- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄385474 > LM1270 (National Semiconductor Corporation) Hi-Brite 200 MHz I2C Compatible RGB Image Enhancer with Video Auto Sizing PDF資料下載
參數(shù)資料
| 型號： | LM1270 |
| 廠商： | National Semiconductor Corporation |
| 英文描述： | Hi-Brite 200 MHz I2C Compatible RGB Image Enhancer with Video Auto Sizing |
| 中文描述： | 高亮度場致200兆赫與I2C兼容的RGB視頻自動(dòng)上漿圖像增強(qiáng) |
| 文件頁數(shù)： | 13/27頁 |
| 文件大?。?/td> | 1302K |
| 代理商： | LM1270 |
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頁當(dāng)前第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
Emphasis
(Continued)
Bits 0 to 3 in register 0C control the center frequency. When
an “8” is programmed into the register the t
is
typically 80 ns.An “F” will give about 145 ns.A“0” will give no
emphasis in the Hi-Brite window.
ESD and Arc-Over Protection
The LM1270 incorporates full ESD protection with special
consideration given to maximizing arc-over robustness. The
monitor designer must still use good circuit design and PCB
layout techniques. The human body model ESD susceptibil-
ity of the LM1270 is 3.5 kV, however, many monitor manu-
facturers are now testing their monitors to level 4 of the IEC
801-2 specification which requires the monitor to survive an
8 kV discharge. External ESD protection is needed to sur-
vive this level of ESD. The LM1270 provides excellent pro-
tection against both ESD and arc-over, but this is not a
substitute for good PCB layout.
Figure 9
shows the recommended input protection for the
LM1270. This provides the best protection against ESD.
When this protection is combined with a good PCB layout
the LM1270 will easily survive the IEC 801-2 level 4 testing
(8 kV ESD). It is strongly recommended that the protection
diodes be added as shown in
Figure 9
. The 1N4148 diode
has a maximum capacitance of 4 pF which will have little
effect on the response of the video system due to the low
impedance of the input video.
The ESD cells of the LM1270 also provide good protection
against arc-over, however good PCB layout is necessary.
The LM1270 should not be exposed directly to the voltages
that may occur during arc-over. The main vulnerability of the
LM1270 to arc-over is through the ground traces on the
PCB. For proper protection all ground connections associ-
ated with the LM1270, including the grounds to the bypass
capacitors, must have short returns to the ground pins. A
significant ground plane should be used to connect all the
LM1270 grounds.
Figure 12
, which shows the demo board
layout, is an excellent example of an effective ground plane.
Figures 10, 11
are the schematic to the demo board. The list
below should be followed to ensure a PCB with good
grounding:
All grounds associated with the LM1270 should be con-
nected together through a large ground plane.
CRT driver ground is connected to the LM1270 and video
pre-amp ground area at one point.
CRT and arc protection grounds are connected directly to
the chassis or main ground. There is no arc-over current
flow from these grounds through the LM1270 grounds.
Input signal traces for SDA, SCL, H Flyback, and Sync
inputs should be kept away from the CRT driver and all
traces that could carry the arc current.
Output signal traces of the LM1270 should be kept away
from the traces that carry the output signals of the CRT
driver.
If any one of the above suggestions is not followed the
LM1270 may become more vulnerable to arc-over. Improper
grounding is by far the most common cause of a video
pre-amp failure during arc-over.
20063527
FIGURE 9. Recommended Video Input ESD Protection
L
www.national.com
13
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LM1270N | Hi-Brite 200 MHz I2C Compatible RGB Image Enhancer with Video Auto Sizing |
| LM1270NA | Hi-Brite 200 MHz I2C Compatible RGB Image Enhancer with Video Auto Sizing |
| LM1279 | 110 MHz RGB Video Amplifier System with OSD |
| LM1279N | 110 MHz RGB Video Amplifier System with OSD |
| LM1281 | 85 MHz RGB Video Amplifier System with On Screen Display (OSD) |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LM1270N | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Hi-Brite 200 MHz I2C Compatible RGB Image Enhancer with Video Auto Sizing |
| LM1270NA | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Hi-Brite 200 MHz I2C Compatible RGB Image Enhancer with Video Auto Sizing |
| LM1276 | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:150 MHz I2C Compatible RGB Preamplifier with Internal 512 Character OSD ROM, 512 Character RAM and 4 DACs |
| LM1276AAA | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:150 MHz I2C Compatible RGB Preamplifier with Internal 512 Character OSD ROM, 512 Character RAM and 4 DACs |
| LM1279 | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:110 MHz RGB Video Amplifier System with OSD |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。