LTC3805
PRODUCTIONAdjustable Frequency Current Mode Flyback DC/DC Controller
- Part Models
- 12
- 1ku List Price
- Starting From $2.17
Overview
- 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
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. Soft-start 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.
| Turn On Voltage | |
| LTC3805 | 8.4V |
| LTC3805-5 | 4.5V |
Applications
- Telecom Power Supplies
- 42V and 12V Automotive Power Supplies
- Isolated Electronic Equipment
Documentation
Data Sheet 1
User Guide 2
Design Note 1
Technical Articles 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. View our quality and reliability program and certifications for more information.
| Part Model | Pin/Package Drawing | Documentation | CAD Symbols, Footprints, and 3D Models |
|---|---|---|---|
| LTC3805EDD#PBF | 10-Lead DFN (3mm x 3mm w/ EP) | ||
| LTC3805EDD#TRPBF | 10-Lead DFN (3mm x 3mm w/ EP) | ||
| LTC3805EMSE#PBF | 10-Lead MSOP w/ EP | ||
| LTC3805EMSE#TRPBF | 10-Lead MSOP w/ EP | ||
| LTC3805HMSE#PBF | 10-Lead MSOP w/ EP | ||
| LTC3805HMSE#TRPBF | 10-Lead MSOP w/ EP | ||
| LTC3805IDD#PBF | 10-Lead DFN (3mm x 3mm w/ EP) | ||
| LTC3805IDD#TRPBF | 10-Lead DFN (3mm x 3mm w/ EP) | ||
| LTC3805IMSE#PBF | 10-Lead MSOP w/ EP | ||
| LTC3805IMSE#TRPBF | 10-Lead MSOP w/ EP | ||
| LTC3805MPMSE#PBF | 10-Lead MSOP w/ EP | ||
| LTC3805MPMSE#TRPBF | 10-Lead MSOP w/ EP |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Feb 14, 2025 - 25_0017 Bond Wire Change from Gold to Copper |
||
| LTC3805EDD#PBF | PRODUCTION | |
| LTC3805EDD#TRPBF | PRODUCTION | |
| LTC3805EMSE#PBF | PRODUCTION | |
| LTC3805EMSE#TRPBF | PRODUCTION | |
| LTC3805HMSE#PBF | PRODUCTION | |
| LTC3805HMSE#TRPBF | PRODUCTION | |
| LTC3805IDD#PBF | PRODUCTION | |
| LTC3805IDD#TRPBF | PRODUCTION | |
| LTC3805IMSE#PBF | PRODUCTION | |
| LTC3805IMSE#TRPBF | PRODUCTION | |
|
Oct 11, 2022 - 22_0244 Epoxy Change from Henkel 8290 to 8290A for MSOP Package |
||
| LTC3805EMSE#PBF | PRODUCTION | |
| LTC3805EMSE#TRPBF | PRODUCTION | |
|
Jul 12, 2022 - 22_0157 UTAC Thai Limited (UTL) as Alternate Assembly Site for MSOP Packages [With Modification in BOM] |
||
| LTC3805EMSE#PBF | PRODUCTION | |
| LTC3805EMSE#TRPBF | PRODUCTION | |
|
Jun 21, 2022 - 22_0050 UTAC Thai Limited (UTL) as Alternate Assembly Site for MSOP Packages / Devices |
||
| LTC3805EMSE#PBF | PRODUCTION | |
| LTC3805EMSE#TRPBF | PRODUCTION | |
|
Feb 4, 2020 - 20_0130 Laser Top Mark Conversion for 10-Lead MSOP Packages Assembled in ADPG and UTAC |
||
| LTC3805EMSE#PBF | PRODUCTION | |
| LTC3805EMSE#TRPBF | PRODUCTION | |
| LTC3805HMSE#PBF | PRODUCTION | |
| LTC3805HMSE#TRPBF | PRODUCTION | |
| LTC3805IMSE#PBF | PRODUCTION | |
| LTC3805IMSE#TRPBF | PRODUCTION | |
| LTC3805MPMSE#PBF | PRODUCTION | |
| LTC3805MPMSE#TRPBF | PRODUCTION | |
This is the most up-to-date revision of the Data Sheet.
Software Resources
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Request a Driver/SoftwareHardware Ecosystem
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Tools & Simulations
LTspice 1
Models for the following parts are available in LTspice:
- LTC3805
- LTC3805-5
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.
