The SN761678B is a synthesized tuner IC designed for TV tuning systems. The circuit consists of a phase-locked loop (PLL) synthesizer, three-band local oscillator and mixer, 30-V output tuning amplifier, and four NPN band-switch drivers. The device is available in a small-outline package. A 15-bit programmable counter and reference divider are controlled by I2C bus protocol. Tuning step frequency is selectable by this reference divider ratio for a crystal oscillator.
● Single-Chip Mixer/Oscillator and Phase-Locked Loop (PLL) Synthesizer
● Three-Band Local Oscillator
● I2C Bus Protocol (Bidirectional Data Transmission)
● 30-V Tuning Voltage Output
● Four NPN-Type Band-Switch Drivers
● Programmable Reference Divider Ratio (512, 640, or 1024)
● External 4-Pin Intermediate Frequency (IF) Filter Between Mixer Output and IF Amplifier Input
● 5-V Power Supply
● 30-Pin Thin Shrink Small-Outline Package (TSSOP)
● APPLICATIONS
● TVs
● VCR/DVD Recorders
● Set-Top Boxes
