2.2V

TRIG. THRESHOLD

0.9V

VPEAK

E’

D95AU370

MONO

STEREO

noisy signal

good signal

ATC_SB OFF

NOISE

≈3V

Figure 5: Behaviour of the Field Strength Controlled Threshold Adiustment

100K

68K

33K

470nF

10K

680pF

MONO

MPX

4)

VR

17

19

20

PILOT_IND

18

16

15

SIGNAL

STRENGTH

47K

47K

47K 1)

68K 1)

100K

100K

VCO_OFF

(FM ENABLE)

330pF

7

10K

10K

MUTE

47nF

24

456KHz

3

5

100nF

10

µF

1nF 2)

1nF 2)

13

14

12

11

IN R

OUT

9

10

IN L

OUT

47K

47K

56pF 3)

56pF 3)

6

LEVEL

(SIGNAL STRENGTH)

D95AU371A

TDA7338

1) has to be adapted to the signal strength

2) for deemphasis = 50

µs

3) not absolutely necessary

4) roll off: to be adjusted to the tuner part

1

Figure 6: Application Diagram

TDA7338

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