
4-247
CD22202, CD22203
Functional Block Diagram
÷
8
60Hz
REJECT
CLOCK
GENERATOR
CHIP CLOCKS
PRE EMP
POWER REGULATOR
5
10
7
V
DD
V
SS
V
SS
VOLTAGE
REF
697
770
852
941
1209
1336
1477
1633
BAND
SPLIT
FILTERS
ZERO
CROSSING
DETECTORS
BANDPASS
FILTERS
AMPLITUDE
DETECTORS
OUTPUT
DECODER
OUTPUT
REGISTER
TIMING
CIRCUITRY
DV
STROBE
DATA STROBE
DV
F.F
CLR
CD22202
CD22203
EARLY
DETECT
OUTPUT
6
CLRDV
15
14
2
1
18
17
16
3
4
DATA CLEAR
IN1633
DV
H/B28
D1
D2
D4
D8
EN
NOTE: Pin 6: Early detect output on CD22203 only.
ANALOG
IN
PREPROCESSOR
9
BS1
BS2
12
11
13
8
ATB
XEN
XIN
XOUT
1M
System Functions
Analog In
The Analog In pin accepts the analog input. It is internally
biased so that the input signal may be either AC or DC cou-
pled, as long as it does not exceed the positive supply volt-
age. Proper input coupling is illustrated below.
FIGURE 1. ANALOG IN
9
V
SS
V
DD
10pF
>100k
(ON CHIP)
270k
33k
ANALOG
IN
1500pF
OPTIONAL
HIGH FREQUENCY
NOISE FILTER
(f
C
= 3.9kHz)
AUDIO
INPUT
(+4dBm
MAXIMUM)
0.01
μ
F
CD22202, CD22203
The CD22202 and CD22203 are designed to accept sinuso-
idal input waveforms, but will operate satisfactorily with any
input that has the correct fundamental frequency with har-
monics that are at least 20dB below the fundamental.
Crystal Oscillator
The CD22202 and CD22203 contain an on-board inverter
with sufficient gain to provide oscillation when connected to
a low cost television “color-burst” (3.579545MHz) crystal.
The crystal oscillator is enabled by tying XEN high. The crys-
tal is connected between XIN and XOUT. A 1M
resistor is
also connected between these pins in this mode. ATB is a
clock frequency output. Other CD22202 and CD22203
devices may use the same frequency reference by tying their
ATB pins to the ATB output of a crystal connected device.
XIN and XEN of the auxiliary devices must then be tied high
and low, respectively. Up to ten devices may be run from a
single crystal connected CD22202 and CD22203 as shown
in Figure 2.