BA7232 View Datasheet(PDF) - ROHM Semiconductor

Part Name

Description

Manufacturer

BA7232

Color TV signal encoder

ROHM Semiconductor 

Multimedia ICs

•Circuit operation

(1) SYNCIN is for composite synch input. During low

input, the synchronization signal is output to YOUT,

VOUT and SYNCOUT.

(2) BFP is for burst flag pulse input. During low input,

the burst signal is output to pins CO and VO. When the

IC is set to PAL, it is this signal that directs the phase

inversion of the chroma signals. This signal also con-

trols the timing of the pedestal clamps of RIN, GIN and

BIN. During low input, the pedestal levels of RIN, GIN

and BIN are kept constant by charging an attached

capacitor.

(3) NT / PAL is the NTSC / PAL selector pin, and con-

nects to VCC when set to NTSC and to GND when set

to PAL.

BA7232FS

(4) SCIN is for color subcarrier input. Set input to a

pulse wave or sine wave (3.579545MHz for NTSC and

4.433619MHz for PAL).

(5) COUT and YOUT are for output of chroma signals

and luminosity signals, respectively. Because the chro-

ma signal and luminosity signals can be output sepa-

rately, the IC can be adapted for S pins. Each has a

75Ω driver.

(6) VOUT is for color TV signal output, and has an

internal 75Ω driver.

(7) ROUT, GOUT and BOUT are for analog RGB sig-

nal output, and have an internal 75Ω driver.

The relationship between chroma phase and burst phase during PAL processing is as follows.

NT / PAL

BFP

Chroma phases

B-Y

R-Y

burst

B-Y

B-Y

burst

R-Y

burst

R-Y

5

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