overview

1. Purpose

<p class="MsoNormal">The RT2855BH is an Advanced Constant On-Time (ACOT™) control architecture step-down converter with the input voltage range from 4.5V to 18V and provides 4A output current. This document explains the function and use of the RT2855BH evaluation board (EVB), and provides information to enable operation, modification of the evaluation board and circuit to suit individual requirements.</p>

2. Introduction

<h3>General Product Information</h3> <p class="bady">The RT2855BH is a high-performance 650kHz 4A step-down regulator with internal power switches and synchronous rectifiers. It features quick transient response using its Advanced Constant On-Time (ACOT™) control architecture that provides stable operation with small ceramic output capacitors and without complicated external compensation, among other benefits. The input voltage range is from 4.5V to 18V and the output is adjustable from 0.765V to 7V.</p>

3. Product Feature

<ul> <li> Fast Transient Response </li> <li> Steady 650kHz Switching Frequency at all Load </li> <li> 4A Output Current </li> <li> Advanced Constant On-Time (ACOT™) Control </li> <li> Optimized for Ceramic Output Capacitors </li> <li> 4.5V to 18V Input Voltage Range </li> <li> Internal 70mΩ Switch and 30mΩ Synchronous Rectifier </li> <li> 0.765V to 7V Adjustable Output Voltage </li> <li> Externally-adjustable, Pre-biased Compatible Soft-Start </li> <li> Cycle-by-Cycle Current Limit </li> <li> Optional Output Discharge Function </li> <li> Output Over- and Under-voltage Shut-down in Hiccup Mode </li> <li> Input Under Voltage Lockout </li> <li> Thermal Shutdown </li> </ul>

4. Key Performance Summary Table

<div> <table width="680" class="MsoTableLightListAccent2" style="border: currentColor; width: 510.2pt; border-collapse: collapse;" border="1" cellspacing="0" cellpadding="0"> <tbody> <tr style="height: 17pt;"> <td style="background: #009eb8; padding: 0cm 5.4pt; border: 1pt solid #009eb8; width: 34.94%; height: 17pt;"> <p class="ListParagraph1CxSpFirst">Key Features</p> </td> <td style="background: #009eb8; border-width: 1pt 1pt 1pt medium; border-style: solid solid solid none; border-color: #009eb8 #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 65.06%; height: 17pt;"> <p class="ListParagraph1CxSpLast">Evaluation Board Number : PCB023_V1</p> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 34.94%; height: 17pt;"> <p class="ListParagraph1CxSpFirst">Default Input Voltage</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 65.06%; height: 17pt;"> <p class="ListParagraph1CxSpLast">12V</p> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 34.94%; height: 17pt;"> <p class="ListParagraph1CxSpFirst">Max Output Current</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 65.06%; height: 17pt;"> <p class="ListParagraph1CxSpLast">4A</p> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 34.94%; height: 17pt;"> <p class="ListParagraph1CxSpFirst">Default Output Voltage</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 65.06%; height: 17pt;"> <p class="ListParagraph1CxSpLast">1.05V</p> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 34.94%; height: 17pt;"> <p class="ListParagraph1CxSpFirst">Default Marking & Package Type</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 65.06%; height: 17pt;"> <p class="ListParagraph1CxSpLast">RT2855BHGQW, WQFN-16 3x3</p> </td> </tr> </tbody> </table> </div>

5. Bench Test Setup Conditions

<h3>Headers Description and Placement </h3> <p class="MsoNormal"><a href="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2855bhgqw/html-images/image001_en.jpg" class="fancybox"><img width="416" height="298" width="416" height="298" id="圖片 1" alt="Technical Document Image Preview" src="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2855bhgqw/html-images/image001_en.jpg" /></a></p> <p class="2">Please carefully inspect the EVB IC and external components, comparing them to the following Bill of Materials, to ensure that all components are installed and undamaged. If any components are missing or damaged during transportation, please contact the distributor or send e-mail to <a href="mailto:evb_service@richtek.com" class="link">evb_service@richtek.com</a></p>

