<!-- Bootstrap core CSS --> <link href="/css/www-style.css" rel="stylesheet"> <link href="/css/bootstrap.css" rel="stylesheet"> <link href="/css/newsletter.css" rel="stylesheet"> <link href="/css/alfontawesome-all.css" rel="stylesheet"> <!-- Custom fonts for this template --> <section> <div class="key-container"> <div class="cus-content-subscribe"> <div class="row no-gutters"> <div class=" col-md-12"> <div class="page-header"> <a class="cus-btn btn-sm" href="https://www.richtek.com/My Richtek/Newsletters.aspx"><i class="fas fa-envelope"></i> Subscribe to Richtek Newsletter</a> </div> </div> </div> </div> </div> <div class="key-container pb-5"> <!-- Title start --> <div class="cus-content"> <div class="row no-gutters "> <div class="col-md-12 "> <div class="page-header"> <h1 class="font-weight-bold">Essential for Low-Noise Power: 5 Key Factors for Choosing an Ideal LDO</h1> <i class="far fa-calendar-alt date-i"></i> <span class="ml-2 date">APR. 28, 2025 | Newsletter Issue 51</span> </div> </div> </div> </div> <!-- Content End --> <div class="cus-content"> <div class="row no-gutters "> <div class="col-md-12 mb-20 text-center"> <a href="https://www.richtek.com/Design%20Support/Technical%20Document/AN082?&utm_source=Newsletter&utm_medium=RTWWW&utm_campaign=Issue51EN&sc_lang=en" target="_blank"> <img class="img-center " style="max-width:600px;" alt="5 Key Factors for Choosing an Ideal LDO" src="/content/dam/richtek-eds/resources/tech-insights/news/newsletter-issue-51/html-images/en_I51_01_EN.jpg"></a> </div> <div class="col-md-12 mb-40"> <p>In noise-sensitive applications such as wireless base stations, RF amplifiers, medical devices, and industrial equipment, low-dropout linear regulators (LDOs) are crucial for filtering switching noise and external interference.</p></div> <div class="col-md-12 "> <div class="mb-2"> <div class="section-title font-weight-bold mb-30 pb-3"> Richtek offers a wide range of low-noise industrial-graded LDOs with the following key features:</div> <ol style="line-height:2;"> <li style="list-style-position:outside;"> <b>High Precision, Low Output Voltage</b>：Richtek’s industrial-graded LDOs support an input voltage range from 1.1V to 6.5V, requiring only a single power input without additional power sources, simplifying system design. Some products provide an ultra-low output voltage down to 0.5V with high accuracy of ±1%.</li> <li style="list-style-position:outside;"> <b>Superior Noise Immunity</b>：With high Power Supply Rejection Ratio (PSRR) of approximately 40dB at 500kHz and excellent noise immunity of 6.8 µVRMS, our industrial-graded LDOs effectively reduce noise interference.</li> <li style="list-style-position:outside;"> <b>Ultra-Low Dropout</b>：Ultra-low dropout voltage reduces power consumption. For example, the <a href="https://www.richtek.com/RedirectToProduct?specid=RTQ2540H&utm_source=Newsletter&utm_medium=RTWWW&utm_campaign=Issue51EN&sc_lang=en" target="_blank" style="text-decoration: none; color: #37a6d9;">RTQ2540H</a> achieves a maximum dropout of just 145mV at 4A load, minimizing heat dissipation while improving efficiency, ideal for high-power applications. </li> <li style="list-style-position:outside;"> <b>Compact Packaging for Space-Constraint Designs</b>：Richtek provides some LDOs housed in ultra-small WQFN 2.2mm × 2.5mm packages, optimized for high-density PCB layouts.</li> <li style="list-style-position:outside;"> <b>Flexible Design Options</b>：Some LDOs feature an NR/SS pin for enhanced noise reduction via an external bypass capacitor. Additionally, our easy-out LDO series allows output voltage setting via pin strapping without resistors, ideal for I/O power and GPIO applications.</li> </ol> </div> </div> <div class="col-md-12 "> <p>When selecting a low-noise LDO, key factors such as input/output range, PSRR, dropout voltage, packaging, and functionality must be considered. Richtek’s industrial-graded LDOs ensure reliable and stable power for diverse applications.