overview

1. Purpose

<p class="MsoNormal">The RT2808A is a current mode asynchronous step-down converter that achieves excellent load and line regulation. This document explains the function and use of the RT2808A evaluation board (EVB) and provides information to enable operation and modification of the evaluation board and circuit to suit individual requirements. </p>

2. Introduction

<h3>General Product Description</h3> <p class="bady">The RT2808A is a current mode asynchronous step-down converter that achieves excellent load and line regulation.Over a wide input voltage range from 5.5V to 36V and supports output current up to 3A. The Current mode operation provides fast transient response and eases loop stabilization. An adjustable soft-start reduces the stress on the input source at start up. In shut down mode, the regulator draws only 25μA of supply current. The RT2808A requires a minimum number of readily available external components, providing a compact solution. The RT2808A provides protection functions inducing input under voltage lockout, cycle-by-cycle current limit, short circuit protection and thermal shutdown protection.The RT2808A is available in the SOP-8 (Exposed Pad) package.</p>

3. Product Features

<ul> <li> 3A Output Current </li> <li> Wide Operating Input Range 5.5V to 36V </li> <li> Adjustable Output Voltage from 1.222V to 26V </li> <li> High Efficiency up to 90% </li> <li> Internal Compensation Minimizes External Parts Count </li> <li> Internal Soft-Start </li> <li> 110mΩ Internal Power MOSFET Switch </li> <li> 25μA Shutdown Mode </li> <li> Fixed 500kHz Frequency </li> <li> Thermal Shutdown </li> <li> Cycle-by-Cycle Current Limit </li> <li> Available In an SOP-8 (Exposed Pad) Package </li> <li> RoHS Compliant and Halogen Free </li> </ul>

4. Application

<ul> <li> Distributive Power Systems </li> <li> Battery Charger </li> <li> DSL Modems </li> <li> Pre-regulator for Linear Regulators </li> </ul>

5. 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 : PCB011_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 VIN 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">3A</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">2.5V</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">RT2808AGSP, SOP-8 (Exposed Pad)</p> </td> </tr> </tbody> </table> </div>

6. Bench Test Setup Conditions

<h3>Headers Description and Placement </h3> <p class="MsoNormal"><a href="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2808agsp/html-images/image001_en.jpg" class="fancybox"><img width="416" height="302" width="416" height="302" id="圖片 4" alt="Technical Document Image Preview" src="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2808agsp/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>

7. Test Points

<p class="bady">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: 17pt;"> <td style="background: #009eb8; padding: 0cm 5.4pt; border: 1pt solid #009eb8; width: 19.46%; height: 17pt;"> <p class="10CxSpFirst">Test point/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: 23.62%; height: 17pt;"> <p class="10CxSpMiddle">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: 56.92%; height: 17pt;"> <p class="10CxSpLast">Comment (expected waveforms or voltage levels on test points)</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: 19.46%; height: 17pt;"> <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: 23.62%; height: 17pt;"> <p class="ListParagraph1CxSpMiddle">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: 56.92%; height: 17pt;"> <p class="ListParagraph1CxSpLast">Input voltage range = 5.5V to 36V</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: 19.46%; height: 17pt;"> <p class="ListParagraph1CxSpFirst">Vout</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: 23.62%; height: 17pt;"> <p class="ListParagraph1CxSpMiddle">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: 56.92%; height: 17pt;"> <p class="ListParagraph1CxSpLast">Output voltage = 2.4V</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: 19.46%; height: 17pt;"> <p class="ListParagraph1CxSpFirst">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: 23.62%; height: 17pt;"> <p class="ListParagraph1CxSpMiddle">Switch Node</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: 56.92%; height: 17pt;"> </td> </tr> <tr style="height: 65.5pt;"> <td style="border-width: medium 1pt 1pt; border-style: none solid solid; border-color: currentColor #009eb8 #009eb8; padding: 0cm 5.4pt; width: 19.46%; height: 65.5pt;"> <p class="ListParagraph1CxSpFirst">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: 23.62%; height: 65.5pt;"> <p class="ListParagraph1CxSpMiddle">Chip Enable Operation</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: 56.92%; height: 65.5pt;"> <p class="ListParagraph1CxSpLast">The EN pin is externally pulled to High by adding a 100kΩ resistor (R4) from the VIN pin in this EVB setting. For another enable operation, the converter is turned on when the EN pin is higher than 1.4V and turned off when the EN pin is lower than 0.4V.</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: 19.46%; height: 1cm;"> <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: 23.62%; height: 1cm;"> <p class="ListParagraph1CxSpLast">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: 56.92%; height: 1cm;"> <p class="MsoNormal">Ground. The exposed pad must be soldered to a large PCB and connected to GND for maximum power dissipation.</p> </td> </tr> </tbody> </table> </div>

