SPCA701A View Datasheet(PDF) - Unspecified

Part Name

Description

Manufacturer

SPCA701A

DIGITAL VIDEO ENCODER FOR VIDEOCD

Unspecified 

Preliminary

SPCA701A

PIXEL INPUT RANGES AND COLORSPACE CONVERSION

YC INPUTS (4:2:2 YCRCB)

Y has a nominal range of 16-235; Cb and Cr have a nominal range of 16-240, with 128 equal to zero. Values of

0 and 255 are interpreted as 1 and 254 respectively. Y values of 1-15 and 236-254, and CrCb values of 1-15

and 241-254, are interpreted as valid linear values. NTSC mode with setup disabled has 2% less black-to-white

range than NTSC mode with setup enabled.

DAC CODING

White is represented by a DAC code of 400. For PAL-B, D, G, H, I, the standard blanking level is represented

by a DAC code of 120. For NTSC, the standard blanking level is represented by a DAC code of 114, 1 IRE is

equivalent to a DAC code of 2.857.

OUTPUTS

All digital-to-analog converters are designed to drive standard video levels into an equivalent 37.5 load.

Unused outputs should be connected directly to ground to minimize supply switching currents. Either two

composite video outputs or Y/C S-Video outputs are available (selectable by the SVIDEO pin). If the SLEEP pin

is high, the DACs are essentially turned off and only the leakage current is present.

COMPOSITE AND LUMINANCE (CVBS/Y)ANALOG OUTPUT

When SVIDEO is a logical zero, digital composite video information drives the 9-bit D/A converter that generates

the CVBS output. When SVIDEO is a logical one, digital luminance information drives the DAC that generates

the analog Y video output.

COMPOSITE AND CHROMINANCE (CVBS/C) ANALOG OUTPUT

When SVIDEO is a logical zero, digital composite video information drives the 9-bit D/A converter that generates

the CVBS output. When SVIDEO is a logical one, digital chrominance information drives the 9-bit D/A converter

that generates the analog C video output.

PC BOARD CONSIDERATIONS

The layout should be optimized for lowest noise on the power and ground planes by providing good decoupling.

The trace length between groups of VAA and GND pins should be as short as possible to minimize inductive

ringing. A well-designed power distribution network is critical to eliminate digital switching noise. The ground

plane must provide a low-impedance return path for the digital circuits. A PC board with a minimum of four

layers is recommended, with layers 1 (top) and 4 (bottom) for signals and layers 2 and 3 for ground and power,

respectively.

Sunplus Technology Co., Ltd.

11

Rev.: 0.2 1999.12.07

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