NE555: Clock generationg: what is the hightest clock output it can do

Sheldon He

Part Number: NE555
Other Parts Discussed in Thread: LMC555, TLC555

Hi expert,

My customer is looking for a cost saving device to generate clock output to drive a power stage in open loop. They find the description of NE555 say that it can generate clock limited by 100kHz. Could you confirm this for us? They'd like to run at higher clock rate, may I know what is the limitation for higher frequency in application circuit?

Thanks

over 5 years ago

0 Ron Michallick over 5 years ago

TI__Guru**** 164476 points

Sheldon,

Here is sample data for that includes over 100kHz (in same format as figure 14 in the data sheet). Above 100kHz, the variance sample to sample and lot to lot will increase. This makes the output frequency less accurate. Also see how the 1k (Ra+2*RB) hits a limit near 300kHz.

The TLC555 and LMC555 can clock well above 100kHz. These two devices should be used for more than 100kHz.

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NE555: Clock generationg: what is the hightest clock output it can do