LT1121
LT1121
PRODUCTIONMicropower Low Dropout Regulators with Shutdown
- Part Models
- 54
- 1ku List Price
- Starting From $2.53
Viewing:
Overview
- 0.4V Dropout Voltage
- 150mA Output Current
- 30µA Quiescent Current
- No Protection Diodes Needed
- Adjustable Output from 3.75V to 30V
- 3.3V and 5V Fixed Output Voltages
- Controlled Quiescent Current in Dropout
- Shutdown
- 16µA Quiescent Current in Shutdown
- Stable with 0.33µF Output Capacitor
- Reverse Battery Protection
- No Reverse Current with Input Low
- Thermal Limiting
- Available in the 8-Lead SO, 8-Lead PDIP, 3-Lead SOT-23 and 3-Lead TO-92 Packages
The LT1121/LT1121-3.3/LT1121-5 are micropower low dropout regulators with shutdown. These devices are capable of supplying 150mA of output current with a dropout voltage of 0.4V. Designed for use in battery-powered systems, the low quiescent current, 30µA operating and 16µA in shutdown, makes them an ideal choice. The quiescent current is well-controlled; it does not rise in dropout as it does with many other low dropout PNP regulators.
Other features of the LT1121/LT1121-3.3/LT1121-5 include the ability to operate with very small output capacitors. They are stable with only 0.33µF on the output while most older devices require between 1µF and 100µF for stability. Small ceramic capacitors can be used, enhancing manufacturability. Also the input may be connected to ground or a reverse voltage without reverse current flow from output to input. This makes the LT1121 series ideal for backup power situations where the output is held high and the input is at ground or reversed. Under these conditions only 16µA will flow from the output pin to ground.
Applications
- Low Current Regulator
- Regulator for Battery-Powered Systems
- Post Regulator for Switching Supplies
Documentation
Data Sheet 1
Application Note 7
Design Note 10
Technical Articles 2
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Oct 8, 2024 - 24_0236 Migrating Bottom Trace Code Marking to Top Side Laser Marking for SOIC_N Package |
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| LT1121ACS8#PBF | PRODUCTION | |
| LT1121ACS8#TRPBF | PRODUCTION | |
| LT1121ACS8-3.3#PBF | PRODUCTION | |
| LT1121ACS8-3.3#TRPBF | PRODUCTION | |
| LT1121ACS8-5#PBF | PRODUCTION | |
| LT1121ACS8-5#TRPBF | PRODUCTION | |
| LT1121AHVCS8#PBF | PRODUCTION | |
| LT1121AHVCS8#TRPBF | PRODUCTION | |
| LT1121AHVIS8#PBF | PRODUCTION | |
| LT1121AHVIS8#TRPBF | PRODUCTION | |
| LT1121AIS8#PBF | PRODUCTION | |
| LT1121AIS8#TRPBF | PRODUCTION | |
| LT1121AIS8-3.3#PBF | PRODUCTION | |
| LT1121AIS8-3.3#TRPBF | PRODUCTION | |
| LT1121AIS8-5#PBF | PRODUCTION | |
| LT1121AIS8-5#TRPBF | PRODUCTION | |
| LT1121CS8#PBF | PRODUCTION | |
| LT1121CS8#TRPBF | PRODUCTION | |
| LT1121CS8-3.3#PBF | PRODUCTION | |
| LT1121CS8-3.3#TRPBF | PRODUCTION | |
| LT1121CS8-5#PBF | PRODUCTION | |
| LT1121CS8-5#TRPBF | PRODUCTION | |
| LT1121IS8#PBF | PRODUCTION | |
| LT1121IS8#TRPBF | PRODUCTION | |
| LT1121IS8-3.3#PBF | PRODUCTION | |
| LT1121IS8-3.3#TRPBF | PRODUCTION | |
| LT1121IS8-5#PBF | PRODUCTION | |
| LT1121IS8-5#TRPBF | PRODUCTION | |
|
Oct 12, 2022 - 22_0254 Epoxy Change from Henkel 8290 to 8290A for 8-Lead SOIC Package (PCN part 1 of 2) |
||
| LT1121ACS8#PBF | PRODUCTION | |
| LT1121ACS8#TRPBF | PRODUCTION | |
| LT1121ACS8-3.3#PBF | PRODUCTION | |
| LT1121ACS8-3.3#TRPBF | PRODUCTION | |
| LT1121ACS8-5#PBF | PRODUCTION | |
| LT1121ACS8-5#TRPBF | PRODUCTION | |
| LT1121AHVCS8#PBF | PRODUCTION | |
| LT1121AHVCS8#TRPBF | PRODUCTION | |
| LT1121AHVIS8#PBF | PRODUCTION | |
| LT1121AHVIS8#TRPBF | PRODUCTION | |
| LT1121AIS8#PBF | PRODUCTION | |
| LT1121AIS8#TRPBF | PRODUCTION | |
| LT1121AIS8-3.3#PBF | PRODUCTION | |
