Features and Benefits
- Wide 4V to 60V Input Voltage Range
- Output Voltages up to 36V
- Adaptive Nonoverlap Circuitry Prevents Switch Shoot-Through
- Reverse Inductor Current Inhibit for Discontinuous Operation Improves Efficiency with Light Loads
- Output Slew Rate Controlled Soft-Start with Auto-Reset
- 100µA No Load Quiescent Current
- Low 10µA Current Shutdown
- 1% Regulation Accuracy
- 200kHz Operating Frequency
- Standard Gate N-Channel Power MOSFETs
- Current Limit Unaffected by Duty Cycle
- Reverse Overcurrent Protection
- 16-Lead Thermally Enhanced TSSOP Package
The LT3800 is a 200kHz fixed frequency high voltage synchronous current mode step-down switching regulator controller. The IC drives standard gate N-channel power MOSFETs and can operate with input voltages from 4V to 60V. An onboard regulator provides IC power directly from VIN and provides for output-derived power to minimize VIN quiescent current. MOSFET drivers employ an internal dynamic bootstrap feature, maximizing gate-source "ON" voltages during normal operation for improved operating efficiencies. The LT3800 incorporates Burst Mode operation, which reduces no load quiescent current to under 100µA. Light load efficiencies are also improved through a reverse inductor current inhibit, allowing the controller to support discontinuous operation. Both Burst Mode operation and the reverse-current inhibit features can be disabled if desired. The LT3800 incorporates a programmable soft-start that directly controls the voltage slew rate of the converter output for reduced startup surge currents and overshoot errors. The LT3800 is available in a 16-lead thermally enhanced TSSOP package.
Protected by U.S. Patents, including 5481178, 6611131, 6304066, 6498466, 6580258.
- 12V and 42V Automotive and Heavy Equipment
- 48V Telecom Power Supplies
- Avionics and Industrial Control Systems
- Distributed Power Converters
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 720 is a 200kHz high voltage, synchronous current-mode DC/DC step-down converter featuring the LT3800. The board operates from a Vin range of 20V to 55V and outputs 12V @ 6.25A (75W).
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.