The LD1117DT33CTR is an 800mA fixed 3.3V LDO linear regulator from STMicroelectronics, 1V dropout at 800mA, maximum input voltage 15V, in a DPak (TO-252) package, suitable for embedded system 3.3V power supply.<\/p>\n
LD1117DT33CTR Overview The LD1117DT33CTR is an 800mA fixed 3.3V LDO linear regulator from STMicroelectronics, 1V dropout at 800mA, maximum input voltage 15V, in a DPak (TO-252) package, suitable for embedded system 3.3V power supply. Key Features Fixed output voltage: 3.3V Maximum output current: 800mA Dropout voltage: 1V at 800mA Maximum input voltage: 15V Line regulation: […]<\/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":[142],"class_list":["post-8063","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-low-dropout-regulators-ldo","chip_brand-st"],"acf":{"brief_explanation":"800mA LDO, 3.3V fixed, 1V dropout, DPAK","date_code":"","package_case":"DPAK (TO-252) (6.60 x 6.20 x 2.40 mm)","in_stock":8444,"datasheet":"https:\/\/www.st.com\/resource\/en\/datasheet\/ld1117.pdf","price":"$0.19 @ 1ku","product_introduction":"The LD1117DT33CTR is a fixed 3.3 V output, 800 mA low-dropout linear voltage regulator from STMicroelectronics in a DPAK (TO-252) surface-mount package. With a typical dropout voltage of 1 V at full load, it can regulate from a 4.3 V input to deliver a stable 3.3 V supply. The device features internal current limiting and thermal shutdown protection, requiring only a 10 uF output capacitor for stability, making it ideal for cost-sensitive point-of-load regulation.","working_principle":"The LD1117DT33CTR uses an NPN pass transistor in a Darlington configuration driven by an error amplifier. The error amplifier compares a fraction of the output voltage (sensed through an internal resistor divider) with a precision bandgap reference. When the output drops below the 3.3 V target, the amplifier increases drive to the pass transistor, raising the output. The NPN structure provides lower dropout than conventional PNP LDOs at moderate loads, while maintaining low quiescent current. The current limiter senses pass transistor current and reduces drive when the limit is exceeded. Thermal shutdown disables the output when junction temperature exceeds approximately 150 degrees C.","pin_description":"
| Pin<\/th> | Name<\/th> | Description<\/th><\/tr> | ||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1<\/td> | GND<\/td> | Ground reference and thermal pad connection<\/td><\/tr> | ||||||||||||||||||||||||||||||||||||
| 2<\/td> | VOUT<\/td> | Regulated 3.3 V output; connect 10 uF capacitor to GND<\/td><\/tr> | ||||||||||||||||||||||||||||||||||||
| 3<\/td> | VIN<\/td> | Unregulated input supply (4.3 V to 15 V)<\/td><\/tr><\/table> Package: DPAK (TO-252), 3 pins. The tab (pin 2) serves as both the output and primary thermal path to the PCB copper pour.<\/p>\n LD1117DT33CTR uses the DPAK (TO-252, SOT-428) surface-mount package with Pin 1 = GND\/Adjust, Pin 2 = VOUT (tab), Pin 3 = VIN. The large tab underneath is electrically connected to VOUT (Pin 2) and must be soldered to a PCB copper pour for both electrical continuity and thermal dissipation. Unlike the LD1117DTTR fixed version, the DT33CTR variant has the 3.3V output voltage internally trimmed. The DPAK package provides superior thermal performance compared to SOT-223, with Rth(j-a) \u2248 50\u00b0C\/W on FR-4 with 1oz copper. Input and output capacitors (10\u00b5F tantalum or ceramic) must be placed within 10mm of the device pins for stable operation.<\/p>","application_scenarios":"
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