SPRADO8 March 2025 AM62L
The processor includes 5 dual-voltage IO supply for IO groups (VDDSHVx [x = 0-4]), where each domain provides power supply to a fixed set of IOs. For dual-voltage IO supply for IO groups, each IO supply for IO group can be configured for 3.3V or 1.8V independently, which determines a common operating voltage for the entire set of IOs powered by the respective IO supply for IO group. VDDSHV0 and VDDSHV1 are fixed 1.8V/3.3V IO supply for IO groups and VDDSHV2, VDDSHV3 and VDDSHV4 are dynamically switched 1.8V/3.3V IO supply for IO groups.
Processor pads (pins) designated as CAP_VDDS_xxx [total 5 pins], and CAP_VDDSHV_MMC connect the external capacitor to the internal IO supply for IO group LDO when the IO groups connect to 3.3V supply (optional when IO groups supplies connect to 1.8V). A 1μF (connected between CAP_VDDS_xxx pins and VSS, see the processor-specific data sheet) capacitor is recommended. See the processor-specific data sheet for the recommended capacitor voltage rating and allowed capacitance range. When IO supply for IO 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 CAP_VDDS_xxx pin (VDDSHVx/2). For CAP_VDDSHV_MMC a 3.3μF is recommended.
To minimize loop inductance requirements, place the capacitors on the back side of the PCB in the array of the BGA. Choice of capacitor voltage rating influences the capacitor package and size selection. Select capacitor with ESR < 1Ω, keep the trace loop inductance < 2.5nH.