SNLA338A January   2020  – August 2022 DP83826E

 

  1.   KSZ8081MNX/RNB to DP83826 System Rollover
  2.   Trademarks
  3. 1Purpose
  4. 2Required Changes
    1. 2.1 Strap Resistor Value
    2. 2.2 External Capacitor on Pin 2
    3. 2.3 Duplex Strap on Pin 16 (DP83826 Basic Mode)
    4. 2.4 Selecting 10M with Auto-Negotiation Enabled (DP83826 Basic Mode)
    5. 2.5 Configuring LED_1 for Tx and Rx Activity for EtherCAT Slave (DP83826 Basic Mode)
    6. 2.6 Thermal Pad Adjustments in Layout
    7. 2.7 Physical Layer ID Register
  5. 3Potential Changes
    1. 3.1 MDIO Pull-Up Resistor on Pin 11
    2. 3.2 MDIO Register Writes
    3. 3.3 Capacitors on Center Tap of Magnetics
  6. 4Informational Changes
  7. 5Pinout Mapping
    1. 5.1 Pin Mapping
  8. 6DP83826 Strap Configurations
    1. 6.1 Bootstrap Configurations
  9. 7Revision History

2.6 Thermal Pad Adjustments in Layout

The DP83826 thermal pad is smaller than KSZ8081. The table below shows the difference in package and DAP dimensions between the KSZ8081 and DP83826. With the rollover between devices, there is still a sufficient gap between pins and DAP so that pins will not be shorted.
Table 2-4 Package and DAP dimension differences

KSZ8081

DP83826

Package dimmsions

5x5 mm

5x5 mm

Max DAP dimensions

3x3 mm

2.2x2.2 mm
The recommended solution for best practices on the layout would be to match the solder paste stencil with the DP83826 thermal pad. This means reducing the solder paste from 3x3mm to 2.1x2.1mm.