AN84: Digital Hybrid with the Si305x DAAs

AN84
D IGITAL H YBRID WITH THE Si305 X DAA S
1. Introduction
This application note is a guide to understanding and
implementing the digital hybrid feature found in Si305x
DAA products. The Si305x contains an on-chip analog
hybrid that performs the 2- to 4-wire conversion and
near-end echo cancellation. This hybrid circuit is
adjusted for each ac termination setting selected to
achieve a minimum transhybrid balance of 20 dB. The
Si305x also offers a digital filter for additional near-end
echo cancellation to compensate for any line
impedance mismatch. For each ac termination setting,
the eight programmable hybrid registers (Registers 4552) can be programmed with coefficients to increase the
cancellation under real-world line conditions. This digital
filter can produce 10 dB or greater of near-end echo
cancellation in addition to the 20 dB from the analog
hybrid circuitry.
1.1. Digital Hybrid Overview
Digital
Filters
Z-1
b1
+
Z-1
Z-1
b7
Figure 1. Digital Hybrid Structure
Figure 1 describes the basic architecture of the digital
hybrid. It is composed of an 8-tap FIR filter. “b0” through
“b7” represent the filter coefficients in 2s complement
form. The initial 4-sample bulk delay is used to
compensate for the round trip delay through the lineside device. This architecture is designed to delay and
filter the transmit signal to match the portion not
cancelled by the analog hybrid.
TX
b0
Z-4
DAC
Figure 2 illustrates the basic signal flow of the DAA. The
digital signal has been upsampled to 16 kHz at the
digital hybrid stage. The transmit signal goes through a
digital filter, digital-to-analog converter, and analog filter
before going out on the line or being used in the analog
hybrid circuitry. After the analog hybrid, the receive
signal passes through an analog filter, analog-to-digital
converter, and digital filter before going back into the
digital hybrid. The analog hybrid path adds
approximately four samples of delay to the signal. The
digital hybrid structure matches this filter delay by
delaying the digital samples by the same amount.
AC
Termination
Line Driver
Analog
Filters
Line
RX
Digital
Hybrid
@16kHz
Digital
Filters
ADC
Analog
Filters
Analog
Hybrid
Figure 2. Signal Flow Diagram
Rev. 0.6 6/07
Copyright © 2007 by Silicon Laboratories
AN84
AN84
DAC
at 16 kHz
TX
HL()
HT()
HD(ej)
at 16 kHz
-
+
+
RX
+
ADC at
16 kHz
HR()
+
+
Figure 3. Model
A model of the DAA and the phone line is shown in
Figure 3. In an ideal system, the analog hybrid yields
perfect cancellation of the near-end echo from the
transmit path. A mismatch between the ac termination
and the load produces an echo that is not removed by
the analog hybrid. To increase the near-end echo
cancellation, the digital hybrid must equalize the
disparity between the impedance mismatch of the ac
termination and the line.
Substituting for HL() in the equation results in:
Z Line
Z Line – Z ACT
H L – 1 = 2  ---------------------------------- – 1 = ---------------------------------Z Line + Z ACT
Z Line + Z ACT
If ZLINE and ZACT are matched, the analog hybrid
perfectly cancels the transmit signal.
Substituting this result into the echo equation yields:
From the above model, the echo is equal to:
Z Line – Z ACT
echo = H T     H R    ---------------------------------Z Line + Z ACT
echo = H T     H L     H R    – H T     H R   
= HT  HR  HL  – 1 
HL() consists of the DAA’s ac termination in
combination with the impedance of the twisted pair
transmission line terminated at the central office (CO)
by a reference impedance. Figure 4 shows the analog
hybrid circuitry and the HL() model expanded to
include the ac termination and line.
2
The model for the HT() and HR() plays a critical role
in this calculation. The models are quite complex, and
sampled data of the models are necessary to calculate
the hybrid coefficients. Contact Silicon Labs to acquire
the sampled data of the HT() and HR() models.
A group delay, which was not illustrated in the model,
must also be taken into consideration. Internal DSP and
filters cause this delay. Taking the group delay into
account, the echo is equal to:
ZACT
echo = H T     H R      H L    – 1 e
j2  --------------
 16000  gd
where gd is the group delay.
