LT8609/LT8609A/LT8609B - 42V, 2A/3A Peak Synchronous Step-Down Regulator with 2.5μA Quiescent Current
Features
- Wide Input Voltage Range: 3.0V to 42V
- Ultralow Quiescent Current Burst Mode® Operation:
<2.5μA IQ Regulating 12VIN to 3.3VOUT
Output Ripple <10mVP-P - High Efficiency 2MHz Synchronous Operation:
>93% Efficiency at 1A, 5VOUT from 12VIN - 2A Maximum Continuous Output, 3A Peak Transient Output
- Fast Minimum Switch-On Time: 45ns
- Adjustable and Synchronizable: 200kHz to 2.2MHz
- Spread Spectrum Frequency Modulation for Low EMI
- Allows Use of Small Inductors
- Low Dropout
- Peak Current Mode Operation
- Accurate 1V Enable Pin Threshold
- Internal Compensation
- Output Soft-Start and Tracking
- Small 10-Lead MSOP Package
AEC-Q100 data available for specific packages
Typical Application
Description
The LT®8609/LT8609A/LT8609B is a compact, high efficiency, high speed synchronous monolithic step-down switching regulator that consumes only 1.7μA of non-switching quiescent current. The LT8609/LT8609A/LT8609B can deliver 2A of continuous current with peak loads of 3A (<1sec). Burst Mode operation enables high efficiency down to very low output currents while keeping the output ripple below 10mVP-P. A SYNC pin allows synchronization to an external clock, or spread spectrum modulation for low EMI operation. Internal compensation with peak current mode topology allows the use of small inductors and results in fast transient response and good loop stability. The EN/UV pin has an accurate 1V threshold and can be used to program VIN UVLO or to shut down the part. A capacitor on the TR/SS pin programs the output voltage ramp rate during start-up while the PG flag signals when VOUT is within ±8.5% of the programmed output voltage as well as fault conditions. The LT8609A has slower switch edges for lower EMI emissions. The LT8609B operates in pulse-skipping mode only.
| PULSE-SKIPPING MODE, Burst Mode OPERATION |
SWITCH EDGE SPEED | |
| LT8609 | Both | Fast |
| LT8609A | Both | Medium |
| LT8609B | Pulse-Skipping | Fast |
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 |
|---|---|---|---|---|---|
| LT8609AEMSE#PBF | MS-10E | MSE | E | 05-08-1664 | Yes |
| LT8609AEMSE#TRPBF | MS-10E | MSE | E | 05-08-1664 | Yes |
| LT8609AIMSE#PBF | MS-10E | MSE | I | 05-08-1664 | Yes |
| LT8609AIMSE#TRPBF | MS-10E | MSE | I | 05-08-1664 | Yes |
| LT8609BEMSE#PBF | MS-10E | MSE | E | 05-08-1664 | Yes |
| LT8609BEMSE#TRPBF | MS-10E | MSE | E | 05-08-1664 | Yes |
| LT8609BIMSE#PBF | MS-10E | MSE | I | 05-08-1664 | Yes |
| LT8609BIMSE#TRPBF | MS-10E | MSE | I | 05-08-1664 | Yes |
| LT8609EMSE#PBF | MS-10E | MSE | E | 05-08-1664 | Yes |
| LT8609EMSE#TRPBF | MS-10E | MSE | E | 05-08-1664 | Yes |
| LT8609HMSE#PBF | MS-10E | MSE | H | 05-08-1664 | Yes |
| LT8609HMSE#TRPBF | MS-10E | MSE | H | 05-08-1664 | Yes |
| LT8609IMSE#PBF | MS-10E | MSE | I | 05-08-1664 | Yes |
| LT8609IMSE#TRPBF | MS-10E | MSE | I | 05-08-1664 | 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 | |
|---|---|---|---|---|---|---|
| LT8609AEMSE#PBF | MS-10E | E | $3.57 | $2.50 | Yes | |
| LT8609AEMSE#TRPBF | MS-10E | E | $3.63 | $2.56 | Yes | |
| LT8609AIMSE#PBF | MS-10E | I | $3.93 | $2.75 | Yes | |
| LT8609AIMSE#TRPBF | MS-10E | I | $3.99 | $2.81 | Yes | |
| LT8609BEMSE#PBF | MS-10E | E | $3.43 | $2.40 | Yes | |
| LT8609BEMSE#TRPBF | MS-10E | E | $3.49 | $2.46 | Yes | |
| LT8609BIMSE#PBF | MS-10E | I | $3.77 | $2.64 | Yes | |
| LT8609BIMSE#TRPBF | MS-10E | I | $3.83 | $2.70 | Yes | |
| LT8609EMSE#PBF | MS-10E | E | $3.57 | $2.50 | Yes | |
| LT8609EMSE#TRPBF | MS-10E | E | $2.56 | Yes | ||
| LT8609HMSE#PBF | MS-10E | H | $4.29 | $3.00 | Yes | |
| LT8609HMSE#TRPBF | MS-10E | H | $3.06 | Yes | ||
| LT8609IMSE#PBF | MS-10E | I | $3.93 | $2.75 | Yes | |
| LT8609IMSE#TRPBF | MS-10E | I | $2.81 | 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 |
|---|---|---|---|
| DC2195A | LT8609EMSE Demo Board | µPower Sync Buck, 5.5V ≤ VIN ≤ 42V, 5Vout at 2A, FSW=2MHz | Contact Factory | |
| DC2195B-A | LT8609AEMSE Demo Board | µPower Sync Buck, Low EMI, 5.5V ≤ VIN ≤ 42V, Vout = 5V @ 2A, FSW = 2MHz | Contact Factory | |
| Buy Now | |||
Designed for Automotive and Transportation Applications
AEC-Q100 data is available for these specific part numbers. Please contact your local sales representative for more information regarding reliability reports or to inquire about parts that are not included. For more information, view our Automotive and Transportation page
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LT8609HMSE#PBF | MS-10E | H | $4.29 | $3.00 | Yes | |
| LT8609HMSE#TRPBF | MS-10E | H | $3.06 | Yes | ||
| LT8609IMSE#PBF | MS-10E | I | $3.93 | $2.75 | Yes | |
| LT8609IMSE#TRPBF | MS-10E | I | $2.81 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- GSM Transceivers
- General Purpose Step Down
- Low EMI Step Down
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Product Notifications
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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
To launch a ready to run LTspice demonstration circuit for this part:
- Step 1: If you have not installed LTspice on this computer, download and install LTspice
- Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
- Step 3: If LTspice does not automatically open after clicking the link above, you can instead run the simulation by right clicking on the link and selecting "Save Target As." After saving the file to your computer, start LTspice and open the demonstration circuit by selecting 'Open' from the 'File' menu
To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.
Models for the following parts are available in LTspice:
LT8609
LT8609A
LT8609B
LT8609S
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:
LT8609
LT8609A
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.
