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CXA1645P/M

Description of Operation

Analog RGB signals input from Pins 2, 3 and 4 are clamped in the clamping circuit and output from Pins 23,

22 and 21, respectively.

The matrix circuit performs operations on each input signal, generating luminance signal Y and color

difference signals R-Y and B-Y. The Y signal enters the delay line to adjust delay time with the color signal C.

Then, after addition of the CSYNC signal input from Pin 10, the Y signal is output from Pin 16.

A subcarrier input from Pin 6 is input to the phase shifter, where its phase is sfited 90°. Then, the subcarrier

is input to the modulators and modulated by the R-Y signal and the B-Y signal. Modulated subcarriers are

mixed, sent to the band pass filter to eliminate higher harmonic components and finally output from Pin 15 as

the C signal. At the same time, Y and C signals are mixed and output from Pin 20 as the composite video

signal.

Burst Signal

The CXA1645P/M generates burst signals at the timing shown below according to the composite sync signal

input.

H synchronization

V synchronization

Burst signal

SYNC

IN

(TTL level)

C VIDEO

OUT

COUT

Burst signal

Synchronizing signal

SYNC

IN

C VIDEO

OUT

ODD

EVEN

ODD

EVEN