Power Consumption
Added by Hayden Smith about 9 hours ago
Hello,
I am currently doing a power analysis of the MitySOM-QC6490 (80-001777RI-2). We are interested in operating the QC6490 SOM in the lowest possible power setting to preserve battery life,
while still actively processing data in real time (i.e. not always in sleep states). Do you know what the minimum quiescent operating power is for the SOM (no carrier board)?
We have been running our own series of tests, utilizing the VBAT current monitor (LTC-2945) to provide power measurements during operation. Does this
current monitor accurately represent the total power consumed exclusively by the SOM, or does it also include peripheral power from the supporting carrier board? We would like to have
a method for isolating power measurements to just the SOM.
Thank you!
Hayden
Replies (1)
RE: Power Consumption - Added by William Evans about 4 hours ago
Hayden,
We don't currently have a minimum quiescent operating power for the SOM. Current consumption on the SOM alone is heavily influenced by the software running on the processor, clock states, and background processes all contribute and can vary significantly between software configurations. This is further compounded by differences between SOM variants.
In saying this, the development board was designed with this in mind. As almost every IC on the baseboard has the option of being powered from the DC supplies, the SOM supplies or being turned off, it should be easy to get a very good idea of only the SOM power consumption.
I would recommend turning all of the peripherals on the development board OFF with the hardware switches. Alternatively, you could have them enabled from the DC supplies but then you do dissipate some current (~1.2uA per power switch) through the control pins as they are pulled up to the SOM supply.
The following are the connected interfaces on the development board that can't be turned off. All listed currents are for a single device. From their datasheets, I listed the max current at their expected state during this test:- U31 - The EEPROM on the baseboard which draw 1uA in standby @ 1.8V
- U24 - Wifi Translator which will draw ~2uA when in partial power down (assuming 3V3-WIFI is off) @ 1.8V
- U17 and U18 - CSI translators. The datasheet doesn't spec a partial power down power draw but a max supply of 1.5uA. @ 1.8V
- U26 - PCIE translator which is the same as the CSI translator so 1.5uA. @ 1.8V
- U40 - I2C translator which draw 8uA
1.8V and 90uA3.3V - U36 and U37 - ADCs for voltage monitoring. It looks like these can be put into power-down to draw 3uA @ 3.3V
- U32 and U33 - SOM voltage monitors. 1.2mA
5V and 900uA3.3V. - Various 10k pullups on 1.8V and 3.3V rails.
Although the baseboard can't be completely isolated I hope this give you an idea of what power draw can be attributed to some of the baseboard components.
If you have any further questions please let me know!
Will
