KSZ8721SL Micrel Inc, KSZ8721SL Datasheet - Page 18

• Manufacturer Part Number: KSZ8721SL
• Description: IC TXRX PHY 10/100 3.3V 48-SSOP
• Manufacturer: Micrel Inc
• Type: Transceiverr

Specifications of KSZ8721SL

• Number Of Drivers/receivers: 1/1
• Protocol: IEEE 802
• Voltage - Supply: 3 V ~ 3.6 V
• Mounting Type: Surface Mount
• Package / Case: 48-SSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 576-1630 - BOARD EVALUATION FOR KSZ8721SL
• Lead Free Status / RoHS Status: Compliant, Lead free / RoHS Compliant
• Other names: 576-1031-5; 576-1512-5; 576-1512-5; KSZ8721SL

Micrel, Inc.
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
replacement 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.”
June 2009
+3.3V
Part Number
KS8721B
KS8721BT
KS8721BI
24
7
VDDI/O
VDDI/O
2.5V/3.3V Supply
VDDC
+2.5V
13
Package
48-SSOP
48-TQFP
48-SSOP
10F
Ferrite Bead
Table 2. Drop-In Replacement
Figure 4. Circuit Design
10F
+2.5VPLL
VDDPLL
IN
47
Regulator
Part Number
KS8721SL
KS8721BL
KS8721SLI
10F
Voltage
18
Ferrite Bead
3.3V Supply with Built-in Regulator
GND
8
10F
12
+2.5VA
OUT
23
42
35
31
36
Package
48-SSOP
48-LQFP
48-SSOP
KS8721BL/SL
39
38
43
44
10F
M9999-062509-1.3
10F
KS8721BL/SL