After reset and boot sequence,
the ADAU1701 processor sometimes does not work normally, I found.
If the RESET ramp rate is slow, could it cause problem?
ADAU1701, does the RESET input have hysteresis ?
Hi, Bob, Richard,
Thanks for your quick reply !
First I was cheking the reset and boot sequence.It seems that there are no problems at the start-up...But I will check the points your advised again.
If the issue is not setteled or there are other problems,I will make new thread again.
The ADAU1701's reset pin does have some hysteresis, see http://ez.analog.com/message/7531#7531
A RC reset is generally considered acceptable. Sorry you're experiencing an intermittent startup -- some possibilities to consider:
One issue with reset we have found in our designs was the ADAU1701 coming out of reset too soon. The ADAU1701 is pretty happy at low voltages, and will happily try to self boot. If your eeprom isn't good at low voltages, it won't be ready to be communicated with. Delaying the reset with either a reset/brown out monitor, or just a larger capacitor on the reset line can alleviate that problem.
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