Datasheet

 2018 Microchip Technology Inc. DS00002813A-page 17
KSZ8721BL/SL
3.23 Circuit Design Reference for Power Supply
Microchip’s integrated built-in, voltage regulator technology and thoughtful implementation allows the user to save BOM
cost on both existing and future designs with the use of the new KSZ8721BL/SL single supply, single port 10/100 Ether-
net PHY.
FIGURE 3-4: CIRCUIT DESIGN
The circuit design in Figure 7-1 shows the power connections for the power supply: the 3.3V to VDDI/O is the only input
power source and the 2.5V at VDDRCV, pin 38, is the output of the voltage regulator that needs to supply through the
rest of the 2.5V VDD pins via the 2.5V power plane.
The 2.5V VDD pins make the drop-in replacement with the existing KSZ8721B/BT part. Ta ble 3 -4 shows the drop-in
replacement from the existing KSZ8721B/BT to the KSZ8721SL/BL. Please contact your local Microchip FAE for
Application Note AN-117, “Drop-in Replacement with KSZ8721BT.”
TABLE 3-4: DROP-IN REPLACEMENT
2.5V/3.3V Supply 3.3V Supply with Built-in Regulator
Part Number Package Part Number Package
KSZ8721B 48-SSOP KSZ8721SL 48-SSOP
KSZ8721BT 48-TQFP KSZ8721BL 48-LQFP
KSZ8721BI 48-SSOP KSZ8721SLI 48-SSOP