LT1129MPST-3.3#PBF Analog Devices Integrated Circuit (SOT223 (3-Pin)) In Stock
The LT1129MPST-3.3#PBF is a 700 mA micropower low-dropout LDO regulator with a fixed 3.3 V output, shutdown pin, and 0.45 V typical dropout voltage in a SOT-223 package. It accepts input voltages from 3.8 V to 20 V and is ideal for battery-powered and automotive supplies. Available from stock with worldwide shipping.
- Manufacturer
- Analog Devices
- Package
- SOT223 (3-Pin)
- Pin Count
- 3
- Lifecycle
- ACTIVE
- Datasheet
- LT1129MPST-3.3#PBF Datasheet PDF
- Category
- Integrated Circuit
- Price
- From $12.0200(MOQ 1)
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- 700 mA output current capability with only 0.45 V typical dropout voltage, maximizing battery life in low-voltage systems
- Wide input voltage range from 3.8 V to 20 V with absolute maximum rating of 30 V for rugged automotive and industrial use
- Integrated shutdown pin enabling microcontroller-controlled power sequencing and sleep-mode current reduction
- Fixed 3.3 V output in a compact SOT-223 package with exposed tab for efficient thermal management on standard PCBs
Applications
The LT1129MPST-3.3#PBF is designed for battery-powered portable equipment, automotive accessories, and industrial sensors requiring a stable 3.3 V rail from higher-voltage inputs. Its 700 mA output and low 0.45 V dropout enable efficient regulation from Li-Ion cells or automotive 12 V buses with minimal heat dissipation. The shutdown pin simplifies power management in multi-rail embedded systems where sub-circuits must be selectively powered down to extend battery runtime.
Specifications
| Pbfree Code | No |
| Manufacturer Package Code | 05-08-1630 |
| YTEOL | 10 |
| Adjustability | FIXED |
| Dropout Voltage1-Max | 0.7V |
| Dropout Voltage1-Nom | 0.45V |
| Input Voltage Absolute-Max | 30V |
| Input Voltage-Max | 20V |
| Input Voltage-Min | 3.8V |
| JESD-30 Code | R-PSSO-G3 |
| JESD-609 Code | e3 |
| Line Regulation-Max | 0.01% |
| Load Regulation-Max | 0.03% |
| Number of Functions | 1 |
| Number of Outputs | 1 |
| Operating Temperature TJ-Max | 125°C |
| Operating Temperature TJ-Min | -55 °C |
| Output Current1-Max | 0.7A |
| Output Voltage1-Max | 3.4V |
| Output Voltage1-Min | 3.2V |
| Output Voltage1-Nom | 3.3V |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | SOT-223 |
| Package Shape | RECTANGULAR |
| Package Style | SMALL OUTLINE |
| Peak Reflow Temperature (Cel) | 260 |
| Qualification Status | Not Qualified |
| Regulator Type | FIXED POSITIVE SINGLE OUTPUT LDO REGULATOR |
| Surface Mount | YES |
| Technology | BIPOLAR |
| Terminal Finish | Matte Tin (Sn) |
| Terminal Form | GULL WING |
| Terminal Pitch | 2.3mm |
| Terminal Position | SINGLE |
| Time@Peak Reflow Temperature-Max (s) | 30 |
| Voltage Tolerance-Max | 3% |
| Package | SOT223 (3-Pin) |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| ECCN | EAR99 |
| HTS Code | 8542.39.00.01 |
| Country of Origin | Thailand |
Alternate & Equivalent Parts
No known alternates. Submit an RFQ and our team can suggest alternatives.
Frequently Asked Questions
What is the dropout voltage of the LT1129MPST-3.3#PBF, and how does this affect battery-powered system design?
The LT1129MPST-3.3#PBF has a typical dropout voltage of 0.45 V and a maximum of 0.7 V at 700 mA load. This means the device maintains a regulated 3.3 V output until the input drops to approximately 3.75 V to 4.0 V, extracting more usable charge from Li-Ion or alkaline batteries compared to standard LDOs with 1.2 V or higher dropout voltages.
How does the shutdown pin on the LT1129MPST-3.3#PBF improve power management in embedded designs?
The active-low shutdown pin disables the regulator output, reducing supply current to microamp-level quiescent draw. This allows a host microcontroller or power management IC to selectively cut the 3.3 V rail to peripherals during sleep modes, enabling significant runtime extension in battery-powered IoT nodes, sensor modules, and portable instruments operating from 3.8 V to 20 V input sources.
For a 12 V automotive accessory design needing a 3.3 V rail, why choose the LT1129MPST-3.3#PBF over a standard LDO?
The LT1129MPST-3.3#PBF tolerates input voltages up to 20 V with a 30 V absolute maximum, making it robust against automotive load-dump transients and 12 V cold-crank conditions. Its 700 mA output handles typical MCU and communication module loads, while the low dropout and SOT-223 package with exposed tab manage the power dissipation from a nominal 12 V to 3.3 V conversion efficiently.
What thermal performance does the SOT-223 package provide for the LT1129MPST-3.3#PBF at high load currents?
The SOT-223 package includes an exposed metal tab connected to the output pin, providing a thermal path to the PCB copper pour. With adequate copper area, junction-to-ambient thermal resistance can be reduced to approximately 40-60 °C/W, allowing the device to sustain 700 mA output with an 8 V to 10 V input-to-output differential without exceeding the maximum junction temperature of 125 °C in typical ambient conditions.
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About Analog Devices
Analog Devices (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing integrated circuits used in virtually all types of electronic equipment.
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