Supply voltage monitoring using internal ADC of the iMXRT1064

[wavhal_m]

Hello,

On my custom board with the iMXRT1064, I need to monitor the supply voltage using its internal ADC. This is crucial to prevent data corruption when writing to external flash. Do you know if SDK offers any examples that could help with this task?

Regards,

Mukund

[wavhal_m]

Hi @EdwinHz,

Thanks for your response.

We tried to use brownout detection according to the PMU section and kept the BO level at 2.80V using 2P5 LDO. However, on our board voltage supervisor circuitry is used. This circuitry continuously monitors the supply voltage, if low voltage (below 3.08V) is detected at its input it resets the microcontroller through POR. Therefore to avoid flash writing at low voltage levels (3.1V) we are thinking to use ADC.

[EdwinHz · Accepted solution]

Hi @wavhal_m,

I understand. In this case, the ADC examples we have for the RT1064 is the "adc_12b1msps_sar" projects, either by interrupt or polling schemes. These examples were not created with the intention of measuring the supply voltage specifically, or having methods of avoiding low voltage flash accessing, but it should still prove to be a good base point for your application. This example code can be found and imported from the latest version of the RT1064 SDK.

BR,
Edwin.

[EdwinHz]

Hi @wavhal_m,

Is there a specific reason why you are trying to achieve this using one of the RT1064's ADC's? As seen on Figure 13-3. Power Management System, the RT1064 includes a series of voltage sensors in order to handle erroneous voltages on the MCU:

These voltage sensors are what allow the MCU to have brownout detection capabilities on its LDOs and allow for the PMU to adequately handle erroneous voltages in order to protect the MCU and its data. Please look into chapter "Power Management Unit (PMU)" for more information about this topic.

BR,
Edwin.