February 1985

4

Philips Semiconductors

Product specification

Quasi-split-sound circuit

TDA2545A

CHARACTERISTICS

Vision carrier (V.C.) modulated with different video signals (see below); modulation depth 100% (proportional to 10%

residual carrier).

Vision-to-sound carrier ratios are VC/SC1 = 13 dB and VC/SC2 = 20 dB.

Sound carriers (SC1, SC2) modulated with f = 1 kHz and deviation

∆f= ± 30 kHz.

For measuring circuit see Fig.2; unless otherwise specified.

Note

1. Incidental phase on the vision carrier, caused by TV transmitter, has to be less than 0,5 degrees for black to white

transient (equivalent to S

+W/W = 56 dB for 6 kHz sinewave).

PARAMETER

SYMBOL

MIN.

TYP.

MAX.

UNIT

Supply (pin 11)

Supply voltage

10,8

12

13,2

V

Supply current

33

45

55

mA

I.F. amplifier

Input voltage for start of gain control

(intercarrier signals

−3 dB)

−

150

200

µV

Input voltage for end of gain control

(intercarrier signals

+ 1 dB)

100

250

−

mV

I.F. gain control range

∆G

v

60

64

−

dB

Control voltage range (see Fig.3)

4

−

V

Input resistance

−

2,5

−

k

Ω

Input capacitance

−

1,5

−

pF

Intercarrier generation

Output voltage; 5,5 MHz (r.m.s. value)

60

100

140

mV

Output voltage; 5,742 MHz (r.m.s. value)

27

45

63

mV

D.C. output voltage

−

5,9

−

V

Allowable d.c. load resistance at the output

7

−−

k

Ω

Allowable output current

−−

1mA

Intercarrier signal-to-noise (see note 1)

(measured behind the FM demodulators)

weighted according to CCIR 468-2, quasi-peak

a. 2T/20T pulses with white bars (see also Fig.4)

at 5,5 MHz

S

+W/W

53

58

−

dB

at 5,742 MHz

S

+W/W

51

56

−

dB

b. 6 kHz sinewave

at 5,5 MHz

S

+W/W

50

53

−

dB

at 5,742 MHz

S

+W/W

50

53

−

dB

c. black level (sync pulses only)

at 5,5 MHz

S

+W/W

60

65

−

dB

at 5,742 MHz

S

+W/W

58

63

−

dB