+
+
ZLINE
The digital hybrid must cancel the echo by intentionally
adding the negative of the echo. The HD() should be:
H D    = – H T     H R      H L    – 1 e
Figure 4. HL()–1 Model
2
Rev. 0.6
j2
 ---------------  gd
 16000

AN84
1.2. Digital Hybrid Calculation Tool
Silicon Labs has developed a useful graphical user
interface tool (shown in Figure 5) that will assist in
calculating the coefficients to use with the digital hybrid
in the Si305x DAA product family. The tool allows the
user to enter the reference termination of the central
office (in an R + R||C format) and the model for the
phone line between the DAA and the central office. The
line can be represented by one of the EIA models,
shown in " Appendix C—EIA Line Models" on page 24,
or as a specified length of wire. The software then
executes the Matlab code found in " Appendix A—
Sample MATLAB Code" on page 7, which graphically
shows the expected trans-hybrid response of the digital
hybrid and lists the best hybrid coefficients to use given
the line characteristics.
Three graphs are shown in Figure 6. An echo graph is
created by intentionally mismatching the 600  ac
termination with the TBR21 mode CO termination. The
digital hybrid response is the 8-tap FIR filter response
calculated using the sample code found in Appendix A.
The cancelled graph is obtained by adding the echo and
the digital hybrid response. The digital hybrid response
looks very similar to an echo. Figure 7 shows the phase
of the echo and the digital hybrid response. The phase
of an echo and the digital hybrid have the opposite
polarity. Figure 8 compares the rejection in dB with and
without the digital hybrid. By properly using the digital
hybrid, near-end echo cancellation has increased by
approximately 20 dB.
To use the Digital Hybrid Calculation Tool, simply enter
the ACIM value recommended in Table 13 of the Si3050
datasheet into the ACIM control. This value determines
the impedance presented by the DAA to the line. It is
governed by the region in which the application will be
deployed. Next, enter values for R1 and R2 in ohms and
C in farads into the appropriate controls. These values
will represent the impedance presented by the central
office to the line. This value is also governed by the
region in which the application will be deployed. Also,
select the line-side device used in the application in the
pull-down box. Finally, select the line model to be used
that will most closely model the line connecting the DAA
to the central office. This is done by either picking a
specific EIA line model or by specifying a wire gauge
and length. Once this is complete, hitting the
"CALCULATE" button will generate the coefficients that
provide the best performance.
For example, if we assume that an application will be
deployed within the U.S., we enter a 0 for the ACIM
value. Also, the central office impedance in the US is
900  in series with 2.16 µF. To enter this information in
the GUI, we enter 900 for R1 and a fairly large value for
R2, since it is not present. For this example, the value of
100,000  was used. For the C value, we enter 2.16e-6
since the expected units are farads. Also, for this
example, we use an EIA model of 0. This means
essentially no loop length, and the central office
impedance is connected directly to the application. Now,
the "CALCULATE" button is pressed, and the resulting
coefficients, 0xF8, 0xF9, 0x03, 0xFE, 0xFE, 0x00,
0xFE, and 0x00, are generated.
Rev. 0.6
3
AN84
Figure 5. Digital Hybrid
4
Rev. 0.6
AN84
1.3. Conclusion
The Si305x DAA product family is designed to increase
the near-echo cancellation with an additional hybrid in
the digital path operating at 16 kHz. Near-end echo is
primarily caused by the mismatch between the ac
termination and the CO termination. The transmit and
receive signal path also affects the echo to a lesser
extent. By introducing a filter that models the near-end
echo 180 degrees out-of-phase to the receive path
echo, the hybrid response can be improved. This
improvement in the hybrid response results in greater
cancellation of the transmit signal when the near-end
echo and digital hybrid response are added together at
the digital hybrid stage.
To generate the coefficients, the 8-tap FIR filter
structure used in the digital hybrid must be taken into
account. This digital filter structure requires the hybrid
response to be represented in the z-domain.
“Appendix A—Sample MATLAB Code” contains sample
MATLAB code to calculate the hybrid coefficients. This
code should help in understanding the process of
calculating the hybrid coefficients.
A hybrid coefficient lookup table can be found in
" Appendix B—Hybrid Coefficient Lookup Tables" on
page 10. These tables provide a set of coefficients to
use for different line conditions.
Figure 6. Echo
Rev. 0.6
5
AN84
Figure 7. Echo Phase
Figure 8. Rejection
6
Rev. 0.6
AN84
APPENDIX A—SAMPLE MATLAB CODE
A sample MATLAB program for use in setting the hybrid coefficients is shown below. The code takes the ACIM
(Register 30) setting and line model as an input and outputs the best coefficient for the digital hybrid to match the
line.
function hdh
HrPhase);
=
dig_hybrid(ACIM,
R1line,
R2line,
Cline,
HtMag,
HtPhase,
HrMag,
% hdh = dig_hybrid(ACIM, R1line, R2line, Cline, HtMag, HtPhase, HrMag, HrPhase);
%
% This function calculates the coefficient values for the digital
% hybrid given a R1+R2||C model for the line.
