LTC6908 - Dual Output Oscillator with Spread Spectrum Modulation
Datasheet 
DocumentationDatasheet
Reliability Data
Product Selector Card
Press Release
Software and Simulation
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Features
- LTC6908-1: Complementary Outputs (0°/180°)
- LTC6908-2: Quadrature Outputs (0°/90°)
- 50kHz to 10MHz Frequency Range
- One External Resistor Sets the Frequency
- Optional Spread Spectrum Frequency Modulation for Improved EMC Performance
- ±10% Frequency Spreading
- 400µA Supply Current Typical (V+ = 5V, 50kHz)
- Frequency Error ≤1.5% Max (TA = 25°C, V+ = 3V)
- ±40ppm/°C Temperature Stability
- Fast Start-Up Time: 260µs Typical (1MHz)
- Outputs Muted Until Stable
- Operates from a Single 2.7V to 5.5V Supply
- Available in Low Profile (1mm) ThinSOT and DFN (2mm × 3mm) Packages
Typical Application
Description
The LTC6908 is an easy-to-use precision oscillator that provides 2-outputs, shifted by either 180° or 90°. The oscillator frequency is programmed by a single external resistor (RSET) and spread spectrum frequency modulation (SSFM) can be activated for improved electromagnetic compatibility (EMC) performance. The LTC6908 operates with a single 2.7V to 5.5V supply and provides rail-to-rail, 50% duty cycle square wave outputs. A single resistor from 10k to 2M is used to select an oscillator frequency from 50kHz to 10MHz (5V supply). The oscillator can be easily programmed using the simple formula outlined below:fOUT =10MHz • 10k/RSET
The LTC6908’s SSFM capability modulates the output frequency by a pseudorandom noise (PRN) signal to decrease the peak electromagnetic radiation level and improve EMC performance. The amount of frequency spreading is fi xed at ±10% of the center frequency. When SSFM is enabled, the rate of modulation is selected by the user. The three possible modulation rates are fOUT/16, fOUT/32 and fOUT/64.
2x3 DFN-6,SOT-23
Package Variations and Pricing
| Part Number | Package | Pins | Temp | Price (1-99) |
Price (1k)* |
|---|---|---|---|---|---|
| LTC6908CDCB-1#PBF | DFN | 6 | C | $2.45 | |
| LTC6908CDCB-1#TRMPBF | DFN | 6 | C | $2.45 | $1.67 |
| LTC6908CDCB-1#TRPBF | DFN | 6 | C | $2.45 | $1.65 |
| LTC6908CDCB-2#PBF | DFN | 6 | C | $2.45 | |
| LTC6908CDCB-2#TRMPBF | DFN | 6 | C | $2.45 | $1.67 |
| LTC6908CDCB-2#TRPBF | DFN | 6 | C | $2.45 | $1.65 |
| LTC6908CS6-1#PBF | SOT | 6 | C | $2.43 | |
| LTC6908CS6-1#TRMPBF | SOT | 6 | C | $2.43 | $1.67 |
| LTC6908CS6-1#TRPBF | SOT | 6 | C | $2.43 | $1.65 |
| LTC6908CS6-2#PBF | SOT | 6 | C | $2.43 | |
| LTC6908CS6-2#TRMPBF | SOT | 6 | C | $2.43 | $1.67 |
| LTC6908CS6-2#TRPBF | SOT | 6 | C | $2.43 | $1.65 |
