{"id":2523,"date":"2026-05-22T03:29:18","date_gmt":"2026-05-22T03:29:18","guid":{"rendered":"https:\/\/materialparts.com\/ucc28740dr\/"},"modified":"2026-05-22T03:29:18","modified_gmt":"2026-05-22T03:29:18","slug":"ucc28740dr","status":"publish","type":"post","link":"https:\/\/materialparts.com\/ar\/ucc28740dr\/","title":{"rendered":"UCC28740DR"},"content":{"rendered":"

\u0646\u0638\u0631\u0629 \u0639\u0627\u0645\u0629 \u0639\u0644\u0649 \u0627\u0644\u0645\u0646\u062a\u062c<\/h2>\n

The UCC28740DR from Texas Instruments is a constant-voltage, constant-current (CVCC) flyback controller using optocoupled feedback for secondary-side voltage regulation and primary-side regulation (PSR) for constant current. It features a 700V startup switch, valley-switching operation, and less than 10mW no-load power consumption in an SOIC-7 package.<\/p>\n

\u0627\u0644\u0645\u0648\u0627\u0635\u0641\u0627\u062a \u0627\u0644\u0631\u0626\u064a\u0633\u064a\u0629<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n\n
\u0627\u0644\u0637\u0648\u0628\u0648\u0644\u0648\u062c\u064a\u0627<\/td>\nFlyback (isolated)<\/td>\n<\/tr>\n
\u0648\u0636\u0639 \u0627\u0644\u062a\u062d\u0643\u0645<\/td>\nSecondary-side regulation (CV), PSR (CC)<\/td>\n<\/tr>\n
Startup Switch Voltage<\/td>\n700V<\/td>\n<\/tr>\n
\u062a\u0631\u062f\u062f \u0627\u0644\u062a\u062d\u0648\u064a\u0644<\/td>\n170Hz to 100kHz<\/td>\n<\/tr>\n
Max Duty Cycle<\/td>\n99%<\/td>\n<\/tr>\n
Bias Voltage Range<\/td>\n8.1V to 35V<\/td>\n<\/tr>\n
No-Load Power<\/td>\n<10mW<\/td>\n<\/tr>\n
Voltage Regulation<\/td>\n+\/-1%<\/td>\n<\/tr>\n
Current Regulation<\/td>\n+\/-5%<\/td>\n<\/tr>\n
\u062f\u0631\u062c\u0629 \u062d\u0631\u0627\u0631\u0629 \u0627\u0644\u062a\u0634\u063a\u064a\u0644<\/td>\n-40C to +125C<\/td>\n<\/tr>\n
\u0627\u0644\u062d\u0632\u0645\u0629<\/td>\nSOIC-7<\/td>\n<\/tr>\n<\/table>\n

\u0627\u0644\u0645\u064a\u0632\u0627\u062a<\/h2>\n
    \n
  • 700V internal startup switch<\/li>\n
  • Optocoupled feedback for CV, PSR for CC regulation<\/li>\n
  • Less than 10mW no-load power<\/li>\n
  • +\/-1% voltage regulation, +\/-5% current regulation<\/li>\n
  • Valley-switching for highest efficiency<\/li>\n
  • Frequency dithering for EMI compliance<\/li>\n
  • Clamped gate-drive output for MOSFET<\/li>\n
  • Overvoltage, low-line, and overcurrent protection<\/li>\n<\/ul>\n

