Features and Benefits
- High Efficiency VOUT Clamp Stops High Voltage Input Surges
- SWITCH-ON Mode 100% Duty Cycle for Normal Operation
- PROTECTIVE PWM Mode for Transients and Faults
- VIN Pin to SGND Range: 3.5V to 60V
- External Input Voltage is Extendable to 200V+
- Adjustable Output Voltage Clamp
- Adjustable Output Overcurrent Protection
- Power Inductor Improves Input EMI in Normal Operation
- Programmable Fault Timer
- Adjustable Soft-Start for Input Inrush Current Limiting
- 4.5% Retry Duty Cycle During Faults
- Adjustable Switching Frequency: 50kHz to 850kHz
- Optional Reverse Input Voltage Protection
- Available in Thermally Enhanced 12-lead MSOP Package
The LTC7860 high efficiency surge stopper protects loads from high voltage transients. High efficiency permits higher currents and smaller solution sizes. During an input overvoltage event, such as a load dump in vehicles, the LTC7860 controls the gate of an external MOSFET to act as a switching DC/DC regulator (PROTECTIVE PWM mode). This operation regulates the output voltage to a safe level, allowing the loads to operate through the input over-voltage event. During normal operation (SWITCH-ON mode), the LTC7860 turns on the external MOSFET continuously, passing the input voltage through to the output. An internal comparator limits the voltage across the current sense resistor and regulates the maximum output current to protect against overcurrent faults.
An adjustable timer limits the time that the LTC7860 can spend in overvoltage or overcurrent regulation. When the timer expires, the external MOSFET is turned off until the LTC7860 restarts after a cool down period. By strictly limiting the time in PROTECTIVE PWM Mode when the power loss is high, the components and thermal design can be optimized for normal operation and safely operate through high voltage input surges and/or overcurrent faults. An additional PMOS can be added for reverse battery protection.
- Industrial and Automotive Power
- Telecom Power
- Vehicle Power Including ISO7637
- Military Power Including MIL1275
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 2392A is a high efficiency switching surge stopper featuring the LTC7860. The board operates from an input range of 7V to 100V, and provides a 7V to 34V output at 0A to 10A. Its output is current limited. A soft-start feature controls output voltage slew rate at startup, reducing current surge and voltage overshoot. The demonstration board includes an optional reverse polarity protection MOSFET and has options for an input filter and diode to attenuate spikes. For a lower output voltage limit of less than 12V, there is an optional feedback circuit.
Demonstration circuit 2239A is a High Efficiency Switching Surge Stopper and EMI Filter featuring the LTC7860. The board operates from an input range of 3.5V to 60V, provides a 3.5V to 17.2V output at 0A to 5A and is output current limited. A soft-start feature controls output voltage slew rate at start-up, reducing current surge and voltage overshoot. The demonstration board has options for smaller MOSFET and diode packages on the back of the board for lower output current requirements.
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:
LTC7860 Companion Parts
Recommended Related Parts
Product Selector Card (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
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.