%
% ACIM : register setting of the AC termination
% R1line : line R1
% R2line : line R2
% Cline : line C
% HtMag : Transmit path response
% HtPhase : Transmit path response
% HrMag : Receive path response
% HrPhase : Receive path response
%
% hdh : digital hybrid coefficients
Nact=ACIM+1;
if(R1line==0), R1line=eps; end
if(R2line==0), R2line=eps; end
if(Cline==0), Cline=eps; end
%eps is the smallest value after 0
% Set sample rate and frequency grid
fs=16000;
f=[eps:1:7999];
w=2*pi*f/fs;
%%%%%% Transmit path (Ht)
Ht = HtMag .* exp(j*HtPhase)
%%%%%%%
Receive path (Hr)
Hr = HrMag .* exp(j*HrPhase)
Rev. 0.6
7
AN84
%%%%%%%%%%
Near end echo (H2)
% Calculate Zline
Zcline=1./(j*2*pi*f*Cline);
Zline=R1line + R2line.*Zcline./(R2line+Zcline);
% Calculate Zref, assume perfect ACT
R1ref=[eps eps 270 220 370
350 eps
600
900
900
600 270];
R2ref=[600 900 750 820 620 1050 820 780 820 1000 900
1e9
1e9
1e9
1e9 750];
Cref =[eps eps 150 117 310
320 370 275 120
230 110 132 110
210
30 2160 1000 2160 1000 150]*1e-9;
Zcact=1./(j*2*pi*f*Cref(Nact));
Zact=R1ref(Nact) + R2ref(Nact).*Zcact./(R2ref(Nact)+Zcact);
C9r=0*1e-9;
Ycact2=(j*2*pi*f*C9r);
Zact=1./(1./Zact + Ycact2);
%%%%%
HL=2*Zline./(Zact+Zline);
HL(1)=0;
% Add extra group delay to match measurements
gde=-0.225;
Hd=-Ht.*Hr.*(HL-1).*exp(j*2*pi/16000*gde*[0:length(Ht)-1]);
Hd=[Hd conj(fliplr(Hd))];
% Estimate impulse response to match
hd=real(ifft(Hd));
% Truncate coefficients and express in [0 255]
hdh=round(hd(5:12)*64);
ind=find(hdh<0);
hdh(ind)=hdh(ind)+256;
echo = Ht.*Hr.*(HL-1).*exp(j*2*pi/16000*gde*[0:length(Ht)-1]);
hyb_coef = [0 0 0 0 hd(5:12)];
dig_hyb = freqz(hyb_coef,1,w);
figure
plot(f,abs(echo),'-',f,abs(dig_hyb),'-.',f,abs(echo+dig_hyb),':')
axis([0 4000 0 0.4])
legend('echo','digital hybrid response','cancelled signal')
8
Rev. 0.6
AN84
xlabel('frequency')
ylabel('echo')
figure
plot(f,angle(echo),'-',f,angle(dig_hyb),'-.')
axis([0 4000 -pi pi])
legend('echo','digital hybrid response')
xlabel('frequency')
ylabel('echo')
figure
plot(f,20*log10(abs(echo)),'-',f,20*log10(abs(echo+dig_hyb)),'-.')
axis([0 4000 -42 0])
legend('echo','cancelled signal')
xlabel('frequency')
ylabel('rejection')
Rev. 0.6
9
AN84
APPENDIX B—HYBRID COEFFICIENT LOOKUP TABLES
Tables 1–14 (for Rev C and prior versions of the Si3019) and Tables 15–28 (for Rev E and later versions of the
Si3019) provide fixed digital hybrid coefficients to best match the line load with specific EIA line models. For this
calculation, the EIA line model was incorporated into the HL(w) model. The first column shows which line type was
used to calculate the hybrid coefficient. The remaining columns display the hybrid coefficients (Registers 45–52).