</p> </div> <div class="col-md-12 mb-20 text-center"> <a href="https://youtu.be/LNk77E9xU7k?&utm_source=Newsletter&utm_medium=RTWWW&utm_campaign=Issue51EN&sc_lang=en" target="_blank"> <img class="img-center " style="max-width:600px;" alt="How to select low noise linear regulators" src="/content/dam/richtek-eds/resources/tech-insights/news/newsletter-issue-51/html-images/en_EDM_video_EN.jpg"></a> </div> <div class="col-md-12 mb-20 text-center"> <p>Please click the link below to get more technical details and Application Note!</p> <div class="btn-block pb-4"> <a href="https://www.richtek.com/Design%20Support/Technical%20Document/AN082?&utm_source=Newsletter&utm_medium=RTWWW&utm_campaign=Issue51EN&sc_lang=en" target="_blank" class="btn-sm btn-primary py-2 px-3">Watch the full AN now! <i class="fas fa-arrow-right pl-2"></i> </a> </div> </div> </div> </div> <div class="cus-content"> <div class="row no-gutters"> <div class="col-md-12 pt-3"> <div class="new-product"> <h3 class="font-weight-bold">FEATURED PRODUCTS</h3> <p>Check out the products that meet your area of interest for more information</p> <p class="font-weight-bold"> ▸ SMALL SIZE WITH EXTREMELY LOW DROPOUT VOLTAGE </p> </div> </div> </div> <div class="row no-gutters"> <div class="col-md-12 text-center"> <table class="table table-hover table-bordered table-sm"> <thead class="thead-dark"> <tr> <th scope="col">Part Number</th> <th scope="col">Iout (A)</th> <th scope="col">Vin (V)</th> <th scope="col">Vout (V)</th> <th scope="col" style="max-width:80px;">RMS Noise (µV<sub>RMS</sub>)</th> <th scope="col" style="max-width:100px;">Typ. PSRR @ 500kHz (dB)</th> <th scope="col" style="max-width:120px;">Max Dropout @ Full load (mV)</th> <th scope="col">Package</th> <th scope="col">Features</th> <th scope="col">Buy</th> </tr> </thead> <tbody> <tr> <th scope="row"><a href="https://www.richtek.com/RedirectToProduct?specid=RTQ2538H&utm_source=Newsletter&utm_medium=RTWWW&utm_campaign=Issue51EN&sc_lang=en" target="_blank" style="text-decoration: none; color: #37a6d9;font-size: 1.1rem;">RTQ2538H</a></th> <td>2</td> <td>1.1~6.5</td> <td>0.8~5.5</td> <td>6.8</td> <td>40</td> <td>90</td> <td>WQFN-12L-2.2x2.5</td> <td>EN, SS, PG</td> <td><a href="https://www.digikey.com/en/products/detail/richtek-usa-inc/RTQ2538HN-TA/22310051?s=N4IgTCBcDaIEoBUCKYCsBmAHACRAXQF8g" target="_blank"><img alt="Buy-on-Line" border="0" src="/content/dam/richtek-eds/resources/tech-insights/news/newsletter-issue-51/html-images/en_ic-cart.png" width="30px;" style="width: 30px;"></a></td> </tr> <tr> <th scope="row"><a href="https://www.richtek.com/RedirectToProduct?specid=RTQ2539A&utm_source=Newsletter&utm_medium=RTWWW&utm_campaign=Issue51EN&sc_lang=en" target="_blank" style="text-decoration: none; color: #37a6d9;font-size: 1.1rem;">RTQ2539A</a></th> <td>3</td> <td>1.1~6.5</td> <td>0.8~5.5</td> <td>6.8</td> <td>40</td> <td>130</td> <td>WQFN-12L-2.2x2.5</td> <td>EN, SS, PG</td> <td><a href="https://www.digikey.com/en/products/detail/richtek-usa-inc/RTQ2539AGQWF/22310058?s=N4IgTCBcDaIEoBUCKYCsBmAnAQRAXQF8g" target="_blank"><img alt="Buy-on-Line" border="0" src="/content/dam/richtek-eds/resources/tech-insights/news/newsletter-issue-51/html-images/en_ic-cart.png" width="30px;" style="width: 30px;"></a></td> </tr> <tr> <th scope="row"><a href="https://www.richtek.com/RedirectToProduct?specid=RTQ2540H&utm_source=Newsletter&utm_medium=RTWWW&utm_campaign=Issue51EN&sc_lang=en" target="_blank" style="text-decoration: none; color: #37a6d9;font-size: 1.1rem;">RTQ2540H</a></th> <td>4</td> <td>1.1~6.5</td> <td>0.8~5.5</td> <td>6.8</td> <td>40</td> <td>145</td> <td>WQFN-12L-2.2x2.5</td> <td>EN, SS, PG</td> <td><a href="https://www.digikey.com/en/products/detail/richtek-usa-inc/RTQ2540HN-TA/22310045?s=N4IgTCBcDaIEoBUCKYCsAWADACRAXQF8g" target="_blank"><img alt="Buy-on-Line" border="0" src="/content/dam/richtek-eds/resources/tech-insights/news/newsletter-issue-51/html-images/en_ic-cart.png" width="30px;" style="width: 30px;"></a></td> </tr> </tbody> </table> </div> </div> <div class="row no-gutters"> <div