TLC555: Looking for the timeir IC TLC555 x 2 channel

user4559181

Prodigy 30 points

Part Number: TLC555
Other Parts Discussed in Thread: TLC556

Hello

This is Takanori from Japan.

I'm looking for the timeir IC which has same fucntion as TLC555 but 2 channel integrated in the one device.

Usasge of the timer is like as below figure. The image is Timer 1 creates Output A and Timer 2 creates Output B.

And hope to realize this with the one device.

I tried TLC556 but it seemed the timer fucntionality was not same as TLC555.

over 5 years ago

0 Ron Michallick over 5 years ago

TI__Guru**** 164876 points

Hello Takanori-san,

Welcome to the e2e forum!

The TLC556 is the dual version of the TLC555 and should perform the same as two TLC555 times.. However there is not automotive qualified TLC556-Q1.

What was your experience that leads you to believe that the TLC556 does not perform the same as TLC555?

0 Ron Michallick over 5 years ago in reply to Ron Michallick

TI__Guru**** 164876 points

Takanori-san,

Your image did not show. There are ways two ways to attach files and images. I prefer the first , black arrow option.

Image using black arrow option.

Image using red arrow option.

0 user4559181 over 5 years ago in reply to Ron Michallick

Prodigy 30 points

Hello Ron san,

Thank you very muc for your feedback!

Attached is the our study result. With using TLC556, it seems the performance is not same as TLC555.

TLC556_study1.pdf

0 Ron Michallick over 5 years ago in reply to user4559181

TI__Guru**** 164876 points

Takanori-san,

I built the circuit, however I had to change 1k to 1.15k due to resistor availability. So expected time is 1.1*1.15k*1uF= 1.265ms

The results were as I expected.

0 Ron Michallick over 5 years ago in reply to Ron Michallick

TI__Guru**** 164876 points

Takanori-san,

I suggest checking the waveforms on all the pins to see why the pulses are much shorter than expected on your test board.

All pins are important, but the timing cap waveforms will be the most useful to see.

0 user4559181 over 5 years ago in reply to Ron Michallick

Prodigy 30 points

Dear Ron san,

Thank you very much for your advice for the testing. And I'm sorry for the late feedback as I was out ot office this week.

Today, we have checked the device once again (with another new one) and confirmed that TLC556 showed correct behavior.

Please find the attached file.

It seemed that the device which we tested may have get some defect...

Again, thank you very much for your strong support and we will proceed our evauation if we can use this device for the serial production.

Best regards,

Takanori Hara

TLC555_556_TimerDuration.pdf

Clock & timing

Clock & timing forum

TLC555: Looking for the timeir IC TLC555 x 2 channel