{"id":7931,"date":"2026-06-28T05:53:58","date_gmt":"2026-06-28T05:53:58","guid":{"rendered":"https:\/\/materialparts.com\/lm7912ct\/"},"modified":"2026-06-28T11:45:51","modified_gmt":"2026-06-28T11:45:51","slug":"lm7912ct","status":"publish","type":"post","link":"https:\/\/materialparts.com\/es\/lm7912ct\/","title":{"rendered":"LM7912CT"},"content":{"rendered":"

Productos<\/h2>\n

The LM7912CT from onsemi\/TI is a 3-terminal 1A negative voltage regulator providing a fixed -12V output with internal thermal shutdown, short-circuit protection, and safe operating area compensation in a TO-220 package.<\/p>\n

Especificaciones<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Output Voltage<\/td>\n-12V fixed (\u00b14% tolerance)<\/td>\n<\/tr>\n
Corriente de salida<\/td>\n1A continuous (1.5A peak)<\/td>\n<\/tr>\n
Input Voltage Range<\/td>\n-14.5V to -27V (for regulation)<\/td>\n<\/tr>\n
Maximum Input Voltage<\/td>\n-35V<\/td>\n<\/tr>\n
Dropout Voltage<\/td>\n1.1V typical @ 1A (TI version)<\/td>\n<\/tr>\n
Line Regulation<\/td>\n10mV typical (TI version)<\/td>\n<\/tr>\n
Load Regulation<\/td>\n12mV typical (5mA to 1A)<\/td>\n<\/tr>\n
Corriente de reposo<\/td>\n1-2mA typical<\/td>\n<\/tr>\n
Ripple Rejection<\/td>\n54-60dB typical @ 120Hz<\/td>\n<\/tr>\n
Short-Circuit Current<\/td>\n300mA typical<\/td>\n<\/tr>\n
Peak Output Current<\/td>\n2.2A typical<\/td>\n<\/tr>\n
Temperatura de funcionamiento<\/td>\n0\u00b0C to +125\u00b0C (junction)<\/td>\n<\/tr>\n
Paquete<\/td>\nTO-220-3 (through-hole)<\/td>\n<\/tr>\n<\/table>\n

Caracter\u00edsticas<\/h2>\n
    \n
  • Fixed -12V output<\/li>\n
  • 1A continuous output current<\/li>\n
  • Internal thermal shutdown protection<\/li>\n
  • Internal short-circuit current limiting<\/li>\n
  • Safe operating area compensation<\/li>\n
  • High ripple rejection: 54-60dB<\/li>\n
  • Complements LM7812 for \u00b112V supplies<\/li>\n<\/ul>\n

    Aplicaciones<\/h2>\n
      \n
    • Negative 12V power supply rail<\/li>\n
    • Op-amp dual supply (with LM7812)<\/li>\n
    • Analog circuit negative rail<\/li>\n
    • RS-232 negative supply generation<\/li>\n
    • Audio amplifier split supply<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The LM7912CT from onsemi\/TI is a 3-terminal 1A negative voltage regulator providing a fixed -12V output with internal thermal shutdown, short-circuit protection, and safe operating area compensation in a TO-220 package. Key Specifications Output Voltage -12V fixed (\u00b14% tolerance) Output Current 1A continuous (1.5A peak) Input Voltage Range -14.5V to -27V (for regulation) […]<\/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-7931","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-microcontrollers-processors","chip_brand-ti"],"acf":{"brief_explanation":"-12V 1A negative linear regulator, TO-220, thermal\/SCP protection","date_code":"","package_case":"TO-220-3 (15.6 x 10.6 x 4.6mm, through-hole, tab=GND)","in_stock":4969,"datasheet":"https:\/\/www.ti.com\/lit\/ds\/symlink\/lm79.pdf","price":"$0.68 @ 1ku","product_introduction":"The LM7912CT from onsemi\/Texas Instruments is a 3-terminal negative voltage regulator providing a fixed -12V output at up to 1A load current. It is the negative-voltage complement to the LM7812CT, and together they form a complete \u00b112V split power supply from a center-tapped transformer. The LM7912 requires an input bypass capacitor (2.2\u00b5F tantalum or 25\u00b5F aluminum) at the input and a 1\u00b5F output capacitor for stability\u2014larger values than the LM7812 due to the negative regulator architecture. Internal protection includes thermal shutdown, short-circuit current limiting, and safe operating area compensation. The pinout differs from the 78xx series: pin 1 is Ground (tab), pin 2 is Input, and pin 3 is Output. The CT suffix denotes the TO-220 through-hole package. Note: TI lists this part as Last Time Buy; the MC7912CTG from onsemi is the current production equivalent.","working_principle":"The LM7912CT uses a series pass transistor between the negative input and the output, controlled by a feedback loop that maintains VOUT = -12V. The error amplifier compares a divided version of the output voltage with an internal reference. When the output becomes less negative (rises toward 0V), the error amplifier drives the pass transistor harder, pulling the output more negative. When the output becomes too negative, the drive is reduced. The negative regulator architecture requires the tab to be connected to ground (not the output), which simplifies heatsink mounting since the tab can be directly attached to the chassis ground. The larger required bypass capacitors (2.2\u00b5F input, 1\u00b5F output, both tantalum recommended) are needed because the negative regulator has different loop dynamics than the positive 78xx series. The quiescent current flows from the output through the ground pin to the reference, which is why the ground pin current varies with load. The thermal shutdown activates at approximately 170\u00b0C junction temperature, and the current limit is approximately 300mA during a short circuit, significantly lower than the 78xx series.","pin_description":"\n
      Pin<\/th>Name<\/th>Type<\/th>Description<\/th><\/tr>\n
      1<\/td>GND<\/td>Ground<\/td>Common ground reference. The TO-220 tab is electrically connected to this pin. Note: 79xx negative regulators have GROUND on Pin 1 (opposite to 78xx where Input is Pin 1). Heatsink tab must be insulated when not at ground potential.<\/td><\/tr>\n
      2<\/td>INPUT<\/td>Power Input<\/td>Negative unregulated input voltage. Must be more negative than -1.2V - Vdropout (at least -3.2V input). Maximum -35V. Bypass with 2.2\u00b5F electrolytic or 0.33\u00b5F ceramic capacitor to GND.<\/td><\/tr>\n
      3<\/td>OUTPUT<\/td>Power Output<\/td>Regulated -1.2V DC output at up to 1.5A continuous current with \u00b14% tolerance. Bypass with 1\u00b5F tantalum or 10\u00b5F electrolytic capacitor to GND for stability. Do not apply positive voltage to output to prevent damage.<\/td><\/tr>\n<\/table>\n

