- 您現(xiàn)在的位置：買賣IC網 > PDF目錄371861 > HMP8115 (Intersil Corporation) NTSC/PAL Video Decoder PDF資料下載
參數(shù)資料
| 型號： | HMP8115 |
| 廠商： | Intersil Corporation |
| 英文描述： | NTSC/PAL Video Decoder |
| 中文描述： | NTSC / PAL視頻解碼器 |
| 文件頁數(shù)： | 5/43頁 |
| 文件大?。?/td> | 183K |
| 代理商： | HMP8115 |
第1頁第2頁第3頁第4頁當前第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁
5
Introduction
The HMP8115 is designed to decode baseband composite
or S-video NTSC and PAL signals, and convert them to
either digital YCbCr or RGB data. In addition to performing
the basic decoding operations, the HMP8115 includes hard-
ware to decode different types of VBI data and to generate
digital video patterns for a blue screen, black screen and full
screen color bars.
The digital PLLs are designed to synchronize to all NTSC
and PAL standards. A chroma PLL is used to maintain
chroma lock for demodulation of the color information; a line-
locked PLL is used to maintain vertical spatial alignment.
The PLLs are designed to maintain lock even in the event of
VCR headswitches and multipath noise.
The HMP8115 contains two 8-bit A/D converters and an I
2
C
interface for programming internal registers.
External Video Processing
Before a video signal can be digitized the decoder has some
external
processing
considerations
addressed. This section discusses those external aspects of
the HMP8115.
that
need
to
be
ANALOG VIDEO INPUTS
The HMP8115 supports either three composite or two com-
posite and one S-video input.
Three analog video inputs (NTSC/PAL 1-3) are used to
select which one of three composite video sources are to be
decoded. To support S-video applications, the Y channel
drives the NTSC/PAL 3 analog input, and the C channel
drives the C analog input.
The analog inputs must be AC-coupled to the video signals,
as shown in the Applications section.
ANTI-ALIASING FILTERS
An external anti-alias filter is required to achieve optimum
performance and prevent high frequency components from
being aliased back into the video image.
For the NTSC/PAL 1-3 inputs, a single filter is connected
between the YOUT and YIN pins. For the C input, the anti-
aliasing filter should be connected before the C input. A rec-
ommended filter is shown in Figure 1.
S-VIDEO CHROMA GAIN CONTROL
The Chroma portion of S-video is AC coupled through an
anti-aliasing filter as shown in the applications section.
Unlike the composite/luma inputs, the Automatic Gain Con-
trol (AGC) for the chroma portion of S-video is done digitally
inside the decoder as determined by bits 7 and 6 of the
COLOR PROCESSING register 06
H
. In addition to the inter-
nal AGC, the designer can also apply some gain to the
chroma before it reaches the internal AGC logic. This gain is
controlled by pin 28. The voltage at this pin determines the
gain of the chroma before it gets digitized by the chroma A/D
with a typical gain performance as shown in Figure 2.
Digitization of Video
Prior to A/D conversion, the video signal is DC restored and
gained to generate known video levels into the digital pro-
cessing logic. This process is addressed in the “AGC and
DC Restoration” section. After digitization, sample rate con-
verters and a comb filter are used to perform color separa-
tion and demodulation.
A/D CONVERSION
Video data is sampled at the CLK2 frequency then pro-
cessed by the input sample rate converter. The output levels
of the ADC after AGC processing are:
(M) NTSC
(M, N) PAL
(B, D, G, H, I, N
C
)
PAL
white
black
blank
sync
224
76
64
0
213
64
64
0
AGC AND DC RESTORATION
The AGC amplifier attenuates or amplifies the analog video
signal to ensure that the sync tip level generates code 0. The
difference from the ideal sync tip level of 0 is used to control
the amount of attenuation or gain of the analog video signal.
The capacitor on the LAGC_CAP pin is used to store the
voltage which sets the gain level of the input video amplifier.
DC restoration positions the video signal such that the DC
level of the back porch generates an average code 64. The
back porch is sampled to determine the average value. The
capacitor on the L_CAP pin is used to store the voltage
FIGURE 1. RECOMMENDED ANTI-ALIASING FILTER
R
1
332
R
2
4.02K
C
2
82pF
L
1
8.2
μ
H
C
1
33pF
YOUT
YIN
7
6
5
4
3
2
1
0
L
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
CONTROL VOLTAGE ON THE GAIN_CTRL PIN
TEMPERATURE = 25
o
C
V
CC
= 5V
FIGURE 2. CHROMINANCE AMPLIFIER GAIN
HMP8115
相關PDF資料 |
PDF描述 |
|---|---|
| HMP8115CN | NTSC/PAL Video Decoder |
| HMR100 | Hadware Manual |
| HMR-100 | Hadware Manual |
| HMS188CWHRLP-20 | x8 SRAM |
| HMS188CS-15 | x8 SRAM |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| HMP8115CN | 制造商:INTERSIL 制造商全稱:Intersil Corporation 功能描述:NTSC/PAL Video Decoder |
| HMP8116 | 制造商:INTERSIL 制造商全稱:Intersil Corporation 功能描述:NTSC/PAL Video Decoder |
| HMP8116CN | 制造商:INTERSIL 制造商全稱:Intersil Corporation 功能描述:NTSC/PAL Video Decoder |
| HMP8117 | 制造商:INTERSIL 制造商全稱:Intersil Corporation 功能描述:NTSC/PAL Video Decoder |
| HMP8117_07 | 制造商:INTERSIL 制造商全稱:Intersil Corporation 功能描述:NTSC/PAL Video Decoder |
發(fā)布緊急采購，3分鐘左右您將得到回復。