No signal at ECL COUNTER output. Please help.

ScottWang

Joined Aug 23, 2012
7,072
Check the pin 26(MR) first, if it is about 3.3V(or a high level) then you have to make a CR power reset circuit to MR. (MR should be a high level pulse)

What's the purpose of H,L and what are they? (are they just the labels?)
 

Deleted member 115935

Joined Dec 31, 1969
0
I’m new to ECL and not seeing output pulses at U15-19 (expecting 925.926 kHz) or at the U16 and U17 outputs. Do I have suitable resistors at pin 27 and P0..P7? (U23 is ECS-3951M-1000-BN-TR.)
View attachment 184364
You don't want to use the TC output as a clock input
it glitches, you need to use t as an enable

Also
ECL is not push pull, you need resistor to a Vtt , else you will get no outputs,
 

Thread Starter

jgabura

Joined Aug 20, 2019
3
Check the pin 26(MR) first, if it is about 3.3V(or a high level) then you have to make a CR power reset circuit to MR. (MR should be a high level pulse)

What's the purpose of H,L and what are they? (are they just the labels?)
Thank you Scott, I followed your suggestions. Pin 26 measured 3.137 V. I pulsed MR high with no change in behavior. H and L are just labels.
 

Thread Starter

jgabura

Joined Aug 20, 2019
3
You don't want to use the TC output as a clock input
it glitches, you need to use t as an enable

Also
ECL is not push pull, you need resistor to a Vtt , else you will get no outputs,
It looks like I overlooked Vtt here and will follow that up. Please clarify your suggestion to use t as an enable? Thanks for your help Andrew.
 

ScottWang

Joined Aug 23, 2012
7,072
Thank you Scott, I followed your suggestions. Pin 26 measured 3.137 V. I pulsed MR high with no change in behavior. H and L are just labels.
The MR pin is used to accept a high pulse and stay on low level voltage as GND, normally it is active a high level voltage at the power up or what time that you want to clear all output pins Q0~Q7 , since you already used the PE function then try to connects the MR pin to Ground.
 
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