Multiple oscilloscope channels

[eccerr0r]

Well of course the more the merrier but have this one assumption that you're not going to be viewing digital signals (use a LA or mixed signal for this),

How many channels do you think is minimum to be truly useful?

I have a 2-channel scope and a lot of the time I just use one channel and it's sufficient. Those of you who have 4-channel, how often do you use three or more channels? What do you use it for?

And even 2-channels, do people use both frequently?

I guess for DSOs that can measure lag, this is sometimes useful but a lot of the time even lag isn't a very useful number in debugging...

Note: Query is for multiple Y axis scopes, not external trigger/sweep/Z scopes...

[Dans2530]

Re: Multiple oscilloscope channels

I'm not a scope expert but I would assume that you could do math operations using the scope on more than one signal as a sort of differential analysis?

If someone that has a heap of scope experience could lend their opinion on this, it would be appreciated, I'm here to learn as well.

[Uniballer]

Re: Multiple oscilloscope channels

I can generally get by with two, but it takes three just to see input, clock, and output for one signal.

[eccerr0r]

Re: Multiple oscilloscope channels

But with clocks, that mostly implies having digital, that which a logic analyzer might be the better solution. But for analog signals?

There are definitely advantages to multiple inputs even on analog, but what kind of math do you do on analog? Especially with three or more channels, it gets kind of confusing. Not to mention that I think most scopes that have multiple channels, the sampling bandwidth of each channel goes down as more channels are used.

I just wonder whether I should forgo a 4-channel unit and look more toward a high sample rate/bandwidth 2-channel unit.

[tom66]

Re: Multiple oscilloscope channels

At MINIMUM two channels.
Two channels lets you sync events. With memory or a camera, you can do virtually anything with just two channels (it'll just take you a lot longer!)
Two + ext trigger is a nice upgrade, frees a channel for a trigger.*

Four channels IMHO... once you go there, you never go back.

Rigol's new DS1054Z scope offers 4 channels at 50MHz/1GSas for under $400. It can be upgraded to 70 or 100MHz bandwidth and supports serial decode, serial trigger, advanced triggering, and up to 24Mpts memory at full sample speed. (Yes, 24 megapoints... That's more than most $2000 Agilent & Tek scopes!!)

Crazy value for the money...

Recently, used four channels on a multiple motor project. I could look at data going into the motor drivers (clock+DATA) plus POS and NEG motor terminals. Then use MATH to extract motor voltage from that and serial decode on I2C lines. And the DS1074Z (upgraded to 100MHz+options) coped with it like champ.

[gmit77]

Re: Multiple oscilloscope channels

ciao, first I would look at the sample rate Vs bandwith. you want to have min 3 time the sample rate of the bandwith. two channels is often enough, it is growing the need for analog + digital and you can find good quality 2 (a) + 16 (d)
some models offer multiple math actions, but this dipend more on your budget.
advanced trigger and decoding is also interesting, use them more as tab instead as display.

the new trend of big name is the 8 channels! maynly for Power and Automotive application.

we see lot of demand for Pico 4824 which is the 8 channels USB pc scope

if you like I can add links to application notes.

ciao