Hello Nasser,
Can LMH1219 OUT0 and OUT1 for 100-ohm differential to drive Fiber optical module?
If no, then could you tell us that which IC is fulfill our above requirements(mentioned in screenshot).
Thank you.
Malav Patel
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Hello Nasser,
Can LMH1219 OUT0 and OUT1 for 100-ohm differential to drive Fiber optical module?
If no, then could you tell us that which IC is fulfill our above requirements(mentioned in screenshot).
Thank you.
Malav Patel
Hi Malav,
Yes you can use LMH1219 for this purpose.
Regards,Nasser
Hello Nasser,
May I used LMH1219 IC interface like below screenshot. This IC work if both the output of the LMH1219 IC will be connect with the optical fiber module instead of connect with FPGA, right? I hope it will drive this signal for optical FIBER transmission.
Thank you.
MALAV Patel
Hi Malav,
Yes your block diagram would work. You are connecting FPGA to IN1 of the LMH1219 device and then connect two 100-ohm outputs to the optical modulae.
Regards,,Nasser
Hello Nasser,
Do we need to take care anything in the schematic design to used LMH1219 as above diagram? or we can make connection as per application schematic given in LMH1219 datasheet and only change are to used both the output of this IC are given to optical module connector.
Could you confirm from your end?
Thank you.
Regards, Malav
Hi Malav,
You just need to use IN1 and connect to the output of the FPGA as shown in Figure 22 of the data sheet. Then through the register setting you need to enable IN1 with 10GbE. You can also use LMH1219 GUI and set this up through this interface as well.
Regards,Nasser
Hello Nasser,
Please find the attached schematic sheet of the LMH1219 connection with used IN1 and connect to the output of the FPGA and outputs of the LMH1219 connect both the outputs with optical fiber connector which work as transmitter.
Could you check my schematic and let me know if any changes required or not and also let me know if any additional option given to the LMH1219 schematic for better work?
Thank you.
Regards,
Hi Malav,
Schematic looks fine. Given your settings, at power up we should be able to lock to the incoming 10GbE data stream on IN1.
One comment, it seems you are using SPI interface. Suggestion is to use SMBus instead. This will allow you to use LMH1219 GUI to control and do any debugging during product development. GUI uses SMBus interface only.
Regards,,Nasser
Hello Nasser,
We have not plane to used that adapter. Remaining things are okay in the schematic?
Hello Nasser,
Could you let me know that in below screenshot I have highlighted one red square in which i want know that for IN0 input need to route 75ohm single ended or it should be 75ohm differential routed?
In my case i am not using IN0 but we have terminated each other and keep differential signal but after datasheet read they mention its single ended 75ohms.
Is it okay if I will route this IN0 signal with 75ohm single ended?
Thanks
Greetings,
You are not using IN0 therefor there are two options:
1). You can leave them floating. Through the register settings you would be using IN1 only so these are not being used and there is no signal on these pins.
2). IN0 is used for 75-ohm single ended application - this does not apply to your design. You can leave these as you have shown in your schematic since these are not used. You can also put 75-ohm R to GND as well - on IN0+ and IN0-. In either case, it should be fine.
Regards,Nasser
Hello Nasser,
So is it okay if I route IN0 with 75-ohm single ended on both IN0+ and IN0- ? Because right now its 100-ohm differential and its making confused so I need to make proper way.