TUA2009XS

This integrated circuit TUA2009XS permits the design of TV-tuners covering the entire frequency range from 48 . 900 MHz split into 3 frequency bands. The application is suitable for all tuners in TV- and VCR-sets.

The integrated circuit TUA2009XS includes 3 balanced mixers (double balanced mixer/ring mixer), one unbalanced oscillator for VHF I and two balanced oscillators for VHF II and UHF, a SAW-filter driver amplifier as well as a reference voltage source and a band switch. Filters between tuner input and IC separate the TV-frequency signal into three bands. The band switch ensures that only one band at a time is activated. In the activated band the signal passes a frontend stage with MOSFETamplifier,a double-tuned bandpass filter and is then fed to the balanced mixer input of the IC which is a high-impedance stage for the VHF I-range and a low-impedance stage for the VHF II- and UHFrange,respectively. The input signal is mixed there with the oscillator signal from the activated oscillator section and fed into common IF-stage for all bands. The IF-signal is further amplified in a SAW-filter driver section in order to drive the SAW-filter with a low impedance