Evaluation Board User Guide UG-189 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 2 A/3 A, 20 V, Nonsynchronous Step-Down Regulators FEATURES GENERAL DESCRIPTION Wide input voltage range: 3.0 V to 20 V Maximum load current 2 A for ADP2302 3 A for ADP2303 ±1.5% output accuracy over temperature Output voltage down to 0.8 V 700 kHz switching frequency Current-mode control architecture Automatic PFM/PWM mode Precision enable pin with hysteresis Integrated high-side MOSFET Integrated bootstrap diode Internal compensation and soft start Power-good output Undervoltage lockout (UVLO) Overcurrent protection (OCP) Thermal shutdown (TSD) 8-lead SOIC package with exposed paddle The ADP2302/ADP2303 are 2 A/3 A, 20 V, nonsynchronous step-down, dc-to-dc regulators with an integrated power MOSFET in a SOIC package with an exposed paddle. The ADP2302/ ADP2303 evaluation boards are complete buck regulator solutions that allow users to evaluate the performance of the regulators. The ADP2302/ADP2303 integrated soft-start circuitry prevents inrush current at power-up. The power-good output indicates that the output voltage is regulated within tolerance, and it can be used to sequence devices that have an enable input. The precision enable feature allows the part to be easily sequenced from external supplies. Other key features include undervoltage lockout (UVLO), output overvoltage protection (OVP), thermal shutdown (TSD), and overcurrent protection (OCP). Full details on the ADP2302/ADP2303 are provided in the ADP2302/ADP2303 data sheet available from Analog Devices, Inc., which should be consulted in conjunction with this user guide. 09315-001 ADP2302/ADP2303 EVALUATION BOARD Figure 1. ADP2302/ADP2303 Evaluation Board PLEASE SEE THE LAST PAGE FOR AN IMPORTANT WARNING AND LEGAL TERMS AND CONDITIONS. Rev. 0 | Page 1 of 12 UG-189 Evaluation Board User Guide TABLE OF CONTENTS Features .............................................................................................. 1 Input and Output Voltmeter ........................................................3 General Description ......................................................................... 1 Turning On the Evaluation Board ..............................................3 ADP2302/ADP2303 Evaluation Board.......................................... 1 Measuring Evaluation Board Performance ...................................3 Revision History ............................................................................... 2 Typical Performance Characteristics ..............................................5 Using the Evaluation Board............................................................. 3 Demonstration Board Schematics and Bill of Materials ..............8 Jumper J5 (Enable) ....................................................................... 3 ADP2302 Schematic and Bill of Materials .................................8 Jumper J8 (PGOOD).................................................................... 3 ADP2303 Schematic and Bill of Materials .................................9 Input Power Source ...................................................................... 3 Demonstration Board Layout ....................................................... 10 Output Load .................................................................................. 3 REVISION HISTORY 8/10—Revision 0: Initial Version Rev. 0 | Page 2 of 12 Evaluation Board User Guide UG-189 USING THE EVALUATION BOARD The ADP2302/ADP2303 evaluation boards are fully assembled and tested. Before applying power to the evaluation board, follow the procedures in this section. TURNING ON THE EVALUATION BOARD JUMPER J5 (ENABLE) Perform the following steps: Jumper J5 enables/disables the ADP2302/ADP2303. Set J5 to EN HIGH to enable the device, and set J5 to EN LOW to disable the device. 