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

TB1226EN 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.
TB1226EN 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, TB1226EN 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

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

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

Text section
• Linear RGB input
• OSD RGB input
• Cut / off-drive adjustment
• RGB primary signal output