LTC6909 - 1 to 8 Output, Multiphase Silicon Oscillator with Spread Spectrum Modulation
Features
- 1-, 2-, 3-, 4-, 5-, 6-, 7- or 8-Phase Outputs
- One External Resistor Sets the Output Frequency from 12.5kHz to 6.67MHz
- Optional Spread Spectrum Frequency for Improved EMI Performance
- ±10% Frequency Spreading
- Outputs Can Be Held Low or Floated (Hi-Z)
- Three Spread Spectrum Modulation Rates fOUT/16, fOUT/32 and fOUT/64
- 400μA Supply Current
- Operates from a Single 2.7V to 5.5V Supply
- Fast Start-Up Time
- First Cycle Accurate
- Outputs Are High Impedance Until Frequency Settles
- MS16 Package
AEC-Q100 data available for specific packages
Typical Application
Description
The LTC6909 is an easy to use precision oscillator that can provide 1-, 2-, 3-, 4-, 5-, 6-, 7- or 8-phase synchronized outputs. The LTC6909 also offers spread spectrum frequency modulation (SSFM), which can be enabled to improve electromagnetic compatibility (EMC) performance.
Eight separate outputs provide up to eight rail-to-rail, 50% duty cycle clock signals. Using three logic inputs, the outputs are configured for phase separation, ranging from 45° to 120° (three to eight phases). The clock outputs can also be held low or configured for Hi-Z. A single resistor, combined with the phase configuration, sets the output frequency, based on the following formula:
The LTC6909 can be used in applications requiring only one or two output phases. Alternatively, the LTC6908 family of parts provides the same two output signals but in a smaller SOT-23 or 2mm × 3mm DFN package. The LTC6908-1 provides complimentary (180°) outputs while the LTC6908-2 provides quadrature (90°) outputs.
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 |
|---|---|---|---|---|---|
| LTC6909CMS#PBF | MS-16 | MS | C | 05-08-1669 | Yes |
| LTC6909CMS#TRPBF | MS-16 | MS | C | 05-08-1669 | Yes |
| LTC6909HMS#PBF | MS-16 | MS | H | 05-08-1669 | Yes |
| LTC6909HMS#TRPBF | MS-16 | MS | H | 05-08-1669 | Yes |
| LTC6909IMS#PBF | MS-16 | MS | I | 05-08-1669 | Yes |
| LTC6909IMS#TRPBF | MS-16 | MS | I | 05-08-1669 | 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 | |
|---|---|---|---|---|---|---|
| LTC6909CMS#PBF | MS-16 | C | $3.43 | $2.46 | Yes | |
| LTC6909CMS#TRPBF | MS-16 | C | $3.49 | $2.52 | Yes | |
| LTC6909HMS#PBF | MS-16 | H | $4.74 | $3.40 | Yes | |
| LTC6909HMS#TRPBF | MS-16 | H | $4.80 | $3.46 | Yes | |
| LTC6909IMS#PBF | MS-16 | I | $4.12 | $2.96 | Yes | |
| LTC6909IMS#TRPBF | MS-16 | I | $4.18 | $3.02 | 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 |
|---|---|---|---|
| DC1446A | LTC6909 DEMO BOARD | $75.00 | |
| 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 | |
|---|---|---|---|---|---|---|
| LTC6909HMS#PBF | MS-16 | H | $4.74 | $3.40 | Yes | |
| LTC6909HMS#TRPBF | MS-16 | H | $4.80 | $3.46 | Yes | |
| LTC6909IMS#PBF | MS-16 | I | $4.12 | $2.96 | Yes | |
| LTC6909IMS#TRPBF | MS-16 | I | $4.18 | $3.02 | Yes | |
| Buy Now • Request Samples | ||||||
Applications
- Synchronizing Multiple Switching Power Supplies
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Design Tools
LTspice
LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice
Models for the following parts are available in LTspice:
LTC6909
OscCalc, an Excel based selection and synthesis tool, allows you to choose and configure the Silicon Oscillator best suited for your application.
- Download and open OscCalc
- Enable Macros
- Enter your desired switching frequency. Suitable silicon oscillators will be highlighted in green. Clicking on a part will show you the external component values and settings required to achieve your desired switching frequency.
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.