Table 1. ACIM = 0000 and CO Termination = 900  + 2.16 µF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
248
249
3
254
254
0
254
0
EIA 1
251
240
255
5
250
2
254
255
EIA 2
2
240
238
7
253
254
2
254
EIA 3
5
239
235
7
252
254
2
254
EIA 4
1
242
240
1
252
255
0
255
EIA 5
7
244
233
1
250
253
0
254
EIA 6
4
244
228
6
7
247
1
253
EIA 7
248
230
8
18
234
2
1
255
2000 ft. 22 awg
253
242
254
5
250
2
255
255
2000 ft. 24 awg
252
240
254
5
250
2
254
255
2000 ft 26 awg
251
240
255
5
250
2
254
255
Table 2. ACIM = 0000 and CO Termination = 600 
Line Type
10
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
0
0
0
0
0
0
0
0
EIA 1
255
247
255
4
253
2
0
0
EIA 2
2
243
241
8
253
255
2
254
EIA 3
5
240
238
9
252
255
2
254
EIA 4
1
242
241
2
253
255
1
255
EIA 5
7
244
234
2
251
254
1
254
EIA 6
4
244
228
6
7
247
1
253
EIA 7
248
230
8
18
234
2
1
255
2000 ft. 22 awg
2
250
254
4
253
1
0
0
2000 ft. 24 awg
1
249
254
4
253
1
0
0
2000 ft 26 awg
255
247
255
4
253
2
0
0
Rev. 0.6
AN84
Table 3. ACIM = 0000 and CO Termination = 1200  + 376  + 112 nF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
240
242
7
255
254
3
254
1
EIA 1
247
232
254
8
249
4
255
0
EIA 2
2
238
234
6
253
254
2
254
EIA 3
4
237
231
5
252
254
2
254
EIA 4
1
241
239
255
251
254
0
255
EIA 5
7
244
233
0
249
252
0
253
EIA 6
4
244
228
6
7
247
1
253
EIA 7
248
230
8
18
234
2
1
255
2000 ft. 22 awg
249
233
253
8
249
3
255
0
2000 ft. 24 awg
248
232
253
8
249
4
255
0
2000 ft 26 awg
247
232
254
8
249
4
255
0
Table 4. . ACIM = 0000 and CO Termination = 150  + 510  + 47 nF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
3
249
252
5
253
1
0
255
EIA 1
2
246
249
7
252
1
1
255
EIA 2
3
244
240
5
254
255
2
255
EIA 3
5
241
238
6
252
255
2
254
EIA 4
1
242
241
2
252
255
1
255
EIA 5
7
244
234
2
251
253
1
254
EIA 6
4
244
228
6
7
247
1
253
EIA 7
248
230
8
18
234
2
1
255
2000 ft. 22 awg
4
248
246
7
253
0
1
255
2000 ft. 24 awg
3
247
247
8
253
0
1
255
2000 ft 26 awg
2
246
249
7
252
1
1
255
Rev. 0.6
11
AN84
Table 5. ACIM = 0000 and CO Termination = 220  + 820  + 150 nF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
6
246
239
5
253
255
2
255
EIA 1
3
246
241
2
254
255
1
255
EIA 2
3
245
240
1
252
254
1
255
EIA 3
5
242
238
4
250
255
0
254
EIA 4
1
242
241
2
251
254
0
254
EIA 5
7
244
234
2
250
252
0
253
EIA 6
4
244
228
6
7
247
1
253
EIA 7
248
230
8
18
234
2
1
255
2000 ft. 22 awg
6
249
237
2
255
253
2
254
2000 ft. 24 awg
5
247
239
3
254
254
2
255
2000 ft 26 awg
3
246
241
2
254
255
1
255
Table 6. ACIM = 0000 and CO Termination = 600  + 1.5 µF
Line Type
12
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
255
254
254
254
254
254
254
254
EIA 1
255
246
253
3
251
0
254
254
EIA 2
2
242
241
7
252
254
1
253
EIA 3
5
240
237
8
252
254
1
253
EIA 4
1
242
241
2
252
255
0
254
EIA 5
7
244
234
1
251
253
1
254
EIA 6
4
244
228
6
7
247
1
253
EIA 7
248
230
8
18
234
2
1
255
2000 ft. 22 awg
1
249
251
2
251
255
254
254
2000 ft. 24 awg
0
247
252
3
251
0
254
254
2000 ft 26 awg
255
246
253
3
251
0
254
254
Rev. 0.6
AN84
