CXA1203N Ver la hoja de datos (PDF) - Sony Semiconductor

Número de pieza

componentes Descripción

Fabricante

CXA1203N

8mm VCR PAL JOG

Sony Semiconductor 

CXA1203M/N

Description of Functions

1. Gain Adjustment Amplifier (DL Signal)

This amplifier adjusts the gain of the DL signal in PAL or PAL-M mode. The amplifier gain varies according

to the DC voltage applied to Pin 19. When 5V is applied to Pin 19, the internally fixed gain is obtained and

the levels of the TH signal and the DL signal (4.43MHz component in PAL mode, 3.58MHz component in

PAL-M mode) become the same.

2. fsc –90° PLL, ×2 and EX Burst Block

fsc

cos ωt

18

LIM

φADJ 23

–90°

cos (ωt – 90°)

cos ωt

V→I

LPF1

2fsc

cos (2ωt – 90°)

cos (ωt – 180°)

cos ωt

1/2fH

EX Burst

√2 cos (ωt – 45°)

√2 cos (ωt – 135°)

Fig. 2

The fsc –90° PLL consists of the –90° phase shifter, multiplier, LPF (low pass filter) 1 and V/I converter.

A signal delayed by 90° to the fsc is obtained in this PLL. By changing the DC voltage at Pin 23, the

amount of phase shift is varied. allowing adjustment of the phase of the EX burst and the duty (DC offset)

of the 2fsc. By applying 5V at Pin 23, the internally fixed phase shift is obtained. The 2fsc is produced

from the multiplier output (×2 output).

The EX burst is produced by adding the fsc (or inverted fsc) to the fsc with 90° delay produced in the –90°

PLL.

The fsc and the inverted fsc are switched in a period of 1/2fH, so the phase of the EX burst changes every

1H.

– 18 –

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