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VCT3801A 参数 Datasheet PDF下载

VCT3801A图片预览
型号: VCT3801A
PDF下载: 下载PDF文件 查看货源
内容描述: 视频/控制/图文电视IC系列 [Video/Controller/Teletext IC Family]
分类和应用: 电视
文件页数/大小: 172 页 / 2219 K
品牌: MICRONAS [ MICRONAS ]
 浏览型号VCT3801A的Datasheet PDF文件第26页浏览型号VCT3801A的Datasheet PDF文件第27页浏览型号VCT3801A的Datasheet PDF文件第28页浏览型号VCT3801A的Datasheet PDF文件第29页浏览型号VCT3801A的Datasheet PDF文件第31页浏览型号VCT3801A的Datasheet PDF文件第32页浏览型号VCT3801A的Datasheet PDF文件第33页浏览型号VCT3801A的Datasheet PDF文件第34页  
VCT 38xxA  
ADVANCE INFORMATION  
HFLB  
PLL3  
1:64  
&
Skew  
Phase  
DAC  
&
LPF  
Sinewave  
Generator  
Measure-  
Comparator DCO  
HOUT  
Output  
ment  
&
Stage  
Low-pass  
Angle &  
+
Bow  
blanking, clamping, etc.  
Main  
Display  
Timing  
PLL2  
MSY  
FSY  
Sync  
Generator  
Sync  
Generation  
INTLC  
Phase  
Front  
Sync  
Interface  
Line  
Counter  
Comparator  
DCO  
&
Low-pass  
vertical reset  
Clock & Control  
VPROT  
EW  
PWM  
E/W  
15-bit  
correction  
Vertical  
Data  
VDATA  
VERT  
PWM  
15-bit  
Sawtooth  
VERTQ  
Fig. 2–24: Deflection processing block diagram  
2.12.4.Vertical and East/West Deflection  
In order to get a faster vertical retrace timing, the out-  
put impedance of the vertical D/A-converter can be  
reduced by 50 % during the retrace.  
The calculations of the vertical and East/West deflec-  
tion waveforms is done by the internal Fast Processor  
(FP). The algorithm uses a chain of accumulators to  
generate the required polynomial waveforms. To pro-  
duce the deflection waveforms, the accumulators are  
initialized at the beginning of each field. The initializa-  
tion values must be computed by the TV control pro-  
cessor and are written to the front-end once. The  
waveforms are described as polynomials in x, where x  
varies from 0 to 1 for one field.  
2.12.5.EHT Compensation  
The vertical waveform can be scaled according to the  
average beam current. This is used to compensate the  
effects of electric high-tension changes due to beam  
current variations. EHT compensation for East/West  
deflection is done with an offset corresponding to the  
average beam current.  
P: a + b(x-0.5) + c(x-0.5)2 + d(x-0.5)3 + e(x-0.5)4  
The initialization values for the accumulators a0..a3 for  
vertical deflection and a0..a4 for East/West deflection  
are 12-bit values.  
Fig. 2–25 shows several vertical and East/West deflec-  
tion waveforms. The polynomial coefficients are also  
stated.  
30  
Micronas  
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