Features and Benefits
- Wide Operating VIN Range: 3.5V to 60V
- Wide VOUT Range: 0.8V to VIN
- Low Operating IQ = 40μA
- Very Low Dropout Operation: 100% Duty Cycle
- Strong High Voltage MOSFET Gate Driver
- Constant Frequency Current Mode Architecture
- Verified FMEA for Adjacent Pin Open/Short
- Selectable High Efficiency Burst Mode® Operation or Pulse-Skipping Mode at Light Loads
- Programmable Fixed Frequency: 50kHz to 850kHz
- Phase-Lockable Frequency: 75kHz to 750kHz
- Accurate Current Limit
- Programmable Soft-Start or Voltage Tracking
- Internal Soft-Start Guarantees Smooth Start-Up
- Power Good Output Voltage Monitor
- Low Shutdown IQ = 7μA
- Available in Small 12-Pin Thermally Enhanced MSOP and DFN Packages
The LTC3864 is a robust, high voltage step-down DC/DC controller optimized for automotive and industrial applications. It drives a P-channel power MOSFET switch allowing 100% duty cycle operation. The wide input and output voltage ranges cover a multitude of applications. This device has been verified with the failure mode and effects analysis (FMEA) procedure for operation during failure conditions.
The LTC3864 offers excellent light load efficiency, drawing only 40μA quiescent current in a user programmable Burst Mode operation. Its peak current mode, constant frequency PWM architecture provides for good control of switching frequency and output current limit. The switching frequency can be programmed from 50kHz to 850kHz with an external resistor and can be synchronized to an external clock from 75kHz to 750kHz.
The LTC3864 offers programmable soft-start or output tracking. Safety features include overvoltage protection, overcurrent and short-circuit protection including frequency foldback and a power good output signal.
The LTC3864 is available in thermally enhanced 12-Pin MSOP and 3mm × 4mm DFN packages.
- Industrial and Automotive Power Supplies
- Telecom Power Supplies
- Distributed Power Systems
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (2)
Demonstration circuit 2434A is a high voltage, current mode DC/DC step-down converter featuring the LTC3864.
The board operates from an input range of 6V to 60V and provides a 12V, 5A output when the input exceeds 12V. The PMOSFET architecture allows it to operate seamlessly up to 100% duty cycle and function as a saturated switch below the regulation threshold, down to 6VIN. It operates at 200kHz and may be synchronized to an external clock. A soft-start feature controls output voltage slew rate at start-up, reducing current surge and voltage overshoot. Burst Mode® operation that improves efficiency at light loads can be enabled with a jumper. A power good output signal is provided.
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.
Design tools for the following parts are available in LTpowerCAD:
Technical Articles (1)
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.
Sample & Buy
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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.