| LT1121AIS8-3.3#TRPBF | PRODUCTION | |
| LT1121AIS8-5#PBF | PRODUCTION | |
| LT1121AIS8-5#TRPBF | PRODUCTION | |
| LT1121CS8-3.3#PBF | PRODUCTION | |
| LT1121CS8-3.3#TRPBF | PRODUCTION | |
|
Jun 11, 2021 - 21_0060 Laser Top Mark for 8SOICN Assembled in ADPG, UTL and CRM |
||
| LT1121ACS8#PBF | PRODUCTION | |
| LT1121ACS8#TRPBF | PRODUCTION | |
| LT1121ACS8-3.3#PBF | PRODUCTION | |
| LT1121ACS8-3.3#TRPBF | PRODUCTION | |
| LT1121ACS8-5#PBF | PRODUCTION | |
| LT1121ACS8-5#TRPBF | PRODUCTION | |
| LT1121AHVCS8#PBF | PRODUCTION | |
| LT1121AHVCS8#TRPBF | PRODUCTION | |
| LT1121AHVIS8#PBF | PRODUCTION | |
| LT1121AHVIS8#TRPBF | PRODUCTION | |
| LT1121AIS8#PBF | PRODUCTION | |
| LT1121AIS8#TRPBF | PRODUCTION | |
| LT1121AIS8-3.3#PBF | PRODUCTION | |
| LT1121AIS8-3.3#TRPBF | PRODUCTION | |
| LT1121AIS8-5#PBF | PRODUCTION | |
| LT1121AIS8-5#TRPBF | PRODUCTION | |
| LT1121CS8#PBF | PRODUCTION | |
| LT1121CS8#TRPBF | PRODUCTION | |
| LT1121CS8-3.3#PBF | PRODUCTION | |
| LT1121CS8-3.3#TRPBF | PRODUCTION | |
| LT1121CS8-5#PBF | PRODUCTION | |
| LT1121CS8-5#TRPBF | PRODUCTION | |
| LT1121HVCS8#PBF | PRODUCTION | |
| LT1121HVCS8#TRPBF | PRODUCTION | |
| LT1121HVIS8#PBF | PRODUCTION | |
| LT1121HVIS8#TRPBF | PRODUCTION | |
| LT1121IS8#PBF | PRODUCTION | |
| LT1121IS8#TRPBF | PRODUCTION | |
| LT1121IS8-3.3#PBF | PRODUCTION | |
| LT1121IS8-3.3#TRPBF | PRODUCTION | |
| LT1121IS8-5#PBF | PRODUCTION | |
| LT1121IS8-5#TRPBF | PRODUCTION | |
|
Oct 8, 2024 - 24_0234 Migrating Bottom Trace Code Marking to Top Side Laser Marking for PDIP Package |
||
| LT1121CN8#PBF | PRODUCTION | |
| LT1121CN8-3.3#PBF | PRODUCTION | |
| LT1121CN8-5#PBF | PRODUCTION | |
| LT1121IN8#PBF | PRODUCTION | |
| LT1121IN8-3.3#PBF | PRODUCTION | |
| LT1121IN8-5#PBF | PRODUCTION | |
|
Oct 11, 2022 - 22_0241 Epoxy Change from Henkel 8290 to 8290A for PDIP Package |
||
| LT1121CN8#PBF | PRODUCTION | |
| LT1121CN8-3.3#PBF | PRODUCTION | |
| LT1121CN8-5#PBF | PRODUCTION | |
| LT1121IN8#PBF | PRODUCTION | |
| LT1121IN8-3.3#PBF | PRODUCTION | |
| LT1121IN8-5#PBF | PRODUCTION | |
|
Aug 6, 2022 - 22_0172 Laser Top Mark Conversion for PDIP Packages Assembled in ADPG [PNG] |
||
| LT1121CN8#PBF | PRODUCTION | |
| LT1121CN8-3.3#PBF | PRODUCTION | |
| LT1121CN8-5#PBF | PRODUCTION | |
| LT1121IN8#PBF | PRODUCTION | |
| LT1121IN8-3.3#PBF | PRODUCTION | |
| LT1121IN8-5#PBF | PRODUCTION | |
|
Nov 14, 2022 - 22_0254 Epoxy Change from Henkel 8290 to 8290A for 8-Lead SOIC Package (PCN part 1 of 2) |
||
| LT1121CS8#PBF | PRODUCTION | |
| LT1121CS8#TRPBF | PRODUCTION | |
| LT1121IS8#PBF | PRODUCTION | |
| LT1121IS8#TRPBF | PRODUCTION | |
|
Dec 14, 2023 - 22_0255 Epoxy Change from Henkel 8290 to 8290A for 8-Lead SOIC Package (PCN part 2 of 2) |
||
| LT1121CS8-5#PBF | PRODUCTION | |
| LT1121CS8-5#TRPBF | PRODUCTION | |
| LT1121HVCS8#PBF | PRODUCTION | |
| LT1121HVCS8#TRPBF | PRODUCTION | |
| LT1121HVIS8#PBF | PRODUCTION | |
| LT1121HVIS8#TRPBF | PRODUCTION | |
| LT1121IS8-3.3#PBF | PRODUCTION | |
| LT1121IS8-3.3#TRPBF | PRODUCTION | |
| LT1121IS8-5#PBF | PRODUCTION | |
| LT1121IS8-5#TRPBF | PRODUCTION | |
|
Feb 20, 2022 - 22_0014 Final Packaging Changes for TO-92, TO-5 and TO-46 |
||
| LT1121IZ-3.3#PBF | PRODUCTION | |
| LT1121IZ-5#PBF | PRODUCTION | |
|
Mar 6, 2022 - 22_0014 Final Packaging Changes for TO-92, TO-5 and TO-46 |
||
| LT1121IZ-3.3#TRPBF | PRODUCTION | |
| LT1121IZ-5#TRPBF | PRODUCTION | |
This is the most up-to-date revision of the Data Sheet.
Software Resources
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Tools & Simulations
LTspice 1
Models for the following parts are available in LTspice:
- LT1121
- LT1121-3.3
- LT1121-5
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.