ADS5401 Device Initialization Timing include ENABLE pin operation

Hi,

Q1:  The Enable pin can come up at the same time as the power supplies come up or any time after the power supplies come up.   So if I were to add the signal Enable to the diagram of Figure2, the Enable pin can come up sometime after the power.  But after Enable goes active, then there must *still* be the wakeup time observed before you could continue with the initialization sequence of reset pulse.   Example:  Enable comes up with the power supplies - wait 3ms minimum before the reset pulse.   Another example:  Enable comes up 5ms after the power supplies, wait another 2.5ms for the wakeup time from Enable before continuing with the reset pulse.  The device needs at least 3ms for the slowest internal circuit to power up, but the Enable pin could be used to delay the power up further.

Q2:  Using the Enable pin to disable the device should *not* cause the contents of the registers to be lost and return to power up default values.   The resisters should retain their values during the disable time.  If this were not true, then if you were to program the register to make the Enable be light sleep and then you used Enable pin to go to light sleep, the register contents need to remain valid or else the register that made the Enable pin control light sleep would no longer be that.   And I believe that even if the Enable pin put the device in complete shutdown, the register contents should still be there when enabled again out of complete shutdown.  I think only taking away power completely would cause the register contents to be lost.  That or a reset pulse. 

Regards,

Richard P.

Hi,

I edited your diagram to reflect the timing I was trying to describe in words previously.

Regards,

Richard P.

Shimizu,

Technically, yes, you can still reset, but this was ever validated.

Regards,

Jim