78Q2120C
10/100BASE-TX
Transceiver
T
r
T
f
CKIN
T
T
clkper
clkhi
External CKIN Oscillator Characteristics
EXTERNAL CKIN OSCILLATOR CHARACTERISTICS
PARAMETER
CKIN Frequency
CKIN Period
SYMBOL
CONDITION
See Note 1
See Note 1
MIN
NOM
25.000
40
MAX
UNIT
MHz
ns
f
Tclkper
CKIN Duty Cycle
Rise / Fall Time
Absolute Jitter
Tclkhi / Tclkper
45
55
4.0
0.1
%
ns
ns
Tr, Tf
Input signaling
requirements = CI
Note 1: IEEE 802.3 frequency tolerance ±50 ppm
Page: 32 of 35
© 2009 Teridian Semiconductor Corporation
Rev 1.3