Features and Benefits
- High Voltage Operation: Up to 60V
- Output Voltages up to 36V (Step-Down)
- Programmable Constant Frequency: 100kHz to 500kHz
- Synchronizable up to 600kHz
- Burst Mode® Operation: 120µA Supply Current
- 10µA Shutdown Supply Current
- ±1.3% Reference Accuracy
- Drives N-Channel MOSFET
- Programmable Soft-Start
- Programmable Undervoltage Lockout
- Internal High Voltage Regulator for Gate Drive
- Thermal Shutdown
- Current Limit Unaffected by Duty Cycle
- 16-Pin Thermally Enhanced TSSOP Package
The LT3844 is a DC/DC controller used for medium power, low part count, high efficiency supplies. It offers a wide 4V to 60V input range (7.5V minimum startup voltage) and can implement step-down, step-up, inverting and SEPIC topologies.
The LT3844 includes Burst Mode operation, which reduces quiescent current below 120µA and maintains high efficiency at light loads. An internal high voltage bias regulator allows for simple biasing.
Additional features include current mode control for fast line and load transient response; programmable fixed operating frequency that can be synchronized to an external clock for noise sensitive applications; a gate driver capable of driving large N-channel MOSFETs; a precision undervoltage lockout function; 10µA shutdown current; short-circuit protection and a programmable soft-start function.
The LT3844 is available in a 16-lead thermally enhanced TSSOP package.
- Industrial Power Distribution
- 12V and 42V Automotive and Heavy Equipment
- High Voltage Single Board Systems
- Distributed Power Systems
- Telecom Power
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 (1)
Demonstration Circuit 974 is a 100kHz to -500kHz programmable frequency, high voltage, current-mode DC/DC step-down converter featuring the LT3844. The operating frequency can be synchronized up to 600kHz. The board operates from a Vin range of 15V to -60V and outputs 12VOUT @ 4.2A (50W).
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.
Design tools for the following parts are available in LTpowerCAD:
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
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.