Evaluation Board User Guide UG-270 One Technology Way • P.O. Box 9106 • Norwood, MA 02062-9106, U.S.A. • Tel: 781.329.4700 • Fax: 781.461.3113 • www.analog.com Evaluation Board for the 800 mA, 3 MHz Buck Regulator FEATURES GENERAL DESCRIPTION Full-featured evaluation board for the ADP2147 Standalone capability Simple device measurements, including line and load regulation, demonstrable with A single voltage supply (added indent) A voltmeter A current meter Load resistors Easy access to external components The ADP2147 is a high efficiency, low quiescent current, synchronous, step-down, dc-to-dc converter. The buck regulator automatically switches operating modes, depending on the load current level. At higher output loads, the buck regulator operates in PWM mode. When the load current falls below a predefined threshold, the regulators operate in power save mode (PSM), improving the light-load efficiency. The output voltage can be changed between two different settings under the control of a VSEL pin. The 3 MHz switching frequency minimizes the size of external components. Full details on the ADP2147 are provided in the ADP2147 data sheet available from Analog Devices, Inc., which should be consulted in conjunction with thisuser guide. 09807-001 DIGITAL PICTURE OF THE EVALUATION BOARD Figure 1. PLEASE SEE THE LAST PAGE FOR AN IMPORTANT WARNING AND LEGAL TERMS AND CONDITIONS. Rev. 0 | Page 1 of 8 UG-270 Evaluation Board User Guide TABLE OF CONTENTS Features .............................................................................................. 1 Powering Up the Evaluation Board ............................................3 General Description ......................................................................... 1 Measuring Evaluation Board Performance ...................................3 Digital Picture of the Evaluation Board......................................... 1 Evaluation Board Schematic andArtwork......................................4 Revision History ............................................................................... 2 Ordering Information.......................................................................5 Using the Evaluation Board............................................................. 3 Bill of Materials..............................................................................5 REVISION HISTORY 5/11—Revision 0: Initial Version Rev. 0 | Page 2 of 8 Evaluation Board User Guide UG-270 USING THE EVALUATION BOARD POWERING UP THE EVALUATION BOARD Turning On the Evaluation Board The ADP2147 evaluation board is supplied fully assembled and tested. Before applying power to the evaluation board, follow the procedures in this section. After the power source and load are connected to the ADP2147 evaluation board, the board can be powered for operation. To do this, perform the following steps: Jumper JP3 (ENABLE) 1. 2. Jumper JP3 (EN) enables/disables the ADP2147. Connect a jumper between Pin 2 of JP3 and Pin 3 (VIN) of JP3, to enable the ADP2147. Connecting Pin 2 of JP3 to Pin 1 of JP3 disables the ADP2147 and brings the current to <1 μA. Ensure that the power source voltage is >2.3 V but <5.5 V. Ensure that JP3 (EN) is high and monitor the output voltage. If the load is not already enabled, enable the load, check that it is drawing the proper current, and that the output voltage maintains voltage regulation. Input Power Source Changing the Output Voltage of the Device If the input power source includes a current meter, use that meter to monitor the input current. Connect the positive terminal of the power source to TB1 (VIN) on the evaluation board, and the negative terminal of the power source to TB5 (GND IN) of the evaluation board. Each ADP2147 has a VSELpin, which determines the output voltage of the buck regulator by either a high selection (the VSEL pin is set high by connecting Pin 2 of JP2 to Pin 3 of JP2) or by a low selection (the VSEL pin is set low by connecting Pin 2 of JP2 to Pin 1 of JP2). If the power source does not include a current meter, connect a current meter in series with the input source voltage. Connect the positive (+) lead of the power source to the ammeter positive (+) connection, the negative (−) lead of the power source to TB5 (GND IN) on the evaluation board, and the negative (−) lead of the ammeter to TB1 (VIN) on the evaluation board. MEASURING