HMP8170 Datasheet, PDF (32/33 Pages) Intersil Corporation – NTSC/PAL Video Encoder

VAA
6.8K
ICL8069
HMP8170, HMP8171, HMP8172, HMP8173
+ _4.7µF
0.01µF
1.235V
Analog Output Filters
The various video standards specify the frequency response
of the video signal. The HMP817x uses 2X oversampling
DACs to simplify the reconstruction filter required. Example
post filters are shown in Figure 28. The analog output filters
should be as close as possible to the HMP817x.
FIGURE 27. EXTERNAL REFERENCE VOLTAGE CIRCUIT
1.0µH
2.2µH
1.0µH
RL
75
82pF
330pF
330pF 39pF
75
FIGURE 28A. HIGH QUALITY FILTER
2.7µH
RL
75
560pF
560pF
75
FIGURE 28B. LOW COST FILTER
FIGURE 28. EXAMPLE POST-FILTER CIRCUITS
Evaluation Kits
The HMP817xEVAL1 is a small (index card size) printed
circuit board containing the encoder, voltage references and
bypassing, analog output filters, and input/output
connectors. The board allows the encoder’s operation and
performance to be observed and measured.
The HMP817xEVAL1 board has a 50 pin, two row receptacle
which allows connection into an existing system. The
connector provides access to all of the encoder’s digital
inputs and outputs.
The HMP8156EVAL2 is the Intersil designed mother board
for the HMP817xEVAL1. The mother board is a standard
size PC add in card with an ISA bus interface and application
software. The HMP8156EVAL2 kit is a complete system
which allows demonstrating all of both encoders’ operating
modes. It has analog video inputs for composite, S-video,
and component RGB signals. The analog signals are
converted/decoded to the digital domain and input to the
encoder. The board also provides a 3 megabyte video RAM
for image capture and display and a BT.656 connector and
interface.
For simpler operation, the HMP817xEVAL1 may also be
driven by external power supplies, a BT.656 signal
generator, and a PC parallel port. The evaluation kit includes
application software to program the part using its I²C bus
connected to the printer port. The board includes the
standard 25 pin BT.656 connector and interface.
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