KS8993 Micrel Inc, KS8993 Datasheet - Page 34

• Manufacturer Part Number: KS8993
• Description: IC SWITCH 10/100 3PORT 128PQFP
• Manufacturer: Micrel Inc

Specifications of KS8993

• Applications: *
• Mounting Type: Surface Mount
• Package / Case: 128-MQFP, 128-PQFP
• Number Of Primary Switch Ports: 3
• Internal Memory Buffer Size: 64
• Operating Supply Voltage (typ): 2.5/3.3V
• Fiber Support: Yes
• Integrated Led Drivers: Yes
• Phy/transceiver Interface: MII/SNI
• 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 Supply Voltage (max): 2.75/3.6V
• Operating Supply Voltage (min): 2.35V
• Operating Temperature Classification: Commercial
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With: 576-1011 - BOARD EVAL EXPERIMENT FOR KS8993
• Lead Free Status / RoHS Status: Not Compliant, Contains lead / RoHS non-compliant

KS8993
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 Crystal
An oscillator or crystal with the following typical characteristics is recommended.
KS8993
The following transformer vendors provide pin-to-pin compatible parts for Micrel’s device:
Type
Transformer only
Integrated RJ45 and Transformer
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
Frequency Tolerance (max.)
The IEEE 802.3u standard for 100BaseTX assumes a transformer loss of 0.5 dB. 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.
Value
1 CT : 1 CT
350 H
0.4 H
12pF
0.9
1.0dB
1500Vrms
Value
25.00000
Table 12. Qualified Transformer Lists
100
Vendor
Pulse
YCL
Trans-Power
Trans-Power
(Note 1)
Quad
34
Part
H1060
PH406080
HB826-10
RJG4-754-C-NL
Test Condition
100mV, 100 KHz, 8mA
1MHz (min.)
0MHz to 65MHz
Units
MHz
ppm
Vendor
Pulse
YCL
Trans-Power
Trans-Power
Single
Part
H1012
20PMT04
HB614-1-LP
RJ754-C-NL
May 2005
Micrel