LT8614 - 42V, 4A Synchronous Step-Down Silent Switcher with 2.5μA Quiescent Current
Features
- Silent Switcher™ Architecture:
Ultralow EMI/EMC Emissions - High Efficiency at High Frequency
Up to 96% Efficiency at 1MHz
Up to 94% Efficiency at 2MHz - Wide Input Voltage Range: 3.4V to 42V
- Ultralow Quiescent Current Burst Mode® Operation:
2.5μA IQ Regulating 12VIN to 3.3VOUT
Output Ripple < 10mVP-P - Fast Minimum Switch-On Time: 30ns
- Low Dropout Under All Conditions: 200mV at 1A
- Safely Tolerates Inductor Saturation in Overload
- Adjustable and Synchronizable: 200kHz to 3MHz
- Peak Current Mode Operation
- Accurate 1V Enable Pin Threshold
- Internal Compensation
- Output Soft-Start and Tracking
- Small 18-Lead 3mm × 4mm QFN
AEC-Q100 data available for specific packages
Typical Application
Description
The LT®8614 step-down regulator features Silent Switcher architecture designed to minimize EMI/EMC emissions while delivering high efficiency at frequencies up to 3MHz. Assembled in a 3mm × 4mm QFN, the monolithic construction with integrated power switches and inclusion of all necessary circuitry yields a solution with a minimal PCB footprint. An ultralow 2.5μA quiescent current—with the output in full regulation— enables applications requiring highest efficiency at very small load currents. Transient response remains excellent and output voltage ripple is below 10mVP-P at any load, from zero to full current.
The LT8614 allows high VIN to low VOUT conversion at high frequency with a fast minimum top switch on-time of 30ns. Operation is safe in overload even with a saturated inductor.
Essential features are included and easy to use: An opendrain PG pin signals when the output is in regulation. The SYNC pin allows clock synchronization and choice of Burst Mode operation or pulse-skipping mode. Soft-start and tracking functionality is accessed via the TR/SS pin. An accurate enable threshold can be set using the EN/UV pin and a resistor at the RT pin programs switch frequency.
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 |
|---|---|---|---|---|---|
| LT8614EUDC#PBF | 3x4 QFN-18 | UDC | E | 05-08-1956 | Yes |
| LT8614EUDC#TRPBF | 3x4 QFN-18 | UDC | E | 05-08-1956 | Yes |
| LT8614HUDC#PBF | 3x4 QFN-18 | UDC | H | 05-08-1956 | Yes |
| LT8614HUDC#TRPBF | 3x4 QFN-18 | UDC | H | 05-08-1956 | Yes |
| LT8614IUDC#PBF | 3x4 QFN-18 | UDC | I | 05-08-1956 | Yes |
| LT8614IUDC#TRPBF | 3x4 QFN-18 | UDC | I | 05-08-1956 | 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 | |
|---|---|---|---|---|---|---|
| LT8614EUDC#PBF | 3x4 QFN-18 | E | $6.07 | $4.25 | Yes | |
| LT8614EUDC#TRPBF | 3x4 QFN-18 | E | $4.31 | Yes | ||
| LT8614HUDC#PBF | 3x4 QFN-18 | H | $7.04 | $4.93 | Yes | |
| LT8614HUDC#TRPBF | 3x4 QFN-18 | H | $4.99 | Yes | ||
| LT8614IUDC#PBF | 3x4 QFN-18 | I | $6.69 | $4.68 | Yes | |
| LT8614IUDC#TRPBF | 3x4 QFN-18 | I | $6.75 | $4.74 | 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 |
|---|---|---|---|
| DC2019B | LT8614 Demo Board | 2MHz Buck Silent Switcher, 5.8V ≤ VIN ≤ 42V, Vout = 5V @ 4A | $175.00 | |
| 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 | |
|---|---|---|---|---|---|---|
| LT8614HUDC#PBF | 3x4 QFN-18 | H | $7.04 | $4.93 | Yes | |
| LT8614HUDC#TRPBF | 3x4 QFN-18 | H | $4.99 | Yes | ||
| LT8614IUDC#PBF | 3x4 QFN-18 | I | $6.69 | $4.68 | Yes | |
| LT8614IUDC#TRPBF | 3x4 QFN-18 | I | $6.75 | $4.74 | Yes | |
| Buy Now • Request Samples | ||||||
Applications
- Automotive and Industrial Supplies
- General Purpose Step-Down
- GSM Power Supplies
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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
- LT8614 Demo Circuit - Ultralow EMI, µPower Buck Converter (5.8-42V to 5V @ 4A)
- LT8614/LT3083 Demo Circuit - Hybrid Wide Dimming Ratio Linear LED Current Controller (3.4-42V to 41V @ 3A Max)
- LT8614/LT6015 Demo Circuit - Hybrid Wide Dimming Ratio Linear LED Current Controller (3.4-42V to 41V @ 3A Max)
- 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:
LT8614
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:
LT8614
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.
