Low cost logic analyzer probe for Rigol MSO5000 EasyEDA project

[gentilkiwi]

When reading all your posts (thank you for them) - just saw that the SN75LVDS driver is for 100 ohms ended.
It seems that, on the MSO5000 side, it's already terminated with 33 ohms resistors - see picture ( from https://www.flickr.com/photos/eevblog/44893167835/in/album-72157701904033821 )

Isn't the best option to NOT populate 100 ohms resistors on PCB side? (to avoid worst result than with 33 ohms)

(maybe a newbie mistake, sorry for that)

[S. Petrukhin]

When reading all your posts (thank you for them) - just saw that the SN75LVDS driver is for 100 ohms ended.
It seems that, on the MSO5000 side, it's already terminated with 33 ohms resistors - see picture ( from https://www.flickr.com/photos/eevblog/44893167835/in/album-72157701904033821 )

Isn't the best option to NOT populate 100 ohms resistors on PCB side? (to avoid worst result than with 33 ohms)

(maybe a newbie mistake, sorry for that)

In the MSO5000, 33 Ohm resistors are installed in series.
I think it's just a protective function and to suppress EMI.
If you remove the 100 Ohm load, the SN75LVDS will be very upset because it tends to maintain current.
The termination resistors should have been inside the MSO5000, but they weren't there. However, the terminator also works well on the other end of the line.

[gentilkiwi]

When reading all your posts (thank you for them) - just saw that the SN75LVDS driver is for 100 ohms ended.
It seems that, on the MSO5000 side, it's already terminated with 33 ohms resistors - see picture ( from https://www.flickr.com/photos/eevblog/44893167835/in/album-72157701904033821 )

Isn't the best option to NOT populate 100 ohms resistors on PCB side? (to avoid worst result than with 33 ohms)

(maybe a newbie mistake, sorry for that)

In the MSO5000, 33 Ohm resistors are installed in series.
I think it's just a protective function and to suppress EMI.
If you remove the 100 Ohm load, the SN75LVDS will be very upset because it tends to maintain current.
The termination resistors should have been inside the MSO5000, but they weren't there. However, the terminator also works well on the other end of the line.

As I don't want the LVDS to be upset, I will try to keep them so Sorry to made you verify, and what a strange design on the MSO side :')

[gentilkiwi]

I made 2 variants base on JLCPB capabilities for PCBA (I'm not good for that)

> https://oshwlab.com/gentilkiwi/mso5000_lp

The first one is based on the SN75LVDS387, and the second one on 16x SN65LVDS1

[S. Petrukhin]

I made 2 variants base on JLCPB capabilities for PCBA (I'm not good for that)

> https://oshwlab.com/gentilkiwi/mso5000_lp

The first one is based on the SN75LVDS387, and the second one on 16x SN65LVDS1

This design looks better than mine, and I think it's preferable. 

[gentilkiwi]

Ho, I still not respect tracks lenght... just made it because components available and because I prefer the right angle connector for probes (because of Saelogic connectors compatibility) even if it costs more space on the board !

May also consider XC6206P332MR-G for the LDO, as it's low ESR & it's 'Basic PCBA'

[S. Petrukhin]

Ho, I still not respect tracks lenght... just made it because components available and because I prefer the right angle connector for probes (because of Saelogic connectors compatibility) even if it costs more space on the board !

May also consider XC6206P332MR-G for the LDO, as it's low ESR & it's 'Basic PCBA'

It is correct to align the length of the differential lines, but Rigol engineers did not take care of this, and practice has shown that it still works stably. I used this at a frequency of 84 MHz and observed a small jitter that did not interfere with comfortable operation.

[develbro]

Hello! Where can I buy DIY kit for logic probe in Russia?

[gentilkiwi]

Hello! Where can I buy DIY kit for logic probe in Russia?

I think most of us order to JLCPCB our boards