KS8997 Micrel Inc, KS8997 Datasheet - Page 36

• Manufacturer Part Number: KS8997
• Description: IC SWITCH 10/100 8PORT 128PQFP
• Manufacturer: Micrel Inc

Specifications of KS8997

• Applications: *
• Mounting Type: Surface Mount
• Package / Case: 128-MQFP, 128-PQFP
• Fiber Support: No
• Integrated Led Drivers: Yes
• Phy/transceiver Interface: MII
• Power Supply Type: Analog/Digital
• Package Type: PQFP
• Data Rate (typ): 10/100Mbps
• Vlan Support: Yes
• Operating Temperature (max): 70C
• Operating Temperature (min): 0C
• Pin Count: 128
• Mounting: Surface Mount
• Jtag Support: No
• Operating Temperature Classification: Commercial
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

KS8997
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.
Selection of Reference Oscillator/Crystal
An oscillator or crystal with the following typical characteristics is recommended.
KS8997
The following transformer vendor 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
Type
Transformer only
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 can be compensated by increasing the line drive current by means of reducing the ISET resistor value.
4-Port Integrated
Vendor
Pulse
Value
1 CT : 1 CT
350 H
0.4 H
12pF
0.9
1.0dB
1500Vrms
Value
25.00000
150
100
Table 8. Qualified Magnetics Lists
Part
H1164
(Note 1)
36
Pulse
Vendor
Test Condition
100mV, 100 KHz, 8mA
1MHz (min.)
0MHz to 65MHz
Test Condition
MHz
ppm
ps(pk-pk)
Single-Port
Part
H1102
August 2003
Micrel