{"id":7957,"date":"2026-06-28T06:10:20","date_gmt":"2026-06-28T06:10:20","guid":{"rendered":"https:\/\/materialparts.com\/lm7812ct-3\/"},"modified":"2026-06-28T11:45:19","modified_gmt":"2026-06-28T11:45:19","slug":"lm7812ct-3","status":"publish","type":"post","link":"https:\/\/materialparts.com\/es\/lm7812ct-3\/","title":{"rendered":"LM7812CT"},"content":{"rendered":"

Productos<\/h2>\n

The LM7812CT from onsemi is a 3-terminal 1A positive voltage regulator providing a fixed 12V output with 71dB ripple rejection and internal protection in a TO-220 package \u2014 the standard 12V regulator for industrial and automotive electronics.<\/p>\n

Especificaciones<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Output Voltage<\/td>\n12V fixed (\u00b14% at 25\u00b0C)<\/td>\n<\/tr>\n
Corriente de salida<\/td>\n1A continuous<\/td>\n<\/tr>\n
Input Voltage Range<\/td>\n14.5V to 35V<\/td>\n<\/tr>\n
Dropout Voltage<\/td>\n2V typical @ 1A<\/td>\n<\/tr>\n
Line Regulation<\/td>\n10mV typical (14.5V to 27V)<\/td>\n<\/tr>\n
Load Regulation<\/td>\n12mV typical (5mA to 1.5A)<\/td>\n<\/tr>\n
Corriente de reposo<\/td>\n5.1mA typical<\/td>\n<\/tr>\n
Ripple Rejection<\/td>\n71dB typical @ 120Hz<\/td>\n<\/tr>\n
Output Noise<\/td>\n76\u00b5V\/VO (10Hz to 100kHz)<\/td>\n<\/tr>\n
Short-Circuit Current<\/td>\n250mA typical<\/td>\n<\/tr>\n
Temperatura de funcionamiento<\/td>\n-40\u00b0C to +125\u00b0C (junction)<\/td>\n<\/tr>\n
Paquete<\/td>\nTO-220-3 (through-hole, tab=GND)<\/td>\n<\/tr>\n<\/table>\n

Caracter\u00edsticas<\/h2>\n
    \n
  • Fixed 12V output \u2014 the most common industrial supply voltage<\/li>\n
  • 1A continuous output current<\/li>\n
  • Internal thermal overload protection<\/li>\n
  • Internal short-circuit current limiting<\/li>\n
  • 71dB ripple rejection<\/li>\n
  • Output transistor SOA protection<\/li>\n<\/ul>\n

    Aplicaciones<\/h2>\n
      \n
    • 12V industrial power supply<\/li>\n
    • Automotive 12V rail<\/li>\n
    • Relay and solenoid power<\/li>\n
    • Op-amp \u00b112V supply<\/li>\n
    • Instrumentation power<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The LM7812CT from onsemi is a 3-terminal 1A positive voltage regulator providing a fixed 12V output with 71dB ripple rejection and internal protection in a TO-220 package \u2014 the standard 12V regulator for industrial and automotive electronics. Key Specifications Output Voltage 12V fixed (\u00b14% at 25\u00b0C) Output Current 1A continuous Input Voltage Range […]<\/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":[13,24],"tags":[],"chip_brand":[138],"class_list":["post-7957","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-microcontrollers-processors","chip_brand-ti"],"acf":{"brief_explanation":"12V 1A positive linear regulator, TO-220, thermal\/SCP protection","date_code":"","package_case":"TO-220-3 (10.16 x 4.7 x 20.4mm, through-hole, tab=GND)","in_stock":25000,"datasheet":"https:\/\/www.onsemi.com\/pub\/Collateral\/LM78XX-D.PDF","price":"$0.48 @ 1ku","product_introduction":"The LM7812CT from onsemi is the 12V member of the LM78XX family \u2014 arguably the most important voltage in the series because 12V is the dominant supply rail in industrial, automotive, and communications equipment. From 12V, 5V can be derived with a secondary regulator (LM7805), and \u00b112V supplies are used for analog op-amp circuits. The minimum input voltage for regulation is 14.5V (12V + 2.5V dropout margin), making it ideal for automotive applications where the 14.4V alternator output directly feeds the regulator. The 71dB ripple rejection attenuates alternator whine and rectified AC ripple. The CT suffix denotes the TO-220 package. Power dissipation can be significant: at VIN=24V and IOUT=500mA, Pd = (24-12)\u00d70.5 = 6W, requiring a heatsink.","working_principle":"The LM7812CT uses a series pass transistor (NPN Darlington) between input and output, controlled by a feedback loop that compares a fraction of the output voltage with an internal bandgap reference. When the output drops below 12V, the error amplifier increases drive to the pass transistor, increasing current flow. When the output rises above 12V, drive is reduced. The thermal protection disables the output at ~170\u00b0C junction temperature. The current limiting restricts output during a short circuit to ~250mA. The safe operating area (SOA) protection further reduces current limit as the input-output differential increases. The 5.1mA quiescent current flows through the ground pin and biases the internal reference and error amplifier. Power dissipation is Pd = (VIN \u2212 12V) \u00d7 IOUT; at VIN=18V, IOUT=1A: Pd = 6W. The heatsink thermal resistance must satisfy: \u03b8SA < (TJ_max \u2212 TA)\/Pd \u2212 \u03b8JC \u2212 \u03b8CS. For TJ=100\u00b0C, TA=50\u00b0C: \u03b8SA < 50\/6 \u2212 5 \u2212 0.5 = 2.83\u00b0C\/W \u2014 a substantial heatsink.","pin_description":"\n
      Pin<\/th>Name<\/th>Type<\/th>Description<\/th><\/tr>\n
      1<\/td>INPUT<\/td>Power Input<\/td>Unregulated input voltage. Must be at least 3.7V (Vout + Vdropout \u2248 3.7V) for proper regulation. Maximum 35V. Bypass with 0.33\u00b5F ceramic capacitor to GND if supply is more than 6 inches from the regulator.<\/td><\/tr>\n
      2<\/td>GND<\/td>Ground<\/td>Common ground reference. The TO-220 tab is electrically connected to this pin and serves as the primary heat dissipation path. Use thermal compound and heatsink for currents above 500mA.<\/td><\/tr>\n
      3<\/td>OUTPUT<\/td>Power Output<\/td>Regulated 1.2V DC output at up to 1A continuous current with \u00b14% tolerance. Bypass with 0.1\u00b5F ceramic capacitor to GND to improve transient response and output impedance. Do not apply external voltage higher than 1.2V to prevent reverse bias damage.<\/td><\/tr>\n<\/table>\n

