Hi,
We are currently evaluating the power consumption of the i.MX 8X for the subset of the SoC that we intend to use. From industrial datasheet IMX8QXPIEC Rev 0 (05/2020), §4.1.5 "Maximum Supply Currents":
1) VDD_A35 is shown at 2500 mA. Is this for the sum of all 4 cores? If so, how much is saved if some cores are turned off?
2) VDD_MAIN is shown at 5000 mA. It is not clear what parts of the SoC VDD_MAIN covers. §4.1.3 "Operating Ranges" gives some details: "Max freq.: HiFi4 DSP 640 MHz; Max freq.: M4 264 MHz; Max freq.: VPU 600 MHz". How is VDD_MAIN max supply current lowered if DSP and VPU are not used?
3) How is max supply current lowered if User Cortex-M4 is disabled?
4) How is max supply current lowered if Display Controller and Imaging Subsystem (MIPI DSI/LVDS/CSI, Parallel Capture, MJPEG) are disabled?
Thanks,
Étienne
We have an App. Note talk about power consumption measurement of i.MX8QXP. This may useful for you.
https://www.nxp.com.cn/docs/en/application-note/AN12338.pdf
For your reference, you can download all the documents of i.MX8QXP from here.
Hi,
Any news?
Thanks.
Hi,
Valuable information. However, the app note only provides power consumption at 25°C. I am surprised that the datasheet does not provide power consumption at higher temperatures (70 or 80 or 105 °C) as for other CPUs...
Étienne
I will check with internal if there is more power consumption information for your reference.
Hi,
Unfortunately, the app note didn't answer any of those questions.
1) No use case only changes the number of active cores, so current/core cannot be isolated (too many variables are changing). Moreover, "CoreMark only" results are confusing: VCC_CPU draws 447 mA when 4 cores are active whereas datasheet rather shows about 2500 mA for VDD_A35... I understand the app note was done at room temperature, but were are talking about a ~5.5 factor...
2) No test case enables the DSP. Current per rail is not provided for VPU tests.
3) No test case disables the User Cortex-M4.
4) Maybe the app note answers: what are the supply voltages associated with the Display Controller and Imaging Subsystem (MIPI DSI/LVDS/CSI, Parallel Capture, MJPEG) ?
My concern is that if I simply multiply the supplies operating voltage ranges with the maximum currents found in the datasheet, the power consumption goes over 10W even without a GPU! I would like to know how much I can save by disabling the User M4 core, 1xA35 core, the Imaging subsystem, Display Controller, VPU, DSP and Audio DMA subsystem.
Thanks,
Étienne