KSZ8721BL Micrel Inc, KSZ8721BL Datasheet - Page 31

• Manufacturer Part Number: KSZ8721BL
• Description: IC TXRX PHY 10/100 3.3V 48-LQFP
• Manufacturer: Micrel Inc
• Type: Transceiverr

Specifications of KSZ8721BL

• Number Of Drivers/receivers: 1/1
• Protocol: MII, RMII
• Voltage - Supply: 3 V ~ 3.6 V
• Mounting Type: Surface Mount
• Package / Case: 48-LQFP
• Data Rate: 100Mbps
• No. Of Ports: 1
• Ethernet Type: IEEE 802.3u
• Supply Current: 151mA
• Supply Voltage Range: 3.3V
• Operating Temperature Range: 0°C To +70°C
• Digital Ic Case Style: LQFP
• No. Of Pins: 48
• Interface Type: MII, RMII
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 576-1627 - BOARD EVALUATION FOR KSZ8721BMC576-1626 - BOARD EVALUATION FOR KSZ8721BL
• Lead Free Status / RoHS Status: Compliant, Lead free / RoHS Compliant
• Other names: 576-1028-5; 576-1511-5; 576-1511-5; KSZ8721BL

Selection of Isolation Transformer
One simple 1:1 isolation transformer is needed at the line interface. An isolation transformer with integrated common-mode
choke is recommended for exceeding FCC requirements. The following table gives recommended transformer characteristics.
Note:
1. The IEEE 802.3u standard for 100BASE-TX assumes a transformer loss of 0.5dB. For the transmit line transformer, insertion loss of up to 1.3dB can
Selection of Reference Crystal
An oscillator or crystal with the following typical characteristics is recommended.
May 2004
KS8721BL/SL
Single Port
Magnetic Manufacturer
Pulse
Bel Fuse
YCL
Transpower
Delta
LanKom
be compensated or by increasing the line drive current by means of reducing the ISET resistor value. Please select the transformer that supports
auto-MDI/MDI-X.
Characteristic
Turns Ratio
Open-Circuit Inductance (min.)
Leakage Inductance (max.)
Inter-Winding Capacitance (max.)
D.C. Resistance (max.)
Insertion Loss (max.)
HIPOT (min.)
Characteristic
Frequency
Frequency Tolerance (max.)
Load Capacitance (max.)
Series Resistance (max.)
Part Number
H1102
S558-5999-U7
PH163112
HB726
LF8505
LF-H41S
Value
1 CT : 1 CT
350 H
0.4 H
12pF
0.9
1.0dB
1500Vrms
Value
25.00000
20
25
100
Table 9. Qualified Transformer List
(1)
31
Test Condition
100mV, 100kHz, 8mA
1MHz (min.)
0MHz to 65MHz
Units
MHz
ppm
pF
Auto-MDI-X
Yes
Yes
Yes
Yes
Yes
Yes
Number
of Ports
M9999-051704
1
1
1
1
1
1
Micrel