Main
Si5351A/B/C
I2C-PROGRAMMABLE ANY-FREQUENCY CMOS CLOCK GENERATOR + VCXO
Functional Block Diagram
Features
Applications Description
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Si5351A/B/C
T ABLE OF C
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1. Electrical Specifications
Table 1. Recommended Operating Conditions
Table 2. DC Characteristics
Si5351A/B/C
Table 3. AC Characteristics
Table 4. Input Clock Characteristics
Table 5. Output Clock Characteristics
Table 6. Crystal Requirements
Table 7. I2C Specifications (SCL,SDA)1
Table 8. Thermal Characteristics
Table 9. Absolute Maximum Ratings
Preliminary Rev. 0.95 9
2. Detailed Block Diagrams
Figure 1. Block Diagrams of 3-Output and 8-Output Si5351A Devices
Si5351A 8-Output
Si5351A 3-Output
Figure 2. Block Diagrams of Si5351B and Si5351C 8-Output Devices
Si5351B
20-QFN, 24-QSOP
Si5351C
3. Functional Description
Figure 3. Si5351 Block Diagram
Figure 4. External XTAL with Optional Load Capacitors
3.1. Input Stage
3.2. Synthesis Stages
Figure 5. Using the Si5351 as a Multi-Output VCXO
3.3. Output Stage
3.4. Spread Spectrum
Figure 6. Available Spread Spectrum Profiles
3.5. Control Pins (OEB, SSEN)
4. I2C Interface
Figure 7. I2C and Control Signals
Figure 8. Si5351 I2C Slave Address
Figure 9. I2C Write Operation
Figure 10. I2C Read Operation
5. Configuring the Si5351
Figure 11.Si5351 Memory Configuration
5.1. Writing a Custom Configuration to RAM
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5.2. Si5351 Application Examples
5.3. Replacing Crystals and Crystal Oscillators
Figure 13. Using the Si5351A to Replace Multiple Crystals, Crystal Oscillators, and PLLs
XA XB
CLK0 CLK1 CLK2 CLK3 CLK4 CLK5
5.4. Replacing Crystals, Crystal Oscillators, and VCXOs
Si5351C
CLKIN
Si5351B
VC
5.6. Replacing a Crystal with a Clock
The Si5351 can be driven with a clock signal through the XA input pin.
Figure 16. Si5351 Driven by a Clock Signal
5.7. HCSL Compatible Outputs
Figure 17. Si5350C Output is HCSL Compatible
6. Design Considerations
6.1. Power Supply Decoupling/Filtering
6.2. Power Supply Sequencing
6.3. External Crystal
6.4. External Crystal Load Capacitors
6.6. Trace Characteristics
Figure 18.Recommended Trace Characteristics with 8 mA Drive Strength Setting
Note:
7. Register Map Summary
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8. Register Descriptions
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Si5351A/B/C
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62 Preliminary Rev. 0.95
9. Si5351A Pin Descriptions (20-Pin QFN, 24-Pin QSOP)
Table 10. Si5351A Pin Descriptions
SSEN 6 12 I Spread spectrum enable. High = enabled, Low = disabled.
1. 2.
Si5351A 20-QFN Top View
10. Si5351B Pin Descriptions (20-Pin QFN, 24-Pin QSOP)
Table 11. Si5351B Pin Descriptions
SSEN 6 12 I Spread spectrum enable. High = enabled, Low = disabled.
*Note: *Note:
Si5351B 20-QFN Top View
11. Si5351C Pin Descriptions (20-Pin QFN, 24-Pin QSOP)
Table 12. Si5351C Pin Descriptions
CLKIN 6 12 I PLL clock input.
Notes: 1. 2.
Si5351C 20-QFN Top View
12. Si5351A Pin Descriptions (10-Pin MSOP)
Table 13. Si5351A 10-MSOP Pin Descriptions
Si5351A 10-MSOP Top View
13. Ordering Information
Si535X EVB
Si5351X XX
Figure 19. Device Part Numbers
Figure 20. Si5351A/B/C Evaluation Kit
A
14. Package Outline (24-Pin QSOP)
Table 14. 24-QSOP Package Dimensions
15. Package Outline (20-Pin QFN)
Table 15. Package Dimensions
16. Package Outline (10-Pin MSOP)
Table 16. 24-QSOP Package Dimensions
DOCUMENT CHANGE LIST
Revision 0.1 to Revision 0.9
Revision 0.9 to Revision 0.95
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72 Preliminary Rev. 0.95
CONTACT INFORMATION
Silicon Laboratories Inc.
