78Q2123CGV/F TERIDIAN [Teridian Semiconductor Corporation], 78Q2123CGV/F Datasheet - Page 34

• Manufacturer Part Number: 78Q2123CGV/F
• Description: 10/100BASE-TX Transceiver
• Manufacturer: TERIDIAN [Teridian Semiconductor Corporation]

ISOLATION TRANSFORMERS
Two simple 1:1 isolation transformers are required at the line interface. Transformers with integrated common-
mode chokes are recommended for exceeding FCC requirements. This table gives the recommended line
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 MR19.15:14.
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.
Page: 34 of 42
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
Drive Level (typ)
Insertion Loss
Turns Ratio
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
VALUE
VALUE
50-100
±50
4**
10
±2
±5
10
60
78Q2123/78Q2133 MicroPHY™
10/100BASE-TX Transceiver
@ 10 mV, 10 kHz
@ 1 MHz (min)
CONDITION
0 - 65 MHz
PPM/yr
UNITS
MHz
PPM
PPM
µW
pF
pF
pF
Ω
Rev 1.5