{"id":8730,"date":"2026-06-30T05:20:05","date_gmt":"2026-06-30T05:20:05","guid":{"rendered":"https:\/\/materialparts.com\/tlvh431idbzr\/"},"modified":"2026-07-01T01:44:41","modified_gmt":"2026-07-01T01:44:41","slug":"tlvh431idbzr","status":"publish","type":"post","link":"https:\/\/materialparts.com\/ar\/tlvh431idbzr\/","title":{"rendered":"TLVH431IDBZR"},"content":{"rendered":"

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

The TLVH431IDBZR is a Texas Instruments 1.5% low-voltage adjustable precision shunt regulator. It features a 1.24 V reference voltage, adjustable output from 1.24 V to 18 V, 100 \u00b5A to 70 mA cathode current range, and 0.25 \u03a9 typical output impedance. The device is packaged in a 3-pin SOT-23 and operates from -40\u00b0C to +85\u00b0C.<\/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
Reference Voltage<\/td>\n1.24 V (typical)<\/td>\n<\/tr>\n
Initial Accuracy<\/td>\n1.5% (standard grade)<\/td>\n<\/tr>\n
Adjustable Output<\/td>\nVREF to 18 V<\/td>\n<\/tr>\n
Cathode Current Range<\/td>\n100 \u00b5A to 70 mA<\/td>\n<\/tr>\n
Output Impedance<\/td>\n0.25 \u03a9 (typical)<\/td>\n<\/tr>\n
\u0627\u0644\u062d\u0632\u0645\u0629<\/td>\nSOT-23-3<\/td>\n<\/tr>\n<\/table>\n

\u0627\u0644\u0645\u064a\u0632\u0627\u062a<\/h2>\n
    \n
  • Low-voltage operation: down to 1.24 V<\/li>\n
  • Adjustable output: VREF to 18 V<\/li>\n
  • 1.5% reference tolerance (standard grade)<\/li>\n
  • 100 \u00b5A minimum cathode current<\/li>\n
  • 0.25 \u03a9 typical output impedance<\/li>\n
  • Sharp turn-on characteristic<\/li>\n
  • Lower VREF than TL431 (1.24 V vs 2.5 V)<\/li>\n<\/ul>\n

    \u0627\u0644\u062a\u0637\u0628\u064a\u0642\u0627\u062a<\/h2>\n
      \n
    • Isolated feedback for 3.3V SMPS<\/li>\n
    • Adjustable voltage reference for converters<\/li>\n
    • Low-voltage Zener replacement<\/li>\n
    • Voltage monitoring and comparator<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The TLVH431IDBZR is a Texas Instruments 1.5% low-voltage adjustable precision shunt regulator. It features a 1.24 V reference voltage, adjustable output from 1.24 V to 18 V, 100 \u00b5A to 70 mA cathode current range, and 0.25 \u03a9 typical output impedance. The device is packaged in a 3-pin SOT-23 and operates from -40\u00b0C […]<\/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":[19,13],"tags":[],"chip_brand":[138],"class_list":["post-8730","post","type-post","status-publish","format-standard","hentry","category-analog-linear-ics","category-integrated-circuits-ics","chip_brand-ti"],"acf":{"brief_explanation":"1.24V-18V adjustable shunt voltage reference, 1.5% tolerance, 100uA-70mA, SOT-23-3","date_code":"","package_case":"3-SOT-23 (2.92 x 1.30 mm)","in_stock":12000,"datasheet":"https:\/\/www.ti.com\/product\/TLVH431","price":"$0.18 @ 1ku","product_introduction":"The Texas Instruments TLVH431IDBZR is a low-voltage adjustable precision shunt regulator with a 1.24V reference voltage and output adjustable from 1.24V to 18V using two external resistors. The device operates with cathode currents from 100 uA to 70 mA\u2014a significant improvement over the widely used TL431 which requires a minimum 1 mA cathode current\u2014making the TLVH431 suitable for low-power and battery-operated designs. The 1.5% initial reference tolerance (I grade, -40C to +85C) provides adequate accuracy for voltage monitoring and feedback regulation in power supplies. The 0.25 ohm typical dynamic impedance ensures tight regulation under varying load conditions. The lower 1.24V reference voltage (compared to TL431 at 2.495V) enables direct regulation of 3.3V and lower output rails without the resistor-divider overhead that reduces efficiency. The SOT-23-3 package occupies minimal PCB area, and the 1 uA maximum off-state cathode current (when REF pin is grounded) eliminates power dissipation concerns in shutdown modes.","working_principle":"The TLVH431 is a three-terminal shunt regulator consisting of an internal 1.24V bandgap reference, a transconductance error amplifier, and an open-collector NPN output transistor. When the voltage at the REF pin exceeds the internal 1.24V reference, the error amplifier drives the cathode (K) pin to sink more current, pulling the cathode voltage lower. Conversely, when REF falls below 1.24V, the cathode current decreases, allowing the cathode voltage to rise. In the typical application with two external resistors R1 and R2 from cathode to REF and REF to anode respectively, the output voltage is set by VO = VREF x (1 + R1\/R2) + Iref x R1, where Iref is typically 0.1 uA. The device enters regulation when the cathode current exceeds the minimum 100 uA threshold. In isolated flyback converters, the TLVH431 is used with an optocoupler to close the feedback loop: the TLVH431 compares a fraction of the output voltage with its reference and drives the optocoupler LED, which modulates the primary-side PWM controller duty cycle.","pin_description":"
      Pin<\/th>Mnemonic<\/th>Description<\/th><\/tr>
      1<\/td>REF<\/td>Reference input (1.24V threshold)<\/td><\/tr>
      2<\/td>K<\/td>Cathode (output, active pull-down)<\/td><\/tr>
      3<\/td>A<\/td>Anode (ground reference)<\/td><\/tr><\/table>","application_scenarios":"
      • Secondary side regulation in 3.3V flyback SMPS with optocoupler feedback, replacing TL431 for lower-voltage outputs<\/li>
      • Adjustable voltage monitoring with 1.24V reference enabling detection of 1.8V and lower logic rails<\/li>
      • Low-cost precision current sink with output voltage set by two external resistors from 1.24V to 18V<\/li>
      • Zener diode replacement with sharp turn-on characteristic and 0.25 ohm dynamic impedance for improved regulation<\/li><\/ul>","alternative_models":"
        Model<\/th>Manufacturer<\/th>Key Difference<\/th><\/tr>
        TL431IDBZR<\/td>TI<\/td>2.495V reference (higher min voltage), widely used<\/td><\/tr>
        TLV431IDBZR<\/td>TI<\/td>1.24V reference, lower max cathode voltage (6V)<\/td><\/tr>
        TLVH432IDBZR<\/td>TI<\/td>Same as TLVH431 with alternative SOT-23 pinout<\/td><\/tr>
        ZR431<\/td>Zetex\/Diodes<\/td>1.24V reference, 1% grade available<\/td><\/tr><\/table>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/posts\/8730","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=8730"}],"version-history":[{"count":1,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/posts\/8730\/revisions"}],"predecessor-version":[{"id":8886,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/posts\/8730\/revisions\/8886"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/media?parent=8730"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/categories?post=8730"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/tags?post=8730"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/chip_brand?post=8730"}],"curies":[{"name":"\u062f\u0628\u0644\u064a\u0648 \u0628\u064a","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}