KS8999_11 MICREL [Micrel Semiconductor], KS8999_11 Datasheet - Page 51

• Manufacturer Part Number: KS8999_11
• Description: Integrated 9-Port 10/100 Switch with PHY and Frame Buffer
• Manufacturer: MICREL [Micrel Semiconductor]

January 2005
Micrel, Inc.
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 100BaseTX assumes a transformer loss of 0.5dB. For the transmit line transformer, insertion loss of up to 1.3dB
Selection of Reference Oscillator/Crystal
An oscillator or crystal with the following typical characteristics is recommended.
The following transformer vendors provide compatible magnetic parts for Micrel’s device:
Characteristics Name
Turns Ratio
Open-Circuit Inductance (min.)
Leakage Inductance (max.)
Inter-Winding Capacitance (max.)
D.C. Resistance (max.)
Insertion Loss (max.)
HIPOT (min.)
Characteristics Name
Frequency
Maximum Frequency Tolerance
Maximum Jitter
can be compensated by increasing the line drive current by means of reducing the ISET resistor value.
Transpower
Bel Fuse
Vendor
Pulse
Delta
YCL
4-Port Integrated
558-5999-Q9
PH406466
HB826-2
LF8731
H1164
Part
MDIX
Table 15. Qualified Magnetics Vendor Lists
Auto
Yes
Yes
Yes
Yes
Yes
of Ports
Number
(1)
1 CT : 1 CT
1500Vrms
25.00000
350µH
4
4
4
4
4
Value
Value
0.4µH
1.0dB
12pF
0.9Ω
±50
150
51
Transpower
Bel Fuse
Vendor
Pulse
Delta
YCL
Single Port
S558-5999-U7
PT163020
LF8505
HB726
H1102
Part
100mV, 100 KHz, 8mA
0MHz to 65MHz
Test Condition
Test Condition
1MHz (min.)
ps(pk-pk)
MHz
ppm
MDIX
Auto
Yes
Yes
Yes
Yes
Yes
of Ports
Number
KS8999
KS8999
1
1
1
1
1