MAX1625 Evaluation Kit The MAX1625 evaluation kit (EV kit) provides a 2.5V output voltage from a 4.5V to 5.5V input. It delivers up to 5A output current with greater than 90% efficiency. The MAX1625 features a resistor-programmable switching frequency from 100kHz to 1MHz, as well as currentmode operation for superior load- and line-transient response. This EV kit operates at a 500kHz switching frequency. It can also be used to evaluate other output voltages by changing feedback resistors R2 and R3. ____________________________Features ♦ 4.5V to 5.5V Input Voltage Range ♦ 2.5V Output Voltage (1.1V to 4.0V adjustable) ♦ 5A Output Current ♦ Efficiency = 91%, VIN = 5V, VOUT = 2.5V @ IOUT = 2.5A ♦ Power-OK Output ♦ 500kHz Switching Frequency ♦ 16-Pin Narrow SO ______________Ordering Information ♦ Low-Profile Components ♦ Fully Assembled and Tested PART MAX1625EVKIT TEMP. RANGE 0°C to +70°C BOARD TYPE Surface Mount _____________________________________________________________Component List DESIGNATION QTY DESCRIPTION C1 1 100µF, 10V electrolytic capacitor Sanyo 10SL100M C2, C3 2 220µF, 4V electrolytic capacitors Sanyo 4SP220M C4, C5, C9 3 0.1µF ceramic capacitors C6 1 2.2µF ceramic capacitor C7, C8 2 4.7µF, 16V tantalum capacitors Sprague 595D475X0016A2T DESIGNATION QTY DESCRIPTION N1, N2 2 N-channel MOSFETs (SO-8) International Rectifier IRF7413 or Siliconix Si4410DY R1 1 0.012Ω, 1%, 1W resistor Dale WSL-2512-R012-F or IRC LR2512-01-R012-F R2 1 127kΩ, 1% resistor R3 1 100kΩ, 1% resistor C10 0 Open R4 1 40.2kΩ, 1% resistor C11, C12 2 4700pF ceramic capacitors R5 1 100kΩ, 5% resistor CC1 1 1000pF ceramic capacitor R6 1 100Ω, 5% resistor CC2 1 0.056µF ceramic capacitor R7, R8 2 39Ω, 5% resistors 1 Schottky diode Nihon NSQ03A02 or Motorola MBRS340T3 R9 1 1kΩ, 5% resistor U1 1 MAX1625ESE 1 Schottky diode Central Semiconductor CMPSH-3 JU1 1 2-pin header None 1 Shunt 1 1.5µH power inductor Coiltronix UP2-1R5, Coilcraft DO3316P-152, or Sumida CDRH127-1R3 None 1 MAX1625 PC board None 1 MAX1625 data sheet D1 (optional) D2 L1 ________________________________________________________________ Maxim Integrated Products 1 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800 Evaluates: MAX1625 _______________General Description Evaluates: MAX1625 MAX1625 Evaluation Kit ______________Component Suppliers SUPPLIER* _______________Detailed Description The MAX1625 provides a 2.5V output from 4.5V to 5.5V input voltage. It delivers up to 5A and operates at 500kHz. Other output voltages can be programmed by changing the feedback resistor R2. R2 is given by: PHONE FAX AVX (803) 946-0690 (803) 626-3123 Central Semiconductor (516) 435-1110 (516) 435-1824 Coilcraft (708) 639-6400 (708) 639-1469 Dale-Vishay (402) 564-3131 (402) 563-6418 International Rectifier (310) 322-3331 (310) 322-3332 IRC (512) 992-7900 (512) 992-3377 Jumper Selection The 2-pin header JU1 selects the shutdown mode. Table 1 lists the selectable jumper options. Motorola (602) 303-5454 (602) 994-6430 Nihon (805) 867-2555 (805) 867-2698 Sanyo (619) 661-6835 (619) 661-1055 Siliconix (408) 988-8000 (408) 970-3950 Sprague (603) 224-1961 (603) 224-1430 Sumida (847) 956-0666 Vishay/Vitramon (203) 268-6261 V R2 = R3 OUT − 1 1.1 where R3 = 100kΩ. Table 1. Jumper JU1 Functions REF PIN (847) 956-0702 SHUNT LOCATION (203) 452-5670 On Connected to GND Shutdown mode, VOUT = 0V Off Floating MAX1625 enabled, VOUT = 2.5V * Please indicate that you are using the MAX1625 when contacting these component suppliers. _________________________Quick Start The MAX1625 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. The ground connects 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. 2 _______________________________________________________________________________________ MAX1625 OUTPUT _______________________________________________________________________________________ CC1 1000pF PWROK ON/OFF JU1 C8 4.7µF 16V R5 100k R4 40.2k 1% CC2 0.056µF R11 1k VIN 11 10 9 2 C6 2.2µF 6 C5 0.1µF 12 FREQ CC2 CC1 PWROK REF VDD U1 VCC 5 7 AGND MAX1625 C7 4.7µF 16V C9 0.1µF DL LX BST DH CSL CSH C12 4700pF C11 4700pF FB PGND R6 100Ω 8 14 13 15 1 16 3 4 1 L 3 R 2 C4 0.1µF R8 39Ω R7 39Ω D2 CMPSH-3 N2 N1 R1 0.012Ω D1 NSQ03A02 (OPTIONAL) L1 1.5µH C10 OPEN C1 100µF 10V R3 100k 1% R2 127k 1% C2 220µF 4V C3 220µF 4V VOUT 2.5V, 5A Evaluates: MAX1625 VIN 4.5V TO 5.5V MAX1625 Evaluation Kit Figure 1. MAX1625 EV Kit Schematic 3 Evaluates: MAX1625 MAX1625 Evaluation Kit 1.0" 1.0" Figure 2. MAX1625 EV Kit Component Placement Guide— Component Side Figure 3. MAX1625 EV Kit PC Board Layout—Component Side 1.0" 1.0" Figure 4. MAX1625 EV Kit PC Board Layout—Two Internal Ground Planes Figure 5. MAX1625 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 © 1997 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.