Coudl you teach me about the output logic level when the VDD1 of AD740x is off ?
VDD1 supply rarely off at fault condition of power circuit in our customer's circuit.
AD7400 and AD7401 datasheet P.1 says that these devices include watchdog.
So, I think that AD7400 and AD7401 output high or low when VDD1 is off.
Is it correctt ?
Regarding to question1 , does AD7402 and AD7403 have the same function ?
Regarding to 1 , could you teach me about the period of watchdog ?
Apologies for the delay. Below is the response for your inquiry.
1. The VDD1 supplies the isolated side which includes the Sigma Delta modulator and the encoder side. The output is not valid since no data will be on the encoder side.
2. Yes. They are of the same family.
3. I'll get back to you on this. I need to check details.
Thank you for your advice.
Please let me know your advice when you checked question3.
Regarding to 1, what is internal watchdog do ?
I thought that this watchdog is the same as the function of typically icoupler product.
( When VDD1 is off, secondery side outpust H or L for informing VDD off )
I just had it confirmed, the watchdog is normally found on standard digital isolators but not on the AD7401A. Regarding the next question, when VDD1 is off, this means something happen on the hot side, the cold side(secondary) will retain the last known state of its output.