KS8721BL TR Micrel Inc, KS8721BL TR Datasheet - Page 33

• Manufacturer Part Number: KS8721BL TR
• Description: IC TXRX PHY 10/100 3.3V 48LQFP
• Manufacturer: Micrel Inc
• Type: Transceiverr

Specifications of KS8721BL TR

• Number Of Drivers/receivers: 1/1
• Protocol: MII, RMII
• Voltage - Supply: 2.375 V ~ 2.625 V
• Mounting Type: Surface Mount
• Package / Case: 48-LQFP
• For Use With: 576-1007 - BOARD EVAL EXPERIMENT KS8721BL
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: KS8721BLTR

Micrel, Inc.
Selection of Isolation Transformers
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.
Selection of Reference Crystal
An oscillator or crystal with the following typical characteristics is recommended.
June 2009
Parameter
Turns ratio
Open-circuit inductance (min)
Leakage inductance (max)
Inter-winding capacitance (max)
D.C. resistance (max)
Insertion loss (max)
HIPOT (min)
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 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.
Characteristics
Frequency
Frequency tolerance (max)
Load capacitance (max)
Series resistance (max)
Single Port Magnetic Manufacturer
Pulse
Bel Fuse
YCL
Transpower
Delta
LanKom
Integrated Transformers
Pulse
Pulse
Part Number
H1102
S558-5999-U7
PT163020
HB726
LF8505
LF-H41S
J0011D21
J00-0061
Table 9. Qualified Transformer Lists
(1)
Value
1 CT : 1 CT
350 μ H
0.4 μ H
12pF
0.9 Ω
1.0dB
1500Vrms
Value
25
± 100
20
40
33
Test Condition
100mV, 100kHz, 8mA
1MHz (min)
0MHz – 65MHz
Units
MHz
ppm
pF
Ω
Auto MDIX
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Number of Ports
M9999-062509-1.3
KS8721BL/SL
1
1
1
1
1
1
1
1