8.1 Block Diagram

The following figure shows the detailed view of the power subsystem on the PIC32CX-BZ6 device.
Figure 8-1. Power Subsystem Block Diagram
The power domains of PIC32CX-BZ6 SoC are as follows:
  • VDD – 1.9–3.6V, Main Supply powering VDDIO, FLASH_VDD, AVDD, PMU_VDDIO, PMU_VDDP and VUSB3V3. All other supplies are derived from VDD with or without filtering.
    • VDDIO (VDD33)
      • 1.9 to 3.6V, powering the Always ON (AON ), PMU Controller, AN/GPIO, INT0/MCLR, BKUP
    • FLASH_AVDD (FAVdd)
      • 1.9V to 3.6V, filtered version of VDD (powering the Flash)
    • AVDD
      • 1.9V to 3.6V, filtered version of VDD for system analog functionality
    • PMU_VDDIO
      • 1.9 to 3.6V, filtered version of VDD (powering the PMU sub-system)
    • PMU_VDDP
      • 1.9 to 3.6V, filtered version of VDD (powering the PMU sub-system)
    • VUSB3V3
      • 3 to 3.6V, filtered version of VDD (powering USB transceiver supply)
  • GND
    • Common GND for digital, analog and RF sub-systems
Other power supply pins as follows:
  • CLDO_OUT, RF LDO OUT (1.2V)
    • Output pin for the internal voltage regulator for decoupling, do not use this pin as an external power supply source
  • CLDO_IN, VDD_RF
    • Loop back path for the CLDO and RF LDO power after external filtering
  • BUCK_PA, BUCK_CLDO, PLL_VDD, SOC_LDO_VDD
    • 1.35V input for all the regulators in the SOC
    • Powered with 1.35V from the combination of DC-DC, MLDO and external board filtering
  • PMU_BK_LX
    • Pin for connecting the inductor for the internal switching regulator
  • PMU_MLDO_OUT (1.35V)
    • 1.35V PMU output pin. This is the shared output pin for both MLDO and the DC-DC converter
    • MLDO_OUT powers the internal LDO’s in the Bluetooth/802.15.4 subsystem

For decoupling recommendations for the different power supplies, refer to the schematic checklist.