TUA6012

The TUA6012, TUA6014 devices combine a digitally programmable phase locked loop (PLL), with a mixer-oscillator block including two balanced mixers and oscillators for use in TV tuners.

The PLL block with four hard-switched chip addresses forms a digitally programmable phase locked loop. With a 4 MHz quartz crystal, the PLL permits precise setting of the frequency of the tuner oscillator up to 900 MHz in increments of 50 kHz, 62.5 kHz or 31.25 kHz. The tuning process is controlled by a microprocessor via an I²C Bus. The device has four output ports, two of them (P0 and P1) can also be used as TTL input ports. A flag is set when the loop is locked. The input ports and lock flag can be read by the processor via the I²C Bus.

The mixer-oscillator block includes two balanced mixers (double balanced mixer with high-impedance input for VHF low, VHF high and low-impedance input for UHF), two frequency and amplitude-stable balanced oscillators for VHF low, VHF high and UHF, a low-noise reference voltage source and a band switch.