Tektronix TLS216 - Really 2GS/s sampling rate on ALL 16 analog channels?

[pascal_sweden]

The Tektronix TLS216 is a 500 MHz oscilloscope with 16 analog channels.

Does it really have a 2GS/s sampling rate on ALL 16 analog channels?

That's seems quite remarkable! Wonder what hardware they used in there? 16 ADC modules?

What about the bandwidth? Does that drop when you use several analog channels at the same time?

If there is no limitation, neither on the bandwidth and the sampling rate, when using all 16 analog channels at the same time, this scope seems very impressive!

So what's the catch behind this? It is real-time sampling right? And not equivalent time sampling, right?
What am I missing here then?

[H.O]

If you look at the overview secion of product specifications it clearly says 2-GS/s Simultaneous Sampling on All Channels and if you look at the specifications it says 16 channels, 16 samplers, 2GS/s. I guess, on its own, samplers could mean sample and hold circuits which is then interfaced to one or more ADCs but in this case it doesn't - or so it appears.

I've personally never seen that machine Before so thanks for pointing it out. Must have cost a fortune when it was introduced.....

[edavid]

The Tektronix TLS216 is a 500 MHz oscilloscope with 16 analog channels.

Does it really have a 2GS/s sampling rate on ALL 16 analog channels?

Yes.

What about the bandwidth? Does that drop when you use several analog channels at the same time?

No.

So what's the catch behind this?

500-2000 point record length
requires special probes
vertical sensitivity 50mV/div

[tautech]

No BNC inputs. 


Maximum Input Voltage - Max nondestructive input ±25 V (DC + Peak AC) 

[pascal_sweden]

I guess it's an analog logic analyzer in that sense

Does it contain any kind of protocol decoding?

[nctnico]

No. It is way too old for that. Don't waste time or money on this piece of antique.

[madao]

I have here  TLS216.

Yes, it has 500Mhz Bandwidth., verified.
But ,obviously, no potocool decoding.
TLS216 is really sluggish by operation.
16 ch and 2Gs/s at all channel, it is possible, because  Tek has using four  TDS640 acquisition chipset (one Chipset  = 4 channel).
But  TDS640 has a big disadvantage: No peak dectet-acquisition, high WFM/s-Acquisition is impossible.
Reason: TDS640 ADC is CCD-based, 2 Gs/s-CCD and 10Ms/s ADC.  To much dead times.

Many TLS216 has problem with  bad  SMD capacitor. My TLS216 is very late TLS216 with TDS700A-CPU Board without capacitor issues, but old firmware(V1.0.3e).


Regards
Matt

[David Hess]

But  TDS640 has a big disadvantage: No peak dectet-acquisition, high WFM/s-Acquisition is impossible.
Reason: TDS640 ADC is CCD-based, 2 Gs/s-CCD and 10Ms/s ADC.  To much dead times.

Earlier and later Tektronix CCD based DSOs did implement peak detection.  It was missing in the early TDS based CCD models.

[Ice-Tea]

The SMD caps on teks from this series/vintage are notoriously shortlived. On the bright side: probes are pretty cheap

[nctnico]

The SMD caps on teks from this series/vintage are notoriously shortlived. On the bright side: probes are pretty cheap

That depends on the age of the device. If you have one from after '94 /95' the caps are OK. From the small sample of scopes I have had through my hands only the earlier models where affected.

[H.O]

That fan looks like it came out of a 300A TIG-welder or something, must be a noisy machine that TLS216

[nctnico]

That fan looks like it came out of a 300A TIG-welder or something, must be a noisy machine that TLS216

It isn't. The fans in these oscilloscopes seem to be a special low-RPM version. In later models Tektronix fitted a smaller (but still low noise) fan. Maybe the manufacturer of the fan was no longer interested in making the special version.

[Ice-Tea]

If you look at his picture, you'll find the small SMD elcos that cause the problem. Later model caps have tantalums instead I think.

[madao]

No,  my  TLS216 has SMD eletrolytics, but it is good.
Nippon Chemicon  is  manufactur of this  electrolytics and has solved this problem in circa 1994. My TLS216 is from 1996.  It has not issues with leaking SMD electrolytics.   Same, nctnico says it.  It confirm my    experience.

The SMD caps on teks from this series/vintage are notoriously shortlived. On the bright side: probes are pretty cheap

That depends on the age of the device. If you have one from after '94 /95' the caps are OK. From the small sample of scopes I have had through my hands only the earlier models where affected.

Fan runs really  slow. 

[nctnico]

If you look at his picture, you'll find the small SMD elcos that cause the problem. Later model caps have tantalums instead I think.

No, ceramics but you can't replace all electrolytics with ceramics if you want to refurbish one of the TDS500/600/700 series scopes. The circuits are designed for electrolytics. Never ever replace electrolytics or ceramic with tantalum capacitors; chances are you reduce the life time because tantalums have constraints on di/dt.

[Ice-Tea]

Nah, I just replace them with new, longer life elcos..

[David Hess]

Never ever replace electrolytics or ceramic with tantalum capacitors; chances are you reduce the life time because tantalums have constraints on di/dt.

Tantalum capacitors have di/dt limits however they are increased greatly with proper voltage derating so this is rarely a problem in bulk decoupling applications.  I would not hesitate to use them and often have for *greater* reliability in the sense that I will not have to change a dried up aluminum electrolytic capacitor again.

Replacing a bulk output capacitor would be much more problematical and in old equipment, hermetically sealed solid or wet tantalum capacitors were often used.  Their construction differences give them much higher di/dt limits.

[nctnico]

Never ever replace electrolytics or ceramic with tantalum capacitors; chances are you reduce the life time because tantalums have constraints on di/dt.

Tantalum capacitors have di/dt limits however they are increased greatly with proper voltage derating so this is rarely a problem in bulk decoupling applications.  I would not hesitate to use them and often have for *greater* reliability in the sense that I will not have to change a dried up aluminum electrolytic capacitor again.

A reasonable quality electrolytic which isn't subjected to heat (either by large ripple currents or sitting next to a heat sink) has decades of life time. The only electrolytics I have replaced where damaged by heat. Tantalums OTOH tend to fail allover the place randomly. I never use tantalums in my designs for that reason. Either ceramic or electrolytics.

[David Hess]

A reasonable quality electrolytic which isn't subjected to heat (either by large ripple currents or sitting next to a heat sink) has decades of life time. The only electrolytics I have replaced where damaged by heat. Tantalums OTOH tend to fail allover the place randomly. I never use tantalums in my designs for that reason. Either ceramic or electrolytics.

Modern tantalums are very reliable if properly derated and used within their surge current rating.

I have replaced aluminum electrolytic capacitors in some modern designs which could only last not much longer than a year because of insufficient derating.  Instead of using a much larger aluminum electrolytic, I selected a suitable tantalum part.