CX28342 Datasheet, PDF (178/195 Pages) List of Unclassifed Manufacturers – Dual/Triple/Quad/Hex/Octal-Enhanced DS3/E3 Framer

Dejitter Circuit Analysis
CX28342/3/4/6/8 Data Sheet
The dejitter control loop is represented as follows, where Φ_in is the incoming
LINECK signal and Φ_out is the output from the VCO (RXCKI).
Figure A-2. Dejitter Control Loop
E(s)
+
Φ_in
1/16
G(s)
Φ_out
-
H(s)
The error signal is the sum of the input signal
divided by 16 and the VCO output divided by
16.
E(s)
=
Φ_in
16
− Φ_out H (s)
Eq. 1
The output signal is the error signal times the
gain of the system
Φ_out = E(s)G(s)
Eq. 2
Rearranging equation 1 for Φ_in
Φ_in = 16E(s) +16Φ_out H (s)
Eq. 3
The ratio of the output to input signal yields
equation 4.
Φ _out
Φ _in
=
16(E
E(s)G(s)
(s) + E(s)G(s))
Eq. 4
Simplifying this to the closed loop equation for
this system.
Φ _out
Φ _in
=
16(1
+
G(s)
G(s)
H
(s))
Eq. 5
A-2
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