19-0643; Rev 1; 10/08 MAX8654 Evaluation Kit Features The MAX8654 evaluation kit (EV kit) is a fully assembled and tested PCB that demonstrates the capabilities of the MAX8654 integrated 8A step-down regulator. The EV kit generates a 3.3V output voltage at load currents up to 8A from a 4.5V to 14V input voltage range. The MAX8654 switches at 500kHz and provides over 93.4% efficiency with the supplied components. o o o o Component Suppliers o SUPPLIER PHONE WEBSITE Murata Electronics 770-436-1300 www.murata-northamerica.com North America, Inc. Taiyo Yuden 800-348-2496 www.t-yuden.com TDK Corp. 847-803-6000 www.component.tdk.com TOKO America, Inc. 847-297-0070 www.tokoam.com Note: Indicate that you are using the MAX8654 when contacting these component suppliers. o o o o o o Internal 26m RDS(ON) MOSFETs Guaranteed 8A Output Current Adjustable Over-Current Protection, 6A to 12A 1% Output Accuracy Over Load, Line, and Temperature Operates from 4.5V to 14V Supply Adjustable Output from 0.6V to 0.85 x VIN Soft-Start Reduces Inrush Supply Current 250kHz to 1.2MHz Adjustable Switching or SYNC Input Compatible with Ceramic, Polymer, and Electrolytic Output Capacitors SYNCOUT Synchronizes 2nd Regulator 180 Out-of-Phase 36-Pin 6mm x 6mm TQFN Package Ordering Information PART MAX8654EVKIT+ TEMP RANGE IC PACKAGE 0C to +70C 36 TQFN (6mm x 6mm) +Denotes a lead-free and RoHS-compliant EV kit. Component Lists MAX8654 Circuit DESIGNATION QTY DESCRIPTION DESIGNATION QTY DESCRIPTION C1A, C1B, C1C 3 10F 20%, 16V X5R ceramic capacitors (1206) Taiyo Yuden EMK316BJ106M C2 1 1F 10%, 6.3V X5R ceramic capacitor (0402) Murata GRM155R60J105K C9 1 4.7F 10%, 16V X5R ceramic capacitor (0603) Murata GRM21BR61C475K C3, C11 2 0.01F 10%, 50V X7R ceramic capacitors (0402) Murata GRM155R71H103K C10 1 0.22F,16V Y5R ceramic capacitor (0402) Taiyo Yuden EMK105BJ224MV-F C4 1 0.22F 20%, 16V X7R ceramic capacitor (0603) TDK C1608X7R1C224M C12 1 470pF 10%, 50V X7R ceramic capacitor (0402) Murata GRM155R71H471K C5A, C5B, C5C 3 22F 20%, 6.3V X5R ceramic capacitors (1206) TDK C3216X5R0J226M C13 1 0.1F 10%, 10V X7R ceramic capacitor (0402) Murata GRM155R61A104K C6 1 6800pF 10%, 50V X7R ceramic capacitor (0402) Murata GRM155R71H682KA88 C14, C15 2 0.22F 20%, 50V X5R ceramic capacitors (0805) Taiyo Yuden UMK212BJ224M C7 1 0.022F, 10V X7R ceramic capacitor (0402) Murata GRM155R71C223CKA0I C16 0 Not installed, 0.01F 10%, 25V X7R ceramic capacitor (0402) Murata GRM155R71E103K C8 1 1000pF, 50V C0G ceramic capacitor (0402) Murata GRM1555C1H1D2TADI ________________________________________________________________ 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: MAX8654/MAX8688 General Description Evaluates: MAX8654/MAX8688 MAX8654 Evaluation Kit Component Lists (continued) MAX8688 Circuit--Not Installed DESIGNATION MAX8654 Circuit DESIGNATION QTY DESCRIPTION JP1-JP7, JP9-JP13 0 Not installed JU1, JU2, JU4 3 2-pin headers JU3 1 3-pin header 1 1H, 7.9m, 12A inductor (7.4mm x 6.7mm x 3mm) TOKO FDV0630-1R0M L1 R1, R2, R10 3 100k 1% resistors (0402), lead free R3 1 1.5k 1% resistor (0402), lead free R4 1 332 1% resistor (0402), lead free R5 1 15 5% resistor (0402), lead free R6 1 475 1% resistor (0402), lead free R7 1 75k 1% resistor (0402), lead free R8 1 2.2 1% resistor (1206), lead free R9, R11 2 1k 1% resistors (0402), lead free R12 1 10 1% resistor (0402), lead free U1 1 8A step-down regulator Maxim MAX8654ETX+ -- 3 Shunts -- 1 PCB: MAX8654 Evaluation Kit+ MAX8688 Circuit--Not Installed DESIGNATION 2 QTY C201, C202, C203, C205, C206, C207 0 C204 0 R201, R204, R206, R208, R209, R214 R202 DESCRIPTION 100nF 10%, 50V X7R ceramic capacitors (0603), open Murata GRM188R71H104K 1F 10%, 10V X5R ceramic capacitor (0603), open Murata GRM188R61A105K 2.2F 10%, 10V X5R ceramic capacitor (0603), open Taiyo Yuden LMK107BJ225K Ceramic capacitor, open C208 0 C209 0 C210 0 D1 0 JP201 JP202, JP203, JP204 R19 0 0.47F 10%, 10V X5R ceramic capacitor (0603), open Murata GRM188R61A474K 3.3V 350mW zener diode (SOT23), open Central Semiconductor CMPZ4620 4-pin header, open 0 3-pin header, open 0 100k resistor, open QTY DESCRIPTION 0 Resistors, open 0 0 resistor (0402) R203 R205, R207, R210 R211 0 1k 1% resistor (0402), open 0 33k 1% resistors (0402), open 0 909 5% resistor (0603), open R213 0 100k 1% resistor (0402), open R215 0 10k 1% resistor (0402), open R216, R217 0 100 1% resistors (0402), open U201 0 MAX8688+, open U202 0 AT24C01A-10TSU-1.8, open Quick Start Recommended Equipment Before beginning, the following equipment is needed: * Up to 12V at +3A DC power supply or battery * Digital multimeter (DMM) * Up to 8A load * Ammeter (optional) Procedure The MAX8654 EV kit is fully assembled and tested. Follow the steps below to verify board operation. Caution: Do not turn on the power supply until all connections are made. 1) Preset the DC power supply to 12V. Turn off the power supply. 2) Ensure that there is a shunt on JU1 and JU2. 3) Ensure that there is a shunt on pins 1-2 of JU3. 4) Connect the positive lead of the power supply to the VIN pad and connect the negative lead of the power supply to the GND pad on the EV kit. 5) Connect the positive lead of the DMM to the VOUT pad and connect the negative lead of the DMM to the GND pad on the EV kit. 6) Turn on the power supply. 7) Verify that the voltage at VOUT is approximately 3.3V. 8) Connect the load between VOUT and GND. 9) Verify that the voltage at VOUT is approximately 3.3V. _______________________________________________________________________________________ MAX8654 Evaluation Kit Evaluating Other Switching Frequencies (FREQ) The switching frequency in fixed-frequency PWM operation is resistor-programmable from 250kHz to 1.2MHz. Set the switching frequency of the IC with a resistor (RFREQ) from FREQ to GND. RFREQ is calculated as: 1 RFREQ = 52.36 x - 0.05s k fs Soft-Start and REFIN The MAX8654 utilizes an adjustable soft-start function to limit inrush current during startup. An 8A (typ) current source charges an external capacitor (C3) connected to SS to increase the capacitor voltage in a controlled manner. The soft-start time is adjusted by the value of the external capacitor from SS to GND. The required capacitance value is determined as: C= 8A x tss 0.6V The UVLO circuitry inhibits switching when VIN or VVDL