ADAU144x/1701 GPIO Inputs 5V tolerant?
I'm working on some simple level controls in both ADAU1701 and ADAU1446 systems. I am going to configure them as up/down push-button controls, but instead of push-buttons I want to send basic 1/0 control signals from an MCU to a couple of GPIO inputs on the DSP. On my EVAL-1701 board, I see that there is a jumper to set DVDD of the GPIO eval board to either 3.3V or 5V, however the manual cautions against using the 5V setting. So, after pouring over the DSP and eval board datasheets, I can find no mention of the GPIO inputs being able to deal with a 5V input. Any ideas?
Thanks!
Audio Signal Processors
adau1446
SigmaDSP Audio Processors
adau1701
audiolab1,
You are correct - neither the ADAU1701 nor the ADAU1442 can deal with input signals above 3.3 V. We only gave the option of supplying the 5 V to the GPIO board in case that GPIO circuitry was going to be used with another 5 V tolerant device, like some of our audio codecs. So, unfortunately you will need level shifters if you want to use 5 V logic with the ADAU1701 or ADAU1446.
Hi audiolab1 & Brett,
The good news is that the aux inputs work at the sample rate, so you can get away with rather slow logic -- for example, open collector pulled up to 3.3V.
Bob
Thank you Brett and Robert! I figured that this was the case, so I'm going to use a simple mosfet circuit to perform the level shifting.
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