Alternative Parts
Overview
Features and Benefits
- No Transformer "Third Winding" or Optoisolator Required
- ±5% Accurate Output Voltage Without User Trims
- Resistor Programmable Output Voltage
- Regulation Maintained Well Into Discontinuous Mode (Light Load)
- Optional Load Compensation
- Operating Frequency: 285kHz
- Easily Synchronized to External Clock
- Available in 16-Pin Narrow SO Package
Product Details
The LT1425 is a monolithic high power switching regulator specifically designed for the isolated flyback topology. No “third winding” or optoisolator is required; the integrated circuit senses the isolated output voltage directly from the primary side flyback waveform. A high current, high efficiency switch is included on the die along with all oscillator, control and protection circuitry.
The LT1425 operates with input supply voltages from 3V to 20V and draws only 7mA quiescent current. It can deliver output power up to 6W with no external power devices. By utilizing current mode switching techniques, it provides excellent AC and DC line regulation.
The LT1425 has a number of features not found on other switching regulator ICs. Its unique control circuitry can maintain regulation well into discontinuous mode in most applications. Optional load compensation circuitry allows for improved load regulation. An externally activated shutdown mode reduces total supply current to 15µA for standby operation.
Applications
- Isolated Flyback Switching Regulators
- Ethernet Isolated 5V to -9V Converter
- Medical Instruments
- Isolated Telecom Supplies
Product Categories
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)
Documentation & Resources
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R387 Reliability Data3/26/2018
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LT1425 - SPECIFICATION NOTICE11/11/2004
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35 Watt Isolated DC/DC Converter Replaces Modules at Half the Cost9/1/1999 LT Journal
Tools & Simulations
LTspice
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.

Models for the following parts are available in LTspice:
Product Recommendations
LT1425 Companion Parts
Design Resources
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 |
---|---|---|---|---|
LT1425CS#PBF | Material Declaration | Reliability Data | 16-Lead SOIC (Narrow 0.15 Inch) | |
LT1425CS#TRPBF | Material Declaration | Reliability Data | 16-Lead SOIC (Narrow 0.15 Inch) | |
LT1425IS#PBF | Material Declaration | Reliability Data | 16-Lead SOIC (Narrow 0.15 Inch) | |
LT1425IS#TRPBF | Material Declaration | Reliability Data | 16-Lead SOIC (Narrow 0.15 Inch) | |
Wafer Fabrication Data | R387 Reliability Data |
PCN-PDN Information
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Support & Discussions
Sample & Buy
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Buy Now Pricing
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List Pricing
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Lead Times
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Evaluation Boards
Pricing displayed is based on 1-piece.
Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.
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.