Table 7. ACIM = 0010 and CO Termination = 220  + 120  + 115 nf
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
9
16
5
254
2
255
0
0
EIA 1
2
10
9
255
1
0
255
1
EIA 2
255
0
3
2
0
1
0
0
EIA 3
1
253
0
4
254
1
0
0
EIA 4
253
252
0
255
0
0
0
0
EIA 5
4
253
249
255
254
255
0
255
EIA 6
1
254
242
4
8
246
2
254
EIA 7
244
241
19
11
244
2
253
1
2000 ft. 22 awg
6
15
6
254
3
255
0
0
2000 ft. 24 awg
5
12
7
255
2
0
0
0
2000 ft 26 awg
2
10
9
255
1
0
255
1
Table 8. ACIM = 0011 and CO Termination = 220  + 820  + 115 nF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
0
0
0
0
0
0
0
0
EIA 1
255
0
255
254
1
255
0
0
EIA 2
255
0
253
252
255
254
255
0
EIA 3
1
254
252
253
253
255
255
255
EIA 4
253
255
255
251
254
254
254
255
EIA 5
4
0
249
252
253
253
254
254
EIA 6
1
1
242
2
9
245
3
253
EIA 7
245
243
18
10
245
0
253
1
2000 ft. 22 awg
1
2
252
255
1
254
1
255
2000 ft. 24 awg
0
1
253
255
1
255
0
0
2000 ft 26 awg
255
0
255
254
1
255
0
0
Rev. 0.6
13
AN84
Table 9. ACIM = 0100 and CO Termination = 370  + 620  + 310 nF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
0
0
0
0
0
0
0
0
EIA 1
254
252
2
1
255
1
255
0
EIA 2
255
248
253
4
253
0
0
255
EIA 3
1
246
251
6
252
1
0
255
EIA 4
252
247
253
2
253
0
255
255
EIA 5
3
248
246
3
252
255
255
254
EIA 6
0
249
240
8
8
247
2
254
EIA 7
244
236
18
14
241
5
254
1
2000 ft. 22 awg
1
255
255
0
255
0
0
0
2000 ft. 24 awg
0
253
0
1
255
1
0
0
2000 ft 26 awg
254
252
2
1
255
1
255
0
Table 10. ACIM = 0100 and CO Termination = 220  + 820  + 120 nF
Line Type
14
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
0
248
254
6
255
2
1
0
EIA 1
254
249
253
4
255
1
1
0
EIA 2
255
249
251
2
254
0
0
0
EIA 3
1
246
250
4
252
1
0
255
EIA 4
252
247
253
1
253
0
255
255
EIA 5
3
248
246
2
252
254
255
254
EIA 6
0
249
240
8
8
247
2
254
EIA 7
244
236
18
14
241
5
254
1
2000 ft. 22 awg
1
251
249
5
0
0
2
255
2000 ft. 24 awg
0
249
251
5
255
0
1
0
2000 ft 26 awg
254
249
253
4
255
1
1
0
Rev. 0.6
AN84
Table 11. ACIM = 0101 and CO Termination = 300  + 1000  + 220 nF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
1
0
255
1
0
0
0
0
EIA 1
254
255
2
0
255
1
0
0
EIA 2
255
252
0
2
254
0
255
255
EIA 3
1
249
255
4
252
1
255
255
EIA 4
252
250
1
1
254
0
255
255
EIA 5
3
251
251
2
253
255
255
254
EIA 6
0
252
244
8
9
247
3
254
EIA 7
244
239
21
14
244
5
254
1
2000 ft. 22 awg
1
1
254
255
1
255
0
0
2000 ft. 24 awg
0
0
0
0
0
0
0
0
2000 ft 26 awg
254
255
2
0
255
1
0
0
Table 12. ACIM = 0101 and CO Termination = 370  + 620  + 310 nF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
0
4
4
0
1
1
0
1
EIA 1
254
0
6
1
0
2
255
1
EIA 2
255
252
1
3
254
1
0
0
EIA 3
1
249
255
5
253
1
0
255
EIA 4
252
250
1
2
255
0
255
0
EIA 5
3
251
250
3
254
255
255
255
EIA 6
0
252
244
8
9
247
3
254
EIA 7
244
239
21
14
244
5
254
1
2000 ft. 22 awg
1
3
3
0
1
0
0
0
2000 ft. 24 awg
0
1
4
1
0
1
0
0
2000 ft 26 awg
254
0
6
1
0
2
255
1
Rev. 0.6
15
AN84
Table 13. ACIM = 0101 and CO Termination = 270  + 750  + 150 nF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
0
254
2
4
1
2
1
0
EIA 1
254
253
2
3
1
2
1
