May 1992

2

Philips Semiconductors

Product specification

Decoder for traffic warning (VWF) radio

transmissions

TDA1579

TDA1579T

GENERAL DESCRIPTION

The TDA1579 decoder is for radio transmissions having

57 kHz amplitude-modulated subcarriers as used in the

German 'Verkehrs Warnfunk' (VWF) traffic warning

system.

Features

• Selective subcarrier amplifier (57 kHz) with gain control

• Transmitter identification signal (SK) decoder

• Area identification signal (BK) and announcement

identification signal (DK) active filtering

• BK and DK decoders (Schmitt trigger with switched

hysteresis)

• BK and DK switch-on/switch-off delay circuits

• Driver output for SK indicator (LED)

• SK and BK control outputs.

QUICK REFERENCE DATA

PACKAGE OUTLINES

TDA1579: 18-lead DIL; plastic (SOT102); SOT102-1; 1996 August 12.

TDA1579T: 20-lead mini-pack; plastic (SO20; SOT163A); SOT163-1; 1996 August 12.

PARAMETER

CONDITIONS

SYMBOL

MIN.

TYP.

MAX.

UNIT

Supply voltage

7.5

8.5

12

V

Supply current

−

6

−

mA

Nominal input voltage

at f = 57 kHz

−

8

−

mV

Input impedance

at f

≤ 57 kHz

100

−−

k

Ω

Control level

−3 dB

−

2.4

−

mV

Input voltage

peak-to-peak value

2

−−

V

SK switch-on

threshold level

−

42

−

%

SK switch hysteresis

−

3.5

−

dB

SK switch-on delay

−

150

−

ms

SK switch-off delay

−

750

−

ms

DK switch-on

threshold level

−

13

−

%

DK switch hysteresis

−

3.6

−

dB

DK switch-on delay

−

750

−

ms

DK switch-off delay

−

750

−

ms

Ambient operating

temperature range

−30

−+ 80

°C