{"id":7992,"date":"2026-06-28T06:32:24","date_gmt":"2026-06-28T06:32:24","guid":{"rendered":"https:\/\/materialparts.com\/sn74ls148n-2\/"},"modified":"2026-06-28T11:44:28","modified_gmt":"2026-06-28T11:44:28","slug":"sn74ls148n-2","status":"publish","type":"post","link":"https:\/\/materialparts.com\/ar\/sn74ls148n-2\/","title":{"rendered":"SN74LS148N"},"content":{"rendered":"

\u0646\u0638\u0631\u0629 \u0639\u0627\u0645\u0629 \u0639\u0644\u0649 \u0627\u0644\u0645\u0646\u062a\u062c<\/h2>\n

The SN74LS148N from Texas Instruments is an 8-line to 3-line priority encoder that accepts 8 active-LOW inputs and produces a 3-bit binary output representing the highest-priority active input in a 16-pin PDIP package.<\/p>\n

\u0627\u0644\u0645\u0648\u0627\u0635\u0641\u0627\u062a \u0627\u0644\u0631\u0626\u064a\u0633\u064a\u0629<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n
\u0627\u0644\u0648\u0638\u064a\u0641\u0629<\/td>\n8-line to 3-line priority encoder<\/td>\n<\/tr>\n
\u0639\u0627\u0626\u0644\u0629 \u0627\u0644\u0645\u0646\u0637\u0642<\/td>\nLS (Low-power Schottky)<\/td>\n<\/tr>\n
\u062c\u0647\u062f \u0627\u0644\u0625\u0645\u062f\u0627\u062f<\/td>\n4.75V to 5.25V<\/td>\n<\/tr>\n
Inputs<\/td>\n0-7 (active LOW, priority 7=highest)<\/td>\n<\/tr>\n
Outputs<\/td>\nA2, A1, A0 (active LOW, binary of highest input)<\/td>\n<\/tr>\n
\u062a\u0645\u0643\u064a\u0646 \u0627\u0644\u0625\u062f\u062e\u0627\u0644<\/td>\nEI (active LOW, enables encoder)<\/td>\n<\/tr>\n
Group Outputs<\/td>\nGS (group signal, active LOW), EO (enable out, active LOW)<\/td>\n<\/tr>\n
\u062a\u0623\u062e\u064a\u0631 \u0627\u0644\u0627\u0646\u062a\u0634\u0627\u0631<\/td>\n10-15ns typical<\/td>\n<\/tr>\n
\u062f\u0631\u062c\u0629 \u062d\u0631\u0627\u0631\u0629 \u0627\u0644\u062a\u0634\u063a\u064a\u0644<\/td>\n0\u00b0C to +70\u00b0C<\/td>\n<\/tr>\n
\u0627\u0644\u062d\u0632\u0645\u0629<\/td>\nPDIP-16 (19.3 x 6.35mm)<\/td>\n<\/tr>\n<\/table>\n

\u0627\u0644\u0645\u064a\u0632\u0627\u062a<\/h2>\n
    \n
  • Priority encoding: highest-numbered active input wins<\/li>\n
  • Cascading via EI, EO, and GS<\/li>\n
  • Active-LOW inputs and outputs<\/li>\n
  • GS output indicates any input is active<\/li>\n
  • EO output indicates no input is active (for cascading)<\/li>\n<\/ul>\n

