Philips Semiconductors
Decoder for traffic warning (VWF) radio
transmissions
Product specification
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
Measured in Fig.1 at ViSK = 8 mV; f = 57 kHz amplitude modulated with fm = 34.95 Hz and m = 60% for
‘BK-traffic area C’ signal; or with fm = 125 Hz and m = 30% for DK signal.
PARAMETER
CONDITIONS
SYMBOL
MIN.
TYP.
MAX.
Supply voltage
Supply current
Nominal input voltage
Input impedance
Control level
Input voltage
SK switch-on
threshold level
SK switch hysteresis
SK switch-on delay
SK switch-off delay
DK switch-on
threshold level
DK switch hysteresis
DK switch-on delay
DK switch-off delay
Ambient operating
temperature range
at f = 57 kHz
at f ≤ 57 kHz
−3 dB
peak-to-peak value
VP
IP
ViSK
Zi
ViSK
Vi(p-p)
mBKon
∆mBK
tdSKon
tdSKoff
mDKon
∆mDK
tdDKon
tdDKoff
Tamb
7.5
8.5
12
−
6
−
−
8
−
100
−
−
−
2.4
−
2
−
−
−
42
−
−
3.5
−
−
150
−
−
750
−
−
13
−
−
3.6
−
−
750
−
−
750
−
−30
−
+ 80
UNIT
V
mA
mV
kΩ
mV
V
%
dB
ms
ms
%
dB
ms
ms
°C
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.
May 1992
2