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| EPM7512BQC208-5资料 | |
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EPM7512BQC208-5 PDF Download |
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File Size : 116 KB
Manufacturer:ALTERA Description:Normally the signal source for the LM1881 is assumed to be clean and relatively noise-free, but some sources may have excessive video peaking, causing high frequency video and chroma components to extend below the black level refer- ence. Some video discs keep the chroma burst pulse present throughout the vertical blanking period so that the burst actually appears on the sync tips for three line periods instead of at black level. A clean composite sync signal can be generated from these sources by filtering the input signal. When the source impedance is low, typically 75Ω, a 620Ω resistor in series with the source and a 510 pF capacitor to ground will form a low pass filter with a corner frequency of 500 kHz. This bandwidth is more than sufficient to pass the sync pulse portion of the waveform; however, any subcarrier content in the signal will be attenuated by almost 18 dB, effectively taking it below the comparator threshold. Filtering will also help if the source is contaminated with thermal noise. The output waveforms will become delayed from be- tween 40 ns to as much as 200 ns due to this filter. This much delay will not usually be significant but it does contrib- ute to the sync delay produced by any additional signal processing. Since the original video may also undergo pro- cessing, the need for time delay correction will depend on the total system, not just the sync stripper. |
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| 1PCS | 100PCS | 1K | 10K | ||
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型 号：EPM7512BQC208-5 厂 家：ALTERA 封 装：310 批 号：07+ 数 量：QFP208 说 明： |
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运 费： 所在地： 新旧程度： |
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| 联系人：关女士 |
| 电 话：86-75584720945 |
| 手 机： |
| QQ：371911117 |
| MSN：gjk8477@hotmail.com,jessica848377@yahoo.com.cn |
| 传 真：86-755 25621209 |
| EMail：kingrand_tek@163.com |
| 公司地址： Huaqiang Electronic World, Futian District, Shenzhen, China |
