S32K3 low power consumption issue Hello, I'm debugging the low-power S32K348 and found that the current is only reaching 3.2mA. However, when I disconnect the MCU's power supply, the external circuit only draws 0.2mA. Could you please take a look and see if anything is still being turned off, and how to further reduce the power consumption? Attached is the NXP project file. Re: S32K3 低功耗问题 db16122_0-1788252143924.pngdb16122_0-1788252143924.pngdb16122_0-1788252143924.pngdb16122_0-1788252143924.pngdb16122_0-1788252143924.pngdb16122_0-1788252143924.pngdb16122_0-1788252143924.png From S32K348 datasheet , during STANDBY mode, the current consumption for FIRC ON (24MHz)(mA) is 1.5137 mA at 25C ambient temperature. You may check the FIRC status and turn it off. You may need control current consumption for system level since CAN consumption is not part of MCU power consumption. BTW, what is your system design for? More schematics may need for better understand your question. Re: S32K3 低功耗问题 Hi Julián, I conducted the test using a self-developed board. I tested the power supply of the board, as shown in the project. Before entering low power consumption, I processed all the pins used. Except for the CAN chip, all other power supplies on the board were controlled. Before entering low power consumption, I turned off the controlled power supplies of 3.3V, 5V, and 15V, and processed the peripherals and pins. The CAN also entered low power consumption, and the MCU also entered low power consumption. During normal operation, the board has a current of more than 200 mA, and after a series of operations, it only has more than 3mA, but it is not enough and still needs to be lowered. Re: S32K3 低功耗问题 Hello @Joker_Y,
I suppose this is a custom design, correct? Power consumption values given in S32K3's Data Sheet are measured only through the MCU's power supply. For example, in S32K3X8EVB-Q289, you must remove J25:
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If you are only measuring the power supply, this measures the current consumption of the whole board, not just consumption of the MCU. It's not so significant in run modes but it's definitely not usable for low power modes.
Can you share how are you measuring current consumption?
I suggest looking at S32K3 Low Power Management AN and demos documentation. Section 10.2 provides some tips for making low-power measurements on the bench, as well as some example cases for current consumption.
Also, keep in mind you need to drive/ pull input pins to either VSS or VDD to avoid leakage current. It was discussed in this community post: Solved: Re: S32K324 Tristate Pins before sleep - NXP Community.
Measurements from S32K3's data sheet are ~3mA@RUN and ~0.05mA@STANDBY approximately.
Best regards, Julián Re: S32K3 低功耗问题 Yes, that means the MCU has a power consumption of around 3mA. Re: S32K3 低功耗问题 If the MCU is completely powered off, will the 0.2mA current still exist? Re: S32K3 低功耗问题 Hello @Joker_Y,
"I tested the power supply of the board" With this, I assume you are indeed measuring the whole board at a system-level, which cannot be compared to S32K3 datasheet values, which are MCU VDD-only measurements.
The ~3.2 mA is the sum of the MCU in Standby + CAN transceiver in low-power mode + any residual leakage the self-developed board may have.
The current values published in the S32K3's datasheet are measured on the MCU's VDD supply pins, under controlled conditions with no external load. The Standby supply current values (as @db16122 mentioned) are ~1.5mA in Standby with FIRC on.
The recommended approach is to insert a current meter in series with the MCU's VDD supply line on your custom board. This is the same methodology described in Section 10.2 of the S32K3 Low Power Management AN and demos. Same as on the S32K3 EVB by removing jumper J25 to break the VDD path and insert a meter in its place. Please identify the equivalent point on your custom board's schematic.
I've tested a simple Standby project and can measure the MCU's current consumption down to ~65uA, which is in line with the typical consumption @25°C.
It also may be worth to check in your project and setup whether any peripheral clocks, power domains, or oscillators may have been left active unintentionally, as well as any leakage in pins (for example, CP_OUT in your project).
Hope this helps.
Best regards, Julián Re: S32K3 低功耗问题 Hello, do you have any relevant demos I can refer to? I'm developing an in-vehicle project. Re: S32K3 低功耗问题 Hi,Julián Do you have any relevant demos for your testing that you can refer to? Additionally, I will also test your suggestions. Thank you. Re: S32K3 低功耗问题 Hello @Joker_Y ,
You can try [RTD701 IP] S32K3X8EVB-Q289 & FRDM-A-S32K358 Standby RTC GPIO Wake-up - NXP Community. This is the example I used to measure the current consumption.
Best regards, Julián Re: S32K3 低功耗问题 Okay, thank you. I'll go and research it out
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