{"id":8548,"date":"2026-06-29T05:13:02","date_gmt":"2026-06-29T05:13:02","guid":{"rendered":"https:\/\/materialparts.com\/lm317dcyr\/"},"modified":"2026-06-29T05:13:02","modified_gmt":"2026-06-29T05:13:02","slug":"lm317dcyr","status":"publish","type":"post","link":"https:\/\/materialparts.com\/zh\/lm317dcyr\/","title":{"rendered":"LM317DCYR"},"content":{"rendered":"

\u4ea7\u54c1\u6982\u89c8<\/h2>\n

The LM317DCYR from Texas Instruments is a classic 1.5A adjustable positive voltage linear regulator in a SOT-223 package. It provides an output voltage range of 1.25V to 37V set by just two external resistors. With excellent line and load regulation, built-in thermal shutdown, and current limiting, the LM317 remains one of the most versatile linear regulators for adjustable power supply designs.<\/p>\n

\u4e3b\u8981\u89c4\u683c<\/h2>\n\n\n\n\n\n\n\n\n\n\n
Output Voltage Range<\/td>\n1.25V ~ 37V (adjustable)<\/td>\n<\/tr>\n
Max Output Current<\/td>\n1.5A<\/td>\n<\/tr>\n
Dropout Voltage<\/td>\n3V (typical)<\/td>\n<\/tr>\n
Line Regulation<\/td>\n0.01%\/V (typical)<\/td>\n<\/tr>\n
Load Regulation<\/td>\n0.1% (typical)<\/td>\n<\/tr>\n
Reference Voltage<\/td>\n1.25V (typical)<\/td>\n<\/tr>\n
Ripple Rejection<\/td>\n80dB (typical)<\/td>\n<\/tr>\n
\u5de5\u4f5c\u6e29\u5ea6<\/td>\n0C ~ +125C<\/td>\n<\/tr>\n
\u5305\u88c5<\/td>\nSOT-223 (DCY suffix)<\/td>\n<\/tr>\n<\/table>\n

\u7279\u70b9<\/h2>\n
    \n
  • Output voltage adjustable from 1.25V to 37V via two resistors<\/li>\n
  • Built-in thermal shutdown and safe operating area protection<\/li>\n
  • Current limit typically 2.2A<\/li>\n
  • Excellent 80dB ripple rejection ratio<\/li>\n
  • Low quiescent current of 50uA typical<\/li>\n
  • Long-established industry standard with wide availability<\/li>\n<\/ul>\n

    \u5e94\u7528<\/h2>\n
      \n
    • Adjustable bench power supplies<\/li>\n
    • Battery charger circuits<\/li>\n
    • Constant current source for LED driving<\/li>\n
    • Local on-card regulation in distributed power systems<\/li>\n
    • Variable voltage reference generation<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The LM317DCYR from Texas Instruments is a classic 1.5A adjustable positive voltage linear regulator in a SOT-223 package. It provides an output voltage range of 1.25V to 37V set by just two external resistors. With excellent line and load regulation, built-in thermal shutdown, and current limiting, the LM317 remains one of the most […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[13,32],"tags":[],"chip_brand":[138],"class_list":["post-8548","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-low-dropout-regulators-ldo","chip_brand-ti"],"acf":{"brief_explanation":"TI 1.5A adjustable positive LDO, 1.25V~37V output, SOT-223, 80dB ripple rejection","date_code":"","package_case":"SOT-223 (DCY suffix, Tab=VOUT)","in_stock":3824,"datasheet":"https:\/\/www.ti.com\/lit\/ds\/symlink\/lm317.pdf","price":"$0.28 @ 1ku","product_introduction":"The LM317DCYR is a 1.5A adjustable positive voltage linear regulator from Texas Instruments, housed in a SOT-223 surface-mount package. As an industry-standard device, it delivers a continuously adjustable output voltage from 1.25V to 37V using only two external resistors to set the output. The device features excellent line regulation of 0.01%\/V and load regulation of 0.1%, making it suitable for precision power supply applications. Internal current limiting, thermal shutdown, and safe operating area compensation provide robust protection against fault conditions. The LM317 maintains a reference voltage of 1.25V between the output and adjustment terminals, with a typical quiescent current of just 50uA flowing through the adjust pin. Its ripple rejection ratio of 80dB makes it effective at cleaning noisy input supplies.","working_principle":"The LM317DCYR maintains a constant 1.25V reference between the VOUT and ADJ pins. A resistor (R1) connected between VOUT and ADJ sets a constant current, while a second resistor (R2) from ADJ to ground determines the output voltage: VOUT = 1.25V x (1 + R2\/R1) + IADJ x R2. The adjustment pin current (IADJ) is typically 50uA and remains constant, minimizing its effect on output accuracy. The internal error amplifier compares the divided output voltage to the internal reference and drives the series pass transistor to maintain regulation. Thermal shutdown activates at approximately 170C junction temperature, while current limiting engages around 2.2A to protect the device during overload conditions.","pin_description":"\n
      Pin<\/th>Name<\/th>Function<\/th><\/tr>\n
      1<\/td>ADJ<\/td>Adjustment Terminal<\/td><\/tr>\n
      2<\/td>VOUT<\/td>Output (connected to Tab)<\/td><\/tr>\n
      3<\/td>VIN<\/td>Input Supply<\/td><\/tr>\n
      Tab<\/td>VOUT<\/td>Output \/ Thermal Pad<\/td><\/tr>\n<\/table>","application_scenarios":"
        \n
      • Adjustable power supplies: Set output from 1.25V to 37V using two external resistors for bench or lab applications<\/li>\n
      • Battery chargers: Configure as constant-voltage or constant-current source for NiCd, NiMH, or lead-acid batteries<\/li>\n
      • LED drivers: Operate in constant-current mode by placing the load between ADJ and ground with a current-setting resistor<\/li>\n
      • Local regulation: Provide clean, regulated voltage on individual PCB cards in distributed power architectures<\/li>\n
      • Audio circuits: Use as a low-noise regulated supply for analog signal chains leveraging the 80dB ripple rejection<\/li>\n<\/ul>","alternative_models":"\n
        Model<\/th>Brand<\/th>Max Current<\/th>Package<\/th>Key Difference<\/th><\/tr>\n
        LM317EMP<\/td>TI<\/td>1.5A<\/td>SOT-223<\/td>Same die, different reel<\/td><\/tr>\n
        LM317AT<\/td>onsemi<\/td>1.5A<\/td>TO-220<\/td>Through-hole version<\/td><\/tr>\n
        LM1117-ADJ<\/td>TI<\/td>800mA<\/td>SOT-223<\/td>Lower current, lower dropout<\/td><\/tr>\n
        LT1086CT<\/td>ADI<\/td>1.5A<\/td>TO-220<\/td>Lower dropout (1.5V)<\/td><\/tr>\n
        AMS1117-ADJ<\/td>Advanced Monolithic<\/td>1A<\/td>SOT-223<\/td>Lower cost alternative<\/td><\/tr>\n<\/table>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/8548","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/comments?post=8548"}],"version-history":[{"count":0,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/8548\/revisions"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/media?parent=8548"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/categories?post=8548"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/tags?post=8548"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/chip_brand?post=8548"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}