6. Test Points

<p class="MsoNormal">The EVB is provided with the test points and pin names listed in the table below.</p> <div> <table width="680" class="MsoTableLightListAccent2" style="border: currentColor; width: 510.2pt; border-collapse: collapse;" border="1" cellspacing="0" cellpadding="0"> <tbody> <tr style="height: 1cm;"> <td style="background: #009eb8; padding: 0cm 5.4pt; border: 1pt solid #009eb8; width: 13.9%; height: 1cm;"> <p class="23CxSpFirst">Test point/</p> <p class="23CxSpMiddle">Pin name</p> </td> <td style="background: #009eb8; border-width: 1pt 1pt 1pt medium; border-style: solid solid solid none; border-color: #009eb8 #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 23.7%; height: 1cm;"> <p class="23CxSpMiddle">Signal</p> </td> <td style="background: #009eb8; border-width: 1pt 1pt 1pt medium; border-style: solid solid solid none; border-color: #009eb8 #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 62.4%; height: 1cm;"> <p class="23CxSpLast">Comment (expected waveforms or voltage levels on test points)</p> </td> </tr> <tr style="height: 1cm;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 13.9%; height: 1cm;"> <p class="ListParagraph1CxSpFirst">VIN</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 23.7%; height: 1cm;"> <p class="ListParagraph1CxSpLast">Input voltage</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 62.4%; height: 1cm;"> <p class="MsoNormal">Power input. Support 4.5V to18V Input Voltage. Must bypass with a suitable large ceramic capacitor at this pin.</p> </td> </tr> <tr style="height: 1cm;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 13.9%; height: 1cm;"> <p class="ListParagraph1">EN</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 23.7%; height: 1cm;"> <p class="MsoNormal">Enable test point</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 62.4%; height: 1cm;"> <p class="MsoNormal">A logic-high enables the converter; a logic-low forces the IC into shutdown mode reducing the supply current to less than 10µA.</p> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 13.9%; height: 17pt;"> <p class="ListParagraph1CxSpFirst">GND</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 23.7%; height: 17pt;"> <p class="ListParagraph1CxSpMiddle">Ground</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 62.4%; height: 17pt;"> <p class="ListParagraph1CxSpLast">Ground.</p> </td> </tr> <tr style="height: 39.7pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 13.9%; height: 39.7pt;"> <p class="ListParagraph1">VCC</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 23.7%; height: 39.7pt;"> <p class="MsoNormal">Internal regulator output</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 62.4%; height: 39.7pt;"> <p class="MsoNormal">VCC supplies power for the internal linear regulator that powers the IC. Connect VIN to the input voltage and bypass to ground with a 0.1µF ceramic capacitor.</p> </td> </tr> <tr style="height: 1cm;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 13.9%; height: 1cm;"> <p class="ListParagraph1">BOOT</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 23.7%; height: 1cm;"> <p class="MsoNormal">Bootstrap supply test point</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 62.4%; height: 1cm;"> <p class="MsoNormal">Bootstrap supply for high-side gate driver. Connect a 0.1µF capacitor</p> <p class="MsoNormal">between BOOT and SW to power the internal gate driver.</p> </td> </tr> <tr style="height: 51pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 13.9%; height: 51pt;"> <p class="ListParagraph1">SW</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 23.7%; height: 51pt;"> <p class="MsoNormal">Switch node test point</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 62.4%; height: 51pt;"> <p class="MsoNormal">SW is the source of the internal N-channel MOSFET switchand the drain of the internal N-channel MOSFET synchronous rectifier. Connect SW to the inductor with a wide short PCB trace and minimize its area to reduce EMI.</p> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 13.9%; height: 17pt;"> <p class="ListParagraph1">VREG5</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 23.7%; height: 17pt;"> <p class="MsoNormal">Internal regulator </p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 62.4%; height: 17pt;"> <p class="MsoNormal">Connect a 1µF capacitor to GND to stabilize output voltage.</p> </td> </tr> <tr style="height: 1cm;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 13.9%; height: 1cm;"> <p class="ListParagraph1">SS</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 23.7%; height: 1cm;"> <p class="MsoNormal">Soft-start control</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 62.4%; height: 1cm;"> <p class="MsoNormal">Connect an external capacitor between this pin and GND to set the soft-start time.</p> </td> </tr> <tr style="height: 1cm;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 13.9%; height: 1cm;"> <p class="ListParagraph1">PG</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 23.7%; height: 1cm;"> <p class="MsoNormal">Open drain power good output</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 62.4%; height: 1cm;"> <p class="MsoNormal">PGOOD connects to PGND whenever V_FB is less than 90% of its regulation threshold (typical).</p> </td> </tr> </tbody> </table> </div>