    \u0627\u0644\u062a\u0637\u0628\u064a\u0642\u0627\u062a<\/h2>\n
      \n
    • USB charger and adapter power supplies<\/li>\n
    • Industrial AC-DC power supplies<\/li>\n
    • EV service equipment chargers<\/li>\n
    • Set-top box and networking power<\/li>\n
    • Appliance power supplies<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The UCC28740DR from Texas Instruments is a constant-voltage, constant-current (CVCC) flyback controller using optocoupled feedback for secondary-side voltage regulation and primary-side regulation (PSR) for constant current. It features a 700V startup switch, valley-switching operation, and less than 10mW no-load power consumption in an SOIC-7 package. Key Specifications Topology Flyback (isolated) Control Mode Secondary-side […]<\/p>\n","protected":false},"author":2,"featured_media":2586,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[13,29],"tags":[],"chip_brand":[138],"class_list":["post-2523","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-integrated-circuits-ics","category-power-management-ics-pmic","chip_brand-ti"],"acf":{"brief_explanation":"CVCC Flyback Controller, 700V startup, opto feedback, <10mW no-load, SOIC-7","date_code":"","package_case":"SOIC-7 (4.9 x 3.9 x 1.75 mm)","in_stock":4840,"datasheet":"https:\/\/www.ti.com\/product\/UCC28740","price":"$0.66 @ 1ku","product_introduction":"The UCC28740DR from Texas Instruments is a constant-voltage, constant-current flyback controller designed for isolated power supply applications. It combines optocoupled secondary-side regulation for precise voltage control (+\/-1%) with primary-side regulation for current control (+\/-5%). The internal 700V startup switch and dynamically controlled operating states support less than 10mW no-load power. Valley-switching and frequency dithering optimize efficiency and EMI performance. The SOIC-7 package enables compact charger and adapter designs.","working_principle":"The UCC28740DR implements a quasi-resonant flyback control scheme. The 700V startup switch charges the VDD capacitor from the rectified AC input. Once VDD reaches the run threshold, the controller begins switching the external MOSFET. Constant-voltage regulation uses an optocoupler feedback path where the FB pin current determines switching frequency and peak primary current. Constant-current regulation uses primary-side sensing through the VS pin, which monitors the auxiliary winding voltage during the flyback period. Valley-switching detects the MOSFET drain voltage resonant ring and turns on at the voltage minimum to reduce switching losses. Frequency dithering spreads the switching harmonic spectrum for easier EMI compliance.","pin_description":"
      Pin<\/th>Name<\/th>Type<\/th>Function<\/th><\/tr>
      1<\/td>VDD<\/td>Power<\/td>Bias supply input (8.1-35V)<\/td><\/tr>
      2<\/td>VS<\/td>Input<\/td>Voltage sense from auxiliary winding<\/td><\/tr>
      3<\/td>FB<\/td>Input<\/td>Feedback input from optocoupler<\/td><\/tr>
      4<\/td>CS<\/td>Input<\/td>Current sense input from sense resistor<\/td><\/tr>
      5<\/td>DRV<\/td>Output<\/td>Gate drive output for MOSFET<\/td><\/tr>
      6<\/td>GND<\/td>Power<\/td>Ground<\/td><\/tr>
      7<\/td>HV<\/td>Input<\/td>High-voltage startup input (up to 700V)<\/td><\/tr><\/table>","application_scenarios":"
      • USB Type-C and PD charger power supplies<\/li>
      • Industrial limited power source AC-DC converters<\/li>
      • EV service equipment (Level 1 and 2 charger) power<\/li>
      • Set-top box and networking equipment power<\/li>
      • Appliance and white goods auxiliary power<\/li><\/ul>","alternative_models":"
        Manufacturer<\/th>Part Number<\/th>Package<\/th>Notes<\/th><\/tr>
        Texas Instruments<\/td>UCC28700DR<\/td>SOIC-7<\/td>PSR-only version (no opto)<\/td><\/tr>
        Texas Instruments<\/td>UCC28740QDRQ1<\/td>SOIC-7<\/td>Automotive AEC-Q100 qualified<\/td><\/tr>
        Power Integrations<\/td>INN3679C-H603<\/td>InSOP-24<\/td>Integrated MOSFET CVCC flyback<\/td><\/tr>
        onsemi<\/td>NCP1342AMDCD1AAG<\/td>TSOP-6<\/td>QR flyback controller<\/td><\/tr><\/table>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/posts\/2523","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/comments?post=2523"}],"version-history":[{"count":0,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/posts\/2523\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/media\/2586"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/media?parent=2523"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/categories?post=2523"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/tags?post=2523"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/chip_brand?post=2523"}],"curies":[{"name":"\u062f\u0628\u0644\u064a\u0648 \u0628\u064a","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}