2.2.2.2 Dual Power Supply
CAUTION: To guarantee reliable
operation of the device, the board design must comply with power-up and power-down sequence
guidelines provided in the "Power Consideration".
For Power Supply Connections, refer to the Schematic Checklist section of the data sheet.
| Signal Name | Associated Ground | Recommended Pin Connection | Comments |
|---|---|---|---|
| VDDIN | GND, AVSS | Capacitors: Refer to REG_21 Ferrite Bead: Refer to REG_23/REG_25 | Supply ripple must not exceed 20 mVrms for 10 khz to 20 MHz range |
| VDDIO | GND | Capacitors: Refer to REG_5 | Supply ripple must not exceed 30 mVrms for 10 kHz to 10 MHz range |
| VDDUTMII | GNDUTMI | Capacitors: Refer to REG_13 Ferrite Bead: Refer to REG_27/REG_29 | Supply ripple must not exceed 20 mVrms for 10 kHz to 10 MHz range |
| VDDPLLUSB | GND, GNDPLLUSB | Capacitors: Refer to REG_11 Ferrite Bead: Refer to REG_27/REG_29 | Supply ripple must not exceed 10 mVrms for 10 kHz to 10 MHz range |
| VDDOUT | - | Capacitors: Refer to REG_17 | - |
| VDDCORE | GND | Capacitors: Refer to REG_1 | - |
| VDDPLL | GND, GNDPLL | Capacitors: Refer to REG_19 Ferrite Bead: Refer to REG_27/REG_29 | - |
| VDDUTMIC | GNDUTMI | Capacitors: Refer to REG_15 Ferrite Bead: Refer to REG_27/REG_29 | - |
Note:
- REG_X values are defined in the Power Supply Electrical Specifications from the Electrical Characteristics chapter.
- Decoupling capacitors must be placed close to the device, low ESR capacitors must be used for better decoupling.
- A ferrite bead is added between the main power supply and VDDUTMII, VDDPLLUSB, VDDIN, VDDUTMIC, VDDPLL and VDDCORE power supplies to attenuate high-frequency noise. Make sure to select a ferrite bead with a low DC resistance to avoid any relevant IR drop across the ferrite bead that could impact analog peripheral performances.