{"id":9978,"date":"2026-07-08T07:37:46","date_gmt":"2026-07-08T07:37:46","guid":{"rendered":"https:\/\/materialparts.com\/74hc138d-2\/"},"modified":"2026-07-08T07:37:46","modified_gmt":"2026-07-08T07:37:46","slug":"74hc138d-2","status":"publish","type":"post","link":"https:\/\/materialparts.com\/zh\/74hc138d-2\/","title":{"rendered":"74HC138D"},"content":{"rendered":"

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

The NXP 74HC138D is a 3-to-8 line decoder\/demultiplexer in SOIC-16 package. Operating from 2.0V to 6.0V, it takes a 3-bit binary input and activates one of eight mutually exclusive outputs. Multiple enable inputs facilitate cascading for larger decoding applications.<\/p>\n

\u4e3b\u8981\u89c4\u683c<\/h2>\n\n\n\n\n\n\n\n\n\n
Logic Type<\/td>\n3-to-8 Line Decoder\/Demultiplexer<\/td>\n<\/tr>\n
Inputs<\/td>\n3 address + 3 enable<\/td>\n<\/tr>\n
Outputs<\/td>\n8 (active-low)<\/td>\n<\/tr>\n
VCC Range<\/td>\n2.0V to 6.0V<\/td>\n<\/tr>\n
\u4f20\u64ad\u5ef6\u8fdf<\/td>\n15ns at 6V (typical)<\/td>\n<\/tr>\n
Output Drive<\/td>\n\u00b15.2mA at 6V<\/td>\n<\/tr>\n
\u5305\u88c5<\/td>\nSOIC-16 (D)<\/td>\n<\/tr>\n
\u5de5\u4f5c\u6e29\u5ea6<\/td>\n-40\u00b0C to +125\u00b0C<\/td>\n<\/tr>\n<\/table>\n

\u7279\u70b9<\/h2>\n
    \n
  • 3-to-8 line decoding<\/li>\n
  • Active-low outputs<\/li>\n
  • 3 enable inputs (2 active-low, 1 active-high)<\/li>\n
  • Cascadable for larger decoder trees<\/li>\n
  • 2.0V to 6.0V wide VCC range<\/li>\n
  • SOIC-16 surface-mount package<\/li>\n<\/ul>\n

    \u5e94\u7528<\/h2>\n
      \n
    • Memory address decoding<\/li>\n
    • I\/O port selection<\/li>\n
    • Demultiplexing data to multiple outputs<\/li>\n
    • Chip select generation<\/li>\n
    • Display digit scanning<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The NXP 74HC138D is a 3-to-8 line decoder\/demultiplexer in SOIC-16 package. Operating from 2.0V to 6.0V, it takes a 3-bit binary input and activates one of eight mutually exclusive outputs. Multiple enable inputs facilitate cascading for larger decoding applications. Key Specifications Logic Type 3-to-8 Line Decoder\/Demultiplexer Inputs 3 address + 3 enable Outputs […]<\/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],"tags":[1273],"chip_brand":[168],"class_list":["post-9978","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","tag-74hc138d","chip_brand-nxp"],"acf":{"brief_explanation":"3-to-8 decoder\/demux, active-low outputs, 3 enables, SOIC-16, NXP 74HC138","date_code":"","package_case":"SOIC-16 (9.9 x 3.9 x 1.5mm)","in_stock":10867,"datasheet":"https:\/\/www.nxp.com\/docs\/en\/data-sheet\/74HC138.pdf","price":"$0.35 @ 1ku","product_introduction":"The NXP 74HC138D is a 3-to-8 line decoder\/demultiplexer in SOIC-16 package. It takes a 3-bit binary address input and activates one of eight active-low outputs. The three enable inputs (two active-low, one active-high) facilitate cascading for larger decoding applications such as memory address decoding and I\/O port selection.","working_principle":"The 74HC138D decodes a 3-bit binary address (A0, A1, A2) to one of eight active-low outputs (Y0-Y7). When the enable conditions are met (E1=L, E2=L, E3=H), the selected output goes low while all others remain high. If any enable condition is not met, all outputs are forced high. This allows easy cascading: two 74HC138 devices can form a 4-to-16 decoder, or three can form a 5-to-24 decoder by using the enable inputs as the higher-order address bits.","pin_description":"
      Pin<\/th>Name<\/th>Type<\/th>Function<\/th><\/tr>
      1<\/td>A0<\/td>Input<\/td>Address input bit 0 (LSB)<\/td><\/tr>
      2<\/td>A1<\/td>Input<\/td>Address input bit 1<\/td><\/tr>
      3<\/td>A2<\/td>Input<\/td>Address input bit 2 (MSB)<\/td><\/tr>
      4<\/td>E2<\/td>Input<\/td>Enable 2 (active-low)<\/td><\/tr>
      5<\/td>E3<\/td>Input<\/td>Enable 3 (active-high)<\/td><\/tr>
      6<\/td>E1<\/td>Input<\/td>Enable 1 (active-low)<\/td><\/tr>
      7<\/td>Y7<\/td>Output<\/td>Decoded output 7<\/td><\/tr>
      8<\/td>GND<\/td>Power<\/td>Ground<\/td><\/tr>
      9<\/td>Y6<\/td>Output<\/td>Decoded output 6<\/td><\/tr>
      10<\/td>Y5<\/td>Output<\/td>Decoded output 5<\/td><\/tr>
      11<\/td>Y4<\/td>Output<\/td>Decoded output 4<\/td><\/tr>
      12<\/td>Y3<\/td>Output<\/td>Decoded output 3<\/td><\/tr>
      13<\/td>Y2<\/td>Output<\/td>Decoded output 2<\/td><\/tr>
      14<\/td>Y1<\/td>Output<\/td>Decoded output 1<\/td><\/tr>
      15<\/td>Y0<\/td>Output<\/td>Decoded output 0<\/td><\/tr>
      16<\/td>VCC<\/td>Power<\/td>Positive supply (2-6V)<\/td><\/tr><\/table>","application_scenarios":"
      • Memory chip select decoding from address bus<\/li>
      • I\/O port address decoding for MCU peripherals<\/li>
      • Display digit scanning (7-segment multiplex)<\/li>
      • Demultiplexing single data line to 8 outputs<\/li>
      • Cascaded 4-to-16 decoder with two 74HC138s<\/li><\/ul>","alternative_models":"
        Manufacturer<\/th>Part Number<\/th>Package<\/th>Notes<\/th><\/tr>
        TI<\/td>SN74HC138DR<\/td>SOIC-16<\/td>Equivalent<\/td><\/tr>
        onsemi<\/td>MC74HC138DR2G<\/td>SOIC-16<\/td>Equivalent<\/td><\/tr>
        NXP<\/td>74HC138PW<\/td>TSSOP-16<\/td>Smaller package<\/td><\/tr>
        NXP<\/td>74HCT138D<\/td>SOIC-16<\/td>TTL-compatible inputs<\/td><\/tr>
        NXP<\/td>74HC238D<\/td>SOIC-16<\/td>Active-high output version<\/td><\/tr><\/table>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/9978","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=9978"}],"version-history":[{"count":0,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/9978\/revisions"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/media?parent=9978"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/categories?post=9978"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/tags?post=9978"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/chip_brand?post=9978"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}