{"id":5467,"date":"2026-06-10T02:25:20","date_gmt":"2026-06-10T02:25:20","guid":{"rendered":"https:\/\/materialparts.com\/lm2940sx-5-0\/"},"modified":"2026-06-10T02:25:20","modified_gmt":"2026-06-10T02:25:20","slug":"lm2940sx-5-0","status":"publish","type":"post","link":"https:\/\/materialparts.com\/ar\/lm2940sx-5-0\/","title":{"rendered":"LM2940SX-5.0"},"content":{"rendered":"

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

The LM2940SX-5.0 from Texas Instruments is a 1A low-dropout positive voltage regulator in a TO-263-3 surface-mount package. With 6-26V input range, 5V fixed output, 500mV typical dropout, reverse battery protection, and automotive-grade transient protection, it is designed for vehicular and industrial power applications.<\/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\n\n\n\n\n\n
\u062c\u0647\u062f \u0627\u0644\u062e\u0631\u062c<\/td>\n5.0V fixed (+\/-5%)<\/td>\n<\/tr>\n
\u062a\u064a\u0627\u0631 \u0627\u0644\u0625\u062e\u0631\u0627\u062c<\/td>\n1A (exceeds 1A)<\/td>\n<\/tr>\n
\u0646\u0637\u0627\u0642 \u062c\u0647\u062f \u0627\u0644\u0625\u062f\u062e\u0627\u0644<\/td>\n6.25V to 26V<\/td>\n<\/tr>\n
\u062c\u0647\u062f \u0627\u0644\u062a\u0633\u0631\u0628<\/td>\n500mV typical @ 1A; 1V max @ 1A<\/td>\n<\/tr>\n
\u062a\u064a\u0627\u0631 \u0627\u0644\u062a\u0647\u062f\u0626\u0629<\/td>\n10-15 mA @ 1A<\/td>\n<\/tr>\n
Quiescent Current (high VIN-VOUT)<\/td>\n30 mA @ 1A (reduced mode above 3V diff)<\/td>\n<\/tr>\n
Line Regulation<\/td>\n50 mV max<\/td>\n<\/tr>\n
Load Regulation<\/td>\n80 mV max<\/td>\n<\/tr>\n
PSRRR<\/td>\n64 dB @ 120Hz<\/td>\n<\/tr>\n
Reverse Battery Protection<\/td>\nYes<\/td>\n<\/tr>\n
Mirror Image Insertion Protection<\/td>\nYes<\/td>\n<\/tr>\n
Load Dump Protection<\/td>\nAuto shutdown during transient<\/td>\n<\/tr>\n
Short-Circuit Protection<\/td>\nYes (internal current limit)<\/td>\n<\/tr>\n
Thermal Shutdown<\/td>\nYes<\/td>\n<\/tr>\n
\u062f\u0631\u062c\u0629 \u062d\u0631\u0627\u0631\u0629 \u0627\u0644\u062a\u0634\u063a\u064a\u0644<\/td>\n-40 to +125 C<\/td>\n<\/tr>\n
\u0627\u0644\u062d\u0632\u0645\u0629<\/td>\nTO-263-3 (10.2 x 8.4 mm)<\/td>\n<\/tr>\n
Status<\/td>\nObsolete (replaced by LM2940-N)<\/td>\n<\/tr>\n<\/table>\n

\u0627\u0644\u0645\u064a\u0632\u0627\u062a<\/h2>\n
    \n
  • 1A output with 500mV typical dropout<\/li>\n
  • 6-26V wide input range for automotive battery<\/li>\n
  • Reverse battery installation protection<\/li>\n
  • Load dump transient shutdown<\/li>\n
  • Mirror-image insertion protection<\/li>\n
  • 64dB PSRR at 120Hz<\/li>\n
  • Reduced quiescent current at high input-output differential<\/li>\n
  • Short-circuit and thermal protection<\/li>\n<\/ul>\n

