hmp8156a Intersil Corporation, hmp8156a Datasheet - Page 33

• Manufacturer Part Number: hmp8156a
• Description: Ntsc/pal Video Encoder
• Manufacturer: Intersil Corporation

Evaluation Kits
The HMP8154EVAL1 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 HMP8154EVAL1 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 HMP8154EVAL1. 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,
FIGURE 37. EXTERNAL REFERENCE VOLTAGE CIRCUIT
ICL8069
6.8K
VAA
+
75
75
4.7µF
33
0.01µF
1.0µH
82pF
FIGURE 38. EXAMPLE POST-FILTER CIRCUITS
FIGURE 38A. HIGH QUALITY FILTER
FIGURE 38B. LOW COST FILTER
1.235V
HMP8154, HMP8156A
560pF
330pF
2.2µH
2.7µH
560pF
330pF
Analog Output Filters
The various video standards specify the frequency response
of the video signal. The HMP8154/HMP8156A uses 2X
oversampling DACs to simplify the reconstruction filter
required. Example post filters are shown in Figure 38. The
analog output filters should be as close as possible to the
HMP8154/HMP8156A.
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 HMP8154EVAL1 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.
1.0µH
39pF
RL
RL
75
75
November 4, 2005
4343.4