A/D转换器分辨率和精度 [英] A/D Converter resolution and accuracy

问题描述

如果将5Vref和3V DC输入施加到PIC16F877微控制器的A/D转换器或任何控制器，那么计数是多少?而且，如果我们将3V直流输入更改为任何其他电压值直到5V，那么将对分辨率和精度产生任何影响??

感谢您的提前答复...

If 5Vref and 3V DC input is applied to A/D converter of PIC16F877 microcontroller or any controller then what will be the count??? And if we change the 3V dc input to any other voltage value till 5V then there will be any affect on the resolution and accuracy???

thank for your answer in advance...

推荐答案

这将是多少?不明白这个问题...就分辨率而言，A/D的位数是有限的，比方说8位.因此，离散状态的数量为2 ^ 8(256个状态).通常，这些数字将基于中间的0(有符号)或0-256(无符号).在这么多状态下，您只需将参考电压除以该值即可，假设A/D的最大电压摆幅为5V，那么最佳分辨率为5/256 = 0.019V(由于状态是离散的，所以您总是有一定程度的量化噪声).如果降低参考值，它应该可以为您提供更好的分辨率，但是与此相关的还有其他问题.由于最大电压摆幅较小，因此您更容易受到噪声的影响(因此发明了消除噪声的差分传输标准).

What will be the count? Don''t understand that question... As far as resolution, well, the A/D has a finite number of bits, let''s say 8bits. So the number of discrete states is 2^8 (256 states). Typically these numbers will be based on either 0 in the middle (signed) or 0-256 (unsigned). With that many states, you just divide your reference by that, lets say the maximum voltage swing for the A/D is 5V, then the best resolution is 5/256=0.019Volts (since the states are discrete, you''ll always have some level of quantization noise). If you lower the reference, it should give you better resolution but there''s other problems associated with that. Since your maximum voltage swing is smaller, you''re more susceptible to noise (hence the invention of noise cancelling differential transmission standards).

这篇关于A/D转换器分辨率和精度的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！