
Philips Electronics
GENERAL DESCRIPTION
The TDA5744 and TDA5745 are 2-band mixers/oscillators intended for VHF/UHF and hyperband tuners (see Fig.1).
The Integrated Circuits (ICs) include two double balanced mixers and two oscillators, for the VHF and UHF band, and an IF amplifier. With proper oscillator application and by using a switchable inductor to split the VHF band into two sub-bands (the full VHF/UHF and hyperband) the TV bands can be covered. Two pins are available between the mixer output and the IF amplifier input to enable IF filtering for improved signal handling. Band selection is made by band switch pin BS.
FEATURES
• Mixers/oscillators for hyperband tuners
• Balanced mixer with a common emitter input for VHF (single input)
• Balanced mixer with a common base input for UHF (double input)
• 4-pin common emitter oscillator for VHF
• 4-pin common emitter oscillator for UHF
• Electronic band switch
• IF amplifier with a low output impedance to drive the SAW filter directly (≈2 kΩ load)
• Low power, low radiation and small size
• Pin compatible single-chip synthesizer mixer/oscillator for Full Scale Tuners (FST) are available: TDA6404, TDA6405 and TDA6405A.
APPLICATIONS
• Hyperband tuners for Europe using a 2-band mixer/oscillator in a switched concept.