Evaluates: MAX8727 19-3616 Rev 1 2/06 MAX8727 Evaluation Kit General Description Features The MAX8727 evaluation kit (EV kit) is a fully assembled 90% Efficiency and tested surface-mount circuit board that contains a 2.6V to 5.5V Input Range pulse-width-modulated (PWM) step-up DC-DC convert- er. The EV kit is configured to operate with a 1.2MHz 15V Output Voltage (Adjustable from V to 24V) IN switching frequency. It operates from a 2.6V to 5.5V DC 600mA Output Current (4.5V Input) supply voltage, is configured for a 15V output, and can provide 600mA with a 4.5V input. 1.2MHz Switching Frequency (Selectable: 640kHz The MAX8727 EV kit features low quiescent current and or 1.2MHz) high conversion efficiency (90%). The high switching Programmable Soft-Start frequency allows for the use of small surface-mount components. 0.1A IC Shutdown Current (typ) Fully Assembled and Tested Ordering Information PART TEMP RANGE IC PACKAGE MAX8727EVKIT 0C to +70C 10 TDFN (3mm x 3mm) Component List DESIGNATION QTY DESCRIPTION DESIGNATION QTY DESCRIPTION Not installed, ceramic capacitor 100F 20%, 6.3V aluminum C1 0 (0805) electrolytic capacitor C10 1 (SMT: 6.3mm x 6.0mm) 10F 10%, 6.3V X5R ceramic Sanyo 6CV100AX capacitor (0805) C2 1 Murata GRM21BR60J106K 3A, 30V Schottky diode (M-flat) D1 1 Taiyo Yuden JMK212BJ106K Toshiba CMS02 JU1 1 2-pin header 1F 10%, 6.3V X5R ceramic JU2 0 Not installed, 3-pin header C3 1 capacitor (0603) Murata GRM188R60J105K 3.6H 30%, 3.5A power inductor L1 1 Sumida CDR7D28MNNP-3R6 0.033F 10%, 25V X7R ceramic C4 1 capacitor (0603) R1 1 309k 1% resistor (0603) Murata GRM188R71E333K R2 1 28.0k 1% resistor (0603) R3, R4 2 100k 5% resistors (0603) 330pF 10%, 50V X7R ceramic C5 1 capacitor (0603) R5 0 Not ins tal l ed shor t by P C tra ce ( 0603) Murata GRM188R71H331K MAX8727ETB+ (10-pin TDFN 3mm x U1 1 3mm) (top mark AMV) 39pF 5%, 50V C0G ceramic 1 Shunt capacitor (0603) C6 1 Murata GRM1885C1H390J 1 MAX8727 EV kit PC board Taiyo Yuden UMK107CG390JZ 4.7F 20%, 25V X7R ceramic capacitors (1206) C7, C8, C9 3 Murata GRM31CR71E475M Taiyo Yuden TMK316BJ475KL Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.MAX8727 Evaluation Kit Recommended Equipment Table 1. Jumper JU1 Functions 2.6V to 5.5V, 5A DC power supply (VIN) SHUNT SHDN PIN MAX8727 OUTPUT Voltmeter LOCATION Quick Start Shutdown mode, Installed Connected to GND V = V - V OUT IN DIODE The MAX8727 EV kit is fully assembled and tested. Follow these steps to verify board operation. Do not Not installed Connected to VIN MAX8727 enabled, turn on the power supply until all connections are (default) through R4 V = 15V OUT completed: 1) Verify that there is no shunt placed across jumper Table 2. Jumper JU2 Functions JU1 to enable the MAX8727. 2) Connect the positive terminal of the DC power supply SHUNT SWITCHING FREQ PIN to the VIN pad. Connect the negative terminal of the LOCATION FREQUENCY DC power supply to the GND pad above the VIN pad. Connected to VIN with 1-2 (default) 1.2MHz 3) Connect the voltmeter across the VOUT and GND a PC trace pads. Connected to GND (cut the 4) Turn on the 2.6V to 5.5V DC power supply and verify 2-3 trace between pins 1-2 640kHz that the output is 15V. before shorting pins 2-3) Detailed Description The MAX8727 EV kit contains a high-efficiency, PWM step-up DC-DC converter. The MAX8727 features a Evaluating Other programmable soft-start, loop compensation pin, and Output Voltages an internal MOSFET switch. The EV kit operates from a The EV kit is configured to provide a 15V output voltage. 2.6V to 5.5V DC power supply, provides a regulated However, the output voltage can be adjusted from V to IN 15V output, and is capable of providing a 600mA load 24V by selecting appropriate R1 and R2 values. Select current with a 4.5V input. The EV kit is configured for a R2 in the 10k to 50k range. R1 is then given by: 5V input, a 15V output, and a 1.2MHz switching fre- quency. Operation at a different input voltage, out- VOUT put voltage, or switching frequency may require a RR12= 1 different inductor, output capacitor, and compensa- V FB tion components. Refer to the MAX8727 data sheet for detailed information on loop compensation and compo- where V = 1.24V. For significantly different operation FB nent selection. points, the EV kit may require a different inductor and component changes. Refer to the MAX8727 data sheet Jumper Selection for proper component selection. Shutdown Mode (SHDN) The EV kit features a shutdown mode that reduces the MAX8727 quiescent current. JU1 selects the shutdown mode. See Table 1 for jumper JU1 functions. Switching-Frequency Selection (FREQ) The MAX8727 EV kit provides the option to configure the switching frequency of the step-up DC-DC convert- er. Table 2 lists jumper JU2 settings for configuring the switching frequency. The EV kit is configured and shipped to operate at 1.2MHz. For operation at 640kHz, cut the trace between pins 1 and 2 of jumper JU2 and short pins 2 and 3. Refer to the MAX8727 data sheet for selecting the proper components. 2 Evaluates: MAX8727