TI Team,
I would like to use the SN74AVC2T245 as a cable driver. Here are my parameters:
- Single Ended Cable (signal + ground)
- Data rate is 4Mbps
- Cable Length is 2 feet
- IC will be powered either from 3.3V or 5.0V on both ends of the cable.
This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
TI Team,
I would like to use the SN74AVC2T245 as a cable driver. Here are my parameters:
Hi, David,
For answering your quesitons, I think we need to know below answers.
1. Could you please let me know the standard of the cable you used? is there any part number?
2. For SN74AVC2T245, the power supply range is from 1.2V to 3.6V. so ,what power supply you will apply for both VCCA and VCCB?
3. Can you provide the equalivent capacitive load for the cable?
one main concern is the larger capacitve load, the smaller Data Rate.
BR
Junjie
Junjie,
I'm actually going to use the SN74LVC1T45. That being said, I haven't characterized the cable, but perhaps you have an application note that explains how to drive cables at this length and data rate.
The SN74LVC1T45 will be powered from either 3.0V or 5.0V at either end. Can you provide guidance without the cable specification you requested?
-David
Hi, David,
Acutally we don't have the applicaiton note for cable driving. I am trying to do some anlaysis by finding a cable for example.
if you can provide the part number of cable or what looks like of the cable, that will be good, I can do the anlaysis by using your cables, you know, the different cable may have the different character for the load estimation. also could you please also provide the device information of your receiver side?
I will do the analysis and provide it to you as soon as I can. by the way, you mean both VccA and VccB has the same voltage 3.3V or 5V.
BR
Junjie
Junjie,
I'm attaching a .PDF file of the cable. I'm trying to get the capacitance/impedance values from Samtec. Ideally, I can adjust the impedance values once you can provide a recommended termination structure, i.e. simple shunt resitor, t-network, etc. Can you do this?
-David
David,
could you please also let me know your receiver information, what part will you use? I will check that cable you provide. the receiver information will let me check whether the transfer signal is OK to be acceptted .
BR
Junjie
Junjie,
The same device will be used on both ends either powered from 3.3V or 5V. Let me know if device will be able to support the signal.
-David
David,
I am trying to do some simulation, will let you know my feedback once I get it.
BR
Junjie
Hello Junjie,
I have additional information to provide you about the cable. After some deliberation, we have decided to use 2 feet of Gray Ribbon Cable Series 2L280XX (1mm pitch). I'm attaching the datasheet for the cable.
Thank you for conducting this simulation.
-David
David,
Based on my checking. the SN74AVC1T45 is Ok in your design . The only thing is the signal intergrity issue, please add the serial resistor for the impedance match, based on the datasheet, if the sigal is G-S-G it has the 90ohms impedance, you need to add about 70ohms or 75ohms serial resistor to do the impedance match. you can adjust the value when you check the signal intergrity issue in your actual design. Here is my assumption. any further thing, please let me know.
BR
Junjie