19-3616; Rev 1; 2/06 MAX8727 Evaluation Kit The MAX8727 evaluation kit (EV kit) is a fully assembled and tested surface-mount circuit board that contains a pulse-width-modulated (PWM) step-up DC-DC converter. The EV kit is configured to operate with a 1.2MHz switching frequency. It operates from a 2.6V to 5.5V DC supply voltage, is configured for a 15V output, and can provide 600mA with a 4.5V input. The MAX8727 EV kit features low quiescent current and high conversion efficiency (90%). The high switching frequency allows for the use of small surface-mount components. Features 90% Efficiency 2.6V to 5.5V Input Range 15V Output Voltage (Adjustable from VIN to 24V) 600mA Output Current (4.5V Input) 1.2MHz Switching Frequency (Selectable: 640kHz or 1.2MHz) Programmable Soft-Start 0.1A IC Shutdown Current (typ) Fully Assembled and Tested Ordering Information PART TEMP RANGE MAX8727EVKIT 0C to +70C IC PACKAGE 10 TDFN (3mm x 3mm) Component List DESIGNATION C1 C2 C3 C4 C5 C6 C7, C8, C9 QTY DESCRIPTION 0 Not installed, ceramic capacitor (0805) 1 10F 10%, 6.3V X5R ceramic capacitor (0805) Murata GRM21BR60J106K Taiyo Yuden JMK212BJ106K 1 1F 10%, 6.3V X5R ceramic capacitor (0603) Murata GRM188R60J105K 1 0.033F 10%, 25V X7R ceramic capacitor (0603) Murata GRM188R71E333K 1 330pF 10%, 50V X7R ceramic capacitor (0603) Murata GRM188R71H331K 1 39pF 5%, 50V C0G ceramic capacitor (0603) Murata GRM1885C1H390J Taiyo Yuden UMK107CG390JZ 3 4.7F 20%, 25V X7R ceramic capacitors (1206) Murata GRM31CR71E475M Taiyo Yuden TMK316BJ475KL DESIGNATION QTY DESCRIPTION C10 1 100F 20%, 6.3V aluminum electrolytic capacitor (SMT: 6.3mm x 6.0mm) Sanyo 6CV100AX D1 1 3A, 30V Schottky diode (M-flat) Toshiba CMS02 JU1 1 2-pin header JU2 0 Not installed, 3-pin header L1 1 3.6H 30%, 3.5A power inductor Sumida CDR7D28MNNP-3R6 R1 1 309k 1% resistor (0603) R2 1 28.0k 1% resistor (0603) R3, R4 2 100k 5% resistors (0603) R5 0 Not installed; short by PC trace (0603) U1 1 MAX8727ETB+ (10-pin TDFN 3mm x 3mm) (top mark AMV) -- 1 Shunt -- 1 MAX8727 EV kit PC board ________________________________________________________________ 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: MAX8727 General Description Evaluates: MAX8727 MAX8727 Evaluation Kit Recommended Equipment * 2.6V to 5.5V, 5A DC power supply (VIN) * Voltmeter Quick Start The MAX8727 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 there is no shunt placed across jumper JU1 to enable the MAX8727. 2) Connect the positive terminal of the DC power supply to the VIN pad. Connect the negative terminal of the DC power supply to the GND pad above the VIN pad. 3) Connect the voltmeter across the VOUT and GND pads. 4) Turn on the 2.6V to 5.5V DC power supply and verify that the output is 15V. Detailed Description The MAX8727 EV kit contains a high-efficiency, PWM step-up DC-DC converter. The MAX8727 features a programmable soft-start, loop compensation pin, and an internal MOSFET switch. The EV kit operates from a 2.6V to 5.5V DC power supply, provides a regulated 15V output, and is capable of providing a 600mA load current with a 4.5V input. The EV kit is configured for a 5V input, a 15V output, and a 1.2MHz switching frequency. Operation at a different input voltage, output voltage, or switching frequency may require a different inductor, output capacitor, and compensation components. Refer to the MAX8727 data sheet for detailed information on loop compensation and component selection. Jumper Selection Table 1. Jumper JU1 Functions SHUNT LOCATION SHDN PIN Installed Connected to GND Not installed (default) Connected to VIN through R4 MAX8727 OUTPUT Shutdown mode, VOUT = VIN - VDIODE MAX8727 enabled, VOUT = 15V Table 2. Jumper JU2 Functions SHUNT LOCATION FREQ PIN SWITCHING FREQUENCY 1-2 (default) Connected to VIN with a PC trace 1.2MHz 2-3 Connected to GND (cut the trace between pins 1-2 before shorting pins 2-3) 640kHz Evaluating Other Output Voltages The EV kit is configured to provide a 15V output voltage. However, the output voltage can be adjusted from VIN to 24V by selecting appropriate R1 and R2 values. Select R2 in the 10k to 50k range. R1 is then given by: VOUT R1 = R2 x - 1 VFB where VFB = 1.24V. For significantly different operation points, the EV kit may require a different inductor and component changes. Refer to the MAX8727 data sheet 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 converter. 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 _______________________________________________________________________________________ MAX8727 Evaluation Kit SUPPLIER PHONE FAX WEBSITE Murata 770-436-1300 770-436-3030 www.murata.com Sanyo 619-661-4134 619-661-1055 www.sanyovideo.com Sumida 847-545-6700 847-545-6720 www.sumida.com Taiyo Yuden 408-573-4150 408-573-4159 www.t-yuden.com Toshiba 949-455-2000 949-859-3963 www.toshiba.com/taec Note: Indicate that you are using the MAX8727 when contacting these suppliers. VIN VIN +4.5V TO +5.5V GND L1 3.6H C10 100F 6.3V C2 10F 6.3V C1 OPEN VIN VIN R4 100k 1 2 3 FB 3 10 C8 4.7F 25V C9 4.7F 25V GND R1 309k 1% 7 LX2 2 U1 9 JU1 C7 4.7F 25V R5 SHORT (PC TRACE) 6 LX1 8 IN C3 1F JU2 VOUT 15V, 600mA D1 R2 28k 1% MAX8727 FREQ GND2 SHDN GND1 4 5 SS C4 0.033F COMP 1 R3 100k C6 39pF C5 330pF EXPOSED PADDLE CONNECTED TO GROUND (PIN 4, GND2) Figure 1. MAX8727 EV Kit Schematic _______________________________________________________________________________________ 3 Evaluates: MAX8727 Component Suppliers Evaluates: MAX8727 MAX8727 Evaluation Kit Figure 2. MAX8727 EV Kit Component Placement Guide-- Component Side Figure 3. MAX8727 EV Kit PC Board Layout--Component Side Figure 4. MAX8727 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 (c) 2006 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc. Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Maxim Integrated: MAX8727EVKIT