Need delay circuit to pull IC pin low for 10 seconds [closed]

Here's a potential solution using three MOSFETs and a few peripheral components:

^{simulate this circuit – Schematic created using CircuitLab}

The edge detector produces a 10ms low pulse at each input transition, both rising and falling. Those pulses trigger a one-shot (monostable) timer to quickly charge C2, and then allow C2 to slowly discharge over many seconds, during which OUT is pulled low.

It works with a 0V/3.3V or 0V/5V digital input.

There are a few reasons not to do this using discrete components:

1. Input impedance is low at 10kΩ. To improve this would require another transistor and resistor.
2. The output rise is sluggish, and could do with more gain, or better still a schmitt trigger stage, requiring more transistors.
3. Switching thresholds depend heavily on transistor characteristics, which vary from device to device.
4. Timing precision has similar dependence on on transistor variations.
5. It is complicated.

There is one good thing about this design; the monostable is resettable. That is, each input edge will start the 5s cycle afresh. Apart from that, everything about this circuit could be improved with an IC.

Here's a design using ICs 74HCT1G86 and 74HC1G132:

^{simulate this circuit}

Much simpler, and performance is superior to the non-IC design in every respect.