The LM1085IT-5.0 is a 3A low-dropout positive voltage regulator from Texas Instruments providing a fixed 5.0V output. With a maximum dropout voltage of 1.5V at 3A, it is pin-compatible with the industry-standard LM317 and housed in a TO-220-3 through-hole package. Ideal for high-efficiency linear regulation, battery charging, and post-regulation applications.<\/p>\n
Product Overview The LM1085IT-5.0 is a 3A low-dropout positive voltage regulator from Texas Instruments providing a fixed 5.0V output. With a maximum dropout voltage of 1.5V at 3A, it is pin-compatible with the industry-standard LM317 and housed in a TO-220-3 through-hole package. Ideal for high-efficiency linear regulation, battery charging, and post-regulation applications. Key Specifications Output […]<\/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-6479","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-low-dropout-regulators-ldo","chip_brand-ti"],"acf":{"brief_explanation":"3A LDO linear regulator, 5.0V fixed output, 1.3V dropout, TO-220-3, pin-compatible with LM317","date_code":"","package_case":"TO-220-3","in_stock":4380,"datasheet":"https:\/\/www.ti.com\/lit\/ds\/symlink\/lm1085.pdf","price":"$0.79","product_introduction":"The LM1085IT-5.0 is a low-dropout positive voltage regulator from Texas Instruments capable of delivering 3A output current with a maximum dropout voltage of 1.5V. The device features a fixed 5.0V output with \u00b14% accuracy, making it ideal for applications requiring a stable 5V rail from a higher voltage source. The internal current limiting and thermal shutdown protection ensure reliable operation under fault conditions. The pinout is compatible with the industry-standard LM317, allowing easy upgrade paths in existing designs. The IT suffix indicates industrial temperature range and tube packaging.","working_principle":"The LM1085IT-5.0 uses a PNP pass transistor in a common-emitter configuration to achieve low dropout voltage. Unlike traditional NPN-based regulators where dropout voltage is at least 2V (V_BE + V_SAT), the PNP architecture reduces dropout to the saturation voltage of the pass transistor (1.3V typical at 3A). The internal bandgap reference provides a stable voltage reference trimmed by Zener zap during manufacturing to set the fixed 5.0V output. The error amplifier compares a fraction of the output voltage with the reference and drives the pass transistor to maintain regulation. Current limiting is achieved by sensing the voltage drop across an internal sense resistor, while thermal shutdown activates at approximately 165\u00b0C junction temperature.","pin_description":"
| Pin<\/th> | Name<\/th> | Function<\/th><\/tr> | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1<\/td> | ADJ\/GND<\/td> | Adjust pin (grounded for fixed output versions)<\/td><\/tr> | ||||||||||||
| 2<\/td> | VOUT<\/td> | Regulated 5.0V output<\/td><\/tr> | ||||||||||||
| 3<\/td> | VIN<\/td> | Unregulated input voltage (2.6V to 29V)<\/td><\/tr><\/table>","application_scenarios":"The LM1085IT-5.0 is commonly used as a 5V post-regulator following a switching power supply, where its low dropout voltage allows efficient operation even when the input voltage is only slightly above 5V. In battery charging applications, the 3A output capability and current limiting make it suitable for charging multi-cell battery packs. As a microprocessor supply, the low output noise (38 \u00b5Vrms) and good PSRR (30 dB at 100 kHz) ensure clean power delivery to noise-sensitive digital circuits. The thermal shutdown protection is critical in enclosed applications where heatsink options are limited.","alternative_models":"
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