SPRADN4 December 2024 AM62P , AM62P-Q1
The processor includes eight dual-voltage IO groups (VDDSHVx [x = 0-3, 5-6], VDDSHV_CANUART and VDDSHV_MCU), and each group provides power supply to a fixed set of IOs. Each IO group is configured for 3.3V or 1.8V independently. The group configuration determines a common operating voltage for the entire set of IOs powered by the respective IO group power supply.
Processor pads (pins) designated as CAP_VDDSn [n = 0-3, 5-6], CAP_VDDS_CANUART, and CAP_VDDS_MCU connect the external capacitor to the internal IO supply group regulator when the IO supply groups connect to 3.3V supply (optional when IO groups supplies connect to 1.8V). A 1μF capacitor connected between the pins and VSS is recommended. See the processor-specific data sheet for the recommended capacitor voltage rating and allowed capacitance range. When IO supply groups are connected to 3.3V, the voltage to be considered for capacitor DC bias effect derating is the steady state DC output which is voltage applied to VDDSHVx/2.
To meet the loop inductance requirements, place the capacitors are placed on the back side of the PCB in the array of the BGA. The choice of capacitor voltage rating influences capacitor package (size) selection.
Select a capacitor with an ESR that is less than 1Ω, keep the trace loop inductance to < 2.5nH.