MSP3400C datasheet(9/73 Pages) MICRONAS

9 / 73 page

MSP 3400C

PRELIMINARY DATA SHEET

MICRONAS INTERMETALL

4. Architecture of the MSP 3400C

Fig. 4–1 shows a simplified block diagram of the IC. Its

architecture is split into three functional blocks:

1. demodulator section

2. digital signal processing (DSP) section performing

audio baseband processing

3. analog section containing two A/D-converters,

6 D/A-converters, and SCART switching facilities

4.1. Demodulator Block

4.1.1. Analog Sound IF – Input Section

The input pins ANA_IN1+, ANA_IN2+, and ANA_IN–

offer the possibility to connect two different sound IF

sources to the MSP 3400C. By means of bit [8] of

AD_CV (see Table 6–3), either terrestrial or satellite

sound IF signals can be selected. The analog-to-digital

conversion of the preselected sound IF signal is done by

a flash-converter, whose output can be used to control

an automatic gain circuit (AGC), providing optimum level

for a wide range of input levels. It is possible to switch

between automatic gain control and a fixed (setable) in-

put gain. In the optimum case, the input range of the A/D

converter is completely covered by the sound IF source.

Some combinations of SAW filters and sound IF mixer

ICs, however, show large picture components on their

outputs. In this case, filtering is recommended. It was

found that the high pass filters formed by the coupling

capacitors at pins ANA_IN1+ and ANA_IN2+ as shown

in the application diagram are sufficient in most cases.

4.1.2. Quadrature Mixers

The digital input coming from the integrated A/D conver-

ter may contain audio information at a frequency range

of theoretically 0 to 9 MHz corresponding to the selected

standards. By means of two programmable quadrature

mixers two different audio sources, for example FM1

and FM2, may be shifted into baseband position. In the

following, the two main channels are provided to pro-

cess either:

– FM mono (channel 2) or

– FM2 (channel 1) and FM1 (channel 2).

Two independent digital oscillators are provided to gen-

erate two pairs of sin/cos-functions. Two programmable

increments, to be divided up into Low- and High Part, de-

termine frequency of the oscillator, which corresponds

to the frequency of the desired audio carrier. In section

6.1., format and values of the increments are listed.

Demodulator

DFP

Sound IF

Loudspeaker

DACM_L

DACA_L

SC1_OUT_L

Headphone

Mono

SCART1

SCART2

D/A

SCART3

SCART 1

SCART 2

FM1 / AM

FM2

SCART_L

SCART_R

SCART_L

SCART_R

I2SL/R

HEADPHONE L

HEADPHONE R

LOUD-

SPEAKER R

LOUD-

SPEAKER L

IDENT

A/D

DACM_R

DACA_R

SC1_OUT_R

SC2_OUT_L

SC2_OUT_R

ANA_IN1+

ANA_IN2+

MONO_IN

SC1_IN_L

SC1_IN_R

SC2_IN_L

SC2_IN_R

SC3_IN_L

SC3_IN_R

S_CL / ADR_CL

S_DA_IN / ADR_DA

I2S_WS

SBUS/ADR Interface

Fig. 4–1: Architecture of the MSP 3400C

SCART Switching Facilities

I2S1/2L/R

I2S_CL

I2S_DA_IN_1/2

I2S_DA_OUT

I2S Interface

S_ID / ADR_WS

S1..4

XTAL_IN

AUD_CL_OUT

Audio PLL

XTAL_OUT

MSP3400C датащи(PDF) 9 Page - Micronas

MSP3400C датащи(HTML) 9 Page - Micronas

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73

датащи скачать

ссылки URL