MSP34X0G Datasheet, PDF(9/96 Page) Micronas – Multistandard Sound Processor Family

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MSP34X0G Datasheet, PDF (9/96 Pages) Micronas – Multistandard Sound Processor Family

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PRELIMINARY DATA SHEET

MSP 34x0G

2.1. Architecture of the MSP 34x0G Family

Fig. 2â1 on page 8 shows a simplified block diagram of

the IC. The block diagram contains all features of the

MSP 3450G. Other members of the MSP 34x0G fam-

ily do not have the complete set of features: The

demodulator handles only a subset of the standards

presented in the demodulator block; NICAM process-

ing is only possible in the MSP 3410G and

MSP 3450G.

2.2. Sound IF Processing

2.2.1. Analog Sound IF Input

The input pins ANA_IN1+, ANA_IN2+, and ANA_INâ

offer the possibility to connect two different sound IF

(SIF) sources to the MSP 34x0G. The analog-to-digital

conversion of the preselected sound IF signal is done

by an A/D-converter. An analog automatic gain circuit

(AGC) allows a wide range of input levels. The high-

pass filters formed by the coupling capacitors at pins

ANA_IN1+ and ANA_IN2+ see Section 8. âAppendix

E: Application Circuitâ on page 95 are sufficient in most

cases to suppress video components. Some combina-

tions of SAW filters and sound IF mixer ICs, however,

show large picture components on their outputs. In this

case, further filtering is recommended.

2.2.2. Demodulator: Standards and Features

The MSP 34x0G is able to demodulate all TV-sound

standards worldwide including the digital NICAM sys-

tem. Depending on the MSP 34x0G version, the fol-

lowing demodulation modes can be performed:

A2 Systems: Detection and demodulation of two sep-

arate FM carriers (FM1 and FM2), demodulation and

evaluation of the identification signal of carrier FM2.

NICAM Systems: Demodulation and decoding of the

NICAM carrier, detection and demodulation of the ana-

log (FM or AM) carrier. For D/K-NICAM, the FM carrier

may have a maximum deviation of 384 kHz.

Very high deviation FM-Mono: Detection and robust

demodulation of one FM carrier with a maximum devi-

ation of 540 kHz.

BTSC-Stereo: Detection and FM demodulation of the

aural carrier resulting in the MTS/MPX signal. Detec-

tion and evaluation of the pilot carrier, AM demodula-

tion of the (LâR)-carrier and detection of the SAP sub-

carrier. Processing of DBX noise reduction or

MICRONAS Noise Reduction (MNR).

BTSC-Mono + SAP: Detection and FM demodulation

of the aural carrier resulting in the MTS/MPX signal.

Detection and evaluation of the pilot carrier, detection

and FM demodulation of the SAP subcarrier. Process-

ing of DBX noise reduction or MICRONAS Noise

Reduction (MNR).

Japan Stereo: Detection and FM demodulation of the

aural carrier resulting in the MPX signal. Demodulation

and evaluation of the identification signal and FM

demodulation of the (LâR)-carrier.

FM-Satellite Sound: Demodulation of one or two FM

carriers. Processing of high-deviation mono or narrow

bandwidth mono, stereo, or bilingual satellite sound

according to the ASTRA specification.

FM-Stereo-Radio: Detection and FM demodulation of

the aural carrier resulting in the MPX signal. Detection

and evaluation of the pilot carrier and AM demodula-

tion of the (LâR)-carrier.

The demodulator blocks of all MSP 34x0G versions

have identical user interfaces. Even completely differ-

ent systems like the BTSC and NICAM systems are

controlled the same way. Standards are selected by

means of MSP Standard Codes. Automatic processes

handle standard detection and identification without

controller interaction. The key features of the

MSP 34x0G demodulator blocks are

Standard Selection: The controlling of the demodula-

tor is minimized: All parameters, such as tuning fre-

quencies or filter bandwidth, are adjusted automati-

cally by transmitting one single value to the

STANDARD SELECT register. For all standards, spe-

cific MSP standard codes are defined.

Automatic Standard Detection: If the TV sound stan-

dard is unknown, the MSP 34x0G can automatically

detect the actual standard, switch to that standard, and

respond the actual MSP standard code.

Automatic Carrier Mute: To prevent noise effects or

FM identification problems in the absence of an FM

carrier, the MSP 34x0G offers a carrier mute feature,

which is activated automatically if the TV sound stan-

dard is selected by means of the STANDARD SELECT

MSP demodulator channels, the corresponding

demodulator output is muted.

MICRONAS INTERMETALL

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