Features and Benefits
- High Voltage Operation: Up to 60V
- Synchronizable Up to 600kHz
- Adjustable Constant Frequency: 100kHz to 500kHz
- Output Voltages Up to 36V
- Stable Operation in Current Limit
- Adaptive Nonoverlap Circuitry Prevents Switch Shoot-Through
- Reverse Inductor Current Inhibit for Discontinuous Operation Improves Efficiency with Light Loads
- Programmable Soft-Start
- 120μA No Load Quiescent Current
- 10μA Shutdown Supply Current
- 1% Regulation Accuracy
- Standard Gate N-Channel Power MOSFETs
- Reverse Overcurrent Protection
- 16-Lead Thermally Enhanced TSSOP Package
The LT3845A is a high voltage, synchronous, current mode controller used for medium to high power, high efficiency supplies. It offers a wide 4V to 60V input range (7.5V minimum start-up voltage). An onboard regulator simplifies the biasing requirements by providing IC power directly from VIN.
Burst Mode® operation maintains high efficiency at light loads by reducing IC quiescent current to 120μA. Light load efficiency is also improved with the reverse inductor current inhibit function which supports discontinuous operation.
Additional features include adjustable fixed operating frequency that can be synchronized to an external clock for noise sensitive applications, gate drivers capable of driving large N-channel MOSFETs, a precision undervoltage lockout, 10μA shutdown current, short-circuit protection and a programmable soft-start.
The LT3845A is available in a 16-lead thermally enhanced TSSOP package.
|LT3845A||Improved Performance In Over Current Conditions|
- 12V and 42V Automotive and Heavy Equipment
- 48V Telecom Power Supplies
- Avionics and Industrial Control Systems
- Distributed Power Converters
Product Lifecycle Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
Demonstration Circuit 1619A is a 100kHz to 500kHz programmable frequency, high voltage, current mode DC/DC step-down converter featuring the LT3845A. The operating frequency can be synchronized up to 600kHz. This demo board is designed for 12V output at up to 10A (120W) from a 16V to 60V input.
Documentation & Resources
R365 Reliability Data3/23/2018
DC1619A - Demo Manual3/14/2011
Tools & Simulations
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.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, 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.
Models for the following parts are available in LTspice:
LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.
To open the project file for this circuit:
Step 1: Download and install LTpowerCAD on your computer.
Step 2: Click on the link(s) in the section below to download part-specific project files.
Step 3: If the project file doesn't run, right-click the link and select "Save Target As." Then start the LTpowerCAD tool and open the project file by selecing "Open Project" from the "File" menu.
LTpowerCAD Project Files
Design tools for the following parts are available in LTpowerCAD:
LT3845A Companion Parts
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 Number||Material Declaration||Reliability Data||Pin/Package Drawing||CAD Symbols, Footprints & 3D Models|
|LT3845AEFE#PBF||Material Declaration||Reliability Data||16-Lead TSSOP w/ EP|
|LT3845AEFE#TRPBF||Material Declaration||Reliability Data||16-Lead TSSOP w/ EP|
|LT3845AIFE#PBF||Material Declaration||Reliability Data||16-Lead TSSOP w/ EP|
|LT3845AIFE#TRPBF||Material Declaration||Reliability Data||16-Lead TSSOP w/ EP|
|LT3845AMPFE#PBF||Material Declaration||Reliability Data||16-Lead TSSOP w/ EP|
|LT3845AMPFE#TRPBF||Material Declaration||Reliability Data||16-Lead TSSOP w/ EP|
|Wafer Fabrication Data||R365 Reliability Data|
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Sample & Buy
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Buy Now Pricing
(**) Displayed Buy Now Price and Price Range is based on small quantity orders.
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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.