LTC3405A-1.8 - 1.8V, 1.5MHz, 300mA Synchronous Step-Down Regulators in ThinSOT
Features
- High Efficiency: Up to 93%
- Very Low Quiescent Current: Only 20µA During Operation
- 300mA Output Current at VIN = 3V
- 2.5V to 5.5V Input Voltage Range
- 1.5MHz Constant Frequency Operation
- No Schottky Diode Required
- Low Dropout Operation: 100% Duty Cycle
- Stable with Ceramic Capacitors
- Shutdown Mode Draws <1µA Supply Current
- ±3% Output Voltage Accuracy
- Current Mode Operation for Excellent Line and Load Transient Response
- Overtemperature Protected
- Low Profile (1mm) ThinSOT™ Package
Typical Application
Description
The LTC3405A-1.5/LTC3405A-1.8 are high efficiency monolithic synchronous buck regulators using a constant frequency, current mode architecture. Supply current during operation is only 20µA and drops to <1µA in shutdown. The 2.5V to 5.5V input voltage range makes the LTC3405A-1.5/LTC3405A-1.8 ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems.
Switching frequency is internally set at 1.5MHz, allowing the use of small surface mount inductors and capacitors.
The LTC3405A-1.5/LTC3405A-1.8 are specifically designed to work well with ceramic output capacitors, achieving very low output voltage ripple and a small PCB footprint.
The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. The LTC3405A-1.5/LTC3405A-1.8 are available in a low profile (1mm) ThinSOT package.
For adjustable output voltage, refer to the LTC3405A data sheet.
Protected by U.S. Patents, including 6580258, 5481178.
| Vout | Features | |
| LTC3405 | Adj. | - |
| LTC3405A | Adj. | Stable With All Ceramic Caps |
| LTC3405A-1.375 | 1.375V | Stable With All Ceramic Caps |
| LTC3405A-1.5 | 1.5V | Stable With All Ceramic Caps |
| LTC3405A-1.8 | 1.8V | Stable With All Ceramic Caps |
Packaging
CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.
For complete and up to date package information and drawings, please refer to our packaging page
| Part Number | Package | Code | Temp | Package Drawing |
RoHS |
|---|---|---|---|---|---|
| LTC3405AES6-1.8#PBF | SOT-23 | S6 | E | 05-08-1636 | Yes |
| LTC3405AES6-1.8#TRMPBF | SOT-23 | S6 | E | 05-08-1636 | Yes |
| LTC3405AES6-1.8#TRPBF | SOT-23 | S6 | E | 05-08-1636 | Yes |
Order Info
- Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
- Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
- Please refer to our general ordering information or the product datasheet for more details
Package Variations and Pricing
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LTC3405AES6-1.8#PBF | SOT-23 | E | $2.37 | Yes | ||
| LTC3405AES6-1.8#TRMPBF | SOT-23 | E | $2.37 | $1.69 | Yes | |
| LTC3405AES6-1.8#TRPBF | SOT-23 | E | $2.37 | $1.67 | Yes | |
| Buy Now • Request Samples | ||||||
Demo Boards
Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC480A-C | LTC3405AES6-1.8 | Thin SOT Synchronous Buck Regulator, 2.5 to 5.5 Vin, 1.8Vout 300mA(3.0 Vin min), (Small size Inductor) | $75.00 | |
| DC480A-D | LTC3405AES6-1.8 | Thin SOT Synchronous Buck Regulator, 2.5 to 5.5 Vin, 1.8Vout 300mA(3.0 Vin min), (High Efficiency Inductor) | $75.00 | |
| Buy Now | |||
Applications
- Cellular Telephones
- Personal Information Appliances
- Wireless and DSL Modems
- Digital Still Cameras
- MP3 Players
- Portable Instruments
People Who Viewed This Product Also Viewed
- LTC3631 - High Efficiency, High Voltage 100mA Synchronous Step-Down Converter
- LTC3115-1 - 40V, 2A Synchronous Buck-Boost DC/DC Converter
- LT8610 - 42V, 2.5A Synchronous Step-Down Regulator with 2.5μA Quiescent Current
- LTC3789 - High Efficiency, Synchronous, 4-Switch Buck-Boost Controller
- LT1934 - Micropower Step-Down Switching Regulators in ThinSOT
- LTC3405A - 1.5MHz, 300mA Synchronous Step-Down Regulator in ThinSOT
- LTC3388 - 20V High Efficiency Nanopower Step-Down Regulator
- LTC3410 - 2.25MHz, 300mA Synchronous Step-Down Regulator in SC70
- LTC4000 - High Voltage High Current Controller for Battery Charging and Power Management
- LTC3104 - 2.6μA Quiescent Current, 15V, 300mA Synchronous Step-Down DC/DC Converter and 10mA LDO
Product Notifications
Please login to your MyLinear account for notifications of datasheet updates, new document releases and LTspice model announcements for your favorite products. If you do not have a MyLinear account you may Sign Up Now.
Forgot your password? Click here.
Need help? Email mylinear@linear.com with questions and comments.
Design Tools
LTspice
LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice
Models for the following parts are available in LTspice:
LTC3405
LTC3405A
LTC3405A-1.375
LTC3405A-1.5
LTC3405A-1.8
LTpowerCAD
The LTpowerCAD design tool is a complete power supply design tool program that can significantly ease the tasks of power supply design. It guides users to a solution, selects power stage components, provides detailed power efficiency, shows quick loop bode plot stability and load transient analysis, and can export a final design to LTspice for simulation. Click here to download LTpowerCAD
To open the project file for this circuit:
- Step 1: If you have not installed LTpowerCAD on this computer, download and install LTpowerCAD
- Step 2: Once LTpowerCAD is installed, click on the link(s) below to open the project file
- Step 3: If LTpowerCAD does not automatically open after clicking the link above, you can open the project file by right clicking on the link and selecting "Save Target As." After saving the file to your computer, start LTpowerCAD and open the project file by selecting 'Open Project' from the 'File' menu
Design tools for the following parts are available in LTpowerCAD:
LTC3405
LTC3405A
LTC3405A-1.375
LTC3405A-1.5
LTC3405A-1.8
Technical Support
- For immediate technical assistance, contact your local sales office or distributor or call 1-800-4-LINEAR (US customers only) or 408-432-1900.
- For less urgent requests, please complete our Technical Support Request Form. Please allow 2-3 business days for reply.
