Other Parts Discussed in Thread: SN74LV123A
Hi,
I would like to ask you about SN74LV123A irregular behavior as below.
0) Setting
- Rt=620K, Ct=0.1uF (60mSec), Tr=310K, Ct=0.1uF (30mSec)
- CLR pin is pull-up via 4.7K to 5V.
- "A" pin is pull-down via 4.7K to GND.
- One trigger signal (up edge) was input to "B" pin, and observed "-Q" pin out wave.
1) In case of PW=60mSec, Rt=620K, Ct=0.1uF
The "-Q" out signal width is not 60mSec. The signal is not stable, the width is 120mSec, 180mSec, etc (60mSec * x, x>=2).
The "Q" out siganl width is 60mSec. But sometimes its width is 120mSec.
2) In case of PW=30mSec, Rt=310K, Ct=0.1uF
Both "-Q" and "Q" signal width are always 30mSec, normal out.
I do not understand the reason why.
Are there limitation of Rt and Ct value? Or some other reason to happen this issue?
I attached the material to help you to understand.
Could you please consider this phenomenon and advise me how to do?
Thank you very much in advance.
Best Regards,74LS123A irregular issue.pdf