1. Ensure that the power source voltage is >VOUT + 2.1 V and <20 V. 2. Ensure that J5 (EN) is high and monitor the output voltage. JUMPER J8 (PGOOD) Jumper J8 connects/disconnects the power-good signal to VIN. To pull the power good (PGOOD) pin up, connect J8 to the input voltage through a 100 kΩ resistor. Disconnect J8 to leave PGOOD open. Once the power source and load are connected to the evaluation board, it can be powered for operation. If the load is not already enabled, enable the load, check that the load is drawing the proper current, and verify that the output voltage maintains voltage regulation. MEASURING EVALUATION BOARD PERFORMANCE Measuring the Switching Waveform INPUT POWER SOURCE To observe the switching waveform with an oscilloscope, place the oscilloscope probe tip at Test Point J7 (SW) with the probe ground at GND. Set the scope to dc with the appropriate voltage and time divisions. The switching waveform should alternate between 0 V and approximate the input voltage. 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 J2 (VIN) on the evaluation board and the negative terminal of the power source to J4 (GND) of the evaluation board. 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 positive (+) ammeter terminal, the negative lead (−) of the power source to J4 (GND), and the negative lead (−) of the ammeter to J2 (VIN). Measuring Load Regulation Load regulation should be tested by increasing the load at the output and by observing the change in output voltage. To minimize voltage drop, it is recommended to use short low resistance wires. OUTPUT LOAD Measuring Line Regulation Make sure that the board is turned off before connecting the 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 J1 (VOUT) and the negative (−) load connection to J3 (GND). Vary the input voltage and examine the change in the output voltage at a fixed output current. Measuring Efficiency The efficiency, η, is measured by comparing the input power with the output power. η= VOUT × I OUT If an ammeter is used, connect it in series with the load. Connect the positive (+) ammeter terminal to J1 (VOUT), the negative (−) ammeter terminal to the positive (+) load terminal, and the negative (−) load terminal to J3 (GND). Measure the input and output voltages as close as possible to the input and output capacitors to reduce the effect of voltage drop. INPUT AND OUTPUT VOLTMETER Measuring Inductor Current 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 source. 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. 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 to this wire. To measure the input voltage, connect the positive terminal of the voltmeter to J2 (VIN) and the negative terminal to J4 (GND). Likewise, to measure the output voltage, connect the positive terminal of the voltmeter to J1 (VOUT) and the negative terminal to J3 (GND). Rev. 0 | Page 3 of 12 V IN × I IN UG-189 Evaluation Board User Guide Measuring Output Voltage Ripple Output Voltage Change To observe the output voltage ripple, place an oscilloscope probe across the output capacitor (C3) with the probe ground lead placed at the negative (−) capacitor terminal and the probe tip placed at the positive (+) capacitor terminal. Set the oscilloscope to ac, 10 mV/division, 2 μs/division time base, and 20 MHz bandwidth. The ADP2302/ADP2303 evaluation board output is preset to 3.3 V; however, the output voltage can be adjusted