Hi all,
I'm trying to use a 555 timer to do a single pulse to control a MOSFET for 4 seconds using the following schematic:
Using a SE555 timer, not the NE555 shown above.
The input voltage for this PCB can range between 6V and 17V, which is why I chose that specific SE555 timer, as it said max recommended voltage is 18V instead of 16V like most other timers I saw.
I thought it would have the same 4sec output for all voltages in the given range, however at 6V, the output pulse is about 4seconds long which is good, but at 17V the pulse duration drops to about 3 seconds. The timer datasheet itself only mentioned a very small drift in timing, not the 25% drop I saw, which was very unexpected.
Looking at other forum posts, inaccuracies were mentioned as a result of lack of decoupling capacitors or using electrolytic capacitors, however I added the decoupling caps and only used ceramic caps, and am still seeing the same issues.
Is there anything I might be missing?
I'm trying to use a 555 timer to do a single pulse to control a MOSFET for 4 seconds using the following schematic:
Using a SE555 timer, not the NE555 shown above.
The input voltage for this PCB can range between 6V and 17V, which is why I chose that specific SE555 timer, as it said max recommended voltage is 18V instead of 16V like most other timers I saw.
I thought it would have the same 4sec output for all voltages in the given range, however at 6V, the output pulse is about 4seconds long which is good, but at 17V the pulse duration drops to about 3 seconds. The timer datasheet itself only mentioned a very small drift in timing, not the 25% drop I saw, which was very unexpected.
Looking at other forum posts, inaccuracies were mentioned as a result of lack of decoupling capacitors or using electrolytic capacitors, however I added the decoupling caps and only used ceramic caps, and am still seeing the same issues.
Is there anything I might be missing?