參數(shù)資料
型號(hào)： LM1270N
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(chǎng)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(yè)數(shù)： 12/27頁(yè)
文件大?。?/td> 1302K
代理商： LM1270N
Video Detection
(Continued)
registers have been enabled either by previously reading the
D_CNTLS register, or by writing a zero to the STAT bit of the
D_CNTL register.
Only one line of data is allowed per field. After the clock
stream of 72 pulses has been detected and accepted and
the data stored in registers 2E-36, no more data will be
accepted until after the registers have been reset. This is to
allow time for the microcontroller to access the data on the
I
2
C bus. If the LIMIT bit in the TEST1 register is set to a “1”
(default value), then the data must arrive during the pro-
grammed vertical blanking period. Any data arriving outside
of this will be ignored. If the bit is set to a “0”, then the data
may arrive anytime, even within the active video area.
The maximum data rate is half of the clock rate. The data is
clocked by the trailing edge of the clock. The clock rate
should be chosen to allow all 72 pixels to occur within the
normal horizontal active video timing.
INTERRUPT SIGNAL
Pin 15, the Blanking/Interrupt pin, can be set to output an
interrupt signal by bit 2 of register 39. The default value for
this bit is “0”, setting pin 15 for a blanking output signal.
However, if bit 2 is set to a “1” then pin 15 outputs an
interrupt signal. When the LM1270 is instructed to read the
information sent by video, then this signal goes low. Once
the clock stream of 72 pulses has occurred, then the inter-
rupt signal goes high again at the leading edge of H Sync.
The interrupt signal remains high until another request to
read the video information is received. Some microcontrol-
lers may require an interrupt signal. Setting pin 15 to output
an interrupt signal will provide the needed signal for these
systems. In this mode of operation the vertical blanking
signal will be unavailable; however, vertical blanking may still
be added to the video outputs. Note that bit 1 of register 1
does change the polarity of the interrupt signal.
Parameter
T
CLK
T
CLK-H
T
CLK-L
T
SETUP-H
T
SETUP-L
Timing
50 ns
25 ns
25 ns
13 ns
13 ns
Emphasis
MEASURING EMPHASIS
Two adjustments are available to optimize the emphasis in
the Hi-Brite window for the various timing modes and bright-
ness levels. One adjustment is the center frequency and the
other adjustment is the amount of overshoot. Referring to
Figure 7
the overshoot is the ratio of the overshoot voltage to
the video level after the emphasis has settle out of the output
signal. The typical output level is 900 mV and the typical
overshoot is about 20%. The peak measurement is taken
9 ns from the rising edge. This delay gives a more accurate
peak measurement by avoiding any ringing that may occur
at the rising edge. Overshoot is defined in percent as:
Bits 0 to 2 in register 0B control the emphasis. When a “4” is
programmed into these bits the overshoot is typically 11%. A
“0” will give no overshoot in the Hi-Brite window.
Shown below in
Figure 8
is how the center frequency is
measured. The center frequency is actually expressed as
the time it takes the overshoot to settle to within 5% of the
DC level of the pulse.
20063523
FIGURE 6. Timing Parameters
20063525
FIGURE 7. Overshoot Measurement
20063526
FIGURE 8. Center Frequency Measurement
L
www.national.com
12
相關(guān)PDF資料
PDF描述
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)
LM1281N 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
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
LM12791DL WAF 制造商:Texas Instruments 功能描述:
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*