7. Power-up & Measurement Procedure

<p class="MsoListParagraph">1. Apply a 12V nominal input power supply (4.5V < V_IN < 18V) to the VIN and GND terminals.</p> <p class="MsoListParagraph">2. Connect JP1 to connect VIN to VCC. Set the jumper at JP2 to connect terminals 2 and 3, connecting EN to VCC to enable operation.</p> <p class="MsoListParagraph">3. Verify the output voltage (approximately 1.05V) between VOUT and GND.</p> <p class="MsoListParagraph">4. Connect an external load up to 4A to the VOUT and GND terminals and verify the output voltage and current.</p>

8. Output Voltage Setting

<p class="MsoNormal">Set the output voltage with the resistive divider (R2, R3) between VOUT and GND with the midpoint connected to FB. The output is set by the following formula :</p> <p class="MsoNormal"><a href="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2855bhgqw/html-images/image003_en.png" class="fancybox"><img width="153" height="37" width="153" height="37" style="border-width: 0px; border-style: solid;" alt="Technical Document Image Preview" src="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2855bhgqw/html-images/image003_en.png" /></a></p>

9. Schematic, Bill of Materials & Board Layout

<h3>EVB Schematic Diagram</h3> <p class="MsoNormal"><a href="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2855bhgqw/html-images/image004_en.jpg" class="fancybox"><img width="662" height="351" width="662" height="351" id="圖片 7" style="border-width: 0px; border-style: solid;" alt="Technical Document Image Preview" src="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2855bhgqw/html-images/image004_en.jpg" /></a></p>

