L9310 View Datasheet(PDF) - Agere -> LSI Corporation
Part Name
Description
MFG CO.
L9310
Agere -> LSI Corporation
L9310 Datasheet PDF : 60 Pages
| |||
L9310 Line Interface and Line Access Circuit
Full-Feature SLIC, Ringing Relay, and Test Access Device
Data Sheet
July 2001
ac Applications (continued)
First-Generation Codec ac Interface Net-
work: Complex Termination (continued)
Receive Gain
Ratios of RRCV, RT3, RGP will set both the low-frequency
termination and receive gain for the complex case. In
the complex case, additional high-frequency compen-
sation, via CN, RN1, and RN2, is needed for the return
loss characteristic. For resistive termination, CN, RN1,
and RN2 are not used and RCVN is tied to ground via a
resistor.
Determine the receive gain, gRCV, taking into account
the impedance transformation in a manner similar to
transmit gain.
RX (dB) = RX (specified[dB]) + 20 log -R----E---Q--
600
RX (dB) = 20 log gRCV
Then:
gRCV = -----------------------4------------------------
1
+
-R-----R---C----V--
RT3
+
R------R----C---V--
RGP
and low-frequency termination
ZTER(low) =
----------------2---4----0----0-----------------
1
+
-R-----T----3-
RGP
+
---R-----T---3----
RRCV
+ 2RP + 76 Ω
ZTER(low) is the specified termination impedance assum-
ing low frequency (C or C´ is open).
RP is the series protection resistor.
These two equations are best solved using a computer
spreadsheet.
Next, solve for the high-frequency return loss compen-
sation circuit, CN, RN1, and RN2:
CNRN2 = (---2---R-----P----+----7----6-----Ω------) CG RTGP
2400
RN1 = RN2 -(--2---R-----2P---4-+---0-7--0--6-----Ω------) RR-----TT---GG----SP- – 1
There is an input offset voltage associated with nodes
RCVN and RCVP. To minimize the effect of mismatch
of this voltage at T/R, the equivalent resistance to ac
ground at RCVN should be approximately equal to that
at RCVP.
Hybrid Balance
Set the hybrid cancellation via RHB.
RHB =
------------R-----X-------------
gRCV × gTX
52
Agere Systems Inc.
Share Link: 