SDAA081 September   2025 DP83825I

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Troubleshooting the Application
    1. 2.1 Schematic Checklist
    2. 2.2 Device Health Checks
      1. 2.2.1 Voltage Checks
      2. 2.2.2 Probe the RESET_N Signal
      3. 2.2.3 Probe RBIAS
      4. 2.2.4 Probe the XI Clock
      5. 2.2.5 Probe the Strap Pins During Initialization
      6. 2.2.6 Probe the Serial Management Interface (MDC, MDIO)
        1. 2.2.6.1 Read and Check Register Values
    3. 2.3 MDI Health Checks
      1. 2.3.1 Magnetics
      2. 2.3.2 Probe the MDI Signals
      3. 2.3.3 Check the Link Quality
      4. 2.3.4 Compliance
    4. 2.4 RMII Health Check
    5. 2.5 Loopback and PRBS
      1. 2.5.1 Loopback Modes
      2. 2.5.2 Transmitting and Receiving Packets with the MAC
      3. 2.5.3 Transmitting and Receiving Packets with BIST
  6. 3Summary
  7. 4References

2.2.1 Voltage Checks

DP83825 needs to have sufficient power as well as one 10nF, 100nF, 1uF, and 10uF decoupling per rail:

Power Supply Decoupling Figure 2-1 Power Supply Decoupling

Power up the device and perform DC measurement of the supplies as close to the pin as possible. Confirm that each measurement is within the limits defined in Table 2-1.

Table 2-1 Recommended Operating Conditions
Min (V) Typ (V) Max (V)
AVDD3V3 3 3.3 3.6
VDDIO (3.3V) 3 3.3 3.6
VDDIO (1.8V) 1.62 1.8 1.98