1
EIA 2
255
252
0
2
255
1
0
0
EIA 3
1
249
254
4
253
1
0
0
EIA 4
252
250
1
1
254
0
255
0
EIA 5
3
251
250
2
253
255
255
255
EIA 6
0
252
244
8
9
247
3
254
EIA 7
244
239
21
14
244
5
254
1
2000 ft. 22 awg
1
0
255
3
2
0
1
0
2000 ft. 24 awg
0
254
0
3
1
1
1
0
2000 ft 26 awg
254
253
2
3
1
2
1
1
Table 14. ACIM = 1010 and CO Termination = 200  + 560 + 100 nF
Line Type
16
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
6
5
249
0
2
254
2
255
EIA 1
4
4
247
255
2
253
2
255
EIA 2
4
2
243
253
2
252
2
255
EIA 3
6
0
242
254
0
253
1
255
EIA 4
2
0
244
251
0
252
1
255
EIA 5
8
1
238
252
254
250
1
254
EIA 6
6
2
231
2
8
245
4
251
EIA 7
249
244
8
12
245
252
0
1
2000 ft. 22 awg
7
6
244
0
3
252
3
255
2000 ft. 24 awg
6
5
246
0
2
253
2
255
2000 ft 26 awg
4
4
247
255
2
253
2
255
Rev. 0.6
AN84
Table 15. ACIM = 0000 and CO Termination = 900  + 2.16 µF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
248
249
3
254
254
0
254
0
EIA 1
251
240
255
5
250
2
254
255
EIA 2
2
240
238
7
253
254
2
254
EIA 3
5
239
235
7
252
254
2
254
EIA 4
1
242
240
1
252
255
0
255
EIA 5
7
244
233
1
250
253
0
254
EIA 6
4
244
228
6
7
247
1
253
EIA 7
248
230
8
18
234
2
1
255
2000 ft. 22 awg
253
242
254
5
250
2
255
255
2000 ft. 24 awg
252
240
254
5
250
2
254
255
2000 ft 26 awg
251
240
255
5
250
2
254
255
Table 16. ACIM = 0000 and CO Termination = 600 
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
0
0
0
0
0
0
0
0
EIA 1
255
247
255
4
253
2
0
0
EIA 2
2
243
241
8
253
255
2
254
EIA 3
5
240
238
9
252
255
2
254
EIA 4
1
242
241
2
253
255
1
255
EIA 5
7
244
234
2
251
254
1
254
EIA 6
4
244
228
6
7
247
1
253
EIA 7
248
230
8
18
234
2
1
255
2000 ft. 22 awg
2
250
254
4
253
1
0
0
2000 ft. 24 awg
1
249
254
4
253
1
0
0
2000 ft 26 awg
255
247
255
4
253
2
0
0
Rev. 0.6
17
AN84
Table 17. ACIM = 0000 and CO Termination = 1200  + 376  + 112 nF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
240
242
7
255
254
3
254
1
EIA 1
247
232
254
8
249
4
255
0
EIA 2
2
238
234
6
253
254
2
254
EIA 3
4
237
231
5
252
254
2
254
EIA 4
1
241
239
255
251
254
0
255
EIA 5
7
244
233
0
249
252
0
253
EIA 6
4
244
228
6
7
247
1
253
EIA 7
248
230
8
18
234
2
1
255
2000 ft. 22 awg
249
233
253
8
249
3
255
0
2000 ft. 24 awg
248
232
253
8
249
4
255
0
2000 ft 26 awg
247
232
254
8
249
4
255
0
Table 18. ACIM = 0000 and CO Termination = 150  + 510  + 47 nF
Line Type
18
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
3
249
252
5
253
1
0
255
EIA 1
2
246
249
7
252
1
1
255
EIA 2
3
244
240
5
254
255
2
255
EIA 3
5
241
238
6
252
255
2
254
EIA 4
1
242
241
2
252
255
1
255
EIA 5
7
244
234
2
251
253
1
254
EIA 6
4
244
228
6
7
247
1
253
EIA 7
248
230
8
18
234
2
1
255
2000 ft. 22 awg
4
248
246
7
253
0
1
255
2000 ft. 24 awg
3
247
247
8
253
0
1
255
2000 ft 26 awg
2
246
249
7
252
1
1
255
Rev. 0.6
AN84
Table 19. ACIM = 0000 and CO Termination = 220  + 820  + 150 nF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
6
246
239
5
253
255
2
255
EIA 1
3
246
241
2
254
255
1
255
EIA 2
3
245
240
1
252
254
1
255
EIA 3
5
242
238
4
250
255
0
254
EIA 4