8. Power-up & Measurement Procedure

<p class="MsoListParagraph">1. Connect input power (5.5V < V_IN < 36V) and input ground to Vin and GND pins respectively.</p> <p class="MsoListParagraph">2. Connect positive end and negative end of load to Vout and GND of output pins respectively.</p> <p class="MsoListParagraph">3. The output voltage of (V_OUT) can be set by R1 and R2.</p> <p class="MsoListParagraph">V_OUT = V_REF * (1 + R1 / R2)</p> <p class="MsoListParagraph">where V_REF = 1.222V (typ.)</p>

9. Specification

<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: 192.3pt; height: 17pt;"> <p class="TableTitleDS">Parameter</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: 63.6pt; height: 17pt;"> <p class="TableTitleDS">Symbol</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: 63.6pt; height: 17pt;"> <p class="TableTitleDS">Min</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: 63.6pt; height: 17pt;"> <p class="TableTitleDS">Typ.</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: 63.6pt; height: 17pt;"> <p class="TableTitleDS">Max</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: 63.6pt; height: 17pt;"> <p class="TableTitleDS">Units</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: 192.3pt; height: 17pt;"> <p class="Tablebadyright">Input Voltage Range</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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">V_IN</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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">5.5</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: 63.6pt; 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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">36</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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">V</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: 192.3pt; height: 17pt;"> <p class="Tablebadyright">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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">V_OUT</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: 63.6pt; 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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">2.4</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: 63.6pt; 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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">V</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: 192.3pt; height: 17pt;"> <p class="Tablebadyright">Oscillator Frequency</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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">f_OSC</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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">400</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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">500</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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">600</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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">kHz</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: 192.3pt; height: 17pt;"> <p class="Tablebadyright">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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">I_OUT</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: 63.6pt; 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: 63.6pt; 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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">3</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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">A</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: 192.3pt; height: 17pt;"> <p class="Tablebadyright">Current Limit</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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">I_LIM</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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">4</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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">5.25</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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">6.5</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: 63.6pt; height: 17pt;"> <p class="Tablebadycenter">A</p> </td> </tr> </tbody> </table> </div>

10. Schematic, Bill of Materials & Board Layout

<h3>EVB Schematic Diagram</h3> <p class="a5"><a href="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2808agsp/html-images/image002_en.jpg" class="fancybox"><img width="529" height="331" width="529" height="331" id="圖片 8" style="border-width: 0px; border-style: solid;" alt="Technical Document Image Preview" src="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2808agsp/html-images/image002_en.jpg" /></a></p>