    \u0627\u0644\u062a\u0637\u0628\u064a\u0642\u0627\u062a<\/h2>\n
      \n
    • Keyboard encoding<\/li>\n
    • Interrupt priority encoding<\/li>\n
    • Microprocessor interrupt controllers<\/li>\n
    • Data input selection<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The SN74LS148N from Texas Instruments is an 8-line to 3-line priority encoder that accepts 8 active-LOW inputs and produces a 3-bit binary output representing the highest-priority active input in a 16-pin PDIP package. Key Specifications Function 8-line to 3-line priority encoder Logic Family LS (Low-power Schottky) Supply Voltage 4.75V to 5.25V Inputs 0-7 […]<\/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":[13,20],"tags":[],"chip_brand":[138],"class_list":["post-7992","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-interface-ics","chip_brand-ti"],"acf":{"brief_explanation":"8-to-3 priority encoder, active-LOW, cascade pins, LS TTL, PDIP-16","date_code":"","package_case":"PDIP-16 (19.3 x 6.35 x 4.57mm, 2.54mm pitch, through-hole)","in_stock":3000,"datasheet":"https:\/\/www.ti.com\/lit\/ds\/symlink\/sn74ls148.pdf","price":"$0.50 @ 1ku","product_introduction":"The SN74LS148N from Texas Instruments is an 8-line to 3-line priority encoder with active-LOW inputs and outputs. It accepts 8 input lines (0-7) and outputs a 3-bit binary code representing the highest-priority (highest-numbered) active input. Input 7 has the highest priority; input 0 has the lowest. If multiple inputs are active simultaneously, only the highest-priority input is encoded. The EI (enable input, active-LOW) must be LOW for the encoder to operate. The GS (group signal) output goes LOW when any input is active, providing a valid-data indicator. The EO (enable output) goes LOW only when no input is active (all inputs HIGH), enabling a lower-priority encoder in a cascaded system. Two 74148 encoders can be cascaded to form a 16-to-4 priority encoder: the higher-priority encoder's EO connects to the lower-priority encoder's EI; the A2-A0 outputs are ORed; and the GS outputs indicate which encoder is active. The N suffix denotes the PDIP-16 through-hole package.","working_principle":"The SN74LS148N operates as a priority encoder. When EI=LOW (enabled): The encoder examines inputs 7 through 0 and finds the highest-numbered active (LOW) input. It outputs the 3-bit complement of that input number on A2, A1, A0. For example, if input 5 is the highest active input, A2,A1,A0 = 010 (complement of 5=101). GS goes LOW (indicating at least one input is active). EO stays HIGH (since there IS an active input). If no input is active (all HIGH): A2,A1,A0 = 111 (complement of 0, but meaningless); GS stays HIGH (no active input); EO goes LOW (indicating no active input, enabling next lower encoder). When EI=HIGH (disabled): All outputs go HIGH regardless of inputs. For 16-to-4 encoding: Higher-priority encoder (inputs 8-15): EI grounded. Its EO \u2192 EI of lower-priority encoder (inputs 0-7). Output bits: A2,A1,A0 of both encoders are NAND-gated; the higher-priority encoder's GS provides the MSB (A3) of the 4-bit output.","pin_description":"\n
      Pin<\/th>Name<\/th>Type<\/th>Description<\/th><\/tr>\n
      1<\/td>A2<\/td>Output<\/td>Encoded output MSB (active LOW)<\/td><\/tr>\n
      2<\/td>EO<\/td>Output<\/td>Enable output (active LOW; LOW = no input active)<\/td><\/tr>\n
      3<\/td>GS<\/td>Output<\/td>Group signal (active LOW; LOW = at least one input active)<\/td><\/tr>\n
      4<\/td>A1<\/td>Output<\/td>Encoded output bit 1 (active LOW)<\/td><\/tr>\n
      5<\/td>A0<\/td>Output<\/td>Encoded output LSB (active LOW)<\/td><\/tr>\n
