SRC4190-Q1: RESET constraints

Hi Hayashi-san,

A less than 500ns pulse of reset may not properly initiate a reset sequence. There are not restrictions on rise and fall time of reset.

Best,

Zak

Hi Hayashi-san,

500ns is the minimum pulse width to guarantee a reset will occur. It does not necessarily mean a reset will not occur for a shorter duration pulse.

Best,

Zak

Hi Hayashi-san,

I would say that ideally you would hold the device in RST by keeping this pin low on startup and releasing once the supplies have settled. I am sure there is a non-zero amount of time between releasing RST and device startup, but we don't have a spec for this. I have measured the time it takes for data to begin fading in after releasing reset at around 37us so you could consider this the time it takes for everything to settle once RST is released. If RST is driven low before this process finishes I would expect the device to stop the startup sequence and go back into reset.

To reiterate, I can't guarantee that if you pulse reset low for less than 500ns a RST will not occur. I can only guarantee that if you pulse RST for more than 500ns, a RST will occur. 

Best,

Zak