{"id":2749,"date":"2026-05-25T02:06:19","date_gmt":"2026-05-25T02:06:19","guid":{"rendered":"https:\/\/materialparts.com\/smbj12a\/"},"modified":"2026-05-25T02:06:19","modified_gmt":"2026-05-25T02:06:19","slug":"smbj12a","status":"publish","type":"post","link":"https:\/\/materialparts.com\/zh\/smbj12a\/","title":{"rendered":"SMBJ12A"},"content":{"rendered":"

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

The SMBJ12A is a 600W unidirectional TVS diode in an SMB (DO-214AA) package. With 12V standoff voltage and 19.9V clamping voltage, it provides transient overvoltage protection for 12V power rails commonly found in automotive and industrial systems.<\/p>\n

\u4e3b\u8981\u89c4\u683c<\/h2>\n\n\n\n\n\n\n\n\n\n
\u7c7b\u578b<\/td>\nUnidirectional TVS Diode<\/td>\n<\/tr>\n
Peak Pulse Power<\/td>\n600W (10\/1000us)<\/td>\n<\/tr>\n
Standoff Voltage (VRWM)<\/td>\n12V<\/td>\n<\/tr>\n
Breakdown Voltage (VBR)<\/td>\n13.3V ~ 14.7V @ 1mA<\/td>\n<\/tr>\n
Clamping Voltage (VC)<\/td>\n19.9V @ IPP=30.2A<\/td>\n<\/tr>\n
Leakage Current<\/td>\n1uA @ VRWM<\/td>\n<\/tr>\n
\u5305\u88c5<\/td>\nSMB (DO-214AA)<\/td>\n<\/tr>\n
\u5de5\u4f5c\u6e29\u5ea6<\/td>\n-55\u00b0C to +150\u00b0C (TJ)<\/td>\n<\/tr>\n<\/table>\n

\u7279\u70b9<\/h2>\n
    \n
  • 600W peak pulse power (10\/1000us)<\/li>\n
  • 12V reverse standoff voltage<\/li>\n
  • 19.9V maximum clamping voltage at 30.2A<\/li>\n
  • Low 1uA leakage at standoff<\/li>\n
  • Unidirectional for DC rail protection<\/li>\n
  • SMB surface-mount package<\/li>\n<\/ul>\n

    \u5e94\u7528<\/h2>\n
      \n
    • 12V automotive power rail transient protection<\/li>\n
    • Industrial 12V bus surge suppression<\/li>\n
    • Telecom equipment power input protection<\/li>\n
    • LED driver output overvoltage clamp<\/li>\n
    • Embedded system power supply ESD protection<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The SMBJ12A is a 600W unidirectional TVS diode in an SMB (DO-214AA) package. With 12V standoff voltage and 19.9V clamping voltage, it provides transient overvoltage protection for 12V power rails commonly found in automotive and industrial systems. Key Specifications Type Unidirectional TVS Diode Peak Pulse Power 600W (10\/1000us) Standoff Voltage (VRWM) 12V Breakdown […]<\/p>\n","protected":false},"author":2,"featured_media":2754,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[13,20],"tags":[],"chip_brand":[136],"class_list":["post-2749","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-integrated-circuits-ics","category-interface-ics","chip_brand-vishay"],"acf":{"brief_explanation":"600W unidirectional TVS, 12V standoff, 19.9V clamp, SMB package","date_code":"","package_case":"SMB (DO-214AA) (4.6 x 3.9 x 2.3 mm)","in_stock":10042,"datasheet":"https:\/\/www.littelfuse.com\/media\/littelfuse-datasheet-smbj.pdf","price":"$0.12 @ 1ku","product_introduction":"The SMBJ12A is a 600W unidirectional transient voltage suppression (TVS) diode in an SMB (DO-214AA) surface-mount package. With 12V reverse standoff voltage and 19.9V maximum clamping voltage at 30.2A peak pulse current, it provides robust protection for 12V power rails against ESD, EFT, and surge transients. The low 1uA leakage current at standby minimizes power draw. Available from multiple manufacturers (Littelfuse, Yageo, MCC, Bourns) ensuring multi-source supply. IEC 61000-4-2 ESD protection to 30kV air discharge. The SMB package provides a balance of power handling and PCB footprint.","working_principle":"The SMBJ12A operates as an avalanche breakdown diode. Under normal conditions (voltage below 12V VRWM), the device draws only 1uA leakage current. When a transient exceeds the breakdown voltage (13.3-14.7V), the device enters avalanche breakdown, conducting heavily and clamping the voltage to 19.9V at the rated 30.2A peak current. The 600W peak pulse power dissipation absorbs transient energy. After the transient passes, the device returns to its high-impedance off-state. The unidirectional configuration protects DC power rails where voltage polarity is fixed, blocking reverse voltage like a normal diode.","pin_description":"
      Pin<\/th>Name<\/th>Type<\/th>Function<\/th><\/tr>
      1<\/td>Cathode<\/td>Power<\/td>Cathode (connect to positive rail)<\/td><\/tr>
      2<\/td>Anode<\/td>Power<\/td>Anode (connect to ground)<\/td><\/tr><\/table>","application_scenarios":"
      • 12V automotive battery rail load dump and ESD protection<\/li>
      • Industrial 12V DC bus transient suppression<\/li>
      • Telecom equipment 12V power input surge clamp<\/li>
      • LED driver and lighting 12V output protection<\/li>
      • Embedded system 12V power supply overvoltage protection<\/li><\/ul>","alternative_models":"
        Manufacturer<\/th>Part Number<\/th>Package<\/th>Notes<\/th><\/tr>
        Yageo<\/td>SMBJ12A<\/td>SMB<\/td>Multi-source equivalent<\/td><\/tr>
        MCC<\/td>SMBJ12A-TP<\/td>SMB<\/td>Multi-source equivalent<\/td><\/tr>
        Bourns<\/td>SMBJ12A-M3\/9AT<\/td>SMB<\/td>Multi-source equivalent<\/td><\/tr>
        ST<\/td>SMBJ12A-TR<\/td>SMB<\/td>Multi-source equivalent<\/td><\/tr><\/table>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/2749","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=2749"}],"version-history":[{"count":0,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/2749\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/media\/2754"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/media?parent=2749"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/categories?post=2749"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/tags?post=2749"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/chip_brand?post=2749"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}