{"id":7021,"date":"2026-06-23T02:04:50","date_gmt":"2026-06-23T02:04:50","guid":{"rendered":"https:\/\/materialparts.com\/a3212elhlt-t\/"},"modified":"2026-06-23T02:04:50","modified_gmt":"2026-06-23T02:04:50","slug":"a3212elhlt-t","status":"publish","type":"post","link":"https:\/\/materialparts.com\/zh\/a3212elhlt-t\/","title":{"rendered":"A3212ELHLT-T"},"content":{"rendered":"

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

The A3212ELHLT-T from Allegro MicroSystems is an ultra-sensitive micropower unipolar Hall-effect switch in a SOT-23-3 package. It features a typical operate point of 7G, 15uA supply current, chopper stabilization for minimal switchpoint drift, and an open-drain output, making it ideal for battery-operated proximity sensing applications.<\/p>\n

\u4e3b\u8981\u89c4\u683c<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n
\u7c7b\u578b<\/td>\nUltra-Sensitive Unipolar Hall-Effect Switch<\/td>\n<\/tr>\n
Operate Point (BOP)<\/td>\n7G (Typical)<\/td>\n<\/tr>\n
Release Point (BRP)<\/td>\n5G (Typical)<\/td>\n<\/tr>\n
Hysteresis<\/td>\n2G (Typical)<\/td>\n<\/tr>\n
\u7535\u6e90\u7535\u538b<\/td>\n2.4V ~ 5.5V<\/td>\n<\/tr>\n
Supply Current<\/td>\n15uA (Typical)<\/td>\n<\/tr>\n
\u8f93\u51fa\u7c7b\u578b<\/td>\nOpen-Drain<\/td>\n<\/tr>\n
Chopper Stabilized<\/td>\nYes<\/td>\n<\/tr>\n
\u5305\u88c5<\/td>\nSOT-23-3 (2.90 x 1.30mm)<\/td>\n<\/tr>\n
\u5de5\u4f5c\u6e29\u5ea6<\/td>\n-40\u00b0C ~ +85\u00b0C (E Grade)<\/td>\n<\/tr>\n<\/table>\n

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    \n
  • Ultra-sensitive 7G operate point for detecting small magnetic fields<\/li>\n
  • Micropower 15uA supply current extends battery life<\/li>\n
  • Chopper stabilization eliminates switchpoint drift over temperature<\/li>\n
  • Open-drain output for easy interfacing with various logic families<\/li>\n
  • Internal bandgap regulator for stable operation across supply range<\/li>\n
  • Tape and reel packaging (-T suffix)<\/li>\n<\/ul>\n

    \u5e94\u7528<\/h2>\n
      \n
    • Cell phone flip\/slide detection<\/li>\n
    • Battery-operated proximity sensing<\/li>\n
    • Door and lid position detection<\/li>\n
    • Consumer appliance reed switch replacement<\/li>\n
    • Portable medical device cover sensing<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The A3212ELHLT-T from Allegro MicroSystems is an ultra-sensitive micropower unipolar Hall-effect switch in a SOT-23-3 package. It features a typical operate point of 7G, 15uA supply current, chopper stabilization for minimal switchpoint drift, and an open-drain output, making it ideal for battery-operated proximity sensing applications. Key Specifications Type Ultra-Sensitive Unipolar Hall-Effect Switch Operate […]<\/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":[13,42],"tags":[],"chip_brand":[176],"class_list":["post-7021","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-sensors","chip_brand-allegro"],"acf":{"brief_explanation":"Ultra-sensitive unipolar Hall switch, 7G BOP, 15uA supply, chopper stabilized, open-drain output in SOT-23-3","date_code":"","package_case":"SOT-23-3 (2.90 x 1.30 x 1.00 mm)","in_stock":10896,"datasheet":"https:\/\/www.allegromicro.com\/en\/products\/sensors\/hall-effect-and-magnetic-sensor-ics\/switches-and-latches\/a3212","price":"$0.55 @ 1ku","product_introduction":"The A3212ELHLT-T from Allegro MicroSystems is an ultra-sensitive, micropower, unipolar Hall-effect switch designed for battery-operated applications where power consumption and sensitivity are critical. The device features a very low operate point of 7G (typical), enabling detection of small magnetic fields from small or distant magnets. The micropower architecture draws only 15uA typical supply current, making it ideal for always-on battery-powered systems. Chopper stabilization circuitry dynamically cancels offset and temperature drift, ensuring consistent switchpoint performance over the -40\u00b0C to +85\u00b0C temperature range. The open-drain output can be pulled up to any voltage up to 24V, providing flexibility for interfacing with different logic families.","working_principle":"The A3212 uses a chopper-stabilized Hall plate architecture. The Hall element is periodically switched between two configurations, and the resulting output is synchronously demodulated to extract the magnetic field signal while canceling DC offset and 1\/f noise. This dynamic offset cancellation technique eliminates the temperature-dependent drift that plagues conventional Hall sensors. When the applied magnetic flux density exceeds the operate point (BOP = 7G typical), the output transistor turns on (open-drain pulls low). When the field decreases below the release point (BRP = 5G typical), the output turns off. The 2G hysteresis prevents output chatter near the switching threshold. The device operates in a latched sample-and-sleep mode to achieve the 15uA supply current.","pin_description":"
      Pin<\/th>Name<\/th>Function<\/th><\/tr>
      1<\/td>VCC<\/td>Supply voltage (2.4V-5.5V)<\/td><\/tr>
      2<\/td>OUT<\/td>Open-drain output - low when B > BOP<\/td><\/tr>
      3<\/td>GND<\/td>Ground<\/td><\/tr><\/table>","application_scenarios":"
      • Cell Phone Flip Detection<\/b>: 7G sensitivity detects small magnet in phone shell; 15uA current allows always-on operation<\/li>
      • Laptop Lid Sensor<\/b>: Detects magnet in display lid for sleep\/wake function<\/li>
      • Smart Meter Tamper Detection<\/b>: Senses magnetic field from external magnet used to tamper with meter<\/li>
      • Reed Switch Replacement<\/b>: Solid-state reliability with no contact bounce; lower power consumption<\/li><\/ul>","alternative_models":"
        Model<\/th>Manufacturer<\/th>Key Difference<\/th><\/tr>
        A3213ELHLT-T<\/td>Allegro<\/td>South-pole sensitive version<\/td><\/tr>
        A1101ELHLT-T<\/td>Allegro<\/td>35G BOP, higher sensitivity, 1.8mA supply<\/td><\/tr>
        HAL502SF-A<\/td>Micronas<\/td>2.5-24V, unipolar, SOT-23<\/td><\/tr>
        TCS40DLR<\/td>TDK<\/td>South-pole, micropower, SOT-23-3<\/td><\/tr>
        AH3213-Z-T<\/td>Diodes Inc<\/td>2.4-5.5V, micropower, SOT-23<\/td><\/tr><\/table>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/7021","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=7021"}],"version-history":[{"count":0,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/7021\/revisions"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/media?parent=7021"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/categories?post=7021"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/tags?post=7021"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/chip_brand?post=7021"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}