{"id":7798,"date":"2026-06-27T03:26:28","date_gmt":"2026-06-27T03:26:28","guid":{"rendered":"https:\/\/materialparts.com\/lm1085it-5-0-2\/"},"modified":"2026-06-27T03:26:28","modified_gmt":"2026-06-27T03:26:28","slug":"lm1085it-5-0-2","status":"publish","type":"post","link":"https:\/\/materialparts.com\/zh\/lm1085it-5-0-2\/","title":{"rendered":"LM1085IT-5.0"},"content":{"rendered":"

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

The LM1085IT-5.0 is a 3A, 5.0V fixed-output low-dropout positive regulator from Texas Instruments with 1.3V typical dropout at full load, current limiting, and thermal shutdown in a TO-220-3 through-hole package.<\/p>\n

\u4e3b\u8981\u89c4\u683c<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n
Output Voltage<\/td>\n5.0 V (fixed)<\/td>\n<\/tr>\n
\u8f93\u51fa\u7535\u6d41<\/td>\n3 A (maximum)<\/td>\n<\/tr>\n
Dropout Voltage<\/td>\n1.3 V typical, 1.5 V max at 3A<\/td>\n<\/tr>\n
\u8f93\u5165\u7535\u538b\u8303\u56f4<\/td>\n2.6 V to 27 V<\/td>\n<\/tr>\n
Line Regulation<\/td>\n0.015% typical (10 mV max)<\/td>\n<\/tr>\n
Load Regulation<\/td>\n0.1% typical (20 mV max)<\/td>\n<\/tr>\n
\u9759\u6001\u7535\u6d41<\/td>\n10 mA max<\/td>\n<\/tr>\n
Output Voltage Tolerance<\/td>\n\u00b12%<\/td>\n<\/tr>\n
\u5de5\u4f5c\u6e29\u5ea6<\/td>\n-40\u00b0C to +125\u00b0C<\/td>\n<\/tr>\n
\u5305\u88c5<\/td>\nTO-220-3 (NDE)<\/td>\n<\/tr>\n<\/table>\n

\u7279\u70b9<\/h2>\n
    \n
  • 3A output current capability<\/li>\n
  • Low dropout: 1.3V typical at 3A<\/li>\n
  • LM317-compatible pinout<\/li>\n
  • Zener-trimmed bandgap reference<\/li>\n
  • Current limiting and thermal shutdown protection<\/li>\n
  • Excellent line and load regulation<\/li>\n
  • Available in 3.3V, 5.0V, 12V and adjustable versions<\/li>\n<\/ul>\n

    \u5e94\u7528<\/h2>\n
      \n
    • Post-regulation for switching supplies<\/li>\n
    • Battery chargers<\/li>\n
    • 5V logic power supplies<\/li>\n
    • High-current linear regulation<\/li>\n
    • Active SCSI terminators<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The LM1085IT-5.0 is a 3A, 5.0V fixed-output low-dropout positive regulator from Texas Instruments with 1.3V typical dropout at full load, current limiting, and thermal shutdown in a TO-220-3 through-hole package. Key Specifications Output Voltage 5.0 V (fixed) Output Current 3 A (maximum) Dropout Voltage 1.3 V typical, 1.5 V max at 3A Input […]<\/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":[13,32],"tags":[],"chip_brand":[138],"class_list":["post-7798","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-low-dropout-regulators-ldo","chip_brand-ti"],"acf":{"brief_explanation":"3A 5V LDO regulator, 1.3V dropout, current limiting, thermal shutdown, TO-220","date_code":"","package_case":"TO-220-3 (10.16 x 4.70 x 8.89 mm)","in_stock":4882,"datasheet":"https:\/\/www.ti.com\/lit\/ds\/symlink\/lm1085.pdf","price":"$0.87 @ 1ku","product_introduction":"The LM1085IT-5.0 is a 3A low-dropout positive voltage regulator from Texas Instruments providing a fixed 5.0V output with only 1.3V typical dropout voltage at full 3A load. It features the same pinout as the industry-standard LM317, making it a drop-in upgrade for applications requiring higher output current or lower dropout. The internal circuit includes a zener-trimmed bandgap reference for precise 5.0V output, current limiting for short-circuit protection, and thermal shutdown to prevent damage from excessive junction temperature. The device achieves 0.015% line regulation and 0.1% load regulation for stable output under varying conditions.","working_principle":"The LM1085IT-5.0 uses an NPN pass transistor driven by a PNP current source in a Darlington-like configuration, enabling low dropout voltage while maintaining the LM317-compatible pinout. The internal zener-trimmed bandgap reference generates a stable voltage that is compared with a fraction of the output voltage through an integrated voltage divider (since this is a fixed-output version). The error amplifier drives the pass transistor to maintain regulation. Current limiting is implemented by sensing the voltage across an internal sense resistor and reducing the drive to the pass transistor when the limit is reached. Thermal shutdown activates when the junction temperature exceeds approximately 165\u00b0C, turning off the output until the device cools. The TO-220 package with exposed tab provides good thermal performance for the 3A output rating.","pin_description":"\n
      Pin<\/th>Name<\/th>Type<\/th>Description<\/th><\/tr>\n
      1<\/td>ADJ\/GND<\/td>Ground<\/td>Adjust pin (connected to ground in fixed version)<\/td><\/tr>\n
      2<\/td>VOUT<\/td>Output<\/td>5.0V regulated output<\/td><\/tr>\n
      3<\/td>VIN<\/td>Input<\/td>Unregulated input supply (6.3V to 27V)<\/td><\/tr>\n
      Tab<\/td>VOUT<\/td>Output<\/td>Thermal tab (connected to VOUT, heatsink to GND)<\/td><\/tr>\n<\/table>","application_scenarios":"
        \n
      • Post-Regulation:<\/strong> Clean 5V output after a switching pre-regulator, eliminating switching noise with low dropout<\/li>\n
      • Battery-Powered Systems:<\/strong> 1.3V dropout at 3A enables regulation from 6.3V+ battery sources<\/li>\n
      • 5V Logic Supply:<\/strong> Fixed 5.0V output with \u00b12% tolerance powers TTL and CMOS logic reliably<\/li>\n
      • SCSI Terminators:<\/strong> 3A current capability supports active termination of SCSI buses<\/li>\n
      • High-Current Linear Supplies:<\/strong> TO-220 with external heatsink delivers full 3A for bench and industrial power supplies<\/li>\n<\/ul>","alternative_models":"\n
        Model<\/th>Manufacturer<\/th>Key Difference<\/th><\/tr>\n
        LM1084IT-5.0<\/td>TI<\/td>5A version, same TO-220 package<\/td><\/tr>\n
        LM1086IT-5.0<\/td>TI<\/td>1.5A version, lower cost<\/td><\/tr>\n
        LM1085IS-5.0\/NOPB<\/td>TI<\/td>TO-263 (D2PAK) SMD version<\/td><\/tr>\n
        LT1085CT-5<\/td>ADI<\/td>Pin-compatible, similar specs<\/td><\/tr>\n
        SPX1085AM-L-5-0<\/td>Sipex\/MaxLinear<\/td>Pin-compatible alternative<\/td><\/tr>\n<\/table>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/7798","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=7798"}],"version-history":[{"count":0,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/7798\/revisions"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/media?parent=7798"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/categories?post=7798"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/tags?post=7798"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/chip_brand?post=7798"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}