KS8721SL A4 Micrel Inc, KS8721SL A4 Datasheet - Page 17

• Manufacturer Part Number: KS8721SL A4
• Manufacturer: Micrel Inc

Specifications of KS8721SL A4

• Lead Free Status / RoHS Status: Not Compliant

Circuit Design Reference for Power Supply
Micrel’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 KS8721BL/SL single supply, single port 10/100 Ethernet PHY.
The circuit design in Figure 4 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 KS8721B/BT part. Table 2 shows the drop-in replace-
ment from the existing KS8721B/BT to the KS8721SL/BL. Please contact your local Micrel FAE for Application Note AN-117,
“Drop-in Replacement with KS8721BT.”
February 2005
KS8721BL/SL
Part Number
KS8721B
KS8721BT
KS8721BI
+3.3V
2.5V/3.3V Supply
24
7
VDDI/O
VDDI/O
VDDC
+2.5V
48-SSOP
48-SSOP
Package
48-TQFP
13
Table 2. Drop-In Replacement
10F
Ferrite Bead
Figure 4. Circuit Design
10F
+2.5VPLL
VDDPLL
IN
47
KS8721SL 48-SSOP
KS8721SLI
Part Number
KS8721BL 48-LQFP
Regulator
17
Voltage
10F
3.3V Supply with Built-in Regulator
Ferrite Bead
GND
8
10F
12
+2.5VA
OUT
23
42
35
31
36
KS8721BL/SL
39
48-SSOP
38
43
Package
44
10F
10F
M9999-022105
Micrel