EVALUATION BOARD PERFORMANCE Output Load Connect an electronic load or resistor to set the load current. If the load includes an ammeter, or if the current is not measured, connect the load directly to the evaluation board, with the positive (+) load connection to TB3 (VOUT) and the negative (−) load connection to TB4 (GND OUT). If an ammeter is used, connect it in series with the load. Connect the positive (+) ammeter terminal to the evaluation board at TB3 (VOUT), the negative (−) ammeter terminal to the positive (+) load terminal, and the negative (−) load terminal to the evaluation board at TB4 (GND OUT). Input and Output Voltmeters Measure the input and output voltages with voltmeters. Make sure that the voltmeters are connected to the appropriate evaluation board terminals and not to the load or power sources themselves. If the voltmeters are not connected directly to the evaluation board, the measured voltages are incorrect due to the voltage drop across the leads and/or connections between the evaluation board, the power source, and/or the load. Connect the input voltage measuring voltmeter positive (+) terminal to the evaluation board at TB1 (VIN), and the negative (−) terminal to the evaluation board at TB5 (GND IN). Connect the output voltage measuring voltmeter positive (+) terminal to the evaluation board at TB3 (VOUT) and the negative (−) terminal to the evaluation board at TB4 (GND OUT). Measuring Output Voltage Ripple To observe the output voltage ripple, place an oscilloscope probe across the output capacitor (COUT) with the probe ground lead at the negative (−) capacitor terminal and the probe tip at the positive (+) capacitor terminal. Set the oscilloscope to ac, 20 mV/division, and 2 μs/division time base. Measuring the Switching Waveform To observe the switching waveform with an oscilloscope, place the oscilloscope probe tip at the end of the inductor with the probe ground at GND OUT. Set the oscilloscope to dc, 2 V/division, and 2 μs/division time base. Measuring Load Regulation The load regulation is tested by increasing the load at the output and looking at the change in output voltage. To minimize voltage drop, use short low resistance wires, especially for loads approaching maximum current. Measuring Line Regulation Vary the input voltage and examine the change in the output voltage. Measuring Efficiency Measure the efficiency, η, by comparing the input power with the output power. η= VOUT × I OUT V IN × I IN Measure the input and output voltages as close as possible to the input and output capacitors to reduce the effect of IR drops. Measuring Inductor Current The inductor current can be measured by removing one end of the inductor from its pad and connecting a current loop in series. A current probe can be connected onto this wire. Rev. 0 | Page 3 of 8 UG-270 Evaluation Board User Guide EVALUATION BOARD SCHEMATIC AND LAYOUTS VIN GND CONN PWR 2-P 2 1 VIN VIN J6 1 VIN 3 CIN JP3 3 2 1 L1 ADP2147 TB1 VIN 3 2 1 4 4.7µF EN 5 VIN SW 2 1 TB3 2 VOUT 1µH GND EN VOUT 6 COUT 4.7µF VSEL U1 ENABLE JP2 3 2 1 VSEL 3 2 1 GND TB4 TB5 GND IN 09807-002 GND OUT 09807-003 09807-004 Figure 2. Evaluation Board Schematic Figure 4. Evaluation Board, Bottom Layer Figure 3. Evaluation Board, Top Layer Rev. 0 | Page 4 of 8 Evaluation Board User Guide UG-270 ORDERING INFORMATION BILL OF MATERIALS Table 1. Quantity 1 1 1 1 Reference Designator U1 CIN COUT L1 Description ADP2147 buck regulator Capacitor, MLCC, 4.7 μF, 6.3 V, 0603, X5R Capacitor, MLCC, 4.7 μF, 6.3 V, 0603, X5R Inductor, 1 μH, 1.4 A, 85 mΩ Rev. 0 | Page 5 of 8 Manufacturer Analog Devices Murata Manufacturing Co., Ltd Murata Manufacturing Co., Ltd Murata Manufacturing Co., Ltd Part Number ADP2147 GRM188R60J475 GRM188R60J475 LQM2MPN1R0NG0B UG-270 Evaluation Board User Guide NOTES Rev. 0 | Page 6 of 8 Evaluation Board User Guide UG-270 NOTES Rev. 0 | Page 7 of 8 UG-270 Evaluation Board User Guide NOTES ESD Caution ESD (electrostatic discharge) sensitive device. Charged devices and circuit boards can discharge without detection. Although this product features patented or proprietary protection circuitry, damage may occur on devices subjected to high energy ESD. Therefore, proper ESD precautions should be taken to avoid performance degradation or loss of functionality. Legal Terms and Conditions By using the evaluation board discussed herein (together with