DocumentationDatasheet
Design Note
Reliability Data
Press Release
cad_symbol
ltspice
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.
| 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 |
3x3 DFN-10,MS-10E
Package Variations and Pricing
| Part Number | Package | Pins | Temp | Price (1-99) |
Price (1k)* |
|---|---|---|---|---|---|
| LTC3809EDD#PBF | DFN | 10 | E | $3.57 | $2.50 |
| LTC3809EDD#TRPBF | DFN | 10 | E | $2.60 | |
| LTC3809EDD-1#PBF | DFN | 10 | E | $3.57 | $2.50 |
| LTC3809EDD-1#TRPBF | DFN | 10 | E | $2.60 | |
| LTC3809EMSE#PBF | MSOP | 10 | E | $3.57 | $2.50 |
| LTC3809EMSE#TRPBF | MSOP | 10 | E | $2.56 | |
| LTC3809EMSE-1#PBF | MSOP | 10 | E | $3.57 | $2.50 |
| LTC3809EMSE-1#TRPBF | MSOP | 10 | E | $2.56 | |
| LTC3809IDD-1#PBF | DFN | 10 | I | $3.70 | $2.59 |
| LTC3809IDD-1#TRPBF | DFN | 10 | I | $3.05 | |
| LTC3809IMSE-1#PBF | MSOP | 10 | I | $3.70 | $2.59 |
| LTC3809IMSE-1#TRPBF | MSOP | 10 | I | $3.05 | |
| LTC3809EDD | DFN | 10 | E | $7.14 | $5.00 |
| LTC3809EDD#TR | DFN | 10 | E | $5.20 | |
| LTC3809EMSE | MSOP | 10 | E | $7.14 | $5.00 |
| LTC3809EMSE#TR | MSOP | 10 | E | $5.12 | |
| LTC3809EDD-1 | DFN | 10 | E | $7.14 | $5.00 |
| LTC3809EDD-1#TR | DFN | 10 | E | $5.20 | |
| LTC3809EMSE-1 | MSOP | 10 | E | $7.14 | $5.00 |
| LTC3809EMSE-1#TR | MSOP | 10 | E | $5.12 |
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 |