1
242
241
2
251
254
0
254
EIA 5
7
244
234
2
250
252
0
253
EIA 6
4
244
228
6
7
247
1
253
EIA 7
248
230
8
18
234
2
1
255
2000 ft. 22 awg
6
249
237
2
255
253
2
254
2000 ft. 24 awg
5
247
239
3
254
254
2
255
2000 ft 26 awg
3
246
241
2
254
255
1
255
Table 20. ACIM = 0000 and CO Termination = 600  + 1.5 µF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
255
254
254
254
254
254
254
254
EIA 1
255
246
253
3
251
0
254
254
EIA 2
2
242
241
7
252
254
1
253
EIA 3
5
240
237
8
252
254
1
253
EIA 4
1
242
241
2
252
255
0
254
EIA 5
7
244
234
1
251
253
1
254
EIA 6
4
244
228
6
7
247
1
253
EIA 7
248
230
8
18
234
2
1
255
2000 ft. 22 awg
1
249
251
2
251
255
254
254
2000 ft. 24 awg
0
247
252
3
251
0
254
254
2000 ft 26 awg
255
246
253
3
251
0
254
254
Rev. 0.6
19
AN84
Table 21. ACIM = 0010 and CO Termination = 220  + 120  + 115 nF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
9
16
5
254
2
255
0
0
EIA 1
2
10
9
255
1
0
255
1
EIA 2
255
0
3
2
0
1
0
0
EIA 3
1
253
0
4
254
1
0
0
EIA 4
253
252
0
255
0
0
0
0
EIA 5
4
253
249
255
254
255
0
255
EIA 6
1
254
242
4
8
246
2
254
EIA 7
244
241
19
11
244
2
253
1
2000 ft. 22 awg
6
15
6
254
3
255
0
0
2000 ft. 24 awg
5
12
7
255
2
0
0
0
2000 ft 26 awg
2
10
9
255
1
0
255
1
Table 22. ACIM = 0011 and CO Termination = 220  + 820  + 115 nF
Line Type
20
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
0
0
0
0
0
0
0
0
EIA 1
255
0
255
254
1
255
0
0
EIA 2
255
0
253
252
255
254
255
0
EIA 3
1
254
252
253
253
255
255
255
EIA 4
253
255
255
251
254
254
254
255
EIA 5
4
0
249
252
253
253
254
254
EIA 6
1
1
242
2
9
245
3
253
EIA 7
245
243
18
10
245
0
253
1
2000 ft. 22 awg
1
2
252
255
1
254
1
255
2000 ft. 24 awg
0
1
253
255
1
255
0
0
2000 ft 26 awg
255
0
255
254
1
255
0
0
Rev. 0.6
AN84
Table 23. ACIM = 0100 and CO Termination = 370  + 620  + 310 nF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
0
0
0
0
0
0
0
0
EIA 1
254
252
2
1
255
1
255
0
EIA 2
255
248
253
4
253
0
0
255
EIA 3
1
246
251
6
252
1
0
255
EIA 4
252
247
253
2
253
0
255
255
EIA 5
3
248
246
3
252
255
255
254
EIA 6
0
249
240
8
8
247
2
254
EIA 7
244
236
18
14
241
5
254
1
2000 ft. 22 awg
1
255
255
0
255
0
0
0
2000 ft. 24 awg
0
253
0
1
255
1
0
0
2000 ft 26 awg
254
252
2
1
255
1
255
0
Table 24. ACIM = 0100 and CO Termination = 220  + 820  + 120 nF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
0
248
254
6
255
2
1
0
EIA 1
254
249
253
4
255
1
1
0
EIA 2
255
249
251
2
254
0
0
0
EIA 3
1
246
250
4
252
1
0
255
EIA 4
252
247
253
1
253
0
255
255
EIA 5
3
248
246
2
252
254
255
254
EIA 6
0
249
240
8
8
247
2
254
EIA 7
244
236
18
14
241
5
254
1
2000 ft. 22 awg
1
251
249
5
0
0
2
255
2000 ft. 24 awg
0
249
251
5
255
0
1
0
2000 ft 26 awg
254
249
253
4
255
1
1
0
Rev. 0.6
21
AN84
Table 25. ACIM = 0101 and CO Termination = 300  + 1000  + 220 nF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
1
0
255
1
0
0
0
0
EIA 1
254
255
2
0
255
1
0
0
EIA 2
255
252
0
2
254
0
255
255
EIA 3
1
249
255
4
252
1
255
255
EIA 4
252
250
1
1
254
0
255
255
EIA 5
3
251
251
2
253
255
255
254
EIA 6
0
252
