{"id":7636,"date":"2026-06-26T07:03:23","date_gmt":"2026-06-26T07:03:23","guid":{"rendered":"https:\/\/materialparts.com\/bss138k-7\/"},"modified":"2026-06-28T10:10:08","modified_gmt":"2026-06-28T10:10:08","slug":"bss138k-7","status":"publish","type":"post","link":"https:\/\/materialparts.com\/zh\/bss138k-7\/","title":{"rendered":"BSS138K-7"},"content":{"rendered":"

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

The BSS138K-7 from Diodes Incorporated is a 50V N-channel logic-level MOSFET with 3.5 Ohm RDS(on), 220mA ID, and ESD protection in SOT-23-3.<\/p>\n

\u4e3b\u8981\u89c4\u683c<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n
VDS<\/td>\n50V<\/td>\n<\/tr>\n
VGS<\/td>\n+\/-20V<\/td>\n<\/tr>\n
\u8eab\u4efd\u8bc1<\/td>\n220 mA<\/td>\n<\/tr>\n
RDS(on) @ VGS=2.5V<\/td>\n3.5 Ohm max<\/td>\n<\/tr>\n
RDS(on) @ VGS=4.5V<\/td>\n1.5 Ohm max<\/td>\n<\/tr>\n
VGS(th)<\/td>\n0.8-1.5V<\/td>\n<\/tr>\n
Qg<\/td>\n2.6 nC typical<\/td>\n<\/tr>\n
ESD Protection<\/td>\nHBM 2kV on gate<\/td>\n<\/tr>\n
\u5305\u88c5<\/td>\nSOT-23-3<\/td>\n<\/tr>\n
\u5de5\u4f5c\u6e29\u5ea6<\/td>\n-55 to +150 C (TJ)<\/td>\n<\/tr>\n<\/table>\n

\u7279\u70b9<\/h2>\n
    \n
  • Logic-level gate threshold (0.8V min)<\/li>\n
  • 2kV ESD protection on gate<\/li>\n
  • Low 2.6nC gate charge<\/li>\n
  • Small SOT-23-3 footprint<\/li>\n<\/ul>\n

    \u5e94\u7528<\/h2>\n
      \n
    • Level shifting between logic domains<\/li>\n
    • Load switching in battery devices<\/li>\n
    • I2C\/SPI bus level translation<\/li>\n
    • Small motor driver<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The BSS138K-7 from Diodes Incorporated is a 50V N-channel logic-level MOSFET with 3.5 Ohm RDS(on), 220mA ID, and ESD protection in SOT-23-3. Key Specifications VDS 50V VGS +\/-20V ID 220 mA RDS(on) @ VGS=2.5V 3.5 Ohm max RDS(on) @ VGS=4.5V 1.5 Ohm max VGS(th) 0.8-1.5V Qg 2.6 nC typical ESD Protection HBM 2kV […]<\/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":[13,22],"tags":[],"chip_brand":[199],"class_list":["post-7636","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-video-ics","chip_brand-diodes"],"acf":{"brief_explanation":"50V N-ch MOSFET, 3.5Ohm, logic-level, SOT-23-3","date_code":"","package_case":"SOT-23-3 (2.90 x 1.30 x 1.00 mm)","in_stock":95000,"datasheet":"https:\/\/www.diodes.com\/assets\/Datasheets\/BSS138K.pdf","price":"$0.03 @ 10ku","product_introduction":"The BSS138K-7 from Diodes Incorporated is a 50V N-channel enhancement-mode logic-level MOSFET in SOT-23-3. The low 0.8V minimum gate threshold enables direct drive from 1.8V\/2.5V\/3.3V logic. The RDS(on) of 3.5 Ohm at VGS=2.5V (1.5 Ohm at 4.5V) provides efficient switching for small-signal loads. The integrated gate-source ESD protection (2kV HBM) enhances reliability. The -7 suffix denotes tape and reel packaging. This device is widely used for bidirectional level shifting in I2C and SPI buses.","working_principle":"The BSS138K-7 operates as a logic-level N-channel MOSFET. (1) The low VGS(th) of 0.8V minimum allows the gate to be driven directly from low-voltage GPIO (1.8V, 2.5V, 3.3V). At VGS=2.5V, the RDS(on) of 3.5 Ohm maximum is suitable for switching currents up to 220mA. (2) For level-shifting applications, the MOSFET is connected with drain pulled up to the higher voltage domain through a resistor, and source connected to the lower voltage domain. When neither side drives the bus, both sides are high. When either side pulls low, the MOSFET conducts and the other side follows. This bidirectional translation is the standard I2C level-shift circuit. (3) The 2kV ESD protection on the gate prevents damage during handling and assembly. The low 2.6nC gate charge enables fast switching at low drive currents.","pin_description":"
      Pin<\/th>Name<\/th>Description<\/th><\/tr>
      1<\/td>GATE<\/td>MOSFET gate drive output for ideal diode function; connect to external N-channel MOSFET gate<\/td><\/tr>
      2<\/td>SOURCE<\/td>MOSFET source sense input; monitors forward voltage drop for regulation<\/td><\/tr>
      3<\/td>DRAIN<\/td>MOSFET drain sense input; monitors reverse voltage for fast turn-off protection<\/td><\/tr><\/table>