class="col-md-12 py-3 "> <p class=" font-weight-bold"> ▸ EASY-OUT BY PIN-STRAPPING</p> </div> </div> <div class="row no-gutters"> <div class="col-md-12 text-center"> <table class="table table-hover table-bordered table-sm"> <thead class="thead-dark"> <tr> <th scope="col">Part Number</th> <th scope="col">Iout (A)</th> <th scope="col">Vin (V)</th> <th scope="col">Vout Adj. (V)</th> <th scope="col" style="max-width:120px;">VOUT Range Easy-out (V)</th> <th scope="col" style="max-width:100px;">RMS Noise (µV<sub>RMS</sub>)</th> <th scope="col" style="max-width:120px;">Typ. PSRR @ 500kHz (dB)</th> <th scope="col" style="max-width:120px;">Max Dropout @ Full load (mV)</th> <th scope="col">Package</th> <th scope="col">Features</th> <th scope="col">Buy</th> </tr> </thead> <tbody> <tr> <th scope="row"><a href="https://www.richtek.com/RedirectToProduct?specid=RTQ2532W&utm_source=Newsletter&utm_medium=RTWWW&utm_campaign=Issue51EN&sc_lang=en" target="_blank" style="text-decoration: none; color: #37a6d9;font-size: 1.1rem;">RTQ2532W</a></th> <td>2</td> <td>1.1~6.5</td> <td>0.8~5.5</td> <td>0.8~3.95</td> <td>6.8</td> <td>40</td> <td>125</td> <td>VQFN-20L-5x5</td> <td>EN, SS, PG</td> <td><a href="https://www.digikey.com/en/products/result?s=N4IgTCBcDaIEoBUCKYCsBmMB1EBdAvkA" target="_blank"><img alt="Buy-on-Line" border="0" src="/content/dam/richtek-eds/resources/tech-insights/news/newsletter-issue-51/html-images/en_ic-cart.png" width="30px;" style="width: 30px;"></a></td> </tr> <tr> <th scope="row"><a href="https://www.richtek.com/RedirectToProduct?specid=RTQ2533W&utm_source=Newsletter&utm_medium=RTWWW&utm_campaign=Issue51EN&sc_lang=en" target="_blank" style="text-decoration: none; color: #37a6d9;font-size: 1.1rem;">RTQ2533W</a></th> <td>3</td> <td>1.1~6.5</td> <td>0.8~5.5</td> <td>0.8~3.95</td> <td>6.8</td> <td>40</td> <td>180</td> <td>VQFN-20L-3.5x3.5</td> <td>EN, SS, PG</td> <td><a href="https://www.digikey.com/en/products/result?s=N4IgTCBcDaIEoBUCKYCsBmdB1EBdAvkA" target="_blank"><img alt="Buy-on-Line" border="0" src="/content/dam/richtek-eds/resources/tech-insights/news/newsletter-issue-51/html-images/en_ic-cart.png" width="30px;" style="width: 30px;"></a></td> </tr> <tr> <th scope="row"><a href="https://www.richtek.com/RedirectToProduct?specid=RTQ2537&utm_source=Newsletter&utm_medium=RTWWW&utm_campaign=Issue51EN&sc_lang=en" target="_blank" style="text-decoration: none; color: #37a6d9;font-size: 1.1rem;">RTQ2537</a></th> <td>4</td> <td>1.1~6.5</td> <td>0.8~5.5</td> <td>0.8~3.95</td> <td>6.8</td> <td>40</td> <td>240</td> <td>VQFN-20L-3.5x3.5</td> <td>EN, SS, PG</td> <td><a href="https://www.digikey.com/en/products/detail/richtek-usa-inc/RTQ2537GQV-2/22535333?s=N4IgTCBcDaIEoBUCKYCsBmA7CAugXyA" target="_blank"><img alt="Buy-on-Line" border="0" src="/content/dam/richtek-eds/resources/tech-insights/news/newsletter-issue-51/html-images/en_ic-cart.png" width="30px;" style="width: 30px;"></a></td> </tr> </tbody> </table> </div> </div> <!-- Content End --> <!-- Keywords start --> <div class="tag-content"> <div class="row no-gutters"> <div class="col-md-12 mb-40"> <div class="new-product"> <p>Want to keep up to date with all our latest news and information? <a class="link" href="https://www.richtek.com/My Richtek/Newsletters.aspx" target="_blank">Subscribe here!</a></p> </div> </div> </div> <div class="row no-gutters align-items-start"> <div class="col-12"> <a class="badge btn-tag" href="https://www.richtek.com/applications/industrial?&utm_source=Newsletter&utm_medium=RTWWW&utm_campaign=Issue51EN&sc_lang=en">Industrial</a> <a class="badge btn-tag" href="https://www.richtek.com/Products/Linear%20Regulator?&utm_source=Newsletter&utm_medium=RTWWW&utm_campaign=Issue51EN&sc_lang=en">Linear Regulators</a> <a class="badge btn-tag" href="https://www.richtek.com/applications/communication-enterprise/telecom?&ActiveTab=Small Cell Base Stations&utm_source=Newsletter&utm_medium=RTWWW&utm_campaign=Issue51EN&sc_lang=en">Small Cell Base Stations</a> </div> </div> </div> </div> </div> </section>