Knock Off PLA2216 designs. - Page 1
Forum section: electronics / testgear

author: LinuxGuy123
author_rank: Regular Contributor
timestamp: January 21, 2025, 11:04:35 pm
content: I'm looking to buy a knock off PLA2216 for a Rigol MSO5000.I have the choice of 2 different board designs as shown here:https://imgur.com/a/pla2216-designs-DOcPW3tWhich one of these is better and by how much ?Thanks

author: thm_w
author_rank: Super Contributor
timestamp: January 22, 2025, 12:20:29 am
content: You'd have to figure out what IC is being used for buffering.Otherwise they basically look the same.

author: LinuxGuy123
author_rank: Regular Contributor
timestamp: January 22, 2025, 01:50:47 am
content: For starters, design number one has serpentine traces. I assume this is so that the delay is the same for each probe ? Or are the traces tuned to a specific impedence ?The drivers on design #1 are SN65LVDS1DBV.https://www.ti.com/product/SN65LVDS1/part-details/SN65LVDS1DBVRI'll ask the other sellers about the driver ICs.

author: ataradov
author_rank: Super Contributor
timestamp: January 22, 2025, 02:44:52 am
content: Neither is ideal. The whole idea of using LVDS drivers is to have those drivers close to the source and have long ribbon cables carry buffered differential signal.Otherwise, they all are pretty much the same.

author: LinuxGuy123
author_rank: Regular Contributor
timestamp: January 22, 2025, 03:48:02 am
content: The other seller says the IC is SN65LVDS391 - 630Mbps, same as the other IC.

author: LinuxGuy123
author_rank: Regular Contributor
timestamp: January 22, 2025, 04:45:24 am
content: Quote from: ataradov on January 22, 2025, 02:44:52 amIs that not the way they work ? The probes attach to the LVDS drivers which are on the end of the ribbon cable ? The other end of the ribbon cable attaches to the scope LA input ?

author: ataradov
author_rank: Super Contributor
timestamp: January 22, 2025, 05:06:05 am
content: Ah yes, sorry. I assumed the board has the scope side of the connector. The way those probes are usually designed is with 4 channels per extension pod with the IC in the pod itself. This way the remote part is small and does not get in a way. But this design works too I guess, it is just more bulky on the probe side.

author: Kean
author_rank: Unknown
timestamp: January 22, 2025, 05:16:57 am
content: I believe design number 2 is probably using SN65LVDS391DNikki published a design using this part, and this look like it could be based on that.https://www.eevblog.com/forum/testgear/low-cost-logic-analyzer-probe-for-rigol-mso5000-easyeda-project/msg5069035/#msg5069035

author: LinuxGuy123
author_rank: Regular Contributor
timestamp: January 22, 2025, 04:58:17 pm
content: I saw an earlier design for a PLA2216 probe design on eev, probably 4-5 years ago. I figured that the design of this device got its start here. I thought about making my own but it was easier to just order one of these.I ordered design #2. I'll report back how I like it after I've used it.I'm over the moon happy to have a 16 channel LA built into my MSO5000. I can't wait to use it.

author: LinuxGuy123
author_rank: Regular Contributor
timestamp: January 22, 2025, 05:01:35 pm
content: Quote from: ataradov on January 22, 2025, 05:06:05 amI kinda like having the pod at the end of the cable and having the probes go out from there.