TPS3808: reset duration

MESH

Part Number: TPS3808
Other Parts Discussed in Thread: , TPS3842

Tool/software:

Hello,
I am designing and testing reset signal circuit using TPS3808.
The reset time is approximately 9.5sec.
So I connect 1,65uF +/-10% capacitor to CT pin of TPS3808.

The reset duration measurement result on prototype circuit is approximately 8sec.
An error of approximately 1.5 second was confirmed in the reset duration.

I would like to confirm whether this level of error actually occurs.
(I guess that the cause is a current error of the internal 220nA current source)

Regards, MESH

7 months ago

+1 Jesse Villanueva 6 months ago

TI__Mastermind 18690 points

Hi Mesh,

For the TPS3808, yes this amount of error is to be expected for the TPS3808. If a higher accuracy is needed, please use the newer version of this device which is the TPS3808E.

https://www.ti.com/product/TPS3808E

Jesse

0 MESH 6 months ago in reply to Jesse Villanueva

Intellectual 880 points

Hi, Jesse !

Thank you for your reply.
I am considering use of TPS3808E.
I would like to know how much the change to TPS3808E improves the accuracy of the reset duration.
* I have compared the datasheets for both and I am not sure.
(Paragraph 6.6 Timing Requirments (TPS3808E) / Paragraph 7.6 Switching Characteristics (TPS3808))

Regards,
MESH

+1 Jesse Villanueva 6 months ago in reply to MESH

TI__Mastermind 18690 points

Hi Mesh,

We are currently in the process in reevaluating a revision of the datasheet with an updated accuracy for the TPS3808E.

We can also recommend the TPS3842 with a higher timing accuracy across temperature.

https://www.ti.com/product/TPS3842

Jesse

0 MESH 6 months ago in reply to Jesse Villanueva

Intellectual 880 points

Hi, Jesse !

Thank you for your reply.

I would consider TPS3842 in addition to TPS3808E.

Regards,

MESH

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TPS3808: reset duration