244
8
9
247
3
254
EIA 7
244
239
21
14
244
5
254
1
2000 ft. 22 awg
1
1
254
255
1
255
0
0
2000 ft. 24 awg
0
0
0
0
0
0
0
0
2000 ft 26 awg
254
255
2
0
255
1
0
0
Table 26. ACIM = 0101 and CO Termination = 370  + 620  + 310 nF
Line Type
22
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
0
4
4
0
1
1
0
1
EIA 1
254
0
6
1
0
2
255
1
EIA 2
255
252
1
3
254
1
0
0
EIA 3
1
249
255
5
253
1
0
255
EIA 4
252
250
1
2
255
0
255
0
EIA 5
3
251
250
3
254
255
255
255
EIA 6
0
252
244
8
9
247
3
254
EIA 7
244
239
21
14
244
5
254
1
2000 ft. 22 awg
1
3
3
0
1
0
0
0
2000 ft. 24 awg
0
1
4
1
0
1
0
0
2000 ft 26 awg
254
0
6
1
0
2
255
1
Rev. 0.6
AN84
Table 27. ACIM = 0101 and CO Termination = 270  + 750  + 150 nF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
0
254
2
4
1
2
1
0
EIA 1
254
253
2
3
1
2
1
1
EIA 2
255
252
0
2
255
1
0
0
EIA 3
1
249
254
4
253
1
0
0
EIA 4
252
250
1
1
254
0
255
0
EIA 5
3
251
250
2
253
255
255
255
EIA 6
0
252
244
8
9
247
3
254
EIA 7
244
239
21
14
244
5
254
1
2000 ft. 22 awg
1
0
255
3
2
0
1
0
2000 ft. 24 awg
0
254
0
3
1
1
1
0
2000 ft 26 awg
254
253
2
3
1
2
1
1
Table 28. ACIM = 1010 and CO Termination = 200  + 560  + 100 nF
Line Type
Hybrid Coefficient #
1
2
3
4
5
6
7
8
EIA 0
1
2
1
0
0
0
0
0
EIA 1
255
1
0
255
1
255
0
0
EIA 2
255
255
252
252
0
255
0
0
EIA 3
1
253
250
254
254
255
0
0
EIA 4
253
253
253
251
255
254
255
0
EIA 5
3
254
246
252
253
253
255
254
EIA 6
1
255
239
1
8
245
3
253
EIA 7
244
242
16
9
245
0
254
1
2000 ft. 22 awg
2
4
253
255
2
254
1
0
2000 ft. 24 awg
1
2
254
255
1
255
1
0
2000 ft 26 awg
255
1
0
255
1
255
0
0
Rev. 0.6
23
AN84
APPENDIX C—EIA LINE MODELS
EIA1
EO
EIA2
EO
2 kft
26 AWG
4 kft
26 AWG
3 kft
24 AWG
EIA3
EO
7 kft
26 AWG
EIA4
EO
12 kft
26 AWG
EIA5
EO
EIA6
EO
EIA7
EO
NI
1.5 kft
26 AWG
3 kft
24
AWG
88
88
6 kft
24
AWG
6 kft
24
AWG
88
88
6 kft
24
AWG
88
88
6 kft
22
AWG
6 kft
22
AWG
Figure 9. EIA Line Models
24
1.5 kft
26 AWG
6 kft
24 AWG
6 kft
24
AWG
Rev. 0.6
NI
NI
9 kft
24 AWG
3 kft
24
AWG
NI
88
88
9 kft
22
AWG
6 kft
22
AWG
88
NI
NI
3 kft
22
AWG
NI
AN84
DOCUMENT CHANGE LIST
Revision 0.3 to Revision 0.4


Added Figure 5 on page 4.
Added " Appendix C—EIA Line Models" on page 24.
Revision 0.4 to Revision 0.5

Updated Figure 5 on page 4.
 Added Tables 17–32 (information for Rev E and later
versions of the Si3019).
Revision 0.5 to Revision 0.6

Updated "1.2. Digital Hybrid Calculation Tool" on
page 3.
 Updated Figure 5 on page 4.
 Updated " Appendix B—Hybrid Coefficient Lookup
Tables" on page 10.
Rev. 0.6
25
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USBXpress® and others are trademarks or registered trademarks of Silicon Laboratories Inc. ARM, CORTEX, Cortex-M3 and THUMB are trademarks or registered trademarks of
ARM Holdings. Keil is a registered trademark of ARM Limited. All other products or brand names mentioned herein are trademarks of their respective holders.
Silicon Laboratories Inc.
400 West Cesar Chavez
Austin, TX 78701
USA
http://www.silabs.com
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