{"id":10345,"date":"2026-07-19T12:25:25","date_gmt":"2026-07-19T12:25:25","guid":{"rendered":"https:\/\/ic-vendor.com\/p4sma18a\/"},"modified":"2026-07-19T12:25:25","modified_gmt":"2026-07-19T12:25:25","slug":"p4sma18a","status":"publish","type":"post","link":"https:\/\/ic-vendor.com\/zh\/p4sma18a\/","title":{"rendered":"P4SMA18A"},"content":{"rendered":"

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

The P4SMA18A is a 400W unidirectional TVS diode from Littelfuse’s P4SMA series in a DO-214AC (SMA) surface-mount package. It provides transient voltage suppression with a reverse standoff voltage of 18V, commonly used for protecting 12V-15V DC power rails and signal lines.<\/p>\n

\u4e3b\u8981\u89c4\u683c<\/h2>\n\n\n\n\n\n\n\n\n\n\n
Reverse Standoff Voltage (Vr)<\/td>\n18V<\/td>\n<\/tr>\n
Breakdown Voltage Min<\/td>\n20.0V<\/td>\n<\/tr>\n
Breakdown Voltage Max<\/td>\n22.1V<\/td>\n<\/tr>\n
Clamping Voltage (Vc)<\/td>\n29.2V<\/td>\n<\/tr>\n
Peak Pulse Power (10\/1000\u03bcs)<\/td>\n400W<\/td>\n<\/tr>\n
Peak Pulse Current (Ipp)<\/td>\n13.7A<\/td>\n<\/tr>\n
\u6781\u6027<\/td>\nUnidirectional<\/td>\n<\/tr>\n
\u5305\u88c5<\/td>\nDO-214AC (SMA)<\/td>\n<\/tr>\n
\u5de5\u4f5c\u6e29\u5ea6<\/td>\n-55\u00b0C \u81f3 +150\u00b0C<\/td>\n<\/tr>\n<\/table>\n

\u7279\u70b9<\/h2>\n
    \n
  • 400W peak pulse power at 10\/1000\u03bcs<\/li>\n
  • Unidirectional protection for DC rails<\/li>\n
  • Low profile SMA package<\/li>\n
  • Excellent clamping ratio<\/li>\n
  • RoHS compliant<\/li>\n<\/ul>\n

    \u5e94\u7528<\/h2>\n
      \n
    • 12V\/15V DC power rail protection<\/li>\n
    • Automotive electronics (non-AEC-Q101)<\/li>\n
    • Industrial controller I\/O protection<\/li>\n
    • Consumer electronics power supply<\/li>\n
    • RS-232\/RS-485 transceiver supply pins<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The P4SMA18A is a 400W unidirectional TVS diode from Littelfuse’s P4SMA series in a DO-214AC (SMA) surface-mount package. It provides transient voltage suppression with a reverse standoff voltage of 18V, commonly used for protecting 12V-15V DC power rails and signal lines. Key Specifications Reverse Standoff Voltage (Vr) 18V Breakdown Voltage Min 20.0V Breakdown […]<\/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":[60],"tags":[1619,1607,1614],"chip_brand":[200],"class_list":["post-10345","post","type-post","status-publish","format-standard","hentry","category-passive-components","tag-p4sma18a","tag-tvs-diode","tag-unidirectional","chip_brand-littelfuse"],"acf":{"brief_explanation":"TVS Diode 400W Uni-Dir 18Vr 29.2Vc DO-214AC SMA, -55~150\u00b0C","date_code":"","package_case":"DO-214AC (SMA)","in_stock":14000,"datasheet":"https:\/\/www.littelfuse.com\/media?res=700089&download=1","price":"","product_introduction":"The P4SMA18A is a 400W unidirectional TVS diode from Littelfuse's P4SMA series, designed for protecting 12V-15V DC power rails and signal lines against voltage transients. With a reverse standoff voltage of 18V and clamping voltage of 29.2V, it provides effective suppression of lightning-induced and switching transients while maintaining minimal leakage current under normal operation. The compact SMA (DO-214AC) package is ideal for space-constrained PCB layouts.","working_principle":"Under normal reverse-bias conditions below 18V, the P4SMA18A presents very high impedance with negligible leakage current. When a positive transient exceeds the breakdown voltage (20.0-22.1V), the avalanche junction rapidly conducts and clamps the voltage to 29.2V maximum at the rated peak pulse current of 13.7A. The unidirectional configuration also conducts forward current like a normal diode. After the transient, the device automatically returns to its blocking state.","pin_description":"
      Pin<\/th>Function<\/th><\/tr>
      1<\/td>Cathode (identified by color band)<\/td><\/tr>
      2<\/td>Anode<\/td><\/tr><\/table>","application_scenarios":"
      • 12V and 15V DC power rail transient protection<\/li>
      • Automotive accessory power supply protection<\/li>
      • Industrial PLC and controller I\/O pin protection<\/li>
      • RS-232\/RS-485 transceiver VCC protection<\/li>
      • Consumer electronics power adapter output<\/li><\/ul>","alternative_models":"
        Manufacturer<\/th>Part Number<\/th>Vr<\/th>Pppm<\/th>Notes<\/th><\/tr>
        Vishay<\/td>SMAJ18A<\/td>18V<\/td>400W<\/td>Direct cross<\/td><\/tr>
        STMicro<\/td>SMAJ18A<\/td>18V<\/td>400W<\/td>Direct cross<\/td><\/tr>
        Bourns<\/td>SMAJ18A<\/td>18V<\/td>400W<\/td>Direct cross<\/td><\/tr><\/table>"},"_links":{"self":[{"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/posts\/10345","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/comments?post=10345"}],"version-history":[{"count":0,"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/posts\/10345\/revisions"}],"wp:attachment":[{"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/media?parent=10345"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/categories?post=10345"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/tags?post=10345"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/ic-vendor.com\/zh\/wp-json\/wp\/v2\/chip_brand?post=10345"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}