3 Power Supply Solution for Non-Safety Applications

In this solution, regulators are needed that can provide VDD and VDDIO to MCU. It is not required to have supervisors to monitor the voltage rails.

1. System Power requirements

   This is one of the important steps when you want to design a power supply and monitoring solution for the MCU and the rest of the system. Calculate the maximum current consumption value of IDD and IDDIO for MCU from the device-specific data sheet and include all the current consumptions of other components on each rail.

2. Selection of LDO /Buck converters
   1. When selecting an LDO as a power supply for VDD and VDDIO, make sure they are auto qualified and accuracy (>1%)
   2. When selecting a Buck converter as a power supply for VDD and VDDIO, make sure they have regulated outputs as 1 and auto qualified
   3. When selecting a Dual Buck converter as a power supply for VDD and VDDIO, make sure they have regulated outputs as 2 and auto qualified

   For the Selection of LDO/Buck converter, see Step 2 in Section 2.2.2.

3. Selection of monitors (Optional)

   Select an IC that can monitor VDD and VDDIO Supply rails. Use either the single Multichannel Supervisor or separate supervisor for each of the power rails. Select ICs that are auto qualified. For the monitoring of VDD, see the device-specific data sheet.

4. Selection of external VREF for ADC (Optional)

   Make sure IC selected is auto qualified.

5. Selection of Watchdog (Optional)

   An external watchdog or supervisor is used with integrated window/Q&A watchdog.

   Figure 3-1 Non-Safety: MCU With External VREFHI and External VREG
   Figure 3-2 Non-Safety: MCU With Internal VREFHI and External VREG