      Critical note: 79xx negative regulators have DIFFERENT pin assignments from 78xx positive regulators. Pin 1 = GND (not Input), Pin 2 = Input (not GND), Pin 3 = Output. This pin swap is a common source of design errors. The tab is connected to GND (Pin 1). Always verify pinout against the datasheet before PCB layout.<\/p>","application_scenarios":"

        \n
      • \u00b112V Split Supply:<\/strong> Center-tapped transformer \u2192 bridge rectifier \u2192 LM7812CT (+12V) and LM7912CT (-12V); dual rail for op-amps<\/li>\n
      • Op-Amp Rail:<\/strong> -12V rail for NE5532\/LM358 circuits; 54dB ripple rejection ensures clean analog supply<\/li>\n
      • RS-232 Supply:<\/strong> -12V rail for MAX232 V- pin (if not using charge pump); or as -12V reference<\/li>\n
      • Audio Amp:<\/strong> -12V rail for TDA2030A negative supply; paired with LM7812CT for \u00b112V<\/li>\n
      • Test Equipment:<\/strong> Negative rail for DAC\/ADC reference circuits; stable -12V with 12mV load regulation<\/li>\n<\/ul>","alternative_models":"\n
        Model<\/th>Manufacturer<\/th>Key Difference<\/th>Package<\/th>Specs<\/th><\/tr>\n
        LM7912ACT<\/td>onsemi<\/td>Tighter output tolerance: \u00b12% vs \u00b14% for precision negative supply rails<\/td>TO-220-3<\/td>-1.2V\/1A<\/td><\/tr>\n
        L7912CV<\/td>STMicroelectronics<\/td>Direct equivalent with 1.5A output current and internal thermal\/current protection<\/td>TO-220-3<\/td>-1.2V\/1.5A<\/td><\/tr>\n
        MC7912CTG<\/td>onsemi<\/td>Current production replacement with RoHS compliance and identical specifications<\/td>TO-220-3<\/td>-1.2V\/1A<\/td><\/tr>\n
        KA7912<\/td>onsemi\/Fairchild<\/td>Budget-friendly version with \u00b14% tolerance for cost-sensitive negative supply designs<\/td>TO-220-3<\/td>-1.2V\/1A<\/td><\/tr>\n
        LM337T<\/td>TI<\/td>Adjustable -1.25V to -37V version providing flexible output voltage with two external resistors<\/td>TO-220-3<\/td>-1.25 to -37V adj<\/td><\/tr>\n<\/table>\n

        LM7912CT is a -1.2V fixed negative voltage regulator in TO-220-3 with 1A output and \u00b14% tolerance. For adjustable negative voltage, the LM337T provides -1.25V to -37V output. All 7912 variants share the same pinout (GND-IN-OUT) and are complementary to the 7812 positive regulators for split-rail supplies.<\/p>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/es\/wp-json\/wp\/v2\/posts\/7931","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=7931"}],"version-history":[{"count":1,"href":"https:\/\/materialparts.com\/es\/wp-json\/wp\/v2\/posts\/7931\/revisions"}],"predecessor-version":[{"id":8232,"href":"https:\/\/materialparts.com\/es\/wp-json\/wp\/v2\/posts\/7931\/revisions\/8232"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/es\/wp-json\/wp\/v2\/media?parent=7931"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/es\/wp-json\/wp\/v2\/categories?post=7931"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/es\/wp-json\/wp\/v2\/tags?post=7931"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/es\/wp-json\/wp\/v2\/chip_brand?post=7931"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}