using the following equation: R5 + R3 ⎞ VOUT = 0.8 V × ⎛⎜ ⎟ ⎝ R5 ⎠ 09315-002 A standard oscilloscope probe has a long wire ground clip. For high frequency measurements, this ground clip picks up high frequency noise and injects it into the measured output ripple. Figure 2 shows an easy way to measure the output ripple properly. It requires removing the oscilloscope probe sheath and wrapping a nonshielded wire around the oscilloscope probe. By keeping the ground length of the oscilloscope probe as short as possible, true ripple can be measured. Figure 2. Measuring Output Voltage Ripple Rev. 0 | Page 4 of 12 Evaluation Board User Guide UG-189 100 100 90 90 80 80 70 60 VOUT = 5.0V VOUT = 3.3V VOUT = 2.5V VOUT = 1.8V VOUT = 1.5V INDUCTOR: VLF10040T-6R8N4R5 DIODE: SSB43L 0 0.5 1.0 1.5 2.0 IOUT (A) INDUCTOR: VLF10040T-4R7N5R4 DIODE: SSB43L 40 0 0.20 0.20 0.15 0.15 0.10 0.10 LINE REGULATION (%) 1.5 2.0 2.5 3.0 0 –0.05 –0.10 –0.15 0.05 0 –0.05 –0.10 –0.15 8 11 14 17 20 VIN (V) –0.20 09315-004 5 8 11 14 17 20 VIN (V) Figure 4. ADP2302 Line Regulation, VOUT = 3.3 V, IOUT = 2 A Figure 7. ADP2303 Line Regulation, VOUT = 3.3 V, IOUT = 3 A 0.20 0.15 0.15 0.10 0.10 LOAD REGULATION (%) 0.20 0.05 0 –0.05 –0.10 0.05 0 –0.05 –0.10 –0.15 0 0.5 1.0 1.5 IOUT (A) 2.0 09315-005 –0.15 –0.20 5 09315-007 LINE REGULATION (%) 1.0 Figure 6. ADP2303 Efficiency, VIN = 12 V 0.05 LOAD REGULATION (%) 0.5 IOUT (A) Figure 3. ADP2302 Efficiency, VIN = 12 V –0.20 VOUT = 5.0V VOUT = 3.3V VOUT = 2.5V VOUT = 1.8V VOUT = 1.5V Figure 5. ADP2302 Load Regulation, VOUT = 3.3 V, VIN = 12 V –0.20 0 0.5 1.0 1.5 IOUT (A) 2.0 2.5 Figure 8. ADP2303 Load Regulation, VOUT = 3.3 V, VIN = 12 V Rev. 0 | Page 5 of 12 3.0 09315-008 40 60 50 09315-003 50 70 09315-006 EFFICIENCY (%) EFFICIENCY (%) TYPICAL PERFORMANCE CHARACTERISTICS UG-189 Evaluation Board User Guide 1 1 4 4 3 2 B W CH2 5V CH4 2A Ω M1µs T 30% A CH2 7.5V CH1 2V BW CH3 10V BW Figure 9. Continuous Conduction Mode (CCM) CH2 10V CH4 2A Ω M1ms T 20.2% A CH3 3.6V 09315-012 CH1 5mV 09315-009 2 Figure 12. Soft Start with Full Load 1 1 4 4 B W CH2 5V CH4 2A Ω M1µs T 30% A CH2 7.5V Figure 10. Discontinuous Conduction Mode (DCM) CH1 200mV B W CH4 2A Ω M200 µs T 20% A CH4 1.88A 09315-013 CH1 5mV 09315-010 2 Figure 13. ADP2303 Load Transient, 0.5 A to 3.0 A, VOUT = 3.3 V, VIN = 12 V, L = 4.7 μH, COUT = 2 × 47 μF 1 1 4 3 B W CH2 5V CH4 2A Ω M200µs T 30% A CH2 7.5V 09315-011 CH1 50mV CH1 20mV CH3 5V Figure 11. Power Saving Mode B W B W CH2 10V B W M1ms T 23.4% A CH3 11V 09315-014 2 2 Figure 14. ADP2303 Line Transient, 7 V to 15 V, VOUT = 3.3 V, IOUT = 3 A, L = 4.7 μH, COUT = 2 × 47 μF Rev. 0 | Page 6 of 12 80 180 64 144 64 144 48 108 48 108 32 72 32 72 16 36 16 36 0 0 0 0 –36 –32 –72 –48 –108 –64 –80 1k 1 10k 100k FREQUENCY (Hz) 2 1M PHASE [B/A] (Degrees) –16 –16 –36 –32 –72 –48 –108 –144 –64 –144 –180 –80 1k Figure 15. ADP2302 Bode Plot, VOUT = 3.3 V, VIN = 12 V, L = 6.8 μH, COUT = 2 × 22 μF 1 10k 100k FREQUENCY (Hz) –180 2 1M Figure 16. ADP2303 Bode Plot, VOUT = 3.3 V, VIN = 12 V L = 4.7 μH, COUT = 2 × 47 μF Rev. 0 | Page 7 of 12 09315-016 180 MAGNITUDE [B/A] (dB) 80 PHASE [B/A] (Degrees) UG-189 09315-015 MAGNITUDE [B/A] (dB) Evaluation Board User Guide UG-189 Evaluation Board User Guide DEMONSTRATION BOARD SCHEMATICS AND BILL OF MATERIALS ADP2302 SCHEMATIC AND BILL OF MATERIALS 1 C1 0.1µF 25V U1 1 J2 2 2 1 VIN C5 10µF 25V J4 2 1 3 4 BST SW VIN GND EN NC PGOOD EPAD 9 FB ADP2302 J7 SW L1 6.8µH 8 1 2 J1 VOUT 7 D1 SSB43L 30V, 4A 6 C2 22µF NP C3 22µF 6.3V C4 22µF 6.3V 5 1 J3 2 GND GND J5 1 2 3 EN R2 10kΩ 1% R3 31.6kΩ 1% R4 1.8kΩ 1% R5 10.2kΩ 1% J8 2 1 R1 100kΩ 1% J6 09315-017 PWG 1 PWG Figure 