I noticed that 1701 will cost 85mA for analog and 60mA for digital. Is there any way to reduce them?
The current consumption is largely dependent on the application.
Smaller programs will consume less current on DVDD. Decreasing the number of analog outputs will decrease the amount of current driven out of the DACs and therefore will lower current consumption on AVDD.
You can disable the auxiliary ADC to save power if you are not using it.
You can power down individual DACs if you are not using them.
You can also power down the audio ADCs if they are not in use.
Yes, I can see the settings on SS Register Control panel.
Do you have detailed data on how much current can be reduced when turn off/power down for each?
How to understand the Reference block, which has 2 options - Power Down Core & Power Down Buffer?
The current savings is about 15 mA when the ADCs are powered down and about 4 mA for each DAC that is powered down ---- Find the answer in datasheeet. Thanks.
Thanks for reporting your findings. The exact power savings will vary depending on the application and the configuration of the circuit, so the best way to determine power savings is to test it on the evaluation board, or (better yet) on your own prototype design that is representative of the intended application.
I measured my eval board ADAU1701 for power consumption at various settings. No signal was applied at the ADC for any of these tests, and there was no load on the DACs or GPIOs.
With the output amp (SSM2306) turned off for all tests, with ADC and all four DACs on, I got 101mA. Looking at the schematic I see about 5mA of overhead (power LED, pot, WB circuit), so that's 96mA. Datasheet says typical is 90mA.
Turning off each DAC saved between 4 and 6mA (datasheet says 4mA). All DACs off saved 22mA.
Turning off the ADC saved 17mA (datasheet says 15mA). Turning off the core & buffers saved another 11mA.
Settings of GPIOs as various functions made no difference (as long as I didn't turn on the SSM or the LEDs).
Sample rate selection made no difference, although I wonder if changing the oscillator frequency would. I'm not going to test that on my eval board though.
Program size made no significant difference, whether a simple program with inputs connected to outputs and no other function, or a large program that used the full resources of the chip, it seemed to be less than 1mA change.
I was not able to test shutting off the oscillator as that function is required on the eval board.
I presume all savings came from 3.3V and not 1.8V supply, such that minimum current I measured is 11mA analog and 40mA digital, so 110mW total minimum.
Sorry for finding your detail data long time later... They are similar as mine. THanks.
Again Brett, we use ADC IN, 3 channels of SDATA IN, 2 channels of SDATA OUT, 4 channels of DAC out. our firmware if almost full in memory... the current is over 100mA. It is quite high.... Any suggestion?
I don't think there is anything you can do if you need all of the functions. My only suggestion for AD is in a future version of the chip, set the DAC pins so they can be used as GPIOs when the DACs are off. I need all GPIOs for other functions, so I have two DACs just for meter LEDs. That's 8mA where two GPIOs could do the job if I had them to spare.
Retrieving data ...