I use a monoshot to extend the duration of a short duration pulse (few microseonds) to 150 milliseconds. The issue is that the monoshot undergoes false triggering in the absence of valid input:
The output of one such monoshot gets latched (Q = High and /Q = Low) and the latch goes away on cycling the power. The output of another monoshot in the same configuration alternates between High and Low from time to time.
I have probed the input of the monoshot with an oscilloscope in falling-edge trigger mode and found that the input is clean, free from spurious inputs.
Power supply is from a DC-DC converter with 5V output. On probing, the max switching noise is 0.2Vpp @ 12kHz. Fairly clean, I feel.
This is the datasheet of the monoshot, which according to the manufacturer is obsolete. I have a few of these lying around, hence using them for a hobby project.
Any ideas on what I might be doing wrong? Thanks!