參數(shù)資料
型號(hào)： TDA8854H
廠商： NXP Semiconductors N.V.
英文描述： I2C-bus controlled PAL/NTSC/SECAM TV processors
中文描述： I2C總線控制的PAL / NTSC制式/ SECAM電視處理器
文件頁(yè)數(shù)： 16/68頁(yè)
文件大小： 316K
代理商： TDA8854H
December 16, 1997
16
Philips Semiconductors
Tentative Device Specification
I
2
C-bus controlled PAL/NTSC/SECAM TV
processors
TDA884X/5X-N2 series
An important property of the 2-point stabilisation is that the
off-set as well as the gain of the RGB path is adjusted by
the feedback loop. Hence the maximum drive voltage for
the cathode is fixed by the relation between the test
pulses, the reference current and the relative gain setting
of the 3 channels. This has the consequence that the drive
level of the CRT cannot be adjusted by adapting the gain
of the RGB output stage. Because different picture tubes
may require different drive levels the typical “cathode drive
level” amplitude can be adjusted by means of an I
2
C-bus
setting. Dependent on the chosen cathode drive level the
typical gain of the RGB output stages can be fixed taking
into account the drive capability of the RGB outputs (pins
19 to 21). More details about the design will be given in the
application report.
The measurement of the “high” and the “l(fā)ow” current of the
2- point stabilisation circuit is carried out in 2 consecutive
fields. The leakage current is measured in each field. The
maximum allowable leakage current is 100
μ
A
When the TV receiver is switched-on the RGB output
signals are blanked and the black current loop will try to set
the right picture tube bias levels. Via the AST bit a choice
can be made between automatic start-up or a start-up via
the
μ
-processor. In the automatic mode the RGB drive
signals are switched-on as soon as the black current loop
has been stabilised. In the other mode the BCF bit is set to
0 when the loop is stabilised. The RGB drive can than be
switched-on by setting the AST bit to 0. In the latter mode
some delay can be introduced between the setting of the
BCF bit and the switching of the AST bit so that switch-on
effects can be suppressed.
It is also possible to start-up the devices with a fixed
internal delay (as with the TDA 837X and the TDA884X/5X
N1). This mode is activated with the BCO bit.
The vertical blanking is adapted to the incoming CVBS
signal (50 Hz or 60 Hz). When the flyback time of the
vertical output stage is longer than the 60 Hz blanking time
the blanking can be increased to the same value as that of
the 50 Hz blanking. This can be set by means of the LBM
bit.
For an easy (manual) adjustment of the V
g2
control voltage
the VSD bit is available. When this bit is activated the black
current loop is switched-off, a fixed black level is inserted
at the RGB outputs and the vertical scan is switched-off so
that a horizontal line is displayed on the screen. This line
can be used as indicator for the V
g2
adjustment. Because
of the different requirements for the optimum cut-off
voltage of the picture tube the RGB output level is
adjustable when the VSD bit is activated. The control
range is 2.5
±
0.7 V and can be controlled via the
brightness control DAC.
It is possible to insert a so called “blue back” back-ground
level when no video is available. This feature can be
activated via the BB bit in the control2 subaddress.
I
2
C-BUS SPECIFICATION
The slave address of the IC’s is given in Fig.7. The circuit
operates up to clock frequencies of 400 kHz.
Start-up procedure
Read the status bytes until POR = 0 and send all
subaddress bytes. The horizontal output signal is
switched-on when the oscillator is calibrated.
Each time before the data in the IC is refreshed, the status
bytes must be read. If POR = 1, the procedure mentioned
above must be carried out to restart the IC.
When this procedure is not followed the horizontal
frequency may be incorrect after power-up or after a
power dip.
handbook, halfpage
MLA743
A5
A4
A3
A2
A1
A0
1
0
0
0
1
0
1
1/0
R/W
Fig.7 Slave address (8A).
相關(guān)PDF資料
PDF描述
TDA8857H I2C-bus controlled PAL/NTSC/SECAM TV processors
TDA8924 2 x 120 W class-D power amplifier
TDA8924TH 2 x 120 W class-D power amplifier
TDA8925 Power stage 2 x 15 to 25Wclass-D audio amplifier
TDA8925J Power stage 2 x 15 to 25Wclass-D audio amplifier
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TDA8857H 制造商:PHILIPS 制造商全稱(chēng):NXP Semiconductors 功能描述:I2C-bus controlled PAL/NTSC/SECAM TV processors
TDA8920 制造商:PHILIPS 制造商全稱(chēng):NXP Semiconductors 功能描述:2 x 50 W class-D power amplifier
TDA8920B 制造商:PHILIPS 制造商全稱(chēng):NXP Semiconductors 功能描述:2 X 100 W class-D power amplifier
TDA8920BJ 制造商:PHILIPS 制造商全稱(chēng):NXP Semiconductors 功能描述:2 X 100 W class-D power amplifier
TDA8920BJ/N2 制造商:JVC Worldwide 功能描述:POWER I.C.
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(xiě)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

*
*
*