78Q2120C09-CGTR/F Maxim Integrated Products, 78Q2120C09-CGTR/F Datasheet - Page 31

• Manufacturer Part Number: 78Q2120C09-CGTR/F
• Description: Telecom ICs 10-100 Fast Ethernet Transceiver Twisted
• Manufacturer: Maxim Integrated Products

Specifications of 78Q2120C09-CGTR/F

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ISOLATION TRANSFORMERS
Two simple 1:1 isolation transformers are required at the line interface. Transformers with integrated common-
mode choke are recommended for exceeding FCC requirements.
transformer characteristics:
Note: The 100Base-TX amplitude specifications assume a transformer loss of 0.4 dB. For the transmit line
transformer with higher insertion losses, up to 1.2 dB of insertion loss can be compensated by selecting the
appropriate setting in the Transmit Amplitude Selection bits in register MR19.11:10.
REFERENCE CRYSTAL
If the internal crystal oscillator is to be used, a crystal with the following characteristics should be chosen:
* Equivalent differential capacitance across the XTLP/XTLN pins.
** If crystal with a larger load is used, external shunt capacitors to ground should be added to make up the
equivalent capacitance difference.
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Parameters at 25
Temperature Stability ( 0 - 70
Motional Capacitance (min)
Inter-Winding Capacitance
Spurious Response (max)
Shunt Capacitance (max)
Series Resistance (max)
Open-Circuit Inductance
Frequency Tolerance
Leakage Inductance
Load Capacitance*
Oscillation Mode
D.C. Resistance
Insertion Loss
Turns Ratio
Drive Level
Frequency
NAME
HIPOT
NAME
Aging
o
C ± 2
o
C ; Drive Level = 0.5 mW
o
C)
Parallel Resonance, Fundamental Mode
> 5 dB below main within 500 kHz
©
2009 Teridian Semiconductor Corporation
1 CT : 1 CT ± 5%
0.40 µH (max)
350 µH (min)
25 pF (max)
0.9 Ω (max)
0.4 dB (typ)
1500 Vrms
25.00000
50 - 100
VALUE
VALUE
±50
4**
10
±2
±5
60
8
This table gives the recommended line
@ 10 mV, 10 kHz
@ 1 MHz (min)
CONDITION
0 - 65 MHz
PPM/yr
UNITS
10/100BASE-TX
MHz
PPM
PPM
µW
pF
pF
f F
Ω
Transceiver
78Q2120C
Rev 1.3