19-2361; Rev 0; 03/02 MAX1921 Evaluation Kit Features ♦ 2V to 5.5V Input Voltage Range ♦ Output Voltage 1.8V Fixed Output Voltage (MAX1921EUT18-T) Adjustable Output Voltage (MAX1920EUT-T) Other Fixed-Output Voltages (MAX1921EUT_ _-T) ♦ Output Current Guaranteed 400mA at ≥2.5V Input Voltage ♦ IC Shutdown Current 0.1µA (typ) ♦ Surface-Mount Components ♦ Fully Assembled and Tested Ordering Information Component List DESIGNATION QTY DESCRIPTION 1 2.2µF ±20%, 10V X5R ceramic capacitor (0805) Taiyo Yuden LMK212BJ225MG or TDK C2012X5R1A225M 1 4.7µF ±20%, 6.3V X5R ceramic capacitor (0805) Taiyo Yuden JMK212BJ475MG or TDK C2012X5R0J475K C3 1 5.6nF ±20%, 50V X7R ceramic capacitor (0603) Murata GRM39X7R562M050AD or equivalent JU1 1 3-pin header L1 1 4.7µH ±20% 1A inductor Toko A914BYW-4R7M or Sumida CDRH3D16-4R7 R1 1 4.75kΩ ±1% resistor (0603) R2 0 Not installed, resistor (0603) 1 MAX1921EUT18-T (6-pin SOT23), top mark ABCM C1 C2 U1 None 1 Shunt None 1 MAX1921 PC board None 1 MAX1921 EV kit data sheet None 1 MAX1920/MAX1921 data sheet PART MAX1921EVKIT TEMP RANGE o o 0 C to +70 C IC PACKAGE 6 SOT23-6 Note: To evaluate other versions of the MAX1921 or the MAX1920, request a free sample with the MAX1921EVKIT. See Table 2. Quick Start The MAX1921 EV kit is a fully assembled and tested surface-mount board. Follow the steps below to verify board operation. Do not turn on the power supply until all connections are completed: 1) Verify that there is a shunt across pins 1 and 2 of JU1 (SHDN). 2) Connect a voltmeter and load (if any) to the VOUT pad. Connect the ground to the GND closest to VOUT. 3) Connect a 2V to 5.5V power supply to the VIN pad. Connect power supply ground to the GND pad closest to VIN. 4) Turn on the power supply and verify that the output voltage is 1.8V. To evaluate other voltages, see the Evaluating Other Output Voltages section. ________________________________________________________________ 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: MAX1920/MAX1921 General Description The MAX1921 evaluation kit (EV kit) provides a fixed 1.8V output voltage from a 2V to 5.5V input source and delivers up to 400mA output current. The MAX1921 is a stepdown switching regulator with an internal power switch and synchronous rectifier in a tiny SOT23 package. The MAX1921 EV kit is a fully assembled and tested surface-mount circuit board. The MAX1921 EV kit can also be used to evaluate other fixed-output voltage versions of the MAX1921 or the MAX1920, which is a stepdown switching regulator with an adjustable output voltage. Additional pads on the board are provided for external feedback resistors to set different output voltages, 1.25V to VIN. Evaluates: MAX1920/MAX1921 MAX1921 Evaluation Kit Component Suppliers SUPPLIER PHONE FAX WEBSITE Sumida 847-545-6700 847-545-6720 www.sumida.com Taiyo Yuden 800-348-2496 847-925-0899 www.t-yuden.com TDK 847-803-6100 847-390-4405 www.tdk.com Toko 847-297-0070 847-699-1194 www.tokoam.com Note: Please indicate that you are using the MAX1920/MAX1921 when contacting these component suppliers. Detailed Description Shutdown Mode The MAX1921 EV kit features a shutdown mode that reduces the MAX1921 quiescent current to 0.1µA, preserving battery life. The setting of jumper JU1 selects the circuit operating modes. Table 1 shows the functions of JU1. Table 2. MAX1921 EV Kit Corresponding Output Voltage Table 1. JU1 Functions MAX1921 EV KIT OUTPUT VOLTAGE (V) SHUNT LOCATION SHDN PIN MAX1921 OUTPUT 1 and 2 Connected to VIN MAX1921 enabled, VOUT = 1.8V MAX1920EUT-T MAX1921EUT15-T 1.5 2 and 3 Connected to GND MAX1921 disabled, VOUT = 0V MAX1921EUT18-T 1.8 MAX1921EUT25-T 2.5 External signal enables or disables the MAX1921 output MAX1921EUT30-T 3.0 MAX1921EUT33-T 3.3 Open 2 Evaluating Other Output Voltages The MAX1921 EV kit can be used to evaluate the MAX1921EUT15-T/25-T/30-T/33-T and the MAX1920EUT-T. Replace MAX1921EUT18-T with a MAX1921EUT15-T/25T/30-T/33-T or MAX1920EUT-T. Table 2 lists the corresponding output voltages. To evaluate different output voltages, select L1, C2, C3, R1, and R2 for optimum performance according to the Design Procedure section of the MAX1920/MAX1921 data sheet. Connected to SHDN pad PART NUMBER Adjustable _______________________________________________________________________________________ MAX1921 Evaluation Kit 1 2V TO 5.5V C1 2.2µF 10V GND LX IN R1 4.75kΩ 1% 5 PGND OUT MAX1921EUT18-T 2 JU1 3 SHDN GND C3 56nF R2 OPEN VIN 1 C2 4.7µF 6.3V 4 U1 SHDN VOUT 1.8V L1 4.7µH 6 Evaluates: MAX1920/MAX1921 VIN AGND 2 3 Figure 1. MAX1921 EV Kit Schematic 1.0" 1.0" Figure 2. MAX1921 EV Kit Component Placement Guide— Component Side Figure 3. MAX1921 EV Kit PC Board Layout—Component Side _______________________________________________________________________________________ 3 Evaluates: MAX1920/MAX1921 MAX1921 Evaluation Kit 1.0" Figure 4. MAX1921 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.