AFE7950: Minimum RESETZ Pulse Width

Jack Zhang

Part Number: AFE7950

Hello,

I noticed that the RESETZ has a Minimum Pulse Width of 1 ms as a timing requirement. I have a 10 Kohm pullup on RESETZ. Does TI have a recommended capacitor pull-down value to meet this timing requirement. In the AFE79XX_Schematic_chcklist file, I see a 1k and a 0.001 uF being used, but wouldn't the RC time constant be 0.001 ms? Could some guidance be provided here? Thank you for your assistance.

over 3 years ago

0 Vijayendra Varma Siddamsetty over 3 years ago

TI__Genius 10875 points

Hi Jack,

The reset pulse width is not based on RC time constant.
it has to be driven low for at least 1ms by the FPGA/ controller for AFE to reset.

Regards,

Vijay

0 Jack Zhang over 3 years ago in reply to Vijayendra Varma Siddamsetty

Intellectual 540 points

Thanks for the response. So, there isn't a need for a capacitor pull-down on the RESETZ line - is that a correct understanding?

0 Vijayendra Varma Siddamsetty over 3 years ago in reply to Jack Zhang

TI__Genius 10875 points

Hi Jack,

The capacitor was just to filter out any glitches that might inadvertently cause a device RESET event. It doesn't play a role in setting the pulse width of actual reset pulse.

Regards,

Vijay

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AFE7950: Minimum RESETZ Pulse Width