TPS3421: adjustable reset pulse duration and delay time

Hi Jesse,

the things is my customer's signal is pull-low not pulse, so it won't pull-high again, which means we want solution like  TPS3421/2 (fix reset time).

Do we have other solution with this function?

Regards,

Fred

Hi Jesse,

1. for TPS342x series, can we choose 0s delay version and add RC delay at input to create our own custom delay?

2. for TPS3421/2 , if I want to trigger the pulse again, I have to pull-high both PBx pin first, right?

HI 

Jesse will check and let you know. 

Regards

Trailokya

Hi

any update?

Hi Fred,

1. I will have to check with design team to make sure that there is nothing internal that could cause an issue in this application.

2. Both buttons does not need to be pulled up before retriggering the reset. Only one PB needs to toggle to reassert Reset if the other PB is already low. You can also tie both PB together if the customer only wants to control one PB.

Hi Jesse,

please help check question one, there's a  huge business impact  behind this

thanks

since they want 80ms delay, the fast way is choose 0s delay and add custom RC delay .

Hi Fred,

Unfortunately, we could not recommend using an RC as an input delay for this device, because of instability of the circuit.

Are there any other requirements aside for the following? 

• Input delay: 85ms
• Reset delay: 10ms
• input does not pull up

Also what is the input behavior after Reset de-assert?

Jesse 

Hi Jesse,

I don't get it ,this should be pure digital logic device,

RC delay is not supposed to affect stability, can you elaborate why?

we don't want to miss this opportunity just because not recommend,

thanks a lot.

Regards,

Fred