10. Bill of Materials

<div> <table width="680" class="MsoTableLightListAccent2" style="border: currentColor; border-collapse: collapse;" border="1" cellspacing="0" cellpadding="0"> <tbody> <tr style="height: 17pt;"> <td style="background: #009eb8; padding: 0cm 5.4pt; border: 1pt solid #009eb8; width: 16.66%; height: 17pt;"> <p class="MsoNormal">Reference</p> </td> <td style="background: #009eb8; border-width: 1pt 1pt 1pt medium; border-style: solid solid solid none; border-color: #009eb8 #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 5.56%; height: 17pt;"> <p class="MsoNormal">Qty</p> </td> <td style="background: #009eb8; border-width: 1pt 1pt 1pt medium; border-style: solid solid solid none; border-color: #009eb8 #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 26.4%; height: 17pt;"> <p class="MsoNormal">Part Number</p> </td> <td style="background: #009eb8; border-width: 1pt 1pt 1pt medium; border-style: solid solid solid none; border-color: #009eb8 #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 22.26%; height: 17pt;"> <p class="MsoNormal">Description</p> </td> <td style="background: #009eb8; border-width: 1pt 1pt 1pt medium; border-style: solid solid solid none; border-color: #009eb8 #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 15.28%; height: 17pt;"> <p class="MsoNormal">Package</p> </td> <td style="background: #009eb8; border-width: 1pt 1pt 1pt medium; border-style: solid solid solid none; border-color: #009eb8 #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 13.84%; height: 17pt;"> <p class="MsoNormal">Manufacture</p> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 16.66%; height: 17pt;"> <p class="MsoNormal">U4</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 5.56%; height: 17pt;"> <p class="MsoNormal">1</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 26.4%; height: 17pt;"> <p class="MsoNormal">RT2855BHGQW</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 22.26%; height: 17pt;"> <p class="MsoNormal">DC/DC Converter</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 15.28%; height: 17pt;"> <p class="MsoNormal">WQFN-16 3x3</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 13.84%; height: 17pt;"> <p class="MsoNormal">RICHTEK</p> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 16.66%; height: 17pt;"> <p class="MsoNormal">C1</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 5.56%; height: 17pt;"> <p class="MsoNormal">1</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 26.4%; height: 17pt;"> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 22.26%; height: 17pt;"> <p class="MsoNormal">NC</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 15.28%; height: 17pt;"> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 13.84%; height: 17pt;"> </td> </tr> <tr style="height: 1cm;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 16.66%; height: 1cm;"> <p class="MsoNormal">C2, C5, C6, C8, C12</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 5.56%; height: 1cm;"> <p class="MsoNormal">5</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 26.4%; height: 1cm;"> <p class="MsoNormal">C1608X7R1H104K080AA</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 22.26%; height: 1cm;"> <p class="MsoNormal">0.1μF/±10%/50V/X7R</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 15.28%; height: 1cm;"> <p class="MsoNormal">C-0603</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 13.84%; height: 1cm;"> <p class="MsoNormal">TDK</p> </td> </tr> <tr style="height: 1cm;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 16.66%; height: 1cm;"> <p class="MsoNormal">C3, C4</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 5.56%; height: 1cm;"> <p class="MsoNormal">2</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 26.4%; height: 1cm;"> <p class="MsoNormal">UMK325BJ106MM</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 22.26%; height: 1cm;"> <p class="MsoNormal">10µF/50V/X7R</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 15.28%; height: 1cm;"> <p class="MsoNormal">C-1210</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 13.84%; height: 1cm;"> <p class="MsoNormal">TAIYO YUDEN</p> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 16.66%; height: 17pt;"> <p class="MsoNormal">C7</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 5.56%; height: 17pt;"> <p class="MsoNormal">1</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 26.4%; height: 17pt;"> <p class="MsoNormal">0603B332K500</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 22.26%; height: 17pt;"> <p class="MsoNormal">3.3nF/50V/X7R</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 15.28%; height: 17pt;"> <p class="MsoNormal">C-0603</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 13.84%; height: 17pt;"> <p class="MsoNormal">WALSIN</p> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 16.66%; height: 17pt;"> <p class="MsoNormal">C9</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 5.56%; height: 17pt;"> <p class="MsoNormal">1</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 26.4%; height: 17pt;"> <p class="MsoNormal">C3225X5R1E226MT</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 22.26%; height: 17pt;"> <p class="MsoNormal">22µF/25V/X5R</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 15.28%; height: 17pt;"> <p class="MsoNormal">C-1210</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 13.84%; height: 17pt;"> <p class="MsoNormal">TDK</p> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 16.66%; height: 17pt;"> <p class="MsoNormal">C10</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 5.56%; height: 17pt;"> <p class="MsoNormal">1</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 26.4%; height: 17pt;"> <p class="MsoNormal">C3225X5R1E226MT</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 22.26%; height: 17pt; white-space: nowrap;"> <p class="MsoNormal">22µF/25V/X5R</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 15.28%; height: 17pt;"> <p class="MsoNormal">C-1210</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 13.84%; height: 17pt;"> <p class="MsoNormal">TDK</p> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 16.66%; height: 17pt;"> <p class="MsoNormal">C13</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 5.56%; height: 17pt;"> <p class="MsoNormal">1</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 26.4%; height: 17pt;"> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 22.26%; height: 17pt; white-space: nowrap;"> <p class="MsoNormal">NA</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 15.28%; height: 17pt;"> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 13.84%; height: 17pt;"> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 16.66%; height: 17pt;"> <p class="MsoNormal">C14</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 5.56%; height: 17pt;"> <p class="MsoNormal">1</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 26.4%; height: 17pt;"> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 22.26%; height: 17pt; white-space: nowrap;"> <p class="MsoNormal">NA</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 15.28%; height: 17pt;"> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 13.84%; height: 17pt;"> </td> </tr> <tr style="height: 1cm;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 16.66%; height: 1cm;"> <p class="MsoNormal">L1</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 5.56%; height: 1cm;"> <p class="MsoNormal">1</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 26.4%; height: 1cm;"> <p class="MsoNormal">NR8040T1R4N</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 22.26%; height: 1cm; white-space: nowrap;"> <p class="MsoNormal">1.4µH/7A</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 15.28%; height: 1cm;"> <p class="MsoNormal">8 x 8 x 4.2 mm</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 13.84%; height: 1cm;"> <p class="MsoNormal">TAIYO YUDEN</p> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 16.66%; height: 17pt;"> <p class="MsoNormal">R1</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 5.56%; height: 17pt;"> <p class="MsoNormal">1</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 26.4%; height: 17pt;"> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 22.26%; height: 17pt;"> <p class="MsoNormal">0</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 15.28%; height: 17pt;"> <p class="MsoNormal">R-0603</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 13.84%; height: 17pt;"> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 16.66%; height: 17pt;"> <p class="MsoNormal">R2</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 5.56%; height: 17pt;"> <p class="MsoNormal">1</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 26.4%; height: 17pt;"> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 22.26%; height: 17pt;"> <p class="MsoNormal">8.25k</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 15.28%; height: 17pt;"> <p class="MsoNormal">R-0603</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 13.84%; height: 17pt;"> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 16.66%; height: 17pt;"> <p class="MsoNormal">R3</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 5.56%; height: 17pt;"> <p class="MsoNormal">1</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 26.4%; height: 17pt;"> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 22.26%; height: 17pt;"> <p class="MsoNormal">22.1k</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 15.28%; height: 17pt;"> <p class="MsoNormal">R-0603</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 13.84%; height: 17pt;"> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 16.66%; height: 17pt;"> <p class="MsoNormal">R4, R5</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 5.56%; height: 17pt;"> <p class="MsoNormal">2</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 26.4%; height: 17pt;"> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 22.26%; height: 17pt;"> <p class="MsoNormal">100k</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 15.28%; height: 17pt;"> <p class="MsoNormal">R-0603 </p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 13.84%; height: 17pt;"> </td> </tr> <tr style="height: 17pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 16.66%; height: 17pt;"> <p class="MsoNormal">R6, R7</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 5.56%; height: 17pt;"> <p class="MsoNormal">2</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 26.4%; height: 17pt;"> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 22.26%; height: 17pt;"> <p class="MsoNormal">NA</p> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 15.28%; height: 17pt;"> </td> <td style="border-width: medium 1pt 1pt medium; border-style: none solid solid none; border-color: currentColor #009eb8 #009eb8 currentColor; padding: 0cm 5.4pt; width: 13.84%; height: 17pt;"> </td> </tr> </tbody> </table> </div>

