S5D2650 Samsung Semiconductor, Inc., S5D2650 Datasheet - Page 24

• Manufacturer Part Number: S5D2650
• Description: Multistandard Video Decoder/scaler
• Manufacturer: Samsung Semiconductor, Inc.

S5D2650 Data Sheet
MULTIMEDIA VIDEO
Figure 18.
Chroma IF Compensation Frequency Response
1.4.2. Demodulation Gain
The demodulation gain block is controlled by feedback from the gain tracking block. For NTSC and PAL type
inputs, the gain constant is derived from a programmable reference compared against the U component of the
input video. This reference is controlled by the SAT register. The default value “0” is the correct gain (saturation for
nominal output). For SECAM type input, the feedback is calculated such that proper frequency demodulation is
obtained. When external calibration is desired, the gain feed back loop can be “opened” by setting TSTCGN=1.
The SAT then controls bits 8 through 1 of a 10 bit multiplier.
For standard auto tracking applications, it is recommended that the SAT register be used as an end user saturation
control. This register is 2’s complement.
1.4.3. Demodulation Low Pass Filter
The demodulation circuit also contains a programmable low pass filter and a coring function for noise reduction.
The chroma low pass filter frequency response for the demodulation circuit for the various video standards are
shown in Figure 19
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7/18/03
ELECTRONICS