is below 4.4V (VIN, VVDL rising) or VVL is below 3.1V (VVL rising). Once these voltages are above the thresholds, UVLO clears and the soft-start function activates. A 100mV hysteresis is built in for glitch immunity. where tSS is the required soft-start time in seconds. The MAX8654 also features an external reference input (REFIN). The IC regulates FB to the voltage applied to REFIN. The internal soft-start is not available when using an external reference. A method of soft-start when using an external reference is shown in the MAX8654 data sheet. Connect REFIN to SS to use the internal 0.6V reference (jumper JU3). Power Good (PWRGD) Jumper Settings PWRGD is an open-drain output that goes high impedance once the soft-start ramp has concluded, provided VFB and VREFIN are above 0.54V. PWRGD pulls low when VFB falls below 0.54V for at least 50s or VREFIN is less than 0.54V. PWRGD is low during shutdown. Jumper JU1 Function Drive EN high by placing a shunt on JU1 to turn on the IC. To shut down the IC and reduce quiescent current to 10A (typ), remove the shunt on JU1. During shutdown, the outputs of the MAX8654 are high impedance. where fS is the desired switching frequency in megahertz. Undervoltage Lockout (UVLO) SYNC and SYNCOUT The MAX8654 features a SYNC function that allows the switching frequency to be synchronized to any external clock frequency that is higher than the internal clock frequency. Drive SYNC with a square wave at the desired synchronization frequency. A rising edge on SYNC triggers the internal SYNC circuitry. Connect SYNC to GND to disable the function and operate with the internal oscillator. The SYNCOUT output generates a clock signal that is 180 out-of-phase with its internal oscillator, or the signal applied to SYNC. This allows for another MAX8654 to be synchronized 180 out-ofphase to reduce the input ripple current. Jumper JU2 Function Place a shunt on jumper JU2 to connect SYNC to GND. Jumper JU3 Function Place a shunt on pins 1-2 of JU3 to connect the REFIN pin to the SS pin. When using an external reference, place a shunt on pins 2-3 of jumper JU3. Evaluating the MAX8688 The MAX8688 is a fully digital power-supply manager that can be tested in conjunction with the MAX8654. Samples of the MAX8688 IC can be ordered from Maxim. To test the MAX8688, populate it with its circuitry, as shown by the schematic or in the component list. Also, place a shunt on pins 2-3 of JU3. For further information, refer to the MAX8688 IC data sheet. _______________________________________________________________________________________ 3 Evaluates: MAX8654/MAX8688 Detailed Description of Hardware 4 VIN VIN VDL VIN JP3 JP2 JP1 2 1 2 1 2 1 JP13 JP12 C1C 10F 1 C1B 10F C1A 10F 1 C9 4.7F C16 DNI R9 1k 1 PGND 31 30 29 28 LX 27 FB R8 2.2 C5A 22F C5B 22F VOUT C5C 22F EN C14 0.22F 2 1 JU4 2 REFIN AGND C10 0.22F R12 10 JP5 JP4 2 1 2 C15 0.22F 9 8 7 6 5 4 3 2 C2 1F C11 0.01F VL VP IN IN IN IN VDL PGND PGND 10 VL EP JU3 R7 75k 1% 11 ILIM PGND Figure 1a. MAX8654 EV Kit Schematic (Sheet 1 of 2) _______________________________________________________________________________________ 3 2 1 13 GND PGND R1 100k 1% 