MC1374

8

MOTOROLA ANALOG IC DEVICE DATA

Figure 19. A Channel 4 Vestigial Sideband Filter

Figure 20. Audio Pre–Emphasis Circuit

Figure 21. Crystal Controlled RF Oscillator

for Channel 3, 61.25 MHz

NOTE: See Application Note AN829 for further information.

VCC

8

9

RL = 75

Ω

2.7k

39

pF

33pF

8.2pF

100

Ω

Output

75

Ω

Both transformer windings

4T #23 AWG

close wound on 1/4

″ ID

on common axis, 3/8

″ spacing.

8T #23 AWG

close wound on 1/8

″ ID,

knife tuned to trap Channel 3

61.25 MHz.

24

Ω

24

Ω

33pF

33pF

24

Ω

8.2pF

0

–10

–20

–30

–40

–50

–60

–70

61

65

69

73

Ch. 4

Pix

Ch. 4

S

f, FREQUENCY (MHz)

“Flat”

Audio

Input

CC = 0.1µF

C = 0.0012

µF

r = 56k

Ω

6.0k

Ω

R

14

Audio

Input

5

Gnd

–+

25

20

15

10

5

0

–5

21

210

2100

21k

2

π RC

1

2

π (r + R)CC

1

f, FREQUENCY (MHz)

2

π (2100 Hz)

1

Pre–emphasis = 75

µs = rC =

2

π rC

1

VCC

C1

0.001

R1

470

R2

R3

61.252

MHz

C2

56pF

Ra

180

Rb

18

L1

7

6

0.15

µH

470

470

MC1374