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Terminal Finish for the Si534x/8x/9x family devices on Clock Generator, Buffer, Crystal Oscillator Knowledge Base
Package: All devices with the QFN packages use NiPdAu plating. Thickness: Following table gives details about the thickness of different materials:
Devices: All the devices from the Si534x (Si5340/41/42/44/45/46/47/48) family, the external crystal devices from the Si539x (Si5391/92/94/95/96/97) family and the Si5381/82/86 devices have the above terminal finish.
Package: All devices with the LGA packages use the Electroplated Ni/Au plating. Thickness: Following table gives details about the thickness of different materials:
Devices: The integrated crystal devices from the Si539x (Si5392/94/95/95/97) and the Si5383/83/88/89 devices have the above terminal finish. If more details are required regarding device composition, please refer our RFI portal. Following are the steps to access the same:
Now if the information you need is not present there, then you have to create a support request using the following link: https://www.silabs.com/support
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Jun 10 2020, 8:58 PM |
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SI5394 : I2C address A0/A1 level
Firstly, leave the A0 and A1 pins unconnected only when they are not used. When you want to operate the I2C mode, you can connect upto 4 slave devices on the single I2C bus using the A0 and A1 pins. You can either connect both pins to ground, either one to ground and other to VDD or both to VDD. So this will give you the two LSBs of the I2C address as follows:
Also use external pull up/pull down resistors to make these pins high or low while operating in the I2C mode. Hope this helps.
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Feb 10 2020, 10:54 PM |
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Si5340 Reference Manual Errors? (different registers than those shown in clockbuilder)
I want to apologize for this confusion and thank you for bringing it to our attention. We will fix these issues in out next revision of the documents. Meanwhile, I would recommend you to follow what Clock Builder Pro suggests. It is very reliable. |
Feb 10 2020, 10:21 PM |
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Posted
Input source and frequencies for clock generators vs jitter attenuators on Knowledge Base
The clock generator devices like Si5340/41/91 as well as the jitter attenuator devices like Si5345/95 are both designed to provide low jitter output clocks. But a major difference is that the jitter attenuators, as the name suggests, will attenuate the noise/jitter at the input while for the clock generators, the noise at the input passes through to the output and contributes to the output jitter value. Therefore, in case of the clock generator devices, the total RMS jitter at the output will tremendously depend on the jitter of the input source and also on the input frequency. In order to get the best jitter performance, it is recommended to use an input frequency between 48MHz to 54MHz at the XAXB pins of these devices and also to avoid using low frequencies like 20MHz or 25MHz at the input. Lower input frequencies cause an increase in noise at the clock output which is seen as increased RMS jitter. The above applies to both the XAXB pins and the clock inputs pins for the clock generators. Also, the signal generator or the oscillator used at the input should have minimum possible jitter. The Rohde & Schwarz SMA 100 signal generator is one of the very low jitter signal generators available Now in case of the jitter attenuating clocks, any allowed input frequency and any signal generator can be used to produce the input signal and it will not have any effect on the output clock jitter. |
Jan 27 2020, 2:12 AM |
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Different methods to define frequency accuracy of the Crystal/XO/TCXO/OCXO on Knowledge Base
Frequency accuracy is an important parameter when selecting a reference clock for any application. In general frequency accuracy is the difference in the measured value of the crystal/XO/TCXO/OCXO frequencies from the ideal expected value. Following factors contribute to the accuracy measurement:
Frequency of a crystal/XO/TCXO/OCXO is measured after placing the device in a temperature-controlled chamber and then varying the temperature from -40°C to 85°C. Then the frequency accuracy at a particular temperature is calculated in ppm as follows: Facc = Frequency accuracy at particular temperature Ft = Frequency at particular temperature Fref = Frequency at 25°C This Ref freq can be calculated using any of the following two techniques (this is usually specified in the datasheet for the device):
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Jan 27 2020, 2:08 AM |
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DCO mode: Why not to update the N divider manually? on Knowledge Base
DCO mode allows the user to dynamically change an output clock frequency in any existing device or OPN if required. The output frequency can be modifying by changing the N divider value which is assigned to the particular clock output. However manually writing to the N dividers is not a recommended way to use the DCO mode. There are certain factors which need to be considered. The N divider which is associated with the DCO enabled output should be in fractional mode. If the N divider is integer in the original project file, then it needs to be changed to operate in the fractional mode. The register PIBYP[4:0] enables to change the N divider mode. Each bit in this register is assigned to one N divider. If N0 needs to be in fractional mode, write 0 to PIBYP[0]. Note that a soft reset should be performed after changing the above mentioned register. The next step involves calculating the frequency step word and then also the corresponding values for either the N divider numerator or the N divider denominator. All these calculations are explained in detail in the following application note: https://www.silabs.com/documents/public/application-notes/AN959.pdf In order to avoid all these complications, the best and easiest way to implement DCO mode is using Clock Builder Pro DCO mode tool. It will perform all the calculations and determine the required register values. |
Jan 27 2020, 1:57 AM |
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Output frequencies should not be rounded off when making a Clock Builder Pro configuration file on Knowledge Base
Many applications require output frequencies that are not integers and are represented using very specific decimal values. Clock generators and Jitter attenuators (Si534x/9x) devices are capable of generating all types of frequency outputs. When a required input-output configuration file is generated, Clock Builder Pro calculates the values of the M, N and P dividers according to the input-output frequencies. The M and N dividers are in the form of a multiplication ratio. Calculating these values is very tricky when the output frequencies are not integers. In order to get the correct multiplication ratio, it is important to express the frequency values in an exact manner. This means that the decimal frequencies should not be rounded. They should be expressed in terms of fractions. Many times, the output frequency is in terms of repeating decimals. If these are rounded, then there is possibility of getting incorrect divider values. For example, if a 33.3333… MHz output is required, it should be expressed as 100/3 MHz and not rounded to 33.333 MHz. The following table will show the difference in the M and N divider register values between 33.333 MHz and 100/3 MHz output frequency.
The left side shows register values when the output frequency is 33.333 MHz and the right side shows when it’s 100/3 MHz. As seen the M divider and N divider values are different and in order to get a perfect multiplication ratio, decimal frequencies should be expressed as fractions. |
Jan 24 2020, 6:13 PM |
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Voted up our_recommendationforminimalinput-to-outputio-QoAN Show more |
Jan 20 2020, 7:52 PM |
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Voted up our_recommendationforminimalinput-to-outputio-QoAN Show more |
Jan 20 2020, 7:42 PM |
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SI5328C-C-GM Derating factor
This question was resolved in the Sales force case (00210088) and following is the summary: We do not de-rate our devices over temperature. Instead we specify the environmental conditions and the guaranteed performance when operating within those conditions.
Best Regards, Jui |
Dec 03 2019, 10:36 PM |