      6<\/td>7<\/td>Input<\/td>Input 7 (highest priority, active LOW)<\/td><\/tr>\n
      7<\/td>6<\/td>Input<\/td>Input 6<\/td><\/tr>\n
      8<\/td>GND<\/td>Power<\/td>Ground<\/td><\/tr>\n
      9<\/td>5<\/td>Input<\/td>Input 5<\/td><\/tr>\n
      10<\/td>4<\/td>Input<\/td>Input 4<\/td><\/tr>\n
      11<\/td>3<\/td>Input<\/td>Input 3<\/td><\/tr>\n
      12<\/td>2<\/td>Input<\/td>Input 2<\/td><\/tr>\n
      13<\/td>1<\/td>Input<\/td>Input 1<\/td><\/tr>\n
      14<\/td>0<\/td>Input<\/td>Input 0 (lowest priority, active LOW)<\/td><\/tr>\n
      15<\/td>EI<\/td>Input<\/td>Enable input (active LOW; LOW = enabled)<\/td><\/tr>\n
      16<\/td>VCC<\/td>Power<\/td>Supply (5V)<\/td><\/tr>\n<\/table>","application_scenarios":"
        \n
      • Interrupt Priority Encoder:<\/strong> 8 interrupt sources \u2192 inputs 0-7; A2-A0 \u2192 MCU interrupt vector; GS \u2192 MCU interrupt pin; highest-priority interrupt serviced first<\/li>\n
      • 16-Input Priority Encoder:<\/strong> Two 74148s; inputs 8-15 on higher-priority, 0-7 on lower; cascaded via EO\u2192EI; outputs combined with NAND gates for 4-bit result<\/li>\n
      • Keyboard Encoder:<\/strong> 8 keys \u2192 inputs 0-7; A2-A0 = key code; GS = key-pressed flag; no multiple-key ambiguity<\/li>\n
      • Active-Low Detection:<\/strong> 8 fault lines \u2192 inputs; GS = any fault active; A2-A0 = highest-priority fault code<\/li>\n<\/ul>","alternative_models":"\n
        Model<\/th>Manufacturer<\/th>Key Difference<\/th>Package<\/th>Supply<\/th><\/tr>\n
        74LS148N<\/td>TI\/Nexperia<\/td>Original TTL version with 5V-only supply, typical propagation delay 10-15ns<\/td>DIP-16<\/td>5V TTL<\/td><\/tr>\n
        74LS148D<\/td>TI\/Nexperia<\/td>Surface-mount SOIC version of LS with identical logic function<\/td>SOIC-16<\/td>5V TTL<\/td><\/tr>\n
        74HC148D<\/td>TI\/Nexperia<\/td>CMOS version with wide 2-6V supply range, lower power consumption and higher noise immunity<\/td>SOIC-16<\/td>2-6V CMOS<\/td><\/tr>\n
        74HC148N<\/td>TI\/Nexperia<\/td>Through-hole DIP version of HC family for prototyping and repair<\/td>DIP-16<\/td>2-6V CMOS<\/td><\/tr>\n
        74HCT148D<\/td>TI\/Nexperia<\/td>CMOS with TTL-compatible input levels, ideal for mixing with LS devices at 5V<\/td>SOIC-16<\/td>4.5-5.5V TTL-in<\/td><\/tr>\n
        74HCT148N<\/td>TI\/Nexperia<\/td>Through-hole DIP version of HCT family for prototyping and repair<\/td>DIP-16<\/td>4.5-5.5V TTL-in<\/td><\/tr>\n<\/table>\n

        The 74148 is a 8-Line to 3-Line Priority Encoder. Family variants span from the original LS TTL (5V only) to modern LVC\/AUP (down to 0.8V). HC and HCT versions offer 2-6V CMOS operation with HCT providing TTL-compatible input thresholds for mixed 5V systems. CD4000-series equivalents offer the widest 3-18V supply range at the cost of lower switching speed. DIP packages (N suffix) are through-hole; SOIC (D suffix) and TSSOP are surface-mount.<\/p>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/posts\/7992","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/comments?post=7992"}],"version-history":[{"count":1,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/posts\/7992\/revisions"}],"predecessor-version":[{"id":8146,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/posts\/7992\/revisions\/8146"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/media?parent=7992"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/categories?post=7992"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/tags?post=7992"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/chip_brand?post=7992"}],"curies":[{"name":"\u062f\u0628\u0644\u064a\u0648 \u0628\u064a","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}