- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄383014 > GS4981 (Electronic Theatre Controls, Inc.) Monolithic Video Sync Separators PDF資料下載
參數(shù)資料
| 型號： | GS4981 |
| 廠商： | Electronic Theatre Controls, Inc. |
| 英文描述： | Monolithic Video Sync Separators |
| 中文描述： | 單片視頻同步分離器 |
| 文件頁數(shù)： | 8/14頁 |
| 文件大?。?/td> | 279K |
| 代理商： | GS4981 |
8
520 - 23 - 03
ODD/EVEN FIELD OUTPUT (pin 7 GS1881, GS4881)
NTSC PAL and SECAM composite video standards are
interlaced video schemes and therefore have odd and even
fields. For odd fields the first broad vertical sync pulse is
coincident with the start of horizontal, while for even fields the
first broad vertical sync pulse starts in the middle of a horizontal
line. Therefore by comparing the vertical sync with an internally
generated horizontal sync the odd/even field information is
determined. This output is clocked out by the falling edge of
vertical sync. The odd/even output is low during even fields
and high during odd fields. This method of detecting odd and
even fields is very noise tolerant.
Noise during the pre-equalizing pulses does not affect the
output since the field decision is made at the beginning of the
vertical interval. This noise immunity is displayed in Figure 15
in which an extra pre-equalizing pulse has been added to the
video input with no negative effect on the odd/even field
information.
Video
Input
Odd/Even
Output
Even Odd
HORIZONTAL OUTPUT (pin 7 GS4981)
As mentioned above, the odd/even field output of the
GS1881 and GS4881 is generated by comparing vertical
sync with an internal horizontal sync signal. This horizontal
sync signal is a true horizontal signal (i.e. maintained during
the vertical interval) and is outputted on pin 7 for the
GS4981. A delay of 190 ns from the video input and a width
of 6.5
μ
s are typically characteristics for this signal.
The windowing circuit which generates horizontal provides
excellent impulse noise immunity as shown in Figure 16. This
output buffer is an open collector stage with an internal
10 k
pull up resistor.
Fig. 15 Odd/Even Output
Impulse
Noise
Impulse
Noise
Video
Input
Horizontal
Output
Fig. 16 Horizontal Output
相關PDF資料 |
PDF描述 |
|---|---|
| GS4981-CDA | Monolithic Video Sync Separators |
| GS4981-CKA | Monolithic Video Sync Separators |
| GS4981-CTA | Monolithic Video Sync Separators |
| GS4981-IDA | Monolithic Video Sync Separators |
| GS4981-IKA | Monolithic Video Sync Separators |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| GS4981-CDA | 制造商:Rochester Electronics LLC 功能描述: 制造商:Gennum Corporation 功能描述: |
| GS4981CKA | 制造商:Gennum Corporation 功能描述: |
| GS4981-CKA | 制造商:Rochester Electronics LLC 功能描述: 制造商:Gennum Corporation 功能描述: |
| GS4981-CKAE3 | 制造商:Gennum Corporation 功能描述:Video Sync Separator 8-Pin SOIC |
| GS4981CTA | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog IC |
發(fā)布緊急采購，3分鐘左右您將得到回復。