Addin Card Design
2-20
Intel740™ Graphics Accelerator Design Guide
2.2.6.7
TV Out Interface
The TV out bus is the group of signals that carry digitized display data from the Intel740
graphics accelerator
to the Bt869 flicker filter TV-out component. This interface is shared with
the BIOS interface.
Table 2-12
gives the maximum trace lengths between components.
2.2.6.8
Analog Signals
It is recommended that all analog signal traces be 75
Ω
±5%. It is important that these traces not
violate the 5x10 mil spacing for the 65
Ω
traces. Analog traces include the DAC R, G, B traces, all
of the inputs to the Bt829B component and outputs from the Bt869 component.
2.2.7
UL and FCC Considerations
Certain precautions should be taken in the design of the of a graphics card to ensure passing safety
and EMI tests. These precautions are listed below.
•
When a signal can be hot plugged, clamping diodes should be used to limit voltage spikes.
•
When a voltage leaves the card, a fuse should be placed in the path to protect from a short
circuit.
•
Sockets, Fans and Brackets should be grounded.
•
Separate Power Planes of the same voltage should be stitched together.
Table 2-12. TV Out/ROMA Trace Lengths (See Figure 2-22)
Signal
Intel740™ to BIOS
Stub
BIOS Stub
BIOS to Bt869
Min
Max
Min
Max
Min
Max
ROMA[17:0]
0.0”
3.5”
0.0”
1.5”
0.0”
4.0”
Figure 2-22. Layout Dimensions, Digital TV Bus
Intel740
0.0” - 3.5”
BIOS ROM
0.0” - 4.0”
0.0” - 1.5”
Bt869
Intel740™
Chip
Summary of Contents for 740
Page 1: ...Intel740 Graphics Accelerator Design Guide August 1998 Order Number 290619 003 ...
Page 9: ...1 Introduction ...
Page 10: ......
Page 13: ...2 Intel740 Graphics Accelerator Addin Card Design ...
Page 14: ......
Page 40: ...Addin Card Design 2 26 Intel740 Graphics Accelerator Design Guide ...
Page 57: ...3 Intel740 Graphics Accelerator 3 Device AGP Motherboard Design ...
Page 58: ......
Page 86: ...3 Device AGP MotherBoard Design 3 28 Intel740 Graphics Accelerator Design Guide ...
Page 128: ...4 Thermal Considerations ...
Page 129: ......
Page 131: ...Thermal Considerations 4 2 Intel740 Graphics Accelerator Design Guide ...
Page 132: ...5 Mechanical Information ...
Page 133: ......
Page 139: ...Mechanical Information 5 6 Intel740 Graphics Accelerator Design Guide ...
Page 140: ...6 Third Party Vendors ...
Page 141: ......
Page 144: ...A Application Notes ...
Page 172: ...Intel740 Graphics Accelerator Thermal Design Considerations 24 Application Note 653 ...
Page 174: ......
Page 178: ......
Page 183: ......
Page 185: ...B Reference Information ...
Page 186: ......
Page 187: ...PC SGRAM Specification Revision 0 9 February 1998 Order Number Not Applicable ...