LTC3809-1 - No Rsense, Low Input Voltage, Synchronous DC/DC Controller with Output Tracking
Features
- Programmable Output Voltage Tracking
- No Current Sense Resistor Required
- Constant Frequency Current Mode Operation for Excellent Line and Load Transient Response
- Wide VIN Range: 2.75V to 9.8V
- Wide VOUT Range: 0.6V to VIN
- 0.6V ±1.5% Reference
- Low Dropout Operation: 100% Duty Cycle
- Selectable Burst Mode/Pulse Skipping/Forced Continuous Operation
- Auxiliary Winding Regulation
- Internal Soft-Start Circuitry
- Selectable Maximum Peak Current Sense Threshold
- Output Overvoltage Protection
- Micropower Shutdown: IQ = 9µA
- Tiny Thermally Enhanced Leadless (3mm × 3mm) DFN or 10-lead MSOP Packages
Typical Application
Description
The LTC3809-1 is a synchronous step-down switching regulator controller that drives external complementary power MOSFETs using few external components. The constant frequency current mode architecture with MOSFET VDS sensing eliminates the need for a current sense resistor and improves efficiency.Optional Burst Mode operation provides high efficiency operation at light loads. 100% duty cycle provides low dropout operation, extending operating time in battery powered systems. Burst Mode is inhibited when the MODE pin is pulled low to reduce noise and RF interference.
The LTC3809-1 allows either coincident or ratiometric output voltage tracking. Switching frequency is fixed at 550kHz. Fault protection is provided by an overvoltage comparator and a short-circuit current limit comparator.
The LTC3809-1 is available in the tiny footprint thermally enhanced DFN and 10-lead MSOP packages.
Packaging
For complete and up to date package information and drawings, please refer to our packaging page
DFN-10, MS-10
Order Info
- Part numbers ending in PBF are lead free. Please contact LTC marketing for information on lead based finish parts.
- 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 | Pins | Temp | Price (1-99) | Price (1k)* | RoHS Data |
|---|---|---|---|---|---|---|
| LTC3809EDD | DFN | 10 | E | $3.57 | $2.50 | View |
| LTC3809EDD#PBF | DFN | 10 | E | $3.57 | $2.50 | View |
| LTC3809EDD#TR | DFN | 10 | E | $2.60 | View | |
| LTC3809EDD#TRPBF | DFN | 10 | E | $2.60 | View | |
| LTC3809EDD-1 | DFN | 10 | E | $3.57 | $2.50 | View |
| LTC3809EDD-1#PBF | DFN | 10 | E | $3.57 | $2.50 | View |
| LTC3809EDD-1#TR | DFN | 10 | E | $2.60 | View | |
| LTC3809EDD-1#TRPBF | DFN | 10 | E | $2.60 | View | |
| LTC3809EMSE | MSOP | 10 | E | $3.57 | $2.50 | View |
| LTC3809EMSE#PBF | MSOP | 10 | E | $3.57 | $2.50 | View |
| LTC3809EMSE#TR | MSOP | 10 | E | $2.56 | View | |
| LTC3809EMSE#TRPBF | MSOP | 10 | E | $2.56 | View | |
| LTC3809EMSE-1 | MSOP | 10 | E | $3.57 | $2.50 | View |
| LTC3809EMSE-1#PBF | MSOP | 10 | E | $3.57 | $2.50 | View |
| LTC3809EMSE-1#TR | MSOP | 10 | E | $2.56 | View | |
| LTC3809EMSE-1#TRPBF | MSOP | 10 | E | $2.56 | View | |
| LTC3809IDD-1#PBF | DFN | 10 | I | $3.70 | $2.59 | View |
| LTC3809IDD-1#TRPBF | DFN | 10 | I | $3.05 | View | |
| LTC3809IMSE-1#PBF | MSOP | 10 | I | $3.70 | $2.59 | View |
| LTC3809IMSE-1#TRPBF | MSOP | 10 | I | $3.05 | View | |
| Buy Now • Request Samples | ||||||
Demo Boards
Linear Technology demo boards are offered free of charge to qualified customers. Contact your local sales office or distributor to request 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 |
|---|---|---|---|
| DC882A | LTC3809EDD-1 | Synch Step-Down Converter | $125.00 | |
| Buy Now | |||
Applications
- 1- or 2-Cell Lithium-Ion Powered Devices
- Notebook and Palmtop Computers, PDAs
- Portable Instruments
- Distributed DC Power Systems
Simulate
LTspice IV is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. To download LTspice IV and other FREE simulation tools, please visit our Design Simulation page.
To launch a ready to run LTspice demonstration circuit for this part:
- Step 1: If you have not installed LTspice on this computer, download and install LTspice IV
- Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
- Step 3: If LTspice IV does not automatically open after clicking the link above, you can instead run the simulation by right clicking on the link and selecting "Save Target As". After saving the file to your computer, start LTspice and open the demonstration circuit by selecting 'Open' from the 'File' menu
To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.
Related models available in LTspice IV
LTC3809-1
LTC3809
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.
