SAA7151 Просмотр технического описания (PDF) - Philips Electronics

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SAA7151

Digital multistandard colour decoder with SCART interface (DMSD2-SCART)

Philips Electronics 

Philips Semiconductors

Digital multistandard colour decoder with

SCART interface (DMSD2-SCART)

Product specification

SAA7151B

handbook, full pagewidth

R

G

B

sync

FS

BP C

R

G

B

sync

I 2C-bus

(select)

CVBS/Y

CVBS

sync

TDA8540 chroma

C

Y/C

Y

VIDEO

SWITCH

CVBS/Y/sync

+ AO

ADI

V2

TDA8709A

8-bit ADC

and multiplexer

(CHROMINANCE)

CUV(7-0)

U/V

S0 S1

HCT4053

FE

CLS CLP

C

MULTIPLEXER

+5 V

CLK

MUXC

LP

TDA8446 U

LP

V

VIDEO

SWITCH AND

MATRIX

SW1 FS*

CPI

SW2

CSO

CPO

HCL

FSO

clamping CPI

GPSW1

from SCART interface SAA7151B

FSI

AO

LP ADI TDA8708A CVBS(7-0)

Y

8-bit ADC

V0

(LUMINANCE)

GA GB

CLK

* fast switching of Y signal for insertion

(UV are switched inside SAA7151B)

GPSW2

GPSW1

MEH305-3

Fig.3 System configuration, RGB fast switch interface included (SCART).

The multipliers operate as a quadrature demodulator for all

PAL and NTSC signals; it operates as a frequency

down-mixer for SECAM signals.

The two multiplier output signals are converted to a serial

UV data stream and applied to two low-pass filter stages,

then to a gain controlled amplifier. A final multiplexed

low-pass filter achieves, together with the preceding

stages, the required bandwidth performance. The from

PAL and NTSC originated signals are applied to a

comb-filter. The signals, originated from SECAM, are fed

through a cloche filter (0 Hz centre frequency), a phase

demodulator and a differentiator to obtain

frequency-demodulated colour-difference signals.

The SECAM signals are fed after de-emphasis to a

cross-over switch, to provide the both serial-transmitted

colour-difference signals. These signals are finally fed via

the fast switch to the output formatter stages and to the

output interface.

Chrominance signals are output in parallel (4:2:2) on the

YUV-bus. The data rate of Y signal (pixel rate) is

13.5 MHz. UV signals have a data rate of 13.5 MHz/2 for

the 4:2.2 format (Table 2) respectively 13.5 MHz/4 for the

4:1.1 format (Table 3).

Component processing and SCART interface control

The 8-bit multiplexed colour-difference input signal (signal

CUV, Fig.1, out of matrixed RGB in Fig.3) is fed via the

input interface to a chrominance stop filter (UV signal only

can pass through; Figures 22 to 24). Here it is clamped

and fed to the offset compensation which can be enabled

or disabled via the I2C-bus.

April 1993

7

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