{"id":3400,"date":"2026-06-04T04:30:45","date_gmt":"2026-06-04T04:30:45","guid":{"rendered":"https:\/\/materialparts.com\/lm809m3x-4-38-nopb\/"},"modified":"2026-06-04T04:30:45","modified_gmt":"2026-06-04T04:30:45","slug":"lm809m3x-4-38-nopb","status":"publish","type":"post","link":"https:\/\/materialparts.com\/ar\/lm809m3x-4-38-nopb\/","title":{"rendered":"LM809M3X-4.38\/NOPB"},"content":{"rendered":"

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

The LM809M3X-4.38\/NOPB from Texas Instruments is a 3-pin microprocessor supervisory reset circuit with an active-low, push-pull reset output. Designed in a SOT-23 (DBZ) package, it monitors supply voltages with a factory-programmed 4.38V threshold, making it ideal for 5V system monitoring in portable and digital equipment.<\/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
Threshold Voltage<\/td>\n4.38 V<\/td>\n<\/tr>\n
\u0646\u0637\u0627\u0642 \u062c\u0647\u062f \u0627\u0644\u0625\u0645\u062f\u0627\u062f<\/td>\n1 V to 5.5 V<\/td>\n<\/tr>\n
Supply Current (Typ)<\/td>\n15 \u00b5A<\/td>\n<\/tr>\n
Reset Output<\/td>\nActive-Low, Push-Pull<\/td>\n<\/tr>\n
Reset Timeout (Typ)<\/td>\n240 ms<\/td>\n<\/tr>\n
Reset Threshold Accuracy<\/td>\n3%<\/td>\n<\/tr>\n
\u062f\u0631\u062c\u0629 \u062d\u0631\u0627\u0631\u0629 \u0627\u0644\u062a\u0634\u063a\u064a\u0644<\/td>\n-40\u00b0C to +105\u00b0C<\/td>\n<\/tr>\n
\u0627\u0644\u062d\u0632\u0645\u0629<\/td>\nSOT-23 (DBZ) | 3 pins<\/td>\n<\/tr>\n<\/table>\n

\u0627\u0644\u0645\u064a\u0632\u0627\u062a<\/h2>\n
    \n
  • Precision monitoring of supply voltages<\/li>\n
  • 140-ms minimum power-on reset pulse width (240-ms typical)<\/li>\n
  • Active-low RESET output<\/li>\n
  • Ensured RESET valid for VCC \u2265 1 V<\/li>\n
  • Low supply current of 15 \u00b5A typical<\/li>\n
  • Power supply transient immunity<\/li>\n
  • Superior upgrade to MAX809\/MAX810<\/li>\n<\/ul>\n

    \u0627\u0644\u062a\u0637\u0628\u064a\u0642\u0627\u062a<\/h2>\n
      \n
    • Microprocessor and digital systems<\/li>\n
    • Portable and battery-powered equipment<\/li>\n
    • Embedded controllers<\/li>\n
    • Intelligent instruments<\/li>\n
    • 5V and 3.3V supply monitoring<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The LM809M3X-4.38\/NOPB from Texas Instruments is a 3-pin microprocessor supervisory reset circuit with an active-low, push-pull reset output. Designed in a SOT-23 (DBZ) package, it monitors supply voltages with a factory-programmed 4.38V threshold, making it ideal for 5V system monitoring in portable and digital equipment. Key Specifications Threshold Voltage 4.38 V Supply Voltage […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[13,29],"tags":[],"chip_brand":[138],"class_list":["post-3400","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-power-management-ics-pmic","chip_brand-ti"],"acf":{"brief_explanation":"3-pin voltage supervisor (reset IC) with 4.38V threshold, active-low push-pull reset output, 15\u00b5A Iq, SOT-23","date_code":"","package_case":"SOT-23 (DBZ) | 3 pins (2.92 x 1.3 x 1.22 mm)","in_stock":2012,"datasheet":"https:\/\/www.ti.com\/lit\/ds\/symlink\/lm809.pdf","price":"$0.262 @ 1ku","product_introduction":"The LM809M3X-4.38\/NOPB is a 3-pin microprocessor supervisory circuit from Texas Instruments that monitors the VCC supply voltage and asserts a reset signal whenever this voltage declines below the factory-programmed 4.38V reset threshold. The reset signal remains asserted for 240 ms after VCC rises above the threshold. The device features an active-low push-pull RESET output with a supply current of only 15 \u00b5A, making it ideal for use in portable and battery-powered equipment. It is fully specified over temperature from -40\u00b0C to +105\u00b0C.","working_principle":"The LM809 operates as a voltage monitoring circuit with two main subsystems: (1) Voltage Comparison: A precision voltage comparator continuously monitors the VCC supply against the 4.38V reference threshold. When VCC drops below the threshold, the comparator triggers the reset output. (2) Reset Timer: Once VCC rises above the threshold, an internal timer holds the RESET output active for a minimum of 140 ms (240 ms typical) to allow the microprocessor to properly initialize before releasing reset. The push-pull output stage provides fast, defined transitions without external pull-up resistors.","pin_description":"
      Pin<\/th>Name<\/th>Type<\/th>Description<\/th><\/tr>
      1<\/td>GND<\/td>Ground<\/td>Ground connection<\/td><\/tr>
      2<\/td>RESET<\/td>Output<\/td>Active-low reset output (push-pull)<\/td><\/tr>
      3<\/td>VCC<\/td>Power<\/td>Supply voltage input (1V to 5.5V)<\/td><\/tr><\/table>","application_scenarios":"
      • 5V microprocessor system power monitoring and reset generation<\/li>
      • Portable equipment brownout detection<\/li>
      • Embedded controller power-on reset<\/li>
      • Battery-powered digital systems requiring low quiescent current<\/li>
      • Intelligent instruments and consumer electronics<\/li><\/ul>","alternative_models":"
        Model<\/th>Manufacturer<\/th>Threshold<\/th>Package<\/th>Notes<\/th><\/tr>
        MAX809LTR-4.38<\/td>Maxim\/ADI<\/td>4.38V<\/td>SOT-23-3<\/td>Direct equivalent<\/td><\/tr>
        CAT809TTBI-G3<\/td>onsemi<\/td>4.38V<\/td>SOT-23-3<\/td>Pin-compatible<\/td><\/tr>
        LM809M3-4.38\/NOPB<\/td>TI<\/td>4.38V<\/td>SOT-23-3<\/td>Smaller reel option<\/td><\/tr>
        APX809-46SA-7<\/td>Diodes Inc<\/td>4.63V<\/td>SOT-23-3<\/td>Higher threshold option<\/td><\/tr><\/table>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/posts\/3400","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=3400"}],"version-history":[{"count":0,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/posts\/3400\/revisions"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/media?parent=3400"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/categories?post=3400"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/tags?post=3400"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/chip_brand?post=3400"}],"curies":[{"name":"\u062f\u0628\u0644\u064a\u0648 \u0628\u064a","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}