78Q21x3-DB Teridian Semiconductor, 78Q21x3-DB Datasheet - Page 3

• Manufacturer Part Number: 78Q21x3-DB
• Description: MII Evaluation Board
• Manufacturer: Teridian Semiconductor

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10/100Mbps Transformer Selection
The line interface for the MicroPHY requires a pair of 1:1 isolation transformers. Integrated common-mode
chokes are recommended for satisfying FCC radiated EMI requirements. Additional filtering is not required with
the MicroPHY due to internal waveform shaping circuitry. The line transformer characteristics are outlined below:
Note 1: The receive line transformer’s Open-Circuit Inductance can be as low as 100 µH for the MicroPHY. The
MicroPHY incorporates baseline wander correction circuitry, which allows the receiver to track the incoming data
signal when there is excessive transformer droop.
For Commercial Temperature (0°C ~ 70°C)
Teridian Semiconductor has performed line testing with the following transformers and found their performance
acceptable with the MicroPHY:
The following transformers are low profile packages (0.100 in/2.5 mm or less).
For Industrial Temperature (-40°C ~ +85°C)
Now most of the transformer vendors also offer industrial temp transformer, which will work with the 78Q2133.
Here is the recommended industrial temp transformer list:
© 2007 Teridian Semiconductor Corporation, Proprietary and Confidential
Manufacturer
TDK
Bel-Fuse
Halo
Pulse
Valor
YCL
TDK
Halo
PCA
Manufacturer
Belfuse
Pulse
Halo
Inter-Winding Capacitance
Open-Circuit Inductance
Leakage Inductance
D.C. Resistance
Insertion Loss
Turns Ratio
HIPOT
Name
Part Number
TLA-6T103
S558-5999-46
TG22-3506ND
PE-68515
ST6118
20PMT04
TLA-6T118
TG110-S050
EPF8023G
Part Number
S558-5999-U5
HX1148
TG110-E050N5
0.9 ohm (max)
0.40 µH (max)
350 µH (min)
25 pF (max)
See Note 1.
1 CT : 1 CT
1.1 dB (typ)
1500 Vrms
Value
- 3 -
@ 10 mV, 10 kHz
@ 1 MHz (min)
0 - 100 MHz
Condition
DEMO BOARD MANUAL
78Q21x3-DB MicroPHY
MII Evaluation Board
Rev_2.3
TM
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