TLC555: Maximum timing capacitor

Hello,

For the monostable circuit, the capacitor can be back calculated based on timing and resistor requirements from the following formula:

C = t/(1.1*R)

For 1M and 33uF I calculate a pulse width time of 36.3 seconds. I have simulated this in Tina-Ti (attached at the bottom of this post). This works as expected. In order to get more precise you could change the resistor value or do a parallel resistor combination to get the exact value resistor you desire for the design such that the timing is more accurate. 

Monostable 30 Seconds.TSC

For more in depth information on both the monostable and a-stable modes we have some information here:

https://e2e.ti.com/support/clock-timing-group/clock-and-timing/f/clock-timing-forum/857914/faq-how-do-i-design-monostable-timer-circuits-using-lmc555-tlc555-lm555-na555-ne555-sa555-or-se555

https://e2e.ti.com/support/clock-timing-group/clock-and-timing/f/clock-timing-forum/879112/faq-how-do-i-design-a-stable-timer-oscillator-circuits-using-lmc555-tlc555-lm555-na555-ne555-sa555-or-se555

Best Regards,

Chris Featherstone