MAX1626 Evaluation Kit ____________________Component List DESIGNATION QTY DESCRIPTION C1, C2 2 68µF, 20V tantalum capacitors AVX TPSE686M020R0150 or Sprague 593D686X0020E2W C3 1 220µF, 10V tantalum capacitor AVX TPSE227M010R0100 or Sprague 593D227X0010E2W C4 1 0.47µF ceramic capacitor C5 1 0.1µF ceramic capacitor C6, C7 0 Open D1 1 Schottky diode Nihon NSQ03A03 or Motorola MBRS340T3 L1 1 22µH inductor Sumida CDRH125-220 or Coilcraft DO3316P-223 P1 1 P-channel MOSFET International Rectifier IRF7416, Siliconix Si4431DY, or Motorola MMSF3P02HD R1 1 0.040Ω, 1%, 1/2W resistor Dale WSL-2010-R040-F or IRC LR2010-01-R040-F R2, R3 0 Open U1 1 MAX1626ESA JU1, JU2 2 Three-pin headers None 2 Shunts None 1 MAX1626 PC board None 1 MAX1626 data sheet ____________________________Features ♦ Selectable 3.3V or 5V Output Voltage ♦ Low Dropout Voltage ♦ 100% Max Duty Cycle ♦ 2A Output Current ♦ 16.5V Max Input Voltage ♦ 1µA Max Shutdown Current ♦ 90µA Max IC Supply Current ♦ Up to 300kHz Switching Frequency ♦ 8-Pin SO, Surface-Mount Construction ♦ Fully Assembled and Tested _______________Ordering Information PART MAX1626EVKIT-SO TEMP. RANGE 0°C to +70°C BOARD TYPE Surface Mount Note: To evaluate the MAX1627, request a MAX1627ESA free sample with the MAX1626EVKIT-SO. ______________Component Suppliers SUPPLIER AVX Coilcraft Dale-Vishay International Rectifier IRC Motorola Nihon Siliconix Sprague Sumida PHONE FAX (803) 946-0690 (800) 282-4975 (847) 639-6400 (402) 564-3131 (803) 626-3123 (310) 322-3331 (310) 322-3332 (512) 992-7900 (602) 303-5454 (805) 867-2555 (408) 988-8000 (800) 554-5565 (603) 224-1961 (847) 956-0666 (512) 992-3377 (602) 994-6430 (805) 867-2698 (408) 970-3950 (847) 639-1469 (402) 563-6418 (603) 224-1430 (847) 956-0702 ________________________________________________________________ Maxim Integrated Products 1 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800 Evaluates: MAX1626/MAX1627 _______________General Description The MAX1626 evaluation kit (EV kit) provides a selectable 3.3V or 5V output voltage. The MAX1626 has a high-switch duty cycle of up to 100%, allowing the external P-channel transistor to turn on fully. The 100% duty cycle and a low 100mV current-sense level permit very low dropout voltages. The circuit is configured to deliver up to 2A of output current with greater than 90% conversion efficiency. This EV kit is a fully assembled and tested surfacemount circuit board. It can also be used to evaluate the MAX1627, which has an adjustable output voltage. Additional pads on the bottom of the board accommodate the external feedback resistors for setting different output voltages. Evaluates: MAX1626/MAX1627 MAX1626 Evaluation Kit _________________________Quick Start The MAX1626 EV kit is a fully assembled and tested surface-mount printed circuit board. Follow these steps to verify board operation. Do not turn on the power supply until all connections are completed. 1) Connect a 5.5V supply to the VIN pad. The ground connects to the GND pad. 2) Connect a voltmeter and load, if any, to the VOUT pad. 3) For normal operation, place the shunts on JU1 across pins 1 and 2, and place the shunts on JU2 across pins 2 and 3. 4) Turn on the power and verify that the output voltage is 5V. For a 3.3V output, remove the shunt from JU2 pins 2 and 3, and place it across JU2 pins 1 and 2. 5) Refer to the Evaluating Other Output Voltages section to modify the board for different output voltages. Inductor Selection The 22µH Sumida CDRH125-220 inductor mounted on the EV kit board is a low-resistance, shielded, mediumcurrent inductor. It provides excellent performance over the line and load ranges. Refer to the Inductor Selection section in the MAX1626/MAX1627 data sheet for instructions on selecting the inductor value. Evaluating Other Output Voltages To generate output voltages other than 3.3V or 5V, replace the MAX1626 with the MAX1627 (adjustable output), and select the external voltage divider resistors R2 and R3 (located on the bottom side of the board). The only other modifications required are cutting the trace across JU3 and removing the shunt from JU2. Refer to the Setting the Output Voltage section in the MAX1626/MAX1627 data sheet for instructions on calculating R2 and R3 values. _______________Detailed Description Jumper Selection The three-pin header JU1 selects shutdown mode. Table 1 lists the selectable jumper options. The three-pin header JU2 selects the output voltage mode. Table 2 lists the selectable jumper options. Table 1. Jumper JU1 Functions SHUNT LOCATION SHDN PIN 2&3 Connected to VIN Shutdown mode, VOUT = 0V 1&2 Connected to GND MAX1626 enabled, VOUT = 5.0V MAX1626 OUTPUT Table 2. Jumper JU2 Functions 2 SHUNT LOCATION FB PIN 2&3 Connected to VIN VOUT = 5V 1&2 Connected to GND VOUT = 3.3V MAX1626 OUTPUT _______________________________________________________________________________________ MAX1626 Evaluation Kit C2 68µF 20V R1 0.04Ω 2 VIN 3 C4 0.47µF 5 3 SHDN Evaluates: MAX1626/MAX1627 C1 68µF 20V 2 CS 6 V+ SHDN U1 3 1 4 JU1 REF EXT 7 P1 C3 220µF 10V D1 6 7 OUT GND VOUT 8 5 MAX1626 C5 0.1µF L1 22µH 1 4 3/5 JU3 CUT HERE 1 R2 OPEN 2 8 3 2 VIN C7 OPEN JU2 1 R3 OPEN C6 OPEN Figure 1. MAX1626 EV Kit Schematic _______________________________________________________________________________________ 3 Evaluates: MAX1626/MAX1627 MAX1626 Evaluation Kit Figure 2. MAX1626 EV Kit Component Placement Guide— Component Side Figure 3. MAX1626 EV Kit Component Placement Guide— Solder Side Figure 4. MAX1626 EV Kit PC Board Layout—Component Side Figure 5. MAX1626 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 © 1996 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.