4-247

CD22202, CD22203

Functional Block Diagram

60Hz

REJECT

CLOCK

GENERATOR

CHIP CLOCKS

PRE EMP

POWER REGULATOR

5

10

7

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

CLRDV

6

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

Ω

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

10pF

>100k

Ω

(ON CHIP)

270k

Ω

33k

Ω

ANALOG

IN

1500pF

OPTIONAL

HIGH FREQUENCY

NOISE FILTER

AUDIO

INPUT

(+4dBm

MAXIMUM)

0.01

µF

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

Ω 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.