TLC555: Regarding Data Sheet 6.3.2

R.Fukunaga

Expert 2435 points

Part Number: TLC555

Tool/software:

Hi all,

1
What is the accuracy of the H level time and L level time obtained from equations (1) and (2)?

I think it depends on variations in the constants of the resistors RA, RB and capacitor C used.

I would like to know if there is a correction value to obtain the maximum and minimum.

2
Is there a range of the constants of the resistors RA, RB and capacitor C used?
In equations (1) and (2), if the resistance value is multiplied by 1000 and the capacitance by 1/1000, the time will be equivalent.
Is there a problem that the constants are too large or too small?

Best Regards,

Ryusuke

29 days ago

0 Ron Michallick 29 days ago

TI__Guru**** 164436 points

Ryusuke-san,

1) Propagation delays and variation in trigger and threshold comparators have some effect.

2) Discharge Ron and parasitic leakages and capacitances could be meaningful at extremes.

[FAQ] How do I design a-stable timer, oscillator, circuits using LMC555, TLC555, LM555, NA555, NE555, SA555, or SE555? - Clock & timing forum - Clock & timing - TI E2E support forums

What frequency, duty cycle and supply voltage is desired?

What is the acceptable variation in frequency and duty cycle? Is low current a priority?