17. Evaluation Board Schematic for ADP2302 Table 1. Bill of Materials for ADP2302 Evaluation Board Qty 1 1 1 1 1 1 1 Reference Designator C1 C2 C3 C4 C5 D1 L1 Part Number GRM188R71E104KA01 Optional GRM31CR60J226KE19 GRM31CR60J226KE19 GRM31CR61E106KA12 SSB43L VLF10040-6R8N5R4 Type Capacitor Capacitor Capacitor Capacitor Capacitor Diode Inductor 1 1 1 1 1 1 R1 R2 R3 R4 R5 U1 CRCW0603100KFKEA CRCW060310K0FKEA CRCW060331K6FKEA CRCW06031K80FKEA CRCW060310K2FKEA ADP2302 Resistor Resistor Resistor Resistor Resistor IC 2 J6, J7 M20-9990245 Test point 5 J1, J2, J3, J4, J8 M20-9990245 Connector 1 J5 M20-9990346 Jumper Description 0.1 μF, 25 V Optional 22 μF, 6.3 V 22 μF, 6.3 V 10 μF, 25 V 30 V, 4 A L = 6.8 μH, IRAT = 4.6 A, DCR = 19.8 mΩ 100 kΩ, 1% 10 kΩ, 1% 31.6 kΩ, 1% 1.8 kΩ, 1% 10.2 kΩ, 1% 2 A, 700 kHz nonsynchronous step-down dc-dc switching regulator 2.54 mm pitch SIL vertical PC tail pin header, 6.1 mm mating pin height, tin 2.54 mm pitch SIL vertical PC tail pin header, 6.1 mm mating pin height, tin, 2-way 0.1-inch header, 3-way Rev. 0 | Page 8 of 12 PCB Footprint C0603 C1206 C1206 C1206 C1206 SMB_SD DS104LC Vendor Murata Murata Murata Murata Murata Vishay Dale TDK R0603 R0603 R0603 R0603 R0603 8-lead, SOIC with exposed paddle Vishay Dale Vishay Dale Vishay Dale Vishay Dale Vishay Dale Analog Devices SIP1 Harwin SIP2 Harwin SIP3 Harwin Evaluation Board User Guide UG-189 ADP2303 SCHEMATIC AND BILL OF MATERIALS 1 C1 0.1µF 25V U1 1 J2 2 2 1 3 VIN C5 10µF 25V J4 2 1 4 BST SW VIN GND ADP2303 EN NC PGOOD EPAD 9 FB J7 SW L1 4.7µH 8 1 2 J1 VOUT 7 D1 SSB43L 30V, 4A 6 C2 47µF NP C3 47µF 6.3V C4 47µF 6.3V 5 1 J3 2 GND GND J5 1 2 3 EN R2 10kΩ 1% R3 31.6kΩ 1% R4 1.8kΩ 1% R5 10.2kΩ 1% J8 2 1 R1 100kΩ 1% J6 09315-018 PWG 1 PWG Figure 18. Evaluation Board Schematic for ADP2303 Table 2. Bill of Materials for ADP2303 Evaluation Board Qty 1 1 1 1 1 1 1 Reference Designator C1 C2 C3 C4 C5 D1 L1 Part Number GRM188R71E104KA01 Optional GRM32ER60J476ME20 GRM32ER60J476ME20 GRM31CR61E106KA12 SSB43L VLF10040-4R7N5R4 Type Capacitor Capacitor Capacitor Capacitor Capacitor Diode Inductor 1 1 1 1 1 1 R1 R2 R3 R4 R5 U1 CRCW0603100KFKEA CRCW060310K0FKEA CRCW060331K6FKEA CRCW06031K80FKEA CRCW060310K2FKEA ADP2303 Resistor Resistor Resistor Resistor Resistor IC 2 J6, J7 M20-9990245 Test point 5 J1, J2, J3, J4, J8 M20-9990245 Connector 1 J5 M20-9990346 Jumper Description 0.1 μF, 25 V Optional 47 μF, 6.3 V 47 μF, 6.3 V 10 μF, 25 V 30 V, 4 A L = 4.7 μH, IRAT = 5.4 A, DCR = 12.7 mΩ 100 kΩ, 1% 10 kΩ, 1% 31.6 kΩ, 1% 1.8 kΩ, 1% 10.2 kΩ, 1% 3 A, 700 kHz nonsynchronous step-down dc-dc switching regulator 2.54 mm pitch SIL vertical PC tail pin header, 6.1 mm mating pin height, tin 2.54 mm pitch SIL vertical PC tail pin header, 6.1 mm mating pin height, tin, 2-way 0.1-inch header, 3-way Rev. 0 | Page 9 of 12 PCB Footprint C0603 C1210 C1210 C1210 C1206 SMB_SD DS104LC Vendor Murata Murata Murata Murata Murata Vishay Dale TDK R0603 R0603 R0603 R0603 R0603 8-lead, SOIC with exposed paddle Vishay Dale Vishay Dale Vishay Dale Vishay Dale Vishay Dale Analog Devices SIP1 Harwin SIP2 Harwin SIP3 Harwin UG-189 Evaluation Board User Guide Figure 20. Demonstration Board Layer 2, Ground Plane 09315-022 Figure 21. Demonstration Board Layer3, Power Plane 09315-020 Figure 19. Demonstration Board Layer1, Component Side 09315-021 09315-019 DEMONSTRATION BOARD LAYOUT Figure 22. Demonstration Board Layer 4, Bottom Side Rev. 0 | Page 10 of 12 Evaluation Board User Guide UG-189 NOTES Rev. 0 | Page 11 of 12 UG-189 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. ©2010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. UG09315-0-8/10(0) Rev. 0 | Page 12 of 12