GENERAL DESCRIPTION
The TDA1581T 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
• SK and BK control outputs.