TDA4557 Ver la hoja de datos (PDF) - Philips Electronics

Número de pieza

componentes Descripción

Lista de partido

TDA4557

Multistandard decoder

Philips Electronics 

Philips Semiconductors

Multistandard decoder

Product specification

TDA4557

PARAMETER

SYMBOL MIN.

TYP.

MAX. UNIT

Sandcastle pulse detector (see note 4)

Input voltage pulse levels (pin 24)

to separate vertical and horizontal

blanking pulses

required pulse amplitude

to separate horizontal blanking pulse

required pulse amplitude

to separate burst gating pulse

required pulse amplitude

Input voltage during horizontal scanning

Input current

V24-9

1.3

V 24(p-p)

2.0

V24-9

3.3

V24(p-p)

4.1

V24-9

6.6

V24(p-p)

7.7

V24-9

−

−I24

−

1.6

1.9 V

2.5

3.0 V

3.6

3.9 V

4.5

4.9 V

7.1

7.6 V

−

VP

V

−

1.0 V

−

100 µA

Notes

1. Value measured without influence of external circuitry.

2. Or not connected.

3. The signal amplitude of the colour difference signals (R-Y) and (B-Y) is dependent on the characteristics of the

external tuned circuits at pins 7, 8 and 4, 5 respectively. Adjustment of the amplitude is achieved by varying the

Q-factor of these tuned circuits. The resonant frequency must be adjusted such that the demodulated output

frequency (fo) provides the same output level as the internally inserted reference voltage (achromatic value).

4. The sandcastle pulse is compared with three internal threshold levels, which are proportional to the supply voltage.

March 1991

8

Share Link: