MAX1709EVKIT

19-1858; Rev 2; 7/05 MAX1709 Evaluation Kit The MAX1709 evaluation kit (EV kit) is a step-up DC-DC switching regulator for 1- to 3-cell battery inputs as well as 2.5V or 3.3V regulated supply inputs. The EV kit accepts a positive input between 0.7V and VOUT and converts it to a higher, pin-selectable output voltage. Efficiency is up to 87% with output load currents to 4A. This EV kit operates at a fixed 600kHz PWM frequency, allowing the use of a small inductor. A movable jumper on the EV kit selects either a 3.3V or 5V output voltage. Additional pads on the board accommodate the resistors for output adjustment. This EV kit uses surface-mount components and is fully assembled and tested for quick evaluation. Component List DESIGNATION QTY Features ♦ 0.7V to VOUT Input Voltage Range ♦ Pin-Selectable 3.3V or 5V Output Voltage (5V as Shipped) ♦ Adjustable Output Voltage (2.5V to 5.5V, External Divider) ♦ Up to 4A Output Current ♦ 600kHz PWM Operation ♦ Internal 10A MOSFET Switch ♦ 4µA IC Shutdown Current ♦ Surface-Mount Components ♦ Fully Assembled and Tested DESCRIPTION C1, C2 2 150µF, 6.3V low-ESR capacitors Sanyo 6TPB150M or Panasonic EEFUE0J151R C4, C5 2 150µF, 6.3V, 15mΩ low-ESR capacitors Panasonic EEFUE0J151R C6 0 Not installed C7 1 0.22µF ceramic capacitor (1206) C8 1 1µF, 16V ceramic capacitor (1206) Taiyo Yuden EMK316BJ105KL TDK C3216X7R1C105M C9, C10, C12 3 0.1µF ceramic capacitors (1206) 1 10A Schottky diode (DPAK) Central Semiconductor CSHD10-45L ON Semiconductor (Motorola) MBRD1035CTL or STM-Microelectronics STPS8L30B SUPPLIER PHONE FAX Central Semiconductor 516-435-1110 516-435-1824 D1 Ordering Information PART TEMP RANGE MAX1709EVKIT 0°C to +70°C IC PACKAGE 28-Pin TSSOP-EP* *Exposed pad. Component Suppliers JU1, JU2, JU3 3 2-pin headers Coilcraft 708-639-6400 708-639-1469 561-241-7876 561-241-9339 1 1µH, 10A power inductor Coilcraft DO3316P-102HC or Coiltronics UP2B-1R0 Coiltronics L1 Dale- Vishay 402-564-3131 402-563-6418 R1, R2, R3 0 Not installed ON Semiconductor (Motorola) 602-303-5454 602-994-6430 R4 1 2Ω ±5% resistor (1206) Panasonic 714-373-7939 714-373-7183 R5–R8 4 1MΩ ±5% resistors (1206) Sanyo 619-661-6835 619-661-1055 U1 1 MAX1709EUI 28-pin TSSOP-EP STM- Microelectronics 617-259-0300 617-259-9442 None 3 Shunts Sumida 847-956-0666 847-956-0702 None 1 MAX1709 PC board Taiyo Yuden 408-573-4150 408-573-4159 None 1 MAX1709EV kit data sheet None 1 MAX1709 data sheet Note: Please indicate that you are using the MAX1709 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: MAX1709 General Description Evaluates: MAX1709 MAX1709 Evaluation Kit Quick Start Reference Detailed Description The MAX1709 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: 1) Connect a voltmeter to the VOUT pad. The MAX1709 EV kit provides a pin-selectable 3.3V or 5V output from a 0.7V to VOUT input voltage. The output voltage can also be adjusted with external resistors for voltages between 2.5V and 5.5V. The MAX1709 includes an internal MOSFET switch with a typical peak current limit of 10A and can deliver loads up to 4A. Connecting an external resistor from SS/LIM to GND (R3) can also reduce the current limit. Connecting a capacitor from SS/LIM to GND (C10) sets the soft-start rate. The EV kit operates at a 600kHz switching frequency and allows the use of a small inductor value. The switching frequency can also be synchronized to an external clock ranging from 350kHz to 1MHz. 2) Connect a 3V supply to the VIN pad. Connect ground to the GND pad. 3) Remove all the shunts from JU1, JU2, and JU3. Turn on the power supply and verify that the output voltage is 5V. Refer to the MAX1709 data sheet for output load during startup. 4) For other output voltages, refer to the Setting the Output Voltage section in the MAX1709 data sheet for instructions on selecting feedback resistors R1 and R2. Jumper Selection Three jumpers on the PC board allow user selection of several configurations. Table 1 lists the jumpers and their functions. Table 1. Jumper Functions JUMPER JU1 JU2 JU3 2 SHUNT LOCATION Not installed ONB connected to GND MAX1709 is enabled if ONA = VOUT. Installed ONB connected to VOUT MAX1709 is disabled if ONA = GND. Not installed ONA connected to GND MAX1709 is disabled if ONB = VOUT. Installed ONA connected to VOUT MAX1709 is enabled if ONB = GND. Not installed 3.3/5 connected to VOUT VOUT is set to 5V. FB pin must be connected to ground (R2 = short). 3.3/5 connected to GND VOUT is set to 3.3V. FB pin must be connected to ground (R2 = short). 3.3/5 connected to GND and resistors R1, R2 are installed VOUT = adjustable between 2.5V to 5.5V. Refer to the Setting the Output Voltage section in the MAX1709 data sheet for instructions on selecting feedback resistors R1 and R2. Also cut PC trace shorting R2. Installed PIN CONNECTION MAX1709 OPERATION _______________________________________________________________________________________ REF 1.25V CLK ONA ONB GND R7 1MΩ R3 OPEN VOUT JU2 VOUT C7 0.22µF C10 0.1µF JU1 VOUT 14 11 13 10 9 6 27 R6 1MΩ 1 R5 1MΩ 28 GND GND REF NC NC SS/LIM U1 MAX1709 CLK/SEL ONA ONB 3.3/5 NC NC FB NC OUT PGND1 PGND1 PGND2 PGND2 PGND3 PGND3 LX1 LX1 LX1 LX2 LX2 LX3 LX3 26 25 24 16 17 15 18 19 20 21 22 23 2 3 4 5 6 7 8 1 C9 0.1µF D1 JU3 2 R8 1MΩ L1 1µH VOUT R4 2Ω C4 150µF 6.3V C1 150µF 6.3V C5 150µF 6.3V C2 150µF 6.3V C6 OPEN R2 SHORT (PC TRACE) R1 OPEN C8 1µF 16V C12 0.1µF VOUT 5V AT 4A GND Evaluates: MAX1709 VIN MAX1709 Evaluation Kit Figure 1. MAX1709 EV Kit Schematic _______________________________________________________________________________________ 3 Evaluates: MAX1709 MAX1709 Evaluation Kit 1.0" 1.0" Figure 2. MAX1709 EV Kit Component Placement Guide— Component Side Figure 3. MAX1709 EV Kit PC Board Layout—Component Side 1.0" Figure 4. MAX1709 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 © 2005 Maxim Integrated Products, Inc. Printed USA is a registered trademark of Maxim Integrated Products.