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
AEC-Q100 data available for specific 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.
| Features |
Package |
|
| LTC3809 | PLL, Selectable Spread Spectrum, Power Good | 3x3 DFN-10, MS-10E |
| LTC3809-1 | Tracking | 3x3 DFN-10, MS-10E |
| LTC3808 | PLL, Selectable Spread Spectrum, Tracking, Power Good | 4x3 DFN-14, SSOP-16 |
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 |
|---|---|---|---|---|---|
| LTC3809EDD-1#PBF | 3x3 DFN-10 | DD | E | 05-08-1699 | Yes |
| LTC3809EDD-1#TRPBF | 3x3 DFN-10 | DD | E | 05-08-1699 | Yes |
| LTC3809EMSE-1#PBF | MS-10E | MSE | E | 05-08-1664 | Yes |
| LTC3809EMSE-1#TRPBF | MS-10E | MSE | E | 05-08-1664 | Yes |
| LTC3809IDD-1#PBF | 3x3 DFN-10 | DD | I | 05-08-1699 | Yes |
| LTC3809IDD-1#TRPBF | 3x3 DFN-10 | DD | I | 05-08-1699 | Yes |
| LTC3809IMSE-1#PBF | MS-10E | MSE | I | 05-08-1664 | Yes |
| LTC3809IMSE-1#TRPBF | MS-10E | MSE | I | 05-08-1664 | 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 | |
|---|---|---|---|---|---|---|
| LTC3809EDD-1#PBF | 3x3 DFN-10 | E | $3.57 | $2.50 | Yes | |
| LTC3809EDD-1#TRPBF | 3x3 DFN-10 | E | $2.60 | Yes | ||
| LTC3809EMSE-1#PBF | MS-10E | E | $3.57 | $2.50 | Yes | |
| LTC3809EMSE-1#TRPBF | MS-10E | E | $2.56 | Yes | ||
| LTC3809IDD-1#PBF | 3x3 DFN-10 | I | $3.70 | $2.59 | Yes | |
| LTC3809IDD-1#TRPBF | 3x3 DFN-10 | I | $3.05 | Yes | ||
| LTC3809IMSE-1#PBF | MS-10E | I | $3.70 | $2.59 | Yes | |
| LTC3809IMSE-1#TRPBF | MS-10E | I | $3.05 | 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 |
|---|---|---|---|
| DC882A | LTC3809EDD-1 | Synch Step-Down Converter | $125.00 | |
| Buy Now | |||
Designed for Automotive and Transportation Applications
AEC-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
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LTC3809IDD-1#PBF | 3x3 DFN-10 | I | $3.70 | $2.59 | Yes | |
| LTC3809IDD-1#TRPBF | 3x3 DFN-10 | I | $3.05 | Yes | ||
| LTC3809IMSE-1#PBF | MS-10E | I | $3.70 | $2.59 | Yes | |
| LTC3809IMSE-1#TRPBF | MS-10E | I | $3.05 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- 1- or 2-Cell Lithium-Ion Powered Devices
- Notebook and Palmtop Computers, PDAs
- Portable Instruments
- Distributed DC Power Systems
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Design Tools
LTspice
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Models for the following parts are available in LTspice:
LTC3809
LTC3809-1
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.
