ad8235 turn on time

Hi JMin634,

The specific parameter you wanted to know is not present on the datasheet.

I will try to look for other data pertaining to the "wake-up" time.

I will get back to you.

Regards,

Fdelaram

Thanks!!

Hi, 

I have just tested 3 units of AD8235 and the "wake-up" time after shutdown is measured to be at ~400uS.

Regards,

Fdelaram

Hello,

     The information was very helpful. I was also noticed that AD8236 didn't have a shutdown pin. If I cut off power to the +Vs pin and start it up, would the AD8235/6 chips startup in 400uS as well?

Thanks!

Jihong

Hi, 

Had an experiment for the AD8235 as well for the power-up, that is +Vs from 0V.

The measured power-up time is ~90uS.

Regards,

Fdelaram

Does that mean that the power-up time is faster than the wake-up time? 

So would it be better to just power up (~90us) the device every time, rather than shutting it down and waking it up (~400us)?

Thanks,

Jihong

Hi,

Please be informed that the 90uS was performed with the following conditions:

+Vs = 5V, -Vs = GND

+IN = -IN = Vref = 2.5V

The Vo was at 2.5V level within around  ~90uS as the +Vs is already enough to produce the said voltage level. But, if the Vo is expected to be higher than 2.5V level or if the Vref is made to be higher, at 90uS, the +Vs is not yet enough. The settling time of +Vs to be stable at 5V is actually at ~400uS as well.

Also, if we opted to turn on and off the device through the +Vs pin, we must also secure that the input voltage is turned-off as the device is still off and the +Vs must be supplied first prior the input signal(proper power-up sequencing) to avoid damage on the device.

Hope this helps. Thank you!

Regards,

Fdelaram

Thanks!