19-3840; Rev 0; 10/05 MAX8632 Evaluation Kit The MAX8632 evaluation kit (EV kit) is designed to evaluate the MAX8632 DDR power-supply solution for notebooks, desktops, and graphics cards. The EV kit board produces VDDQ at the output of the synchronous PWM buck, VTT at the output of the sourcing/sinking LDO linear regulator, and VTTR at the output of the reference buffer. The VDDQ output is preset to 1.8V and sources up to 10A. The VTT output is always VDDQ / 2 and can source/sink up to 3A of peak current and 1.5A of continuous current. The VTTR output is also always VDDQ /2 and can source/sink up to 10mA. The MAX8632 EV kit was conveniently designed with jumpers to select the OVP/UVP, TON, SKIP, STBY, and SHDN modes. The board’s default settings enable OVP (overvoltage protection), 300kHz switching frequency, low-noise PWM mode, VDDQ, VTT, and VTTR. The VIN input accepts voltages from 7V to 20.5V and VDD requires a 5V bias supply. Features ♦ VDDQ Preset to 1.8V/10A ♦ VTT 0.9V Source/Sink 1.5A Continuous/3A Peak ♦ VTTR 0.9V Source/Sink 10mA ♦ VIN Range: 7V to 20.5V ♦ Optimized Switching Frequency: 300kHz ♦ Overvoltage/Undervoltage Protection ♦ Independent Shutdown and Standby Controls ♦ Power OK Ordering Information PART TEMP RANGE IC PACKAGE MAX8632EVKIT 0°C to +70°C 28 Thin QFN 5mm x 5mm Component List DESIGNATION QTY C1 C2, C4A, C4B C3, C6 C5 C7, C10 C8A, C8B, C8C DESCRIPTION 1 0.1µF ±10%, 16V X7R (0603) ceramic capacitor Taiyo Yuden EMK107BJ104MA 3 10µF ±10%, 6.3V X5R (0805) ceramic capacitors Kemet C0805C106K9PAC Taiyo Yuden JMK212BJ106MG 2 1µF ±10%, 10V X5R (0603) ceramic capacitors TDK C1608X5R1A105K 1 4.7µF ±20%, 6.3V (0805) X5R ceramic capacitor TDK C2012X5R0J475M 2 0.22µF ±20%, 16V X7R (0603) ceramic capacitors TDK C1608X7R1C224M 3 10µF ±20%, 25V X5R (1210) ceramic capacitors Taiyo Yuden TMK325BJ106MM TDK C3225X5R1E106M DESIGNATION QTY DESCRIPTION C9 1 4700pF ±10%, 50V X7R (0603) ceramic capacitor Kemet C0603C472K5RAC or equivalent C11, C12 2 150µF, 4V, 18mΩ POS capacitors Sanyo 4TPE150MI D1 1 Schottky diode, 30V, 100mA (SOD-323) Central CMDSH-3 JU1–JU4, JU6 5 3-pin headers, 0.1in center 36-pin header, 0.1in center Sullins PTC36SAAN or equivalent Digi-key S1012-36-ND L1 1 1.4µH, 15.5A, 2.8mΩ power inductor Sumida CEP125-1R4MC-U Q1 1 30V, 12mΩ (SO-8) n-channel MOSFET International Rectifier IRF7821 Q2 1 30V, 4mΩ (SO-8) n-channel MOSFET International Rectifier IRF7832 ________________________________________________________________ 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: MAX8632 General Description Evaluates: MAX8632 MAX8632 Evaluation Kit Component List (continued) DESIGNATION QTY DESCRIPTION R1 1 10Ω ±5% (0603) resistor R2, R3, R4 3 100kΩ ±5% (0603) resistors R5 1 36.5kΩ ±1% (0603) resistor R13 1 20Ω ±5% (0603) resistor R18 1 0Ω ±5% (0603) resistor U1 1 Integrated DDR power supply (28-pin, 5mm x 5mm, Thin QFN) MAX8632ETI+ — 5 Shunts Sullins STC02SYAN Digi-key S9000-ND or equivalent Component Suppliers SUPPLIER PHONE 631-435-1110 www.centralsemi.com International Rectifier 310-322-3331 www.irf.com Kemet 864-963-6300 www.kemet.com Sanyo USA 619-661-6835 www.sanyo.com Sumida Taiyo Yuden 7) Connect the 12VDC power supply across the VIN pad and the corresponding GND pad. 8) Turn on both of the power supplies. 9) Set JU4 (1-2). This turns VDDQ on. 10)Using one of the DVMs, verify that the VDDQ voltage between the VDDQ and PGND pads is 1.8V (±2%). 11)Using the other DVM, verify that the VTT voltage between the VTT and PGND pads is 0.9V (±2%). Detailed Description Jumper Selection Table 1. Overvoltage/Undervoltage Control Input (OVP/UVP) JUMPER SHUNT POSITION 847-545-6700 www.sumida.com JU2 1-2 Disable OVP and UVP. 800-348-2496 www.t-yuden.com JU2 1-3 Enable UVP. Disable OVP. 847-803-6100 www.component.tdk.com JU2 1-4* Enable OVP and UVP. JU2 Open Note: Indicate that you are using the MAX8632 when contacting these component suppliers. Recommended Equipment • 5VDC power supply (500mA rated) • 7VDC to 20.5VDC power supply (5A rated) • Two digital voltmeters (DVM) Quick Start The MAX8632 EV kit is fully assembled and tested. Follow these steps to verify board operation. Do not turn on the power supplies until all connections are completed. 1) Ensure a shunt is placed across pins 1-4 of jumper JU2 to enable OVP and UVP. 2) Ensure jumper JU1 is open to set the switching frequency to approximately 300kHz. 2 6) Connect the 5VDC power supply across the VDD pad and the GND pad nearest VIN. WEBSITE Central Semiconductor TDK 3) Ensure a shunt is placed across pins 1-2 of jumper JU3 to enable low-noise PWM mode. 4) Ensure a shunt is placed across pins 2-3 of jumper JU4 to disable the VDDQ buck output. 5) Ensure a shunt is placed across pins 2-3 of jumper JU6 to set the board in normal operation mode. DESCRIPTION Enable OVP. Disable UVP. *Default position. Note: Refer to the MAX8632 data sheet for additional information on OVP/UVP. Setting the Buck Regulator Output Voltage (VDDQ) The output voltage of the buck regulator is preset to 1.8V on the MAX8632 EV kit for DDR memory applications. To pin-strap the output voltage to 2.5V, follow the steps below: 1) Remove R18. 2) Solder the 0Ω resistor from step 1 in the R9 location. Refer to the MAX8632 data sheet to change the external components for optimum performance. _______________________________________________________________________________________ MAX8632 Evaluation Kit Table 4. Shutdown Control Input (SHDN) JUMPER SHUNT POSITION DESCRIPTION JUMPER SHUNT POSITION DESCRIPTION JU1 1-2 600kHz switching frequency JU4 1-2 The VDDQ buck output is enabled. JU1 1-3 450kHz switching frequency JU1 1-4 200kHz switching frequency JU4 2-3* The VDDQ buck output is shut down. JU1 Open* 300kHz switching frequency *Default position. Note: Refer to the MAX8632 data sheet for additional information on TON. Table 3. Pulse-Skipping Control Input (SKIP) JUMPER SHUNT POSITION JU3 1-2* Low-noise PWM mode. JU3 2-3 Pulse-skipping mode. DESCRIPTION *Default position. Note: Refer to the MAX8632 data sheet for additional information on SKIP. *Default position. Note: Refer to the MAX8632 data sheet for additional information on SHDN. Table 5. Standby Control Input (STBY) JUMPER SHUNT POSITION JU6 2-3 The VTT output is shut down. JU6 1-2* Normal operation. DESCRIPTION *Default position. Note: Refer to the MAX8632 data sheet for additional information on STBY. _______________________________________________________________________________________ 3 Evaluates: MAX8632 Table 2. On-Time Selection Input (TON) 4 VDD POK2 POK1 GND VTTR 0.9V AT 10mA GND VTT 0.9V AT 3A R6 OPEN R7 OPEN J15 J3 J14 J2 J13 J1 C14 OPEN REF 3 VDD REF R5 36.5kΩ C10 0.22µF 2 VDD C4A 10µF C9 4700pF R4 100kΩ 2 JU2 4 1 3 REF R3 100kΩ 4 1 JU1 VDD R16 OPEN R2 100kΩ C6 1µF C4B 10µF R17 SHORT C16 OPEN 9 8 4 REFIN VTTI SS ILIM R14 SHORT Figure 1. MAX8632 EV Kit Schematic _______________________________________________________________________________________ TAB 29 TPO 28 SKIP 25 C1 0.1µF R19 OPEN MAX8632 U1 14 13 OVP/UVP TON POK2 POK1 GND VTTR PGND2 VTT VTTS 3 REF 2 1 6 5 24 10 11 12 C2 10µF VTTI JP1 VIN 2 VDD OUT FB STBY SHDN PGND1 DL LX DH BST VDD 16 15 7 27 23 21 19 18 20 22 26 17 3 3 1 2 JU4 VDD R11 SHORT R10 SHORT JU3 1 VDD AVDD R13 20Ω R9 OPEN R8 OPEN 3 JU6 1 2 R18 0Ω Q2 IRF7832 VDD Q1 J5 J7 C7 IRF7821 0.22µF D1 CMDSH-3 R1 10Ω C3 1µF VDD STBY SHDN C15 OPEN R12 OPEN C8A–C8C 3 x 10µF 25V L1 1.4µH VDD C5 4.7µF C11 150µF 4V J12 J10 J11 C12 150µF 4V VDD 4.5V TO 5.5V PGND VIN 7V TO 20.5V C13 OPEN J8 J9 PGND VDDQ 1.8V AT 10A Evaluates: MAX8632 MAX8632 Evaluation Kit MAX8632 Evaluation KitMAX8632 Evaluation Kit Evaluates: MAX8632 Figure 2. MAX8632 EV Kit Component Placement Guide—Component Side _______________________________________________________________________________________ 5 Evaluates: MAX8632 MAX8632 Evaluation Kit Figure 3. MAX8632 EV Kit PC Board Layout—Component Side 6 _______________________________________________________________________________________ MAX8632 Evaluation Kit Evaluates: MAX8632 Figure 4. MAX8632 EV Kit PC Board Layout—Inner Layer 2 _______________________________________________________________________________________ 7 Evaluates: MAX8632 MAX8632 Evaluation Kit Figure 5. MAX8632 EV Kit PC Board Layout—Inner Layer 3 8 _______________________________________________________________________________________ MAX8632 Evaluation KitMAX8632 Evaluation Kit Evaluates: MAX8632 Figure 6. MAX8632 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 _____________________ 9 © 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.