{"id":6884,"date":"2026-06-22T01:48:14","date_gmt":"2026-06-22T01:48:14","guid":{"rendered":"https:\/\/materialparts.com\/bap1321-02-2\/"},"modified":"2026-06-22T01:48:14","modified_gmt":"2026-06-22T01:48:14","slug":"bap1321-02-2","status":"publish","type":"post","link":"https:\/\/materialparts.com\/zh\/bap1321-02-2\/","title":{"rendered":"BAP1321-02"},"content":{"rendered":"

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

The BAP1321-02 from Nexperia is a silicon planar varactor (tuning) diode with a capacitance ratio of 5.5 and high Q factor, suitable for RF tuning and VCO applications in an SOD-323 package.<\/p>\n

\u4e3b\u8981\u89c4\u683c<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n
\u7c7b\u578b<\/td>\nSilicon Planar Varactor Diode (Tuning Diode)<\/td>\n<\/tr>\n
Reverse Voltage (max)<\/td>\n20 V<\/td>\n<\/tr>\n
Forward Current (max)<\/td>\n20 mA<\/td>\n<\/tr>\n
Capacitance @ VR=1V<\/td>\n95 pF (typical)<\/td>\n<\/tr>\n
Capacitance @ VR=28V<\/td>\n17 pF (typical)<\/td>\n<\/tr>\n
Capacitance Ratio (C1\/C28)<\/td>\n5.5 (typical)<\/td>\n<\/tr>\n
Q Factor<\/td>\n>100 @ VR=3V, f=50 MHz<\/td>\n<\/tr>\n
Total Power Dissipation<\/td>\n250 mW<\/td>\n<\/tr>\n
\u5305\u88c5<\/td>\nSOD-323<\/td>\n<\/tr>\n
\u5de5\u4f5c\u6e29\u5ea6<\/td>\n-55C to +150C<\/td>\n<\/tr>\n<\/table>\n

\u7279\u70b9<\/h2>\n
    \n
  • Variable capacitance with reverse voltage<\/li>\n
  • Capacitance ratio of 5.5:1 (1V to 28V)<\/li>\n
  • 95 pF capacitance at 1V<\/li>\n
  • High Q factor >100 at 50 MHz<\/li>\n
  • SOD-323 surface mount package<\/li>\n<\/ul>\n

    \u5e94\u7528<\/h2>\n
      \n
    • Voltage-controlled oscillators (VCO)<\/li>\n
    • RF tuning circuits<\/li>\n
    • Frequency modulators<\/li>\n
    • Automatic frequency control (AFC)<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The BAP1321-02 from Nexperia is a silicon planar varactor (tuning) diode with a capacitance ratio of 5.5 and high Q factor, suitable for RF tuning and VCO applications in an SOD-323 package. Key Specifications Type Silicon Planar Varactor Diode (Tuning Diode) Reverse Voltage (max) 20 V Forward Current (max) 20 mA Capacitance @ […]<\/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":[19,13],"tags":[],"chip_brand":[140],"class_list":["post-6884","post","type-post","status-publish","format-standard","hentry","category-analog-linear-ics","category-integrated-circuits-ics","chip_brand-nexperia"],"acf":{"brief_explanation":"Varactor Tuning Diode, 95pF@1V, C-ratio 5.5, SOD-323","date_code":"","package_case":"SOD-323 (1.7 x 1.25 x 0.85 mm)","in_stock":6789,"datasheet":"https:\/\/assets.nexperia.com\/documents\/data-sheet\/BAP1321.pdf","price":"$0.08 @ 1ku","product_introduction":"The BAP1321-02 from Nexperia is a silicon planar varactor diode (also known as a tuning diode or varicap) in an SOD-323 surface mount package. The device exploits the voltage-dependent capacitance of a reverse-biased P-N junction, where the depletion width increases with reverse voltage, reducing the junction capacitance from 95 pF at 1V to 17 pF at 28V, yielding a capacitance ratio of 5.5. This variable capacitance is the fundamental building block for voltage-controlled oscillators, frequency tuners, and automatic frequency control circuits. The high Q factor (>100 at 50 MHz) ensures low signal loss in RF resonant circuits. The SOD-323 package provides a compact footprint with low parasitic inductance for RF applications.","working_principle":"The BAP1321-02 operates as a voltage-variable capacitor by exploiting the depletion region of a reverse-biased P-N junction. When a reverse voltage (VR) is applied, the depletion region widens, effectively increasing the dielectric thickness of the capacitor formed by the P and N regions. The junction capacitance follows the relationship: C = C0 \/ (1 + VR\/Vbi)^n, where C0 is the zero-bias capacitance, Vbi is the built-in potential (~0.7V for silicon), and n is the grading coefficient (typically 0.5 for abrupt junctions). The 5.5:1 capacitance ratio from 1V to 28V makes this device suitable for wide-range VCO tuning. The Q factor of >100 at 50 MHz is determined by the ratio of the junction capacitance to the series resistance (including bulk semiconductor resistance and contact resistance). High Q is critical for VCO phase noise performance. The varactor must always be operated in reverse bias to avoid forward conduction, which would short-circuit the RF signal.","pin_description":"
      Pin<\/th>Name<\/th>Type<\/th>Function<\/th><\/tr>
      1<\/td>Anode<\/td>Terminal<\/td>P-side (ground in typical circuit)<\/td><\/tr>
      2<\/td>Cathode<\/td>Terminal<\/td>N-side (reverse bias \/ tuning voltage)<\/td><\/tr><\/table>","application_scenarios":"
      • VCO in 100-500 MHz PLL with 5.5:1 tuning range for FM radio<\/li>
      • LC tank tuning circuit for automatic frequency control in TV tuners<\/li>
      • Frequency modulator with linearity compensation using anti-series varactor pair<\/li>
      • RF filter center frequency adjustment with DC tuning voltage<\/li><\/ul>","alternative_models":"
        Manufacturer<\/th>Part Number<\/th>Package<\/th>Notes<\/th><\/tr>
        Nexperia<\/td>BAP1321-02,235<\/td>SOD-323<\/td>Same device, different packing<\/td><\/tr>
        NXP<\/td>BBY58-02V<\/td>SOD-323<\/td>Varactor, similar class<\/td><\/tr>
        Infineon<\/td>BBY58-02V<\/td>SOD-323<\/td>Varactor, similar class<\/td><\/tr>
        Nexperia<\/td>BAP64-02<\/td>SOD-323<\/td>Pin diode, different function<\/td><\/tr>
        Skyworks<\/td>SMV1231-079LF<\/td>SOD-323<\/td>Hyperabrupt varactor, wider ratio<\/td><\/tr><\/table>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/6884","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=6884"}],"version-history":[{"count":0,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/6884\/revisions"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/media?parent=6884"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/categories?post=6884"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/tags?post=6884"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/chip_brand?post=6884"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}