11. PCB Layout

<p class="23CxSpFirst"><a href="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2855bhgqw/html-images/image005_en.jpg" class="fancybox"><img width="492" height="355" width="492" height="355" id="圖片 2" style="border-width: 0px; border-style: solid;" alt="Technical Document Image Preview" src="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2855bhgqw/html-images/image005_en.jpg" /></a></p> <p class="23CxSpLast">Top View (1^st layer)</p> <p class="MsoNormal"><a href="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2855bhgqw/html-images/image006_en.jpg" class="fancybox"><img width="491" height="354" width="491" height="354" id="圖片 5" style="border-width: 0px; border-style: solid;" alt="Technical Document Image Preview" src="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2855bhgqw/html-images/image006_en.jpg" /></a></p> <p class="10">PCB Layout—Inner Side (2^nd Layer)</p> <p class="MsoNormal"><a href="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2855bhgqw/html-images/image007_en.jpg" class="fancybox"><img width="492" height="353" width="492" height="353" id="圖片 3" style="border-width: 0px; border-style: solid;" alt="Technical Document Image Preview" src="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2855bhgqw/html-images/image007_en.jpg" /></a></p> <p class="10">PCB Layout—Inner Side (3^rd Layer)</p> <p class="MsoNormal"><a href="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2855bhgqw/html-images/image008_en.jpg" class="fancybox"><img width="492" height="353" width="492" height="353" id="圖片 6" style="border-width: 0px; border-style: solid;" alt="Technical Document Image Preview" src="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2855bhgqw/html-images/image008_en.jpg" /></a></p> <p class="23">Bottom View (4^th Layer)</p>