Please see the attached document for Frequently Asked Questions (FAQ) and their answers regarding the Si5347 and Si5346 Quad and Dual DSPLL Any-Frequency, Any-Output Jitter Attenuators.

The topics from the Table of Contents are listed below.

PCB Design and Layout Guidance

Where can I find the IBIS model for the Si5347/46?

Where can I find the Si5347/46 schematic footprints and symbols?

Where can I find the package and PCB footprint information?

Do you have layout recommendations I should follow?

Do you have a list of recommended crystals?

I don’t want to use a crystal with the Si5347/46.  Can I use an XO or TCXO as the XA/XB reference instead?  And if so, how do I interface an external oscillator to the device?

Are there any power supply filtering requirements or recommendations?

Is there any specific power supply sequencing requirement?

What serial interfaces does the device support?

How do I properly terminate input and output clocks?

Where can I get detailed material composition information on these devices?

Is the part RoHS compliant?

What is the Moisture Sensitivity Level (MSL) rating for the Si5347/46?

What is the recommend profile for solder reflow process?

Frequency Plan and Clock Design Decisions

What development software/tools do you have available to use with the Si5347/46?

Where can I find ClockBuilder Pro Documentation?

How do I select proper jitter attenuation bandwidth?

Does the device support automatic input clock selection and does it support hitless switching?

Is there a recommended full device programming procedure?

Can I change one output frequency without disturbing other output(s)?

Do I need to write pre-amble/post-amble for Frequency-On-The-Fly?

Should I use Soft_Reset_All or Soft_Reset_DSPLLx for Frequency-On-The-Fly?

Do I need to update any divider if I strobe Soft_Reset_All?

How do I do DCO mode?

Do I have to provide an input clock in DCO mode?

How do I calculate a frequency plan without CBPro?

Does the Si5347/46 support Zero-Delay Buffer operation?

Please see the attached document for Frequently Asked Questions (FAQ) and their answers regarding the Si5345, Si5344, and Si5342 10-Channel, 4-Channel, and 2-Channel Any-Frequency, Any-Output Jitter Attenuator/Clock Multipliers.

The topics from the Table of Contents are listed below.

PCB Design Considerations

Where should I look for schematic design assistance?

Where should I look for layout recommendations?

Where can I find the package and PCB footprint information?

Which ordering part number (OPN) is right for me?

Where can I find Si5345/44/42 layout footprints and schematic symbols?

Where can I find the IBIS model for the Si5345/44/42?

What reference clock should be used on the XA/XB input?

What serial interfaces does the device support?

Are there any power supply filtering requirements or recommendations?

How do I properly terminate input and output clocks?

Where can I get detailed material composition information on these devices?

Is the part RoHS compliant, REACH compliant and lead (Pb) free?

What is the Moisture Sensitivity Level (MSL) rating for the SI5345/44/42?

What is the recommended profiled for solder reflow process?

Frequency Plan and Clock Design Considerations

What development software do you have available to use with Si5345/44/42?

Where can I find ClockBuilder Pro Documentation?

Is there a recommended full device programming procedure?

What input buffer should I select?

Does the device support automatic input clock selection hitless switching?

How do I select proper jitter attenuation bandwidth?

Can I change an output frequency on the fly?

What is the best way to configure output clocks to optimize jitter performance?

Where can I look for help with DCO mode?

How much power will my frequency plan draw?

How can I know the performance of my frequency plan if I can’t measure phase noise or jitter?

Does the Si5345/44/42 support Zero-Delay Buffer operation?

Common Debug Questions

The device is not generating output clocks, what can I do?

I am unable to establish communication with the device via the serial interface, what can I do? 

• I burned a project file to my device with a new Base I2C address, but the base address in the device was not changed after the burn process was complete (non-firmware based devices).

The I2C address will not be changed during the burn process. Changes to the base I2C address in the CBPro Configuration Wizard will be included in exports and the project file used to create orderable part numbers. However, this change is not burned to the device using the NVM Burn Tool. The image below shows this message in CBPro. 

     
To permanently change the I2C base address on your device, you need to use the I2C Address Burn Tool. See the images below to use the tool.

• Why can’t I communicate with the Si534x8x device on my hardware using the CBPro Dongle?

General Steps to Resolve a Communication Issue (Non-Firmware based devices)
1. Verify which communication protocol your hardware is using – SPI or I2C.
2. Verify the voltage level on the I2C_SEL control pin on the DUT. This level should be logic low (0 V) if your communication protocol is SPI. This level should be logic high (1.8 V or 3.3 V – refer step 3 below) if your communication protocol is I2C.
3. Verify the value of the IO_VDD_SEL bit (Register 0x0943[0]) for the DUT. If IO_VDD_SEL is 0, the I/O Voltage setting should be 1.8V. If IO_VDD_SEL is 1, the I/O Voltage setting should 3.3V. If you do not know this value, you can try both voltages to determine
which voltage level will work successfully.
4. If the communication protocol is I2C, verify the I2C address setting (Register 0x000B) for the device. You may also need to verify
the voltage level on the A0/CSb and A1/SDO pins if they are not connected to the field programmer. The level on these pins set bit 1 and bit 0 in the I2C address. If these are connected to the CBPro Dongle, they are both driven low.  For more information on this issue refer to section 7.1 in UG286: ClockBuilderPro Field Programmer Kit

General Steps to Resolve a Communication Issue (Firmware based devices)
1. Verify the I2C address for the device.
2. Verify the voltage level on the A0/CSb and A1/SDO pins if they are not connected to the field programmer. The level on these pins set bit1 and bit 0 in the I2C address. If these are connected to the CBPro Dongle, they are both driven low. For more information on this issue refer to section 7.1 in UG286: ClockBuilderPro Field Programmer Kit

• Why do I have a communication error when I write my new project to the device?

