VIDEO, CHROMA AND SYNCHRONIZING SIGNALS PROCESSING IC FOR PAL / NTSC / SECAM SYSTEM COLOR TV

TB1227CNG that is a signal processing IC for the PAL / NTSC / SECAM color TV system integrates video, chroma and synchronizing signal processing circuits together in a 56-pin shrink DIP plastic package. TB1227CNG incorporates a high performance picture quality compensation circuit in the video section, an automatic PAL / NTSC / SECAM discrimination circuit in the chroma section, and an automatic 50 / 60Hz discrimination circuit in the synchronizing section. Besides a crystal oscillator that internally generates 4.43MHz, 3.58MHz and M / N-PAL clock signals for color demodulation, there is a horizontal PLL circuit built in the IC.
The PAL / SECAM demodulation circuit which is an adjustment-free circuit incorporates a 1H DL circuit inside for operating the base band signal processing system.
Also, TB1227CNG makes it possible to set or control various functions through the built-in I2C bus line.

FEATURES
Video section
   • Built-in trap filter
   • Black expansion circuit
   • Variable DC regeneration rate
   • Y delay line
   • Sharpness control by aperture control
   • γ correction
   • VSM output

Chroma section
   • Built-in 1H Delay circuit
   • PAL / SECAM base band demodulation system
   • One crystal color demodulation circuit
      (4.43MHz, 3.58MHz, M / N-PAL)
   • Automatic system discrimination, system forced mode
   • 1H delay line also serves as comb filter in NTSC demodulation
   • Built-in band-pass filter, SECAM bell filter
   • Color limiter circuit
   • Fsc output
  
Synchronizing deflecting section
   • Built-in horizontal VCO resonator
   • Adjustment-free horizontal / vertical oscillation by count-down circuit
   • Double AFC circuit
   • Vertical frequency automatic discrimination circuit
   • Horizontal / vertical holding adjustment
   • Vertical ramp output
   • Vertical amplitude adjustment
   • Vertical linearity / S-shaped curve adjustment
   • SCP (Sand Castle Pulse) output
  
Text section
   • Linear RGB input
   • OSD RGB input
   • Cut / off-drive adjustment
   • RGB primary signal output