19-2271; Rev 0; 1/02 MAX1896 Evaluation Kit Features ♦ 2.5V to 5.5V Input Voltage Range The EV kit provides low quiescent current and high efficiency. It can also be used to evaluate other output voltages from VIN voltage up to 13.0V by changing the feedback resistors, R1 and R2. ♦ 1.4MHz Fixed-Frequency PWM Operation ♦ Output Voltage Fixed 12.0V Adjustable Output (From VIN to 13.0V) ♦ Up to 100mA Output Current ♦ 0.01µA IC Shutdown Current ♦ Surface-Mount Components ♦ Fully Assembled and Tested Ordering Information PART MAX1896EVKIT TEMP RANGE IC PACKAGE 0oC to +70oC 6 SOT23-6 Component List DESIGNATION QTY DESCRIPTION C1 1 10µF, 10.0V tantalum capacitor (A) AVX TAJA106K010 C2 1 4.7µF, 16.0V, X5R ceramic capacitor (1206) Taiyo Yuden EMK316BJ475ML C3 1 0.1µF, 16.0V, X7R ceramic capacitor (0603) Taiyo Yuden EMK107BJ104KA C4 C5 1 1 100pF, 50.0V ceramic capacitor (0603) Taiyo Yuden UMK107CH101JZ or Murata GRM39C0G101J050AD 0.033µF, 16.0V, X7R ceramic capacitor (0603) Taiyo Yuden EMK107BJ333KA or equivalent DESIGNATION QTY DESCRIPTION L1 1 10µH inductor Sumida CR43-100MC D1 1 1A, 30.0V Schottky diode Toshiba CRS02 or Nihon EP10QY03 JU1 1 3-pin header R1 1 107kΩ ±1% resistor (0603) R2 1 12.4kΩ ±1% resistor (0603) R3 1 10kΩ ±5% resistor (0603) U1 1 MAX1896EUT (SOT23-6) top mark AAUX None 1 Shunt None 1 MAX1896 PC board None None 1 1 MAX1896 EV kit data sheet MAX1896 data sheet ________________________________________________________________ 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: MAX1896 General Description The MAX1896 evaluation kit (EV kit) is a fully assembled and tested surface-mount circuit board that contains a fixed-frequency 1.4MHz, pulse-width-modulated (PWM), step-up DC-DC converter. The EV kit provides a 12.0V output voltage from a 2.5V to 5.5V input source. It delivers up to 100mA output current. Evaluates: MAX1896 MAX1896 Evaluation Kit Component Suppliers PHONE FAX WEBSITE AVX SUPPLIER 843-946-0238 843-626-3123 www.avxcorp.com Murata 770-436-1300 770-436-3030 www.murata.com Nihon 81-33343-3411 81-33342-5407 www.niec.co.jp Sumida 847-545-6700 847-545-6720 www.sumida.com Taiyo Yuden 800-348-2496 847-925-0899 www.t-yuden.com Toshiba 949-455-2000 949-859-3963 www.toshiba.com Note: Please indicate that you are using the MAX1896 when contacting these component suppliers. Quick Start The MAX1896 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) Verify that the shunt is across jumper JU1 (SHDN) pins 1 and 2. 2) Connect a voltmeter and load (if any) to the VOUT pad. Connect the load and voltmeter ground to the GND pad closest to VOUT. 3) Connect a 2.5V to 5.5V power supply to the VIN pad. Connect the power-supply ground to the GND pad closest to VIN. 4) Turn on the power supply and verify that the output voltage is 12.0V. To evaluate other output voltages, see the Evaluating Other Output Voltages section. Detailed Description Shutdown Jumper Selection The MAX1896 EV kit features a shutdown mode that reduces quiescent current to 0.01µA (typ) to preserve battery life. JU1 options select the circuit operating modes (shutdown or normal). Table1 shows JU1 functions. Soft-Start Control The MAX1896 EV kit uses a 0.033µF ceramic capacitor (C5) for soft-start control. The full-load current limit will be reached after about 8.25ms. To change the soft-start duration, replace the soft-start capacitor C5, so C5 (µF) = desired soft-start duration (ms) / 250 (ms/µF). For no softstart operation, remove C5 and leave the SS pin open. Evaluating Other Output Voltages The EV kit default output voltage is 12.0V. The output voltage can also be adjusted from VIN to 13.0V by selecting R1 and R2 values. Choose R2 between 10kΩ and 50Ω: R1 = R2 [(VOUT / VFB) -1] where VFB = 1.24V. Table 1. Jumper JU1 Functions 2 SHUNT LOCATION 1 and 2 SHDN PIN Connected to VIN 2 and 3 Connected to GND None Connected to SHDN pad (driven by external source) MAX1896 OUTPUT MAX1896 enabled, VOUT = 12.0V Shutdown mode, VOUT = VIN - Forward Diode Voltage Drop MAX1896 output depends on external SHDN signal _______________________________________________________________________________________ MAX1896 Evaluation Kit Evaluates: MAX1896 L1 10µH 2.5V TO 5.5V VIN GND 6 C1 10µF 10.0V SHDN 1 3 JU1 LX IN C3 0.1µF 1 U1 MAX1896 4 2 12.0V VOUT D1 SHDN FB 3 R3 10kΩ 5% R1 107kΩ 1% C4 100pF C2 4.7µF 16.0V GND R2 12.4kΩ 1% 5 SS GND 2 C5 0.033µF Figure 1. MAX1896 EV Kit Schematic _______________________________________________________________________________________ 3 Evaluates: MAX1896 MAX1896 Evaluation Kit 1.0" 1.0" Figure 2. MAX1896 EV Kit Component Placement Guide— Component Side Figure 3. MAX1896 EV Kit PC Board Layout—Component Side 1.0" Figure 4. MAX1896 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 © 2002 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.