Advance Information

Triple 8-Bit Video ADC Three-State Outputs

CMOS

The MC44251 contains three independent parallel analog–to–digital flash converters (ADC). Each ADC consists of 256 latching comparators and an encoder. Video may be ac or dc coupled. With ac coupling, input clamping provides for internal dc restoration. The MC44251 also contains a dithering generator for video processing performance enhancements.

The MC44251 is especially suitable as a front–end converter in TV–picture digital processing (picture–in–picture, frame storage, etc.). The high speed conversion rate of the ADC is suitable for video bandwidth of well over 6 MHz.

• 18 MHz Maximum Sampling Rate

• Three–State Output Buffers

• Output Latching Minimizes Skew

• Input Clamps Suitable for RGB and YUV Applications

• Built–In Dither Generator with Subsequent Digital Correction

• Single 5–Volt Power Supply

• Operating Temperature Range: – 40 to + 85°C

• VTN and HZ Input Threshold Hysteresis Built–In