| LTC6908HS6-1#PBF | SOT | 6 | H | $3.46 | |
| LTC6908HS6-1#TRMPBF | SOT | 6 | H | $3.46 | $2.46 |
| LTC6908HS6-1#TRPBF | SOT | 6 | H | $3.46 | $2.44 |
| LTC6908HS6-2#PBF | SOT | 6 | H | $3.46 | |
| LTC6908HS6-2#TRMPBF | SOT | 6 | H | $3.46 | $2.46 |
| LTC6908HS6-2#TRPBF | SOT | 6 | H | $3.46 | $2.44 |
| LTC6908IDCB-1#PBF | DFN | 18 | I | $2.92 | |
| LTC6908IDCB-1#TRMPBF | DFN | 6 | I | $2.92 | $2.06 |
| LTC6908IDCB-1#TRPBF | DFN | 6 | I | $2.92 | $2.04 |
| LTC6908IDCB-2#PBF | DFN | 6 | I | $2.92 | |
| LTC6908IDCB-2#TRMPBF | DFN | 6 | I | $2.92 | $2.06 |
| LTC6908IDCB-2#TRPBF | DFN | 6 | I | $2.92 | $2.04 |
| LTC6908IS6-1#PBF | SOT | 6 | I | $2.90 | |
| LTC6908IS6-1#TRMPBF | SOT | 6 | I | $2.90 | $2.06 |
| LTC6908IS6-1#TRPBF | SOT | 6 | I | $2.90 | $2.04 |
| LTC6908IS6-2#PBF | SOT | 6 | I | $2.90 | |
| LTC6908IS6-2#TRMPBF | SOT | 6 | I | $2.90 | $2.06 |
| LTC6908IS6-2#TRPBF | SOT | 6 | I | $2.90 | $2.04 |
| LTC6908CS6-1 | SOT | 6 | C | $4.86 | |
| LTC6908CS6-1#TR | SOT | 6 | C | $4.86 | $3.30 |
| LTC6908IS6-1 | SOT | 6 | I | $5.80 | |
| LTC6908IS6-1#TR | SOT | 6 | I | $5.80 | $4.08 |
| LTC6908CS6-2 | SOT | 6 | C | $4.86 | |
| LTC6908CS6-2#TR | SOT | 6 | C | $4.86 | $3.30 |
| LTC6908IS6-2 | SOT | 6 | I | $5.80 | |
| LTC6908IS6-2#TR | SOT | 6 | I | $5.80 | $4.08 |
| LTC6908CDCB-1 | DFN | 6 | C | $4.90 | |
| LTC6908CDCB-1#TR | DFN | 6 | C | $4.90 | $3.30 |
| LTC6908IDCB-1 | DFN | 6 | I | $5.84 | |
| LTC6908IDCB-1#TR | DFN | 6 | I | $5.84 | $4.08 |
| LTC6908CDCB-2 | DFN | 6 | C | $4.90 | |
| LTC6908CDCB-2#TR | DFN | 6 | C | $4.90 | $3.30 |
| LTC6908IDCB-2 | DFN | 6 | I | $5.84 | |
| LTC6908IDCB-2#TR | DFN | 6 | I | $5.84 | $4.08 |
| LTC6908HS6-1 | SOT | 6 | H | $6.92 | |
| LTC6908HS6-1#TR | SOT | 6 | H | $6.92 | $4.88 |
| LTC6908HS6-2 | SOT | 6 | H | $6.92 | |
| LTC6908HS6-2#TR | SOT | 6 | H | $6.92 | $4.88 |
| LTC6908CDCB-1#TRM | DFN | 6 | C | $4.90 | $3.34 |
| LTC6908CDCB-2#TRM | DFN | 6 | C | $4.90 | $3.34 |
| LTC6908CS6-1#TRM | SOT | 6 | C | $4.86 | $3.34 |
| LTC6908CS6-2#TRM | SOT | 6 | C | $4.86 | $3.34 |
| LTC6908HS6-1#TRM | SOT | 6 | H | $6.92 | $4.92 |
| LTC6908HS6-2#TRM | SOT | 6 | H | $6.92 | $4.92 |
| LTC6908IDCB-1#TRM | DFN | 6 | I | $5.84 | $4.12 |
| LTC6908IDCB-2#TRM | DFN | 6 | I | $5.84 | $4.12 |
| LTC6908IS6-1#TRM | SOT | 6 | I | $5.80 | $4.12 |
| LTC6908IS6-2#TRM | SOT | 6 | I | $5.80 | $4.12 |
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 |
|---|---|---|---|
| DC2073A-J | LTC6908-1 Silicon Oscillator Demo Board | $50.00 | |
| DC2073B-B | LTC1799 Silicon Oscillator Demo Board | $50.00 | |
| DC814A2-K | LTC6908-2 DEMO BOARD | BUFFER BOARD W/ ASSOCIATED DIP8 CLOCK BOARD | $50.00 |