- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄373030 > BT865AKPF Color Encoder Circuit PDF資料下載
參數(shù)資料
| 型號： | BT865AKPF |
| 英文描述： | Color Encoder Circuit |
| 中文描述： | 顏色編碼器電路 |
| 文件頁數(shù)： | 65/76頁 |
| 文件大?。?/td> | 1050K |
| 代理商： | BT865AKPF |
第1頁第2頁第3頁第4頁第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頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁當(dāng)前第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁
Bt864A/865A
3.0 PC Board Considerations
YCrCb to NTSC/PAL Digital Video Encoder
3.5 Applications Information
100138B
Conexant
3-9
3.5.6 Luminance Delay on CVBS/B
Postfiltering of the video signal can introduce a variable delay between the lower
frequency luminance components and the higher frequency chrominance
subcarrier components. The group delay distortion is often specified in system as
chroma-luma delay inequality or as Sinx/x pulse group delay. Group delay
distortion is commonly induced by postfilters which peak the chrominance level,
by trap circuits intended to reduce video energy in the aural subcarrier frequency
range, and by Vestigial Sideband (VSB) filtering in RF tuners. Since
oversampling encoders greatly reduce the need for peaking filters, delay
compensation of the luminance signal largely benefits the channel through the RF
modulation and tuner path where group delay distortion can amount to several
hundred nanoseconds or several pixels of misregistration.
While flat group delay correction as observed from a Sinx/x pulse spectrum
can require several LC stages with active buffers, a simplified approach where
only luma-chroma delay must be equalized is to shift the luminance signal
through pipeline delays to match any additional group delay induced on the
chrominance components by postfiltering. This alignment of the lower frequency
luminance components with the chrominance components does not strictly satisfy
broadcast quality requirements but provides perceptible improvements in display
registration.
While VSB delays are prescribed in ITU-R BT.470-3 as about 170 ns, the
luminance delay compensation for postfilter aural traps depends on the
attenuation required at the aural carrier frequency. In the case of NTSC signals
sampled at CCIR601 resolution, the coincidence of the aural carrier (4.5 MHz) at
one third of the sample rate means that any video component which transitions at
intervals of every third pixel clock can generate significant energy at the aural
carrier frequency. In the case of hard-edged, unblended characters having a font
cell size which is a multiple of three pixels, harmonic energy at the aural carrier
frequency may be only 15 dB below the maximum video level, or roughly equal
to the power of the sound subcarrier in the RF spectrum.
Trap attenuation of about 20 dB can assure that the resultant interference with
the FM aural signal will degrade the noise level at the monaural decoded receiver
about 1 dB (
–
44 dB range) with less than 50 ns additional chroma delay
[Multichannel stereo (e.g.,BTSC) or Second Audio Program (SAP) encoder may
require greater attenuation due to lower level subcarriers]. Therefore, luminance
delay compensation of about 225 ns on just the RF feed (e.g. CVBS/B) can
correct for the chroma delay artifacts of additional processing in the RF channel
without compromising the inherently low group delay distortion of the baseband
channels (e.g. CVBS/Y/C).
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| BT867KPF | Color Encoder Circuit |
| BT867KPJ | Color Encoder Circuit |
| BT8920EPJ | Analog-to-Digital Converter， 16-Bit |
| BT8920EPJ600 | Analog-to-Digital Converter， 16-Bit |
| BT8921ESS | xDSL Interface |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| BT865AKRF | 制造商:CONEXANT 制造商全稱:CONEXANT 功能描述:YCrCb to NTSC/PAL Digital Video Encoder |
| BT866KPF | 制造商:Brooktree 功能描述:Video/TV Circuit, Color Encoder Circuit, 52 Pin, Plastic, QFP |
| BT866KPJ | 制造商:BT 功能描述:Video/TV Circuit, Color Encoder Circuit, 68 Pin, Plastic, PLCC 制造商:Burns and Towne Inc 功能描述:Video/TV Circuit, Color Encoder Circuit, 68 Pin, Plastic, PLCC |
| BT867KPF | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Color Encoder Circuit |
| BT867KPJ | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Color Encoder Circuit |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。