Does the new plan change the IO_VDD_SEL Bit (Register 0x0943[0]) value? In order for the CBPro Dongle to communicate with the device correctly, the dongle’s IO voltage needs to match the IO_VDD_SEL bit in the device. If the plan changes this bit during the writing process, communication will fail. To determine if the new plan is changing this bit, perform the following steps:
• Read the current value in the device by using the DUT Register Editor tab in the EVB GUI window.
• Determine if the new plan changes the value. This can be done by looking at the Host Interface tab in the Design Dashboard of the new project.
• If VDD (Core) radio button selected and 0x943 = 0, no change from new plan,
Else VDD (Core) radio button selected and 0x943 = 1, new plan is changing IO_VDD_SEL refer to Section 7.3 in document UG286: ClockBuilderPro Field Programmer Kit.
• If VDDA (3.3V) radio button selected and 0x943 = 1, no change from new plan,
Else VDDA (3.3V) radio button selected and 0x943 = 0, new plan is changing IO_VDD_SEL refer to Section 7.3 in document UG286: ClockBuilderPro Field Programmer Kit.
The following window shows how to read the IO_VDD_SEL bit from the device and check the project Host Interface setting.
 

• Can I use my I2C master to communicate with the device on a Silicon Labs Evaluation Board?

You can communicate with the DUT using I2C, but there are a few steps and issues that need to be considered:

- You will need to connect your I2C master to the evaluation board. This can be done using J17 for the Si5340, Si5342, Si5344, and Si5346 boards. This can be done using J36 for the Si5341, Si5345, Si5347, Si5348, Si5380, Si5381, and Si5382 boards. Remove the jumpers J17 or J36 and connect your I2C master to the pins labeled SDA, SCLk, and GND. You may also want to drive the pins labaled A0 and A1 low to use the base I2C address of the device.

- Remove the jumper labeled "I2C_SEL" to allow this signal to be pulled high which puts the device in I2C mode. Do not run ClockBuilder Pro while trying to communicate with the device using your I2C master. If ClockBuilder Pro is running, it will override the I2C_SEL jumper and drive this signal low putting the device in SPI mode. If you need to run ClockBuilder to work with the evaluation board before using your I2C master(board regulators, look at register values), exit ClockBuilder Pro and press the button on the board labeled "MCU Reset" before using your I2C master. Pressing the MCU reset button will reset the onboard MCU of the evaluation board and the I2C_SEL will be pulled high putting the device in I2C mode. The MCU reset button will not reset the device or any other settings on the board (it only resets the MCU).

- Communicate with the device using I2C and the I2C address of the device (base address plus the levels on the A1 and A0 pins of the device. 

• Can I use Field Programmer to communicate with the device on a Silicon Labs Evaluation Board using I2C?

You can communicate with the DUT using I2C, but there are a few steps and issues that need to be considered:

- You will need to connect the field programmer to the evaluation board. This can be done using J17 for the Si5340, Si5342, Si5344, and Si5346 boards. This can be done using J36 for the Si5341, Si5345, Si5347, Si5348, Si5380, Si5381, and Si5382 boards. Remove the jumpers on J17 or J36 and connect the Field Programmer to the pins labeled SDA, SCLk, A0, A1, and GND.  

- Remove the jumper labeled "I2C_SEL" to allow this signal to be pulled high which puts the device in I2C mode.

- Connect the Field Programmer to a USB port on your computer. You will need to provide power to the evaluation board with either a powered USB hub not connected to your computer or a USB charger that is capable of providing 500 mA of current. If the evaluation board is connected to your computer, you cannot run CBPro. If CBPro detects the evaluation board, it will drive the I2C_SEL pin low putting the device in SPI mode.

Note**: If you need to control functionality on the evaluation board, such as enabling output regulators, you connect the evalution board to your computer through a powered usb hub and perform the following steps:

1. Open CBPro and setup the evaluation board (e.g. enable output regulators)
2. Disconnect the hub from your PC 
   • Do not disconnect power from the hub
   • Do not disconnect the evaluation board from the hub
3. Press the button on the evaluation board labeled "MCU RST"
   • This only resets the MCU on the evaluation board. The Si538x4x device is not reset.
4. Confirm the jumper labeled "I2C_SEL" is not installed

With the field programmer connected to your computer and the evalution board powered with another source, start CBPro and setup the field programmer for I2C communication.

Please see the attached PDF for the answers to some of the most common Si547 questions. 

Please see the attached PDF for the answers to some of the most common Si546questions. 

Please see the attached PDF for the answers to some of the most common Si545 questions. 

Please see the attached PDF for the answers to some of the most common Si542 questions. 

Please see the attached PDF for the answers to some of the most common Si541 questions.