MAX1639 Evaluation Kit ____________________________Features ♦ +4.5V to +5.5V Input Voltage Range ____________________Component List DESIGNATION QTY C1 1 C2, C3 2 C4, C5, C9 CC1 CC2 3 1 1 C6 1 C7 1 C8 1 C10, D1 0 D2 1 L1 1 N1, N2 1 R1 1 R2 R3 R4 R5 R6 U1 JU1 None None None 1 1 1 1 1 1 1 1 1 1 DESCRIPTION 330µF, 6.3V, low-ESR capacitor Sanyo 6SA330M 560µF, 4V, low-ESR capacitors Sanyo 4SP560M 0.1µF ceramic capacitors 1000pF ceramic capacitor 0.056µF ceramic capacitor 2.2µF, 10V ceramic capacitor TDK C3216X7R1C225M or Taiyo Yuden EMK316BJ225ML 10µF, 10V tantalum capacitor Sprague 595D106X0010A2T 4.7µF, 16V tantalum capacitor Sprague 595D475X0016A2T Not installed Schottky diode Central Semiconductor CMPSH-3 1.0µH power inductor Coiltronics UP2B-1R0 or Coilcraft DO3316P-102HC N-channel MOSFETs (SO-8) Fairchild FDS6680 0.009Ω, 1%, 1W resistor Dale WSL-2512-R009-F or IRC LR2512-01-R009-F 12.7kΩ, 1% resistor 10kΩ, 1% resistor 10Ω, 5% resistor 100kΩ, 5% resistor 1kΩ, 5% resistor MAX1639ESE 2-pin header Shunt MAX1639 PC board MAX1639 data sheet ♦ 2.5V Output Voltage (1.1V to 4.0V adjustable) ♦ 8A Output Current ♦ Power-Good Output ♦ 600kHz Switching Frequency ♦ 16-Pin Narrow SO Package ♦ Fully Assembled and Tested _______________Ordering Information PART MAX1639EVKIT TEMP. RANGE PIN-PACKAGE 0°C to +70°C 16 Narrow SO _________________________Quick Start The MAX1639 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 +5V supply voltage to the VIN pad. Connect ground to the GND pad. 2) Connect a voltmeter and load, if any, to the VOUT pad. 3) Remove the shunt from JU1. 4) Turn on the power supply to the board. Verify that the output voltage is 2.5V. _______________Detailed Description The MAX1639 provides a 2.5V output from 4.5V to 5.5V input voltage. It delivers up to 8A and operates at 600kHz. Other output voltages can be programmed by changing the feedback resistor R2. R2 is given by: V R2 = R3 OUT − 1 1.1 where R3 =10kΩ. For output voltages greater than 3.3V, use appropriately rated output capacitors (C2, C3). Jumper Selection The 2-pin header JU1 selects the shutdown mode. Table 1 lists the selectable jumper options. The 4-pin header JU2 selects the switching frequency. Table 2 lists the selectable jumper options. The EV kit’s components are selected for 600kHz operation. If 300kHz or 1MHz operation is selected, component values need to be changed and the PC board trace between pins 1 and 2 of JU2 must be cut (refer to the Design Procedure section in the MAX1639 data sheet). ________________________________________________________________ Maxim Integrated Products 1 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 408-737-7600 ext. 3468. Evaluates: MAX1639 ________________General Description The MAX1639 evaluation kit (EV kit) provides a 2.5V output voltage from a +4.5V to +5.5V input supply. It delivers up to 8A output current with greater than 90% efficiency. Features include pin-selectable switching frequencies of 300kHz, 600kHz, and 1MHz, as well as current-mode operation for superior load- and line-transient response. This EV kit operates at 600kHz switching frequency. It can also be used to evaluate other output voltages by changing the feedback resistors R2 and R3. This EV kit is fully assembled and tested, and is offered in a 16-pin narrow SO package. Evaluates: MAX1639 MAX1639 Evaluation Kit __________________Component Suppliers Table 1. Jumper JU1 Functions SHUNT LOCATION REF PIN MAX1639 OUTPUT ON Connected to GND Shutdown mode, VOUT = 0V OFF Floating MAX1639 enabled, VOUT = 2.5V SUPPLIER AVX Central Semiconductor Coilcraft Dale-Vishay Fairchild International Rectifier IRC Motorola Nihon Sanyo Sprague Sumida Taiyo Yuden TDK Vishay/Vitramon Table 2. Jumper JU2 Functions SHUNT LOCATION FREQ PIN 1 and 3 1 and 2 1 and 4 Connected to GND Connected to REF Connected to VCC SWITCHING FREQUENCY (kHz) 300 600 1000 Note: 1MHz operation can affect the allowable output voltage range (due to duty factor limitations); it also affects soft-start and foldback current limiting (see the MAX1639 data sheet). 1 L C1 330µF 6.3V 2 R VCC C9 0.1µF FAX (803) 626-3123 (516) 435-1824 (847) 639-1469 (402) 563-6418 (408) 721-1635 (310) 322-3332 (512) 992-3377 (602) 994-6430 (805) 867-2698 (619) 661-1055 (603) 224-1430 (847) 956-0702 (408) 573-4159 (847) 390-4428 (203) 452-5670 Note: Please indicate that you are using the MAX1639 when contacting these component suppliers. VIN 4.5V TO 5.5V R4 10Ω PHONE (803) 946-0690 (516) 435-1110 (847) 639-6400 (402) 564-3131 (408) 721-2181 (310) 322-3331 (512) 992-7900 (602) 303-5454 (805) 867-2555 (619) 661-6835 (603) 224-1961 (847) 956-0666 (408) 573-4150 (847) 390-4373 (203) 268-6261 D2 CMPSH-3 3 C7 10µF 10V 12 C8 4.7µH 16V C5 0.1µF 5 VCC VDD DH BST REF 6 ON/OFF JU1 VIN R5 100k PWRGD 2 R6 CC1 1000pF REF C6 2.2µF 10V 9 1k 10 CC2 0.056µF 11 U1 LX MAX1639 DL PGND 4 N1 1, 2, 3 1 15 CSH CC1 CSL CC2 FREQ 1 C4 0.1µF 5, 6, 7, 8 13 4 1, 2, 3 N2 14 L1 1µH D1* OPEN R1 0.009Ω VOUT 2.5V 1% C2 560µF 4V FB 4 C10 OPEN 3 R2 12.7k 1% 8 AGND 7 R3 10k 1% REF 4 5, 6, 7, 8 PWROK JU2 VCC 16 2 3 *OPTIONAL Figure 1. MAX1639 EV Kit Schematic Diagram 2 _______________________________________________________________________________________ C3 560µF 4V VOUT = 1.1(1 + R2 / R3) MAX1639 Evaluation Kit Evaluates: MAX1639 1.0" 1.0" Figure 2. MAX1639 EV Kit Component Placement Guide— Component Side 1.0" Figure 3. MAX1639 EV Kit PC Board Layout—Component Side 1.0" Figure 4. MAX1639 EV Kit PC Board Layout—Two Internal Ground Planes Figure 5. MAX1639 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. 3 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 1998 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.