About TPS3808's /MR Pin

Pokkun

Genius 4695 points

Other Parts Discussed in Thread: TPS3808

Hello.
My customer is currently in using TPS3808,now.
I have gotten a question about this product .

So, please teach me about TPS3808.

＜Question＞

・Are there provisions of the rise and down time for this device's / MR pin input signal ?

　　As my recognition, this pin is provision for input to the logic circuit is considered unnecessary.

　　But if there are any important points, please tell me.

Could you help us?

Best Regards,

Masumi Sekiguchi

over 9 years ago

0 Samuel Sanchezarmas Omana over 9 years ago

TI__Prodigy 115 points

Hello Masumi-san,

The propagation delay for the /MR pin is 150ns typically. This means that the TPS3808 will take 150ns to respond to the change in state of the /MR.

The /RESET will transition from high to low 150ns after the /MR goes low. The /RESET will transition from low to high after the /RESET delay time (td).

Best Regards,
Samuel

0 Pokkun over 9 years ago in reply to Samuel Sanchezarmas Omana

Genius 4695 points

Thank you for the answer！

If it is meaning of that the recognition of the internal logic,is there no delay?
（Is there a limit to the speed of the slew rate ?）

0 Samuel Sanchezarmas Omana over 9 years ago in reply to Pokkun

TI__Prodigy 115 points

Masumi-san,

The propagation delay of 150ns includes the time it takes to recognize the change of state on the /MR pin and the time it takes for /RESET to change state in response.

Kind Regards,
Samuel

0 Pokkun over 9 years ago in reply to Samuel Sanchezarmas Omana

Genius 4695 points

Thank you very much to Samuel-san.
I am sorry in the lack of understanding .
I'd like to confirm,please.

Does this device have the provisions of the slew rate of the input signal to the /MR pin ?

Best Regards,
Masumi Sekiguchi

0 Samuel Sanchezarmas Omana over 9 years ago in reply to Pokkun

TI__Prodigy 115 points

Masumi-san,

The device does not have a specified limitation for the slew rate.

Kind Regards,

Samuel

0 Pokkun over 9 years ago in reply to Samuel Sanchezarmas Omana

Genius 4695 points

Thank you very much to Samuel-san.
I am sorry in the lack of understanding .
Could you tell me little more?

① Is MR PIN's internal constitution the type of Schmitt trigger ?
② When the MR pin launch slowly, do you Through current flow ?

0 Pokkun over 9 years ago in reply to Pokkun

Genius 4695 points

Could you answer me about this matter ?

Best Regards.

0 Samuel Sanchezarmas Omana over 9 years ago in reply to Pokkun

TI__Prodigy 115 points

Hi Masumi-san,

1-. The /MR pin is not Schmitt trigger design. It is made of inverters.

2-. When the /MR pin changes state slowly there will be a rise in current. To avoid through current the change in state needs to be fast.

Best Regards,

Samuel

Power management

Power management forum

About TPS3808's /MR Pin