      Package: SOT-23-3. N-Channel MOSFET. VDS: 50 V. ID: 220 mA continuous. RDS(on): 3.5 Ohm max at VGS=4.5 V, 6 Ohm max at VGS=2.5 V. VGS(th): 1.0 V min, 1.5 V typ, 2.0 V max. Gate charge: 2.5 nC at 4.5 V. Thermal resistance Rth(j-a): 625 C\/W on FR-4.<\/p>","application_scenarios":"

      • Bidirectional Logic Level Shifting:<\/strong> Low VGS(th) of 1.0 V enables I2C, SPI, and UART bidirectional voltage translation between 1.8 V and 5 V logic domains using two MOSFETs in back-to-back configuration<\/li>
      • Load Switching in Battery Devices:<\/strong> 3.5 Ohm RDS(on) and 220 mA continuous current suitable for power gating and load switching in coin-cell and Li-ion battery powered devices<\/li>
      • Small-Signal Switching:<\/strong> 2.5 nC low gate charge and 50 V VDS rating for analog signal routing, multiplexing, and sample-and-hold circuits in precision instrumentation<\/li>
      • Open-Drain Bus Interfacing:<\/strong> Converting push-pull MCU outputs to open-drain for shared bus lines (I2C, 1-Wire, SMBus) with ESD protection on gate and drain terminals<\/li>
      • LED Matrix Row\/Column Driving:<\/strong> 220 mA pulsed current capability for multiplexed LED matrix row and column control in small display panels<\/li><\/ul>","alternative_models":"\n
        Model<\/th>Manufacturer<\/th>Key Difference<\/th>Package<\/th>VDS\/ID<\/th><\/tr>\n
        BSS138-7-F<\/td>Diodes Inc<\/td>Non-ESD standard version with identical 50V\/220mA ratings and 3.5 Ohm RDS(on)<\/td>SOT-23-3<\/td>50V\/220mA<\/td><\/tr>\n
        2N7002K-7<\/td>Diodes Inc<\/td>60V\/300mA N-channel MOSFET with higher VDS for voltage spike margin in switching circuits<\/td>SOT-23-3<\/td>60V\/300mA<\/td><\/tr>\n
        BSS138L-7<\/td>Diodes Inc<\/td>Lower threshold voltage variant (0.65V min) for sub-2V logic level shifting applications<\/td>SOT-23-3<\/td>60V\/200mA<\/td><\/tr>\n
        SI2302CDS-T1-GE3<\/td>Vishay<\/td>20V\/2.2A N-channel with much lower 62mOhm RDS(on) for power switching applications<\/td>SOT-23-3<\/td>20V\/2.2A<\/td><\/tr>\n
        2N7002ET3G<\/td>onsemi<\/td>60V\/260mA with AEC-Q101 automotive qualification and ESD protected gate<\/td>SOT-23-3<\/td>60V\/260mA<\/td><\/tr>\n<\/table>\n

        The BSS138K-7 is a 50V N-channel enhancement-mode MOSFET in SOT-23-3 with 3.5 Ohm RDS(on) and ESD protection. It is the industry-standard choice for I2C and SPI bidirectional level shifting. The K suffix indicates ESD-protected gate. For higher current switching, the SI2302CDS offers 2.2A with 62mOhm RDS(on).<\/p>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/7636","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=7636"}],"version-history":[{"count":1,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/7636\/revisions"}],"predecessor-version":[{"id":7671,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/7636\/revisions\/7671"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/media?parent=7636"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/categories?post=7636"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/tags?post=7636"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/chip_brand?post=7636"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}