What is the minimum time required for PB about SRC0CS25D at Power-UP?

[TNaru.4]

What is the minimum time required for PB  about SRC0CS25D at Power-UP?

When PB is pulled to Low, even though PSHOLD is High, the EN may fall Low.

PB Low time was about 200ms. 

The time PB Low to PSHOLD High was about 150ms.

If the PB Low time was about 400ms, EN remained high state.