LT1103 - Offline Switching Regulator
Features
- Obsolete - Datasheet For Information Purposes Only. Contact Linear Technology for Potential Replacement
- ±1% Line and Load Regulation with No Optocoupler
- Switch Frequency Up to 200kHz
- Internal 2A Switch and Current Sense (LT1103)
- Internal 1A Totem-Pole Driver (LT1105)
- Start-Up Mode Draws Only 200µA
- Fully Protected Against Overloads
- Overvoltage Lockout of Main Supply
- Protected Against Underdrive or Overdrive to FET
- Operates in Continuous or Discontinuous Mode
- Ideal for Flyback and Forward Topologies
- Isolated Flyback Mode Has Fully Floating Outputs
Typical Application
Description
Obsolete - Datasheet For Information Purposes Only. Contact Linear Technology for Potential Replacement
The LT1103 Offline Switching Regulator is designed for high input voltage applications using an external FET switch whose source is driven by the open collect or output of the LT1103. The LT1103 is optimized for 15W to 100W applications. For higher power applications or additional switch current flexibility, the LT1105 is available and its totem pole output drives the gate of an external FET. Unique design of the LT1103/LT1105 eliminates the need for an optocoupler while still providing ±1% load and line regulation in a magnetic flux-sensed converter. This significantly simplifies the design of offline power supplies and reduces the number of components which must cross the isolation barrier to one, the transformer.
The LT1103/LT1105 current mode switching techniques are well suited to transformer isolated flyback and forward topologies while providing ease of frequency compensation with a minimum of external components. Low external part count for a typical application combines with a
Packaging
For complete and up to date package information and drawings, please refer to our packaging page
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
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 |
|---|---|---|---|
| DC012A | LT1103CT7 | OFFLINE POWER SUPPLY EVALUATION BOX | Contact Factory | |
| Buy Now | |||
Applications
- Up to 250W Isolated Mains Converter
- Up to 50W Isolated Telecom Converter
- Fully Isolated Multiple Outputs
- Distributed Power Conversion Networks
People Who Viewed This Product Also Viewed
- LT3798 - Isolated No Opto-Coupler Flyback Controller with Active PFC
- LT3799 - Offline Isolated Flyback LED Controller with Active PFC
- LT1105 - Offline Switching Regulator
- LT3758 - High Input Voltage, Boost, Flyback, SEPIC and Inverting Controller
- LT3799-1 - Offline Isolated Flyback LED Controller with Active PFC
- LT3652 - Power Tracking 2A Battery Charger for Solar Power
- LT1509 - Power Factor and PWM Controller
- LT4320/LT4320-1 - Ideal Diode Bridge Controller
- LT1028 - Ultra Low Noise Precision High Speed Op Amps
- LTC1966 - Precision Micropower, Delta Sigma RMS-to-DC Converter
Product Notifications
Please login to your MyLinear account for notifications of datasheet updates, new document releases and LTspice model announcements for your favorite products. If you do not have a MyLinear account you may Sign Up Now.
Forgot your password? Click here.
Need help? Email mylinear@linear.com with questions and comments.
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:
LT1103
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.