June 1993

8

Philips Semiconductors

Preliminary specification

Generic multi-standard decoder

TDA4657

SECAM

colour difference output signals

independent of supply voltage; note 4

−(R−Y) output (peak-to-peak value)

0.95

1.05

1.15

V

−(B−Y) output (peak-to-peak value)

1.20

1.33

1.46

V

ratio of CD signal amplitudes

V(R

−Y)/V(B−Y)

0.75

0.79

0.83

−

m

signal linearity at nominal output voltage

0.8

−−

−

cut-off frequency

−3dB

−

730

−

kHz

chrominance delay time

400

500

600

ns

S/N

signal to noise ratio for 100 mV (p-p) input

signal and nominal output voltages

note 3

40

−−

dB

residual carrier at CD outputs:

1

× subcarrier frequency

(peak-to-peak value)

−−

10

mV

2

× subcarrier frequency

(peak-to-peak value)

−−

20

mV

∆V

3

blanking level

−(B−Y) output

note 8

−

0

±13

mV

−(R−Y) output

−

0

±10

mV

Impedance and currents see PAL or NTSC specification

Capacitor for SECAM de-emphasis (pin 2)

value of external capacitor

−

220

−

pF

value of internal de-emphasis resistors

2.4

2.8

3.2

k

Ω

4.8

5.6

6.4

k

Ω

−−

±5%

Capacitors for SECAM demodulator control (pins 4 and 8; note 5)

external leakage current

−−

0.3

mV/nA

Resistor for SECAM oscillator (pin 6)

DC voltage

2.4

2.81

3.2

V

value of external resistor (

±1%)

−

5.62

−

k

Ω

value of external capacitor (

±20%)

−

10

−

nF

Chrominance input (pin 9)

input signal (peak-to-peak value)

note 6

20

200

400

mV

input resistance

16

20

24

k

Ω

input capacitance

−−

10

pF

Capacitor for ACC (pin 10; note 7)

change of CD output signals during field

blanking due to external leakage current

−

0.2

−

%/nA

SYMBOL

PARAMETER

CONDITIONS

MIN.

TYP.

MAX.

UNIT