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TDA7421N

August 2000

This is preliminary information on a new product now in development or undergoing evaluation. Details are subject to change without notice.

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HIGH PERFORMANCE FRONT-END IC FOR

AM/FM RECEIVERS

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FULLY INTEGRATED HIGH-SPEED PLL FOR

OPTIMIZED RDS APPLICATIONS

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FM MPX/AM AUDIO OUTPUT, 450kHz AM IF

OUTPUT FOR STEREO AM APPLICATIONS

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AM DOUBLE CONVERSION ARCHITECTURE

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AM/FM STATION DETECTOR AND DIGITAL

IF-COUNTER

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SINGLE FREQUENCY REFERENCE FOR

BOTH AM AND FM

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FULL ELECTRICAL ADJUSTMENT

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DESCRIPTION

The TDA7421N is a high-performance tuner circuit

which integrates AM and FM sections, PLL frequency

sinthesizer and IF counter on a single chip.

Use of BICMOS technology allows the implementa-

tion of tuning functions with a minimum of external

components.Value spread of external components

can be fully compensated by means of on-chip elec-

trical adjustment controlled by external

µP.

The FM quality detection circuit, in conjunction with

the digital IF counter, enables the stop-station func-

tion in “seek” mode and MPX mute during reception.

The combination of programmable level detector and

IF counter allows reliable AM stop-station perfor-

mance.

The Automatic Gain Control (AGC) operates on dif-

ferent signal bandwidths in order to optimize sensitiv-

ity and dynamic range.

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gains, PLL and counter settings.

TQFP64

ORDERING NUMBER: TDA7421N

PRELIMINARY DATA

AM/FM TUNER FOR CAR RADIO AND HI-FI APPLICATIONS

PIN CONNECTIONS

1

2

3

5

6

4

7

8

9

10

27

11

28 29 30 31 32

59 58 57 56

54

55

53 52 51 50 49

43

42

41

39

38

40

48

47

46

44

45

FM AGC OUT

FM RF AGC IN

FM MIX IN +

AM MIX1 IN +

AM MIX1 IN -

FM MIX IN -

XTAL D

OSC GND

VCO E

RF GND

VCO B

FM BW TC

FM MUTE DRIVE

FM SMETER AM SMETER

FM DET ADJ

FM QUAD+

FM SD AM SD

FM IF AMP2 OUT

IF1 VCC

FM LIM IN +

IF1 GND

FM LIM IN -

D98AU909

22 23 24 25 26

60

61

62

63

64

17 18 19 20 21

37

36

34

33

35

FM QUAD-

IF2 VCC

AM REF

AM BPF

AM IF2 IN

12

13

14

15

16

PLL VCC

FM RF ADJ

FM ANT ADJ

XTAL G

OSC VCC

AUDIO OUT