11. 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: 78pt; height: 17pt; white-space: nowrap;"> <p class="TableTitleDS">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: 27.8pt; height: 17pt; white-space: nowrap;"> <p class="TableTitleDS">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: 135.55pt; height: 17pt; white-space: nowrap;"> <p class="TableTitleDS">P/N</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: 113.05pt; height: 17pt; white-space: nowrap;"> <p class="TableTitleDS">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: 3cm; height: 17pt; white-space: nowrap;"> <p class="TableTitleDS">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: 70.75pt; height: 17pt; white-space: nowrap;"> <p class="TableTitleDS">Manufacture</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: 78pt; height: 1cm; white-space: nowrap;"> <p class="Tablebadyright">U1</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: 27.8pt; height: 1cm; white-space: nowrap;"> <p class="Tablebadycenter">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: 135.55pt; height: 1cm; white-space: nowrap;"> <p class="Tablebadyright">RT2808AGSP</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: 113.05pt; height: 1cm; white-space: nowrap;"> <p class="Tablebadyright">Step-down 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: 3cm; height: 1cm; white-space: nowrap;"> <p class="Tablebadyright">SOP-8</p> <p class="Tablebadyright">(Exposed Pad)</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: 70.75pt; height: 1cm; white-space: nowrap;"> <p class="Tablebadyright">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: 78pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">C1, C2</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: 27.8pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadycenter">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: 135.55pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">GRM32ER71H475K</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: 113.05pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">4.7μF/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: 3cm; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">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: 70.75pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">MURATA</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: 78pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">C3, C6, C11</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: 27.8pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadycenter">3</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: 135.55pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">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: 113.05pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">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: 3cm; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">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: 70.75pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">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: 78pt; height: 17pt;"> <p class="Tablebadyright">C4, C5</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: 27.8pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadycenter">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: 135.55pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">GRM32ER61C226KE20</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: 113.05pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">22μF/±10%/16V/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: 3cm; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">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: 70.75pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">MURATA</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: 78pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">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: 27.8pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadycenter">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: 135.55pt; height: 17pt; white-space: nowrap;"></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: 113.05pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">82pF</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: 3cm; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">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: 70.75pt; height: 17pt; white-space: nowrap;"></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: 78pt; height: 1cm; white-space: nowrap;"> <p class="Tablebadyright">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: 27.8pt; height: 1cm; white-space: nowrap;"> <p class="Tablebadycenter">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: 135.55pt; height: 1cm; white-space: nowrap;"> <p class="Tablebadyright">NR8040T6R8N</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: 113.05pt; height: 1cm; white-space: nowrap;"> <p class="Tablebadyright">6.8µH</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: 3cm; height: 1cm; white-space: nowrap;"></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: 70.75pt; height: 1cm; white-space: nowrap;"> <p class="Tablebadyright">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: 78pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">D1</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: 27.8pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadycenter">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: 135.55pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">B550C</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: 113.05pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">50V/5A</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: 3cm; height: 17pt; white-space: nowrap;"></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: 70.75pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">DIODES</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: 78pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">R1, R2, R4</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: 27.8pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadycenter">3</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: 135.55pt; height: 17pt; white-space: nowrap;"></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: 113.05pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">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: 3cm; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">R-0402</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: 70.75pt; height: 17pt; white-space: nowrap;"></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: 78pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">C8, 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: 27.8pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadycenter">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: 135.55pt; height: 17pt; white-space: nowrap;"></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: 113.05pt; height: 17pt; white-space: nowrap;"> <p class="Tablebadyright">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: 3cm; height: 17pt; white-space: nowrap;"></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: 70.75pt; height: 17pt; white-space: nowrap;"></td> </tr> </tbody> </table> </div>

12. PCB Layout

<p class="23CxSpFirst"><a href="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2808agsp/html-images/image003_en.jpg" class="fancybox"><img width="491" height="353" width="491" height="353" style="border-width: 0px; border-style: solid;" alt="Technical Document Image Preview" src="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2808agsp/html-images/image003_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_rt2808agsp/html-images/image004_en.jpg" class="fancybox"><img width="491" height="355" width="491" height="355" 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_rt2808agsp/html-images/image004_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_rt2808agsp/html-images/image005_en.jpg" class="fancybox"><img width="492" height="357" width="492" height="357" 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_rt2808agsp/html-images/image005_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_rt2808agsp/html-images/image006_en.jpg" class="fancybox"><img width="491" height="354" width="491" height="354" 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_rt2808agsp/html-images/image006_en.jpg" /></a></p> <p class="23">Bottom View (4^th Layer)</p>

13. Step-Down Converter Efficiency Test

<p class="a5"><a href="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2808agsp/html-images/image007_en.jpg" class="fancybox"><img width="362" height="302" width="362" height="302" id="圖片 1" style="border-width: 0px; border-style: solid;" alt="Technical Document Image Preview" src="/content/dam/richtek-eds/resources/evaluation-boards/evb_rt2808agsp/html-images/image007_en.jpg" /></a></p>