PM5348-1 Datasheet, PDF (196/238 Pages) PMC-Sierra, Inc – DUAL SATURN USER NETWORK INTERFACE

DATA SHEET
PMC-950919
ISSUE 7
PM5348 S/UNI-DUAL
SATURN USER NETWORK INTERFACE
Table 4
-
Line Rate
(Mbit/s)
155.52
51.84
R1 (Ω±1%)
68.1
68.1
R2 (Ω±1%)
200
200
C1, C2
(µF±20%)
4.7
15
RE (Ω±1%)
100
100
Note:
The above component values are provisional. The capacitors (C1, C2) determine
the amount of "peaking" in the jitter transfer curve. Capacitor C1 should be non-
polarized because when the S/UNI-DUAL is held in reset, the capacitor is
reverse-biased at approximately 2.0V. Also, for some process extremes, the
capacitor may operate with a D.C. reverse-bias of up to 1.0V.
In STS-1 mode (51.84 Mbit/s), the recommended value for C1 may not be readily
available in non-polarized versions. Therefore, two polarized capacitors can be
connected "back-to-back" (in series, anode-to-anode or cathode to cathode) to
implement the capacitance in Figure 19. Since these back-to-back capacitors
will be in series, they should be of twice the value of the desired capacitance.
Please see insert of Figure 19. This back-to-back configuration effectively
creates a "bi-polar" capacitor. AVX Corporation has published several application
notes on this issue.
4.7µF non-polarized ceramic surface mount capacitors are available from Taiyo
Yuden Inc. (part No. EMK325BJ475MN-B), TDK (part No. CC1206JX5R475K),
and PHILIPS (Part No. 2220RR475K8AB0C).
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE 182