The scenario
A battery-powered device needs a fixed-duration pulse from a momentary trigger, using an LMC555 CMOS timer operating at 1.8 V.
What is in this drawing
Read the decisions behind it.
01
Use LMC555 for 1.8 V low-power operation
02
Set R1 = 1.8 MΩ and C1 = 1 µF to achieve ~2 s pulse (T = 1.1·R·C)
03
Pull TRIG high with R2 and use SPST momentary switch to ground for triggering
04
Tie RESET to VCC and add C2 for control-voltage noise bypass
Use for low-voltage battery timers, one-shot pulse generators, and debounced manual triggers in portable equipment.
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