      Pin assignment follows standard TO-220-3 layout: Pin 1 (left) = Input, Pin 2 (center) = Ground\/Tab, Pin 3 (right) = Output, when viewed from the front with pins pointing down. The metal tab on the back is electrically connected to Pin 2 (GND) and must be insulated from the heatsink when the heatsink is not at ground potential. Output capacitance of 0.1\u00b5F is required for stability; input capacitance of 0.33\u00b5F is recommended when the input supply is remote.<\/p>","application_scenarios":"

        \n
      • 12V Industrial Supply:<\/strong> 18V DC (from transformer+rectifier+filter) \u2192 LM7812CT \u2192 12V rail; 0.33\u00b5F input + 0.1\u00b5F output caps<\/li>\n
      • Dual 12V\/5V:<\/strong> 18V \u2192 LM7812CT \u2192 12V rail; 12V \u2192 LM7805CT \u2192 5V rail; cascaded regulation<\/li>\n
      • \u00b112V Op-Amp Supply:<\/strong> LM7812CT (+12V) + LM7912CT (-12V) from center-tapped transformer; clean \u00b112V for NE5532<\/li>\n
      • Automotive 12V:<\/strong> Car 14.4V \u2192 LM7812CT \u2192 stable 12V; 71dB rejection of alternator noise<\/li>\n<\/ul>","alternative_models":"\n
        Model<\/th>Manufacturer<\/th>Key Difference<\/th>Package<\/th>Specs<\/th><\/tr>\n
        LM7812ACT<\/td>onsemi<\/td>Tighter output tolerance: \u00b12% vs \u00b14% for precision power supply applications<\/td>TO-220-3<\/td>1.2V\/1A<\/td><\/tr>\n
        L7812CV<\/td>STMicroelectronics<\/td>Direct equivalent with 1.5A output current, internal thermal shutdown and current limiting<\/td>TO-220-3<\/td>1.2V\/1.5A<\/td><\/tr>\n
        MC7812CTG<\/td>onsemi<\/td>Current production replacement with identical electrical specifications and RoHS compliance<\/td>TO-220-3<\/td>1.2V\/1A<\/td><\/tr>\n
        KA7812<\/td>onsemi\/Fairchild<\/td>Budget-friendly version with \u00b14% tolerance and standard 1A output current rating<\/td>TO-220-3<\/td>1.2V\/1A<\/td><\/tr>\n
        MC7812ABD2TG<\/td>onsemi<\/td>Surface-mount DPAK version with \u00b12% A-grade tolerance for compact PCB layouts<\/td>DPAK-3<\/td>1.2V\/1A<\/td><\/tr>\n
        LM2940CT-1.2<\/td>TI<\/td>Low-dropout version with 0.5V max dropout at 1A for battery-powered and automotive systems<\/td>TO-220-3<\/td>1.2V\/1A LDO<\/td><\/tr>\n<\/table>\n

        LM7812CT is a 1.2V fixed positive voltage regulator in TO-220-3 with 1A output and \u00b14% tolerance. The ACT suffix offers \u00b12% precision. For surface-mount designs, use MC7812ABD2TG (DPAK). For battery-powered systems, the LM2940CT-1.2 LDO version reduces dropout to 0.5V. All 7812 variants are pin-compatible (IN-GND-OUT) and require only input\/output capacitors.<\/p>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/es\/wp-json\/wp\/v2\/posts\/7957","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/materialparts.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/materialparts.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/materialparts.com\/es\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/materialparts.com\/es\/wp-json\/wp\/v2\/comments?post=7957"}],"version-history":[{"count":1,"href":"https:\/\/materialparts.com\/es\/wp-json\/wp\/v2\/posts\/7957\/revisions"}],"predecessor-version":[{"id":8219,"href":"https:\/\/materialparts.com\/es\/wp-json\/wp\/v2\/posts\/7957\/revisions\/8219"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/es\/wp-json\/wp\/v2\/media?parent=7957"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/es\/wp-json\/wp\/v2\/categories?post=7957"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/es\/wp-json\/wp\/v2\/tags?post=7957"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/es\/wp-json\/wp\/v2\/chip_brand?post=7957"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}