This device is a programmable 3-band mixer oscillator and synthesizer intended for LOW, MID and HIGH band TV and VCR tuners. It has three double balanced mixers and three oscillators for the LOW, MID and HIGH band respectively, a PLL synthesizer, and an IF amplifier. There are four package variants: TDA6508, TDA6509, TDA6508A and TDA6509A. Versions TDA6508; TDA6509 have a symmetrical IF amplifier; versions TDA6508A; TDA6509A have an asymmetrical IF amplifier.
“What is a phase-locked loop (PLL)? A phase-locked loop (PLL) is an electronic circuit with a voltage or voltage-driven oscillator that constantly adjusts to match the frequency of an input signal. PLLs are used to generate, stabilize, modulate, demodulate, filter …