12 FREQ PGND GND N.C. 14 REFIN EN 16 COMP REFIN 15 SS MAX8654 U1 32 33 LX C3 0.01F C8 1000pF 18 PWRGD R6 475 17 FB N.C. SYNC BST LX LX LX LX LX C7 0.022F SYNCOUT LX 19 20 21 22 23 24 25 26 C4 0.22F C12 470pF R3 1.5k 1% R4 332 1% R2 100k C6 6800pF R5 15 VL 2 1 2 1 2 1 2 1 2 34 L1 1H LX 2 JP11 2 35 C13 0.1F R10 100k 1 1 36 2 1 VIN R11 1k 1 37 ENABLE JU1 EN JP6 JP7 JU2 PWRGD SYNCOUT SYNC GND_SIGNAL VOUT JP9 JP10 Evaluates: MAX8654/MAX8688 MAX8654 Evaluation Kit JP204 JP203 JP202 JP201 3 2 1 3 2 1 3 2 1 4 3 2 1 TP6 V33 SCL SDA SCL EN RST SDA 5 6 4 2 1 FLT- R215 10k C202 100nF CLKIN V33 OTP V33 C201 100nF 3 TP4 TP2 R204 OPEN SDA RST CLKIN DVDD DGND OTP1 22 19 7 8 9 10 11 12 R19 100k V33 EP A2 A1 DACOUT AGND AVDD REFOUT RS- RSC 20 TP3 C203 100nF R217 100 SCL NC8 NC9 ENOUT FLT A3 MAX8688 RS+ 21 U201 ISNC ISN+ ISN- 24 23 ISN- ISN+ 25 13 14 15 16 17 18 A3 V33 R201 OPEN C204 1F R203 1k TP5 A2 A1 V33 V33 C205 100nF GND_SIGNAL VOUT C210 0.47F R216 100 C206 100nF 4 5 VCC WP SDA 3 2 1 A2 A1 A3 C207 100nF VSS SCL VIN+ U202 AT24C01A VIN VOUT LX D1 CMPZ4620 R211 909 R202 0 R213 100k R214 OPEN V33 V33 R210 33k R209 OPEN R208 OPEN R207 33k R206 OPEN R205 33k C208 2.2F PMBUS ADDRESS: 0x5A V33 C209 OPEN REFIN FB Evaluates: MAX8654/MAX8688 TP1 MAX8654 Evaluation Kit Figure 1b. MAX8654 EV Kit Schematic (Sheet 2 of 2) _______________________________________________________________________________________ 5 Evaluates: MAX8654/MAX8688 MAX8654 Evaluation Kit Figure 2. MAX8654 EV Kit Component Placement Guide--Component Side 6 _______________________________________________________________________________________ MAX8654 Evaluation Kit Evaluates: MAX8654/MAX8688 Figure 3. MAX8654 EV Kit PCB Layout--Component Side _______________________________________________________________________________________ 7 Evaluates: MAX8654/MAX8688 MAX8654 Evaluation Kit Figure 4. MAX8654 EV Kit PCB Layout--Inner Layer 1 8 _______________________________________________________________________________________ MAX8654 Evaluation Kit Evaluates: MAX8654/MAX8688 Figure 5. MAX8654 EV Kit PCB Layout--Inner Layer 2 _______________________________________________________________________________________ 9 Evaluates: MAX8654/MAX8688 MAX8654 Evaluation Kit Figure 6. MAX8654 EV Kit PCB Layout--Inner Layer 3 10 ______________________________________________________________________________________ MAX8654 Evaluation Kit Evaluates: MAX8654/MAX8688 Figure 7. MAX8654 EV Kit PCB Layout--Inner Layer 4 ______________________________________________________________________________________ 11 Evaluates: MAX8654/MAX8688 MAX8654 Evaluation Kit Figure 8. MAX8654 EV Kit PCB Layout--Solder Side 12 ______________________________________________________________________________________ MAX8654 Evaluation Kit REVISION NUMBER REVISION DATE DESCRIPTION 0 5/07 Initial release 1 10/08 Change in compensation components (C6, C7, C8, R5, and R6) PAGES CHANGED -- 1, 2, 4 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. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 13 (c) 2008 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc. Evaluates: MAX8654/MAX8688 Revision History