SNLA437A December 2023 – October 2025 DP83822H , DP83822HF , DP83822I , DP83822IF , DP83826I
The RBIAS resistor is used to develop the internal bias currents and voltages in the PHY. It is specified for 1% tolerance so that the PHY can meet the tightest IEEE 802.3 specifications. The preference is to have a single component over multiple in series as the tolerance range can increase.
Measure the DC value of the voltage across the RBIAS resistor and confirm that the voltage is 1V.
Power down the board and verify that the RBIAS resistor value is 4.87k? ±1%.
Figure 2-4 DP83822 RBIAS Signal during AVD Power Up. Green is AVD and blue is RBIAS. When the device is properly ramped, RBIAS is expected to go high and stay high at 1V.