LT3804 - Secondary Side Dual Output Controller with Opto Driver
Features
- Regulates Two Secondary Outputs
- Optocoupler Feedback Driver and Second Output Synchronous Driver Controller
- True Differential Remote Sensing Regulation
- High Switching Frequency: up to 800kHz
- Programmable Current Limit
- Programmable Soft-Start and Power Good
- Automatic Frequency Synchronization
- Available in Thermally Enhanced 28-Lead TSSOP
Typical Application
Description
The LT3804 is a high efficiency step-down switching regulator with optocoupler feedback control for regulating multiple outputs in single-secondary winding isolated power supplies.
The LT3804 contains an error amplifier and an optocoupler driver to regulate the first (main) output. For the second output regulation, the LT3804 contains a complete PWM controller to drive dual synchronous N-channel MOSFETs. With leading edge modulation, it operates with either current or voltage mode control of the primary side. The LT3804 is synchronized to the falling edge of the transformer secondary winding and can be used in single ended or double-ended isolated power converter topologies. A user selectable discontinuous conduction mode improves light load efficiency.
True differential Kelvin sensing is used for each output feedback amplifier to achieve high regulation accuracy and design simplicity. Other features include soft start, current limit and power good flags.
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 |
|---|---|---|---|---|---|
| LT3804EFE#PBF | TSSOP-28 | FE | E | 05-08-1663 (EB) | Yes |
| LT3804EFE#TRPBF | TSSOP-28 | FE | E | 05-08-1663 (EB) | 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 | |
|---|---|---|---|---|---|---|
| LT3804EFE#PBF | TSSOP-28 | E | $7.59 | $5.35 | Yes | |
| LT3804EFE#TRPBF | TSSOP-28 | E | $5.47 | 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 |
|---|---|---|---|
| DC610A | LT3804EFE LT3781EG LTC1693-1IS8 | Dual Output Isolated Power Supply, 36V to 72V Input, +Vo1=3.3V @ 15A, +Vo2 = 1.8V @ 15A | $175.00 | |
| Buy Now | |||
Applications
- 48V Input Isolated DC/DC Converters
- Multiple Output Power Supplies
- Offline Converters
- DC/DC Power Modules
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Design Tools
Linear Technology provides a variety of custom design simulation tools and device models to allow even novice designers to quickly and easily evaluate circuits using high performance switching regulators, amplifiers, data converters, filters and more. Please visit our Design Tools page to view and download:
- LTspice - A powerful SPICE simulator, schematic capture and waveform viewer with enhancements and models for easing the simulation of switching regulators
- LTpowerCAD - A complete power supply selection, synthesis and design tool
- LTpowerPlay - A development environment supporting Linear Technology's Digital Power System Management (PSM) products
- PScope & QuikEval - USB-based product demonstration and data acquisition system for use with our ADCs, DACs, and more
- Linduino - Arduino compatible system for developing and distributing firmware libraries and example code
- LinearLab Tools - A collection of Matlab and Python programs that provide direct access to Linear Technology’s data converter evaluation boards
- And More!
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.
