TDA7461 - PL-1

Stereo decoder part

4 Stereo decoder part

TDA7461

4.1 Stereo decoder feature

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No external components necessary

PLL with adjustment free fully integrated VCO

Automatic pilot dependent mono/stereo switching

Very high suppression of intermodulation and interference

Programmable roll-off compensation

Dedicated RDS Softmute

High cut and stereo blend characteristics programmable in a wide range

Internal Noise blanker with threshold controls

Multipath detector with programmable internal/external influence

I

2

C bus control of all necessary functions

4.2 Stereo decoder electrical characteristics

Table 8.

Symbol

.

Stereo decoder electrical characteristics

(V

S

= 9 V; de-emphasis time constant = 50

μs, V

MPX

= 500 mV, 75 kHz deviation, f = 1 kHz.

G

I

= 6 dB, T amb

= 25 °C; unless otherwise specified)

Parameter Test condition Min.

Typ.

Max.

Unit

V

IN

R in

G min

G max

G

STEP

SVRR a

THD

MPX input level

Input resistance

Minimum input gain

Max input gain

Input gain = 3.5 dB

Step resolution

Supply voltage ripple rejection V ripple

= 100 mV, f = 1 kHz

Max channel separation

Total harmonic distortion

70

1.5

8.5

1.75

30

2.5

55

50

0.02

0.5

100

3.5

11

1.25

130

4.5

12.5

3.25

0.3

dB dB dB

%

V

RMS

K

Ω dB dB

S +

N

N

Signal plus noise to noise ratio S = 2 V rms

80 91 dB

Mono/stereo switch

PLL

V

PTHST1

V

PTHST0

V

PTHMO1

V

PTHMO0

Δf/f

Pilot threshold voltage

Pilot threshold voltage

Pilot threshold voltage

Pilot threshold voltage

Capture range for Stereo, PTH = 1 for Stereo, PTH = 0 for Mono, PTH = 1 for Stereo, PTH = 0

10

15

7

10

0.5

15

25

12

19

25

35

17

25 mV mV mV mV

%

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TDA7461 Stereo decoder part

Table 8.

Symbol

Stereo decoder electrical characteristics (continued)

(V

S

= 9 V; de-emphasis time constant = 50

μs, V

MPX

= 500 mV, 75 kHz deviation, f = 1 kHz.

G

I

= 6 dB, T amb

= 25 °C; unless otherwise specified)

Parameter Test condition Min.

Typ.

Max.

Unit

De-emphasis and high cut

(1)

τ

HC50

τ

HC75

τ

HC50

τ

HC75

De-emphasis time constant

De-emphasis time constant

High cut time constant

High cut time constant

Bit = 7, Subadr. 10 = 0

V

LEVEL

>> V

HCH

Bit = 7, Subadr. 10 = 1

V

LEVEL

>> V

HCH

Bit = 7, Subadr. 10 = 0

V

LEVEL

>> V

HCL

Bit = 7, Subadr. 10 = 1

V

LEVEL

>> V

HCL

Stereo blend and high cut-control

REF5V Internal reference voltage

TC

REF5V

L

Gmin

L

Gmax

L

Gstep

V

SBLmin

V

SBLmax

V

SBLstep

VHCH min

VHCH max

VHCH step

VHCL min

VHCL max

Temperature coefficient

Min. level gain

Max. level gain

Level gain step resolution

Min. voltage for mono

Max. voltage for mono

Step resolution

Min.voltage for no high cut

Max. voltage for no high cut

Step resolution

Min. voltage for full high cut

Max. voltage for full high cut

Carrier and harmonic suppression at the output

α19

α38

α57

α76

Pilot signal

Sub carrier

Sub carrier

Sub carrier

Intermodulation

(2)

) f = 19 kHz f = 38 kHz f = 57 kHz f = 76 kHz

α2

α3

Pilot signal f mod

= 10 kHz f spur

= 1 kHz; f mod

= 13 kHz; f spur

= 1 kHz;

25

50

100

150

4.7

12

46

70

12

21

37

+1

12

1.0

37

62

8.4

42

66

8.4

17

33

5

3300

0

10

0.67

33

58

5.0

36

62

5

13

29

-1

8

0.3

29

54

40

50

75

150

225

50

75

62

90

65

75

75

100

200

300

5.3

μs

μs

μs

μs dB dB dB dB dB dB

V ppm dB dB dB

%REF5V

%REF5V

%REF5V

%REF5V

%REF5V

%REF5V

%VHCH

%VHCH

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Stereo decoder part TDA7461

Table 8.

Symbol

Stereo decoder electrical characteristics (continued)

(V

S

= 9 V; de-emphasis time constant = 50

μs, V

MPX

= 500 mV, 75 kHz deviation, f = 1 kHz.

G

I

= 6 dB, T amb

= 25 °C; unless otherwise specified)

Parameter Test condition Min.

Typ.

Max.

Unit

Traffic radio

(3)

α57

Signal f = 57 kHz

SCA - Subsidiary communications authorization

(4)

α67

Signal

ACI - Adjacent channel interference

(5) f = 67 kHz

70

75 dB dB

α114

α190

Signal

Signal f = 114 kHz f = 190 kHz

95

84 dB dB

1.

By design/characterization but functionally guaranteed through dedicated test mode structure

2.

Intermodulation Suppression: measured with: 91% pilot signal; fm = 10kHz or 13kHz.

3.

Traffic radio (V.F.) suppression: measured with: 91 % stereo signal; 9 % pilot signal; fm=1 kHz; 5% sub carrier (f = 57 kHz, fm = 23 Hz AM, m = 60 %)

4.

SCA (subsidiary communications authorization) measured with: 81% mono signal; 9% pilot signal; fm = 1 kHz; 1 0% SCA sub carrier (fs = 6 7 kHz, unmodulated).

5.

ACI (adjacent channel interference) measured with: 90% mono signal; 9% pilot signal; fm = 1 kHz; 1% spurious signal

(fs = 110 kHz or 186 kHz, unmodulated).

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