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发表于 2010-1-24 12:22:52
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13# pop_mos
看样子楼主很急切的要人来理睬一下咯,哈哈
SH其实有误差是无所谓啦,比