19-0419; Rev 1; 9/95 MAX688-4A Evaluation Kit The MAX688-4A evaluation kit (EV kit) provides a regulated 3.3V output voltage while operating on input voltages from 3.5V to 11V. It delivers up to 4A output current from a 4.5V to 5.5V input, with low dropout. The MAX688-4A EV kit is a fully assembled and tested printed circuit board. The board comes with a 3.3V-output MAX688 IC installed, but can also be used to evaluate the MAX689 (3.0V output). ____________________________Features ♦ 3.5V to 11V Input Supply Range ♦ 3.3V Output Voltage ♦ Up to 4A Output Current ♦ <0.02µA/MAX688 Shutdown Supply Current ♦ 150µA Quiescent Current ♦ External PNP Pass Transistor ♦ Adjustable Current Limit ♦ Fully Assembled and Tested ____________________Component List DESIGNATION QTY ______________Ordering Information PART MAX688EVKIT-4A DESCRIPTION C3 1 1µF ceramic capacitor Marcon THCR30E1E105M C4 1 4.7µF, 16V tantalum capacitor Sprague 595D475X0016A2B C1, C2 2 150µF, 35V aluminum electrolytic caps. Nichicon UPL1V151MPH6 or Sanyo 35MV150GX C16 1 0.01µF ceramic capacitor C5 1 1200µF, 16V aluminum electrolytic cap. Nichicon UPL1C122MRH6 or Sanyo 16MV1200GX OR 1000µF, 25V aluminum electrolytic cap. Sanyo 25MV100GX R4 1 10Ω, 5% resistor R1 1 100kΩ, 5% resistor R3 1 1kΩ, 5% resistor Q1 1 PNP power transistor (TO-220) Motorola TIP42A Q2 1 PNP transistor, Motorola 2N4403 None 1 Heatsink, Thermalloy 6072B U1 1 Maxim MAX688CSA (8-pin SO) JU1 1 3-pin header JU2 1 2-pin header None 2 Shunt None 1 PC board None 1 MAX688 data sheet TEMP. RANGE 0°C to +70°C ______________Component Suppliers SUPPLIER AVX IRC Marcon Sanyo Sprague PHONE (803) 946-0238 (213) 772-2000 (708) 913-9980 (619) 661-6835 (508) 339-8900 FAX (803) 626-3123 (213) 772-9028 (708) 913-1150 (619) 661-1055 (508) 339-5063 _________________________Quick Start The MAX688-4A EV kit is a fully assembled and tested board. Follow these steps to verify board operation. Do not turn on the power supply until all connections are completed. 1) 2) 3) 4) Connect a 5V power supply to the pad marked VIN. The ground connects to the GND pad. Connect a voltmeter and load (if any) to the VOUT pad. Place one shunt across JU1 pins 2 and 3 and the other shunt across JU2 for normal operation. Turn on the power and verify that the output voltage is 3.3V. Instructions for modifying the board for a 3.0V output appear in the section Evaluating the MAX689. ________________________________________________________________ Maxim Integrated Products Call toll free 1-800-998-8800 for free samples or literature. 1 Evaluates: MAX688/MAX689 _______________General Description Evaluates: MAX688/MAX689 MAX688-4A Evaluation Kit _______________Detailed Description Evaluating the MAX689 The MAX688 can be replaced with a MAX689 to generate a 3.0V output voltage with output current up to 4A. The only modification required is to replace the IC. Shutdown Function The MAX688 has an active-low shutdown control input to turn its output on or off at any time. The 3-pin header JU1 selects the shutdown mode. Remove the shunt when driving shutdown with an external signal. Table 1 lists the jumper selectable options. Base-Current Limiting The output current can be limited by installing a currentlimiting resistor, R2, between BASE (pin 7) and BLIM (pin 6) of U1. This EV kit comes with a shunt across JU2, which limits base current to 20mA. For lower base current limit, refer to the MAX687/ MAX688/MAX689 data sheet for instructions on selecting the current-limiting resistor value. Table 1. Jumper JU1 Functions SHUNT LOCATION SHDN PIN MAX688 OUTPUT 2&3 Connected to VIN MAX6884A Enabled, VOUT = 3.3V 2&1 Connected to GND Shutdown Mode, VOUT = 0V Q1 TIP-42 R3 1k, 5% VIN 3 2 1 C4 C3 C1 C2 4.7µF 16V 1µF 150µF 150µF JU1 1 2 U1 CC IN MAX688 SHDN BASE 8 C16 0.01µF R4 Q2 2N4403 10Ω, 5% 7 SHDN JU2 3 PFO PFO BLIM 6 R2 OPEN, 5% 4 GND R1 100k * NOTE: RECOMMENDED FOR FAST 0.2A TO 4A TRANSIENT LOAD OUT 5 VOUT C5 1000µF 25V C6* 220µF 6.3V C7* 1µF x 10 OPTIONAL * Figure 1. MAX688-4A EV Kit Schematic Diagram 2 _______________________________________________________________________________________ MAX688-4A Evaluation Kit Evaluates: MAX688/MAX689 Figure 2. Component Placement Guide—Component Side Figure 3. PC Board Layout—Component Side Figure 4. PC Board Layout—Solder Side _______________________________________________________________________________________ 3 Evaluates: MAX688/MAX689 MAX688-4A Evaluation Kit 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 © 1995 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.