Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

TLC555-Q1: Questions about TLC555 timer operating conditions

Part Number: TLC555-Q1
Other Parts Discussed in Thread: TLC555

Tool/software:

I designed a circuit using a TLC555 timer. Trigger input connect 5V(fault detect signal)

-> When a fault occurs (5V->0), a trigger is generated, and when FLT is restored (0->5V), a 2-second delay occurs through the RC time constant.

I expected that when a fault occurs and recovery is made, the output would be restored with a 2 second delay.

However, when FLT occurs and a certain amount of time passes(ex.10second) before it is restored, it is restored immediately without a 2-second delay.

After a short period of time(ex. 0.5second), when the restoration was complete, the 2-second timer started running.

Quesion: Why doesn't the delay work when the restore is done after a certain amount of time has passed since the trigger occurred?

This will result in the same result as not having a 555 timer.