    \u0627\u0644\u062a\u0637\u0628\u064a\u0642\u0627\u062a<\/h2>\n
      \n
    • Automotive 12V\/24V battery-powered systems<\/li>\n
    • Vehicle electronics power supply<\/li>\n
    • Industrial 5V regulation from 12V\/24V rails<\/li>\n
    • Battery-powered instrumentation<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The LM2940SX-5.0 from Texas Instruments is a 1A low-dropout positive voltage regulator in a TO-263-3 surface-mount package. With 6-26V input range, 5V fixed output, 500mV typical dropout, reverse battery protection, and automotive-grade transient protection, it is designed for vehicular and industrial power applications. Key Specifications Output Voltage 5.0V fixed (+\/-5%) Output Current 1A […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[31,13],"tags":[],"chip_brand":[138],"class_list":["post-5467","post","type-post","status-publish","format-standard","hentry","category-dc-dc-converters","category-integrated-circuits-ics","chip_brand-ti"],"acf":{"brief_explanation":"1A LDO, 6-26V in, 5V out, reverse battery protection, TO-263","date_code":"","package_case":"TO-263-3 \/ DDPAK (10.2 x 8.4 x 4.4 mm)","in_stock":1532,"datasheet":"https:\/\/www.ti.com\/lit\/ds\/symlink\/lm2940-n.pdf","price":"$1.00 @ 1ku","product_introduction":"The LM2940SX-5.0 from Texas Instruments is a 1A low-dropout positive voltage regulator in a TO-263-3 (DDPAK) surface-mount package. The SX denotes the TO-263-3 package with tape and reel (500 pcs\/reel), -5.0 denotes 5.0V fixed output. This device is part of the LM2940\/LM2940C\/LM2940-N family specifically designed for vehicular applications. The 6-26V input range accommodates 12V and 24V automotive battery systems, including cold-crank voltage dips and normal operating ranges. A key automotive feature is reverse battery protection: the regulator and all internal circuitry survive incorrect battery polarity installation or 2-battery jump starts. During load-dump transients (when the input voltage can momentarily exceed 26V), the regulator automatically shuts down to protect internal circuits and the load. The mirror-image insertion protection prevents damage if the TO-263 package is installed rotated 180 degrees. A quiescent current reduction circuit decreases ground current when VIN-VOUT exceeds 3V, reducing dissipation at high input voltages. The 64dB PSRR at 120Hz provides excellent automotive alternator ripple rejection. Note: The original LM2940 is obsolete; the LM2940-N (pin-compatible replacement) is the active version.","working_principle":"The LM2940SX-5.0 operates as a series-pass linear regulator with automotive protection features: (1) PNP Pass Transistor: A PNP pass element provides the low 500mV dropout voltage at 1A. The error amplifier drives the PNP base to regulate VOUT at 5.0V. (2) Reverse Battery Protection: When the battery is connected with reverse polarity (negative on VIN, positive on GND), internal circuitry prevents current flow through the pass transistor and protects all internal circuitry. No external protection diodes are needed. (3) Load Dump Protection: During automotive load dump events (battery disconnected while alternator is charging), the input voltage can spike to 40-60V. The LM2940 detects this overvoltage condition and shuts down the pass transistor, protecting both the regulator and the load. The device resumes normal operation when the input returns to the safe range. (4) Quiescent Current Reduction: When VIN-VOUT exceeds approximately 3V, a bias circuit reduces the quiescent current from the typical 10mA to about 30mA at 1A load (vs 150mA+ for conventional LDOs at high differential), significantly reducing power dissipation. (5) Thermal Shutdown: If the die temperature exceeds approximately 150C, the pass transistor is disabled until the temperature drops.","pin_description":"
      Pin<\/th>Name<\/th>Type<\/th>Description<\/th><\/tr>
      1<\/td>VIN<\/td>Power<\/td>Input voltage (6-26V)<\/td><\/tr>
      2<\/td>GND<\/td>Power<\/td>Ground (tab and pin)<\/td><\/tr>
      3<\/td>VOUT<\/td>Power<\/td>Regulated 5.0V output<\/td><\/tr>
      Tab<\/td>GND<\/td>Power<\/td>Ground \/ thermal pad (connected to pin 2)<\/td><\/tr><\/table>","application_scenarios":"
      • Automotive 12V battery to 5V microcontroller supply with reverse battery protection, load dump shutdown, and 64dB alternator ripple rejection<\/li>
      • Vehicle infotainment 5V rail from 12V battery with mirror-image insertion protection for assembly line robustness<\/li>
      • Industrial 24V to 5V sensor supply with 26V maximum input and quiescent current reduction at high differential voltage<\/li>
      • Battery-powered instrumentation 5V supply from 9V battery with 500mV dropout ensuring regulation down to 5.5V input<\/li><\/ul>","alternative_models":"
        Model<\/th>Manufacturer<\/th>Vout<\/th>Vin<\/th>Notes<\/th><\/tr>
        LM2940S-5.0\/NOPB<\/td>TI<\/td>5V<\/td>6-26V<\/td>Active replacement (LM2940-N), tube<\/td><\/tr>
        LM2940SX-3.3<\/td>TI<\/td>3.3V<\/td>5-26V<\/td>3.3V output version<\/td><\/tr>
        LF33CV<\/td>STMicro<\/td>3.3V<\/td>4-26V<\/td>Lower current (0.5A), TO-220<\/td><\/tr>
        UA78S05CDCY<\/td>TI<\/td>5V<\/td>7-25V<\/td>2A, higher dropout<\/td><\/tr><\/table>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/posts\/5467","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=5467"}],"version-history":[{"count":0,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/posts\/5467\/revisions"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/media?parent=5467"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/categories?post=5467"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/tags?post=5467"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/chip_brand?post=5467"}],"curies":[{"name":"\u062f\u0628\u0644\u064a\u0648 \u0628\u064a","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}