Datasheet

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