EV-ADE9153ASHIELDZ, What to do after changing Shunt resister

Hi,

The mSure autocalibration technology in the ADE9153A injects a small signal and then measures the response to characterize both the shunt and the potential divider. From that operation, the ADE9153A creates a Conversion Constant (or multiplication factor) for each ADC channel which it makes available in the MS_ACAL_AICC, MS_ACAL_BICC and MS_ACAL_AVCC registers. 

Adjustment will be needed for the code if the shunt is changed. The application note AN-1571 goes into detail in the "Target Conversion Constants" section. In "ADE9153AAPI_Test.ino" specifically, this means the constants used to generate the "Igain" and "Vgain" variables will change.

Its best to make use of the full dynamic of the ADC. There may be a benefit to adjust the PGA gain which would be an adjustment in code to set the ADE9153A registers.   

Circuit changes may be required depending on how much higher currents the measured currents will be. Remember EV-ADE9153ASHELDZ was designed to carry at most 10A. There are limits to how much current can be carried by the PCB's copper traces.

If there are multiple devices on the SPI bus, there may need to be some adjustments for the MISO_ISO signal. The ADuM4152 MI pin is always driven. This will cause contention issues on the MISO line when other devices on the SPI bus are selected. 

Regards,

Jason

Thank you for your answer.

When I checked AN-1571 data, I found TARGET_AICC = 838.19082 nA/Code in Current Channel A if Imax is 10A.
In addition, I checked the hardware design choices and found that for 1mohm / 10A RMS, AI Headroom=4,41942 and TARGET_AICC = 838.19082 nA/Code came out.

Additionally, I found that in the ADE9153AAPI.h file, CAL_IRMS_CC was entered as 0.838190 //(uA/code).

Then, in case of EV-ADE9153ASHIELDZ, can it be measured up to 10ARMS without any problems?

I wonder if the product is valid only for measured values up to 5A and if values up to 10A are valid.

Regards

Hi HJChang,

Are you still having issues with the EV-ADE9153ASHIELDZ?

One note is that the TARGET_AICC is not dependent on the current flowing through the sensor, for example, 5A or 10A, it is dependent on the sensor and the signal path. If you leave the shunt as populated then the 838.19 nA/Code is valid but if you switch out the shunt or change the PGA gain then you will have the recalculate the nA/Code based on the new shunt value. The other limiting factor is the PCB itself and the amount of current it can carry. With the 1mOhm shunt and even the highest PGA gain setting of 38.4x, you could still measure up to 18A but I wouldn't recommend putting 18Arms through the eval board for more than a short period of time.