LT1425 - Isolated Flyback Switching Regulators
Features
- No Transformer "Third Winding" or Optoisolator Required
- ±5% Accurate Output Voltage Without User Trims (See Circuit Below)
- 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
Typical Application
Description
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.Packaging
CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.
For complete and up to date package information and drawings, please refer to our packaging page
| Part Number | Package | Code | Temp | Package Drawing |
RoHS |
|---|---|---|---|---|---|
| LT1425CS#PBF | SO-16 | S | C | 05-08-1610 (S16) | Yes |
| LT1425CS#TRPBF | SO-16 | S | C | 05-08-1610 (S16) | Yes |
| LT1425IS#PBF | SO-16 | S | I | 05-08-1610 (S16) | Yes |
| LT1425IS#TRPBF | SO-16 | S | I | 05-08-1610 (S16) | Yes |
Order Info
- Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
- Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
- Please refer to our general ordering information or the product datasheet for more details
Package Variations and Pricing
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LT1425CS#PBF | SO-16 | C | $3.55 | $2.90 | Yes | |
| LT1425CS#TRPBF | SO-16 | C | $2.96 | Yes | ||
| LT1425IS#PBF | SO-16 | I | $4.90 | $3.95 | Yes | |
| LT1425IS#TRPBF | SO-16 | I | $4.01 | Yes | ||
| Buy Now • Request Samples | ||||||
Demo Boards
Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC159A-A | LT1425CS | ISOLATED FLYBACK CONVERTER, 5V to 15V INPUT, +/- 5V OUTPUT @ 220 mA | $125.00 | |
| DC159A-B | LT1425CS | ISOLATED FLYBACK CONVERTER, 5V to 15V INPUT, +/- 15V OUTPUT @ 60mA | $125.00 | |
| Buy Now | |||
Applications
- Isolated Flyback Switching Regulators
- Ethernet Isolated 5V to -9V Converter
- Medical Instruments
- Isolated Telecom Supplies
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Design Tools
LTspice
LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice
Models for the following parts are available in LTspice:
LT1425
Technical Support
- For immediate technical assistance, contact your local sales office or distributor or call 1-800-4-LINEAR (US customers only) or 408-432-1900.
- For less urgent requests, please complete our Technical Support Request Form. Please allow 2-3 business days for reply.
