LTC3805 - Adjustable Frequency Current Mode Flyback DC/DC Controller
- VIN and VOUT Limited Only by External Components
- Adjustable Slope Compensation
- Adjustable Overcurrent Protection with Automatic Restart
- Adjustable Operating Frequency (70kHz to 700kHz) with One External Resistor
- Synchronizable to an External Clock
- ±1.5% Reference Accuracy
- Current Mode Operation for Excellent Line and Load Transient Response
- RUN Pin with Precision Threshold and Adjustable Hysteresis
- Programmable Soft-Start with One External Capacitor
- Low Quiescent Current: 360μA
- Small 10-Lead MSOP and 3mm × 3mm DFN
AEC-Q100 data available for specific packages
The LTC3805 is a current mode controller for flyback DC/DC converters designed to drive an N-channel MOSFET in high input and output voltage converter applications. Operating frequency and slope compensation can be programmed by external resistors. Programmable overcurrent sensing protects the converter from short-circuits. Softstart can be programmed using an external capacitor and the soft-start capacitor also programs an automatic restart feature.
The LTC3805 provides ±1.5% output voltage accuracy and consumes only 360μA of quiescent current during normal operation and only 40μA during micropower startup. Using a 9.5V internal shunt regulator, the LTC3805 can be powered from a high VIN through a resistor or it can be powered directly from a low impedance DC voltage of 9V or less.
The LTC3805 is available in the 10-lead MSOP package and the 3mm × 3mm DFN package.
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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 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
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Demo BoardsLinear 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.
|DC1045A||LTC3805EMSE Isolated Demo Board | 36V ≤ Vin ≤ 72V, Vout = 3.3V/3A||$75.00|
|DC1311A-A||LTC3805 Isolated Demo Board | Flyback Controller, 18V ≤ VIN ≤ 72V, Vout = 3.3V @ 3A||$75.00|
Designed for Automotive and Transportation ApplicationsAEC-Q100 data is available for these specific part numbers. Please contact your local sales representative for more information regarding reliability reports or to inquire about parts that are not included. For more information, view our Automotive and Transportation page
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- Telecom Power Supplies
- 42V and 12V Automotive Power Supplies
- Isolated Electronic Equipment
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