類比數位轉換器的基本原理（臺灣）National Semiconductor

简介：這次線上座談會,美國國家半導體的專家將介紹DAC和ADC的基本原理和工作原理如傳輸函數，量化，DAC和ADC的結構，工作方式，性能特點以及應用範圍.一些在應用系統中使用ADC和DAC的技巧和方法也將會所介紹。

问：how to measue the DNL,INL of the adc?
答： You need to use an accurate signal generator and exact power input to check with sine wave and triangle wave. So, we can find the DNL & INL.

问：ADC and DAC used in oscillograph,speed is the important issue,which models are for oscillograph?
答： National has the best solution for this application, and I recommend to use ADC08D1000 or ADC08D500, which are 8 bits and 1000MHz/500MHz sample rate ADC.

问：How do you define the SNR and Input Dynamic Range in ADC Spec. Is there any relationship between them?
答： To prevent to select an over-spec ADC, I"ll suggest to calculate the smallest signal and biggest signal in your system so that we can count the Dynamic Range. From the dynamica range you get, you can select an ADC which can meet your requirement. Ther

问：為了有系統的精進專業 不知貴單位可有機會 在台灣新竹地區開辦中短期專業理論實作的課程呢? 謝謝!
答： We can think about this suggestion, but for the schedule we need to discuss with our colleagues to give you answer. If possible, I recommend you can contact with our sales office for more information. Once we have courses, we can inform you by phone or by

问：在设计ADC时，系统级仿真主要仿真那些东西?它能解决什么问题？

答： For example,
DC performance:
INL,DNL
FS error
AC performance:
SNR, THD,SFDR

to evaluate ADC in your system requirment. thanks!

问：SAR ADC结构中的比较器采用静态比较器还是动态比较器？应该注意那些问题？

答： We usually use dynamic one to get faster speed. You don"t need to care about it because we had already integrated it into ADC. The only thing you need to pay attention is to provide clean power to ADC.

问：请谈一下，影响ADC频率进一步提高的主要障碍在什么地方？谢谢
答： Mainly at ADC"s architecture ,like Sigma-Delta ADC to SAR ADC (20MSPS), from flash to pipeline (200MSPS). If you want faster, you still need to check if your process can support it or not.

问：请谈一下噪声特性
答： here is some noise resource you can consider when you design:

Inadequate Supply Bypassing
Inadequate VA - VDR* Supply Decoupling
Noisy Components/Conditioning Circuitry
Quantization
Clock
Output to Input Coupling

问：對感測器的非線性如何進行補償和校正? 
答： You can do it in Analog Domain (before ADC) or in Digital Domain (after ADC). It"s easier to handle it at DSP or MCU side. Besides, you need to measure the real non-linarity of your sensor, so that you can handle it after ADC.

问：从市场应用来看流水线结构和西格码德尔他结构的AD哪个更有发展前景；而整个AD/DA领域的技术、市场、地位将来有多大和什么样的发展空间？对IC设计工程师而言，投身AD/DA领域的风险和前途如何？
答： These two architecture should be applied to different application, so it"s very hard to say which one is better than the other.