CA16-Type 2.5 Gbits/sDWDMTransponder with
16-Channel 155 Mbits/s Multiplexer/Demultiplexer
Advance Data Sheet
March 2001
differently than the TXD and PICLK inputs. Differentially,
the input impedance at this input is 100 Ω, but due to
the way it is biased internally, when driven single-
ended, the impedance appears as 60 Ω. The proper
termination scheme for the TXREFCLK input is shown in
Figure 4.
Functional Description (continued)
Transponder Interfacing (continued)
TxREFCLKP/N
The TXREFCLK input is different than the other inputs to
the transmitter because it is internally terminated, ac-
coupled, and self-biased. Therefore, it must be treated
CA16 TRANSPONDER
MULTIPLEXER
LVPECL
SONET/SDH
INTERFACE
IC
TXREFCLKP
PLL
CLOCK
SYNTHESIZER
TXREFCLKN
(VCC = 3.3 V)
50 Ω TRANSMISSION LINES
DIFFERENTIAL INTERFACE
CA16 TRANSPONDER
MULTIPLEXER
LVPECL
SONET/SDH
INTERFACE
IC
TXREFCLKP
TXREFCLKN
PLL
CLOCK
SYNTHESIZER
(VCC = 3.3 V)
0.1 µF
50 Ω TRANSMISSION LINES
FOR A SINGLE-ENDED INPUT,
THE INPUT IMPEDANCE IS
EQUIVALENT TO 60 Ω.
SINGLE-ENDED INTERFACE
1-1084 (F).c
Figure 4. Interfacing to the TxRefClk Input
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Agere Systems Inc.
AGERE [ AGERE SYSTEMS ]
