Heatsink mounting hardware 4–40 screws 8 None 1 MAX8525 PC board 2 N-channel MOSFETs (8-pin SO) Fairchild FDS6688 or International Rectifier IRF7832 _______________________________________________________________________________________ MAX8525 Evaluation Kit SUPPLIER PHONE FAX WEBSITE Bergquist 952-835-2322 952-835-4156 www.bergquistcompany.com Central Semiconductor 516-435-1110 516-435-1824 www.centralsemi.com Fairchild 408-721-2181 408-721-1635 www.fairchildsemi.com International Rectifier 310-322-3331 310-322-3332 www.irf.com Murata 770-436-1300 770-436-3030 www.murata.com Panasonic 714-373-7939 714-373-7183 www.panasonic.com Sanyo 619-661-6835 619-661-1055 www.sanyovideo.com Taiyo Yuden 408-573-4150 408-573-4159 www.t-yuden.com TDK 847-390-4373 847-390-4428 www.component.tdk.com Thermshield 603-524-3714 603-524-6602 www.thermshield.com Note: Please indicate that you are using the MAX8523 and MAX8525 when contacting these component suppliers. Detailed Description This 100A, quad-phase, buck-regulator design is optimized for a 210kHz frequency and output-voltage settings near 1.20V. The output voltage can be digitally set from 0.8375V to 1.5875V from the VID0–VID5 pins (Table 1). At VOUT = 1.20V and VIN = 12V, the inductor ripple is approximately 35% (LIR = 0.35). The switching frequency is set by an external resistor R23 (332kΩ) from OSC to ground. The MAX8525 includes a 6-bit DAC and meets Intel’s VRM 10.0 specifications. The kit features controlled VID voltage transition for dynamic VID changes and eliminates both undervoltage and overvoltage overshoot. The PWRGD signal is blanked during VID code changes to avoid any false fault signal due to the output voltage change requested by the CPU. Peak current-mode control provides the fastest transient response. The proprietary current-sharing scheme reduces current imbalance between phases to