any tools, components documentation or support materials, the “Evaluation Board”), you are agreeing to be bound by the terms and conditions set forth below (“Agreement”) unless you have purchased the Evaluation Board, in which case the Analog Devices Standard Terms and Conditions of Sale shall govern. Do not use the Evaluation Board until you have read and agreed to the Agreement. Your use of the Evaluation Board shall signify your acceptance of the Agreement. This Agreement is made by and between you (“Customer”) and Analog Devices, Inc. (“ADI”), with its principal place of business at One Technology Way, Norwood, MA 02062, USA. Subject to the terms and conditions of the Agreement, ADI hereby grants to Customer a free, limited, personal, temporary, non-exclusive, non-sublicensable, non-transferable license to use the Evaluation Board FOR EVALUATION PURPOSES ONLY. Customer understands and agrees that the Evaluation Board is provided for the sole and exclusive purpose referenced above, and agrees not to use the Evaluation Board for any other purpose. Furthermore, the license granted is expressly made subject to the following additional limitations: Customer shall not (i) rent, lease, display, sell, transfer, assign, sublicense, or distribute the Evaluation Board; and (ii) permit any Third Party to access the Evaluation Board. As used herein, the term “Third Party” includes any entity other than ADI, Customer, their employees, affiliates and in-house consultants. The Evaluation Board is NOT sold to Customer; all rights not expressly granted herein, including ownership of the Evaluation Board, are reserved by ADI. CONFIDENTIALITY. This Agreement and the Evaluation Board shall all be considered the confidential and proprietary information of ADI. Customer may not disclose or transfer any portion of the Evaluation Board to any other party for any reason. Upon discontinuation of use of the Evaluation Board or termination of this Agreement, Customer agrees to promptly return the Evaluation Board to ADI. ADDITIONAL RESTRICTIONS. Customer may not disassemble, decompile or reverse engineer chips on the Evaluation Board. Customer shall inform ADI of any occurred damages or any modifications or alterations it makes to the Evaluation Board, including but not limited to soldering or any other activity that affects the material content of the Evaluation Board. Modifications to the Evaluation Board must comply with applicable law, including but not limited to the RoHS Directive. TERMINATION. ADI may terminate this Agreement at any time upon giving written notice to Customer. Customer agrees to return to ADI the Evaluation Board at that time. LIMITATION OF LIABILITY. THE EVALUATION BOARD PROVIDED HEREUNDER IS PROVIDED “AS IS” AND ADI MAKES NO WARRANTIES OR REPRESENTATIONS OF ANY KIND WITH RESPECT TO IT. ADI SPECIFICALLY DISCLAIMS ANY REPRESENTATIONS, ENDORSEMENTS, GUARANTEES, OR WARRANTIES, EXPRESS OR IMPLIED, RELATED TO THE EVALUATION BOARD INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, TITLE, FITNESS FOR A PARTICULAR PURPOSE OR NONINFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS. IN NO EVENT WILL ADI AND ITS LICENSORS BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT, OR CONSEQUENTIAL DAMAGES RESULTING FROM CUSTOMER’S POSSESSION OR USE OF THE EVALUATION BOARD, INCLUDING BUT NOT LIMITED TO LOST PROFITS, DELAY COSTS, LABOR COSTS OR LOSS OF GOODWILL. ADI’S TOTAL LIABILITY FROM ANY AND ALL CAUSES SHALL BE LIMITED TO THE AMOUNT OF ONE HUNDRED US DOLLARS ($100.00). EXPORT. Customer agrees that it will not directly or indirectly export the Evaluation Board to another country, and that it will comply with all applicable United States federal laws and regulations relating to exports. GOVERNING LAW. This Agreement shall be governed by and construed in accordance with the substantive laws of the Commonwealth of Massachusetts (excluding conflict of law rules). Any legal action regarding this Agreement will be heard in the state or federal courts having jurisdiction in Suffolk County, Massachusetts, and Customer hereby submits to the personal jurisdiction and venue of such courts. The United Nations Convention on Contracts for the International Sale of Goods shall not apply to this Agreement and is expressly disclaimed. ©2011 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. UG09807-0-5/11(0) Rev. 0 | Page 8 of 8