MAX1917EVKIT

19-2491; Rev 0; 7/02 MAX1917 Evaluation Kit The MAX1917 evaluation kit (EV kit) demonstrates the MAX1917’s standard 7A application circuit. This DC-DC converter provides a complete power-management solution for DDR memory. This EV kit is a fully assembled and tested circuit board. The MAX1917 EV kit generates a regulated voltage for VTT and VTTR that is half the voltage at the DDR input. The input voltage range is 2.5V to 14V. The circuit is configured to deliver 7A of output current. The DC-DC converter uses buck topology with synchronous rectification to achieve low output voltage with greater than 90% efficiency. The converter output is capable of sourcing and sinking current. Sink capabilities at low voltage arise from the use of a synchronous rectifier, which allows the inductor current to reverse. The EV kit operates at 550kHz switching frequency and has superior load-transient response that meets JEDEC specifications for DDR memory. Features ♦ Automatically Sets VTT and VTTR to 1/2 VDDR ♦ ±1% Output Voltage Accuracy ♦ 2.5V to 14V Input Voltage Range ♦ 7A Output Current Capability ♦ Sourcing and Sinking Current ♦ 550kHz Switching Frequency ♦ 16-Pin QSOP Package ♦ Low-Profile Components ♦ Fully Assembled and Tested Ordering Information PART MAX1917EVKIT TEMP RANGE 0°C to +70°C IC PACKAGE 16 QSOP Component List DESIGNATION QTY C1, C2, C3 3 C4, C5 0 C6–C9 C10, C11 C12 C13, C14 4 2 1 2 C15 1 C16, C17 2 D1 1 J1 1 JU1 1 DESCRIPTION 10µF, 25V X5R ceramic capacitors (1812) Taiyo Yuden TMK432BJ106KM or TDK C4532X5R1E106M Not installed, E case 270µF, 2V, 15mΩ low-ESR specialty polymer capacitors, E case Panasonic EEFUE0E271R 10µF, 6.3V X5R ceramic capacitors (1206) Taiyo Yuden JMK212BJ106MG or TDK C3216X5R0J106M 0.47µF, 25V X5R ceramic capacitor (1206) Taiyo Yuden TMK316BJ474ML 0.47µF, 6.3V X5R ceramic capacitors (0603) Taiyo Yuden JMK107BJ474MA 4.7µF, 6.3V X5R ceramic capacitor (0805) Taiyo Yuden JMK212BJ475MG 1µF, 6.3V X5R ceramic capacitors (0603) Taiyo Yuden JMK107BJ105MA 100mA Schottky diode Central Semiconductor CMPSH-3 Scope probe connector Berg Electronics 33JR135-1 3-pin header DESIGNATION QTY JU2, JU3 2 2-pin headers DESCRIPTION JU4 1 L1 1 N1, N2 2 Q1 1 Q2 0 Not installed 0.8µH, 16A power inductor Sumida CDEP105L-0R8 N-channel MOSFETs (8-pin SO) International Rectifier IRF7811W N-channel MOSFET (SOT23) Central Semiconductor 2N7002 Not installed, complementary P-N MOSFETs (SC-89) Siliconix Si1029X R1, R5, R7 0 Not installed (0805) R2 1 5.1kΩ ±5% resistor (0805) R3 1 100kΩ ±5% resistor (0805) R4 1 R6 1 0.002Ω ±1%, 1W resistor (2512) Panasonic ERJM1WTF2M0U 10kΩ ±5% resistor (0805) R8 0 Not installed (short PC trace) (0805) R9 1 20Ω ±5% resistor (0805) U1 1 MAX1917EEE (16-pin QSOP) None 3 None 4 None 1 Shunts Rubber bumpers 3M SJ-5007 Mouser 517-SJ-5007BK or equivalent MAX1917 PC board None 1 MAX1917 data sheet None 1 MAX1917 EV kit data sheet ________________________________________________________________ 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: MAX1917 General Description Evaluates: MAX1917 MAX1917 Evaluation Kit Component Suppliers SUPPLIER PHONE FAX WEBSITE Central Semiconductor 516-435-1110 516-435-1824 International Rectifier 310-322-3331 310-322-3332 www.irf.com Panasonic 714-373-7334 714-373-7323 www.panasonic.com Taiyo Yuden 408-573-4150 408-573-4159 www.t-yuden.com TDK 847-390-4373 847-390-4428 www.component.tdk.com www.centralsemi.com Note: Please indicate that you are using the MAX1917 when contacting these component suppliers. Quick Start The following equipment is needed: • 2.5V to 14V power supply (VIN), battery, or notebook AC adapter • DC-bias power supply (V+), 5.5V to 14V at 100mA • Dummy load capable of sourcing/sinking 7A • Digital multimeter (DMM) Jumper Settings Tables 1-4 show jumper settings. Table 1. Jumper JU1 Functions (POK) SHUNT LOCATION 1 and 2 2 and 3 • 100MHz dual-trace oscilloscope POK PIN Connected to VLOGIC through pullup resistor R3 Connected to VL through pullup resistor R3 The MAX1917 EV kit is a fully assembled and tested surface-mount board. Follow the steps below to verify board operation. Do not turn on the power supply until all connections are completed: 1) Ensure that the circuit is connected correctly to the supplies and dummy load prior to applying any power. Table 2. Jumper JU2 Functions (Switching-Frequency Selection) 2) Verify that the shunts are across JU1 pins 2 and 3, JU2, and JU3, and not JU4. Table 3. Jumper JU3 Functions (Fixed/ Adjustable Current-Limit Selection) JU2 Not Installed Installed FSEL PIN Floating Connected to GND FREQUENCY (kHz) 300 550 (as shipped) 3) Apply external reference to the DDR pad. 4) Turn on power supplies and observe the output with the DMM and/or oscilloscope. Look at the LX switching node and MOSFET gate-drive signals while varying the load current. SHUNT LOCATION ON Detailed Description The MAX1917 EV kit provides a complete power-management solution for DDR memory. The EV kit is a synchronous, buck-switching, DC-DC converter that generates half the voltage at the DDR input pad for VTT and VTTR. The synchronous rectification mode ensures balanced sourcing and sinking current capability up to 7A. The EV kit operates at 550kHz switching frequency and has superior line- and load-transient response. 2 OFF ILIM PIN Connected to VL. Connected to GND through resistor R1 (not provided). Refer to the Overcurrent Protection section in the MAX1917 data sheet for information on selecting R1. CURRENT-LIMIT THRESHOLD 100mV (default) Adjustable current limit Table 4. Jumper JU4 Functions (V+) SHUNT LOCATION ON Connected to VL V+ VOLTAGE RANGE (V) 4.5 to 5.5 OFF Not connected to VL 5.5 to 14 V+ PIN _______________________________________________________________________________________ MAX1917 Evaluation Kit VLOGIC 1 JU1 3 VL 2 GND VL POK 3 R9 20Ω 4 5 Q2-A OPEN 6 2 1 2 C17 1μF 6.3V VIN R5 OPEN 3 Q2-B OPEN BST DDR EN/HSD LX 3 C15 4.7μF 6.3V 15 6 C14 0.47μF 6.3V 5 12 VTT 13 6 VTTR ILIM FSEL JU2 GND 8 J1 3 7 R4 0.002Ω 8 C4 OPEN C5 OPEN C6 270μF 2V 2 C7 270μF 2V 3 R7 OPEN VOUT 9 VL 5 2 N2 4 1 C13 0.47μF 6.3V GND N1 REF PGND C3 10μF 25V 8 L1 0.8μH MAX1917 REF 7 16 R6 10kΩ R1 OPEN 5 4 6 DL 7 C2 10μF 25V 14 U1 Q1 JU3 C1 10μF 25V 1 2 REF 2V 2.5V TO 14V D1 DH 1 1 VIN VL 11 POK R2 5.1kΩ EN JU4 10 V+ R3 100kΩ DDR Evaluates: MAX1917 C12 0.47μF 25V V+ 5.5V TO 14V VTTR 9 C16 1μF 6.3V R8 SHORT (PC TRACE) C8 270μF 2V C9 270μF 2V C10 10μF 6.3V C11 10μF 6.3V PGND FLOAT = 300kHz GND = 550KHz Figure 1. MAX1917 EV Kit Schematic _______________________________________________________________________________________ 3 Evaluates: MAX1917 MAX1917 Evaluation Kit Figure 2. MAX1917EV Kit Component Placement Guide— Component Side Figure 3. MAX1917 EV Kit PC Board Layout—Component Side Figure 4. MAX1917 EV Kit PC Board Layout—Ground Plane Figure 5. MAX1917 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. 4 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2002 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.