xr XRT85L61
REV. 1.0.2 BITS (BUILDING INTEGRATED TIMING SUPPLY) CLOCK EXTRACTOR
16
TRANSFORMER RECOMENDATION
For all applications a 1:1 transformer ratio is required. 64kbps applications require a larger Inductance
transformer. Although E1 and T1 can use lower inductance transformers, Exar reccomends the use of the
PULSE ENGINEERING PE-65535 1:2CT transformer in a 1:1 mode by using pins 1 & 3 for the Line input and
Pins 6 & 5 as the secondary input to the XRT85L61. See
Figure 15 below. Smaller transformers will be
evaluated in the future and recommendations will be published at that time.
FIGURE 14. 64KBPS APPLICATION FOR TWISTED PAIR
FIGURE 15. CONNECTING THE PULSE ENGINEERING PE-65535 1:2CT TRANSFORMER TO THE XRT85L61
1:1
110 Ω
RTP
Receive
Input
RRing
RPOS
RNEG
RxClk
DVDD
AVDD
0.1
uF
10
uF
+
XRT59L81
BITS
Clock Extractor
+3.3V
Twisted Pair
1
5
43
6
to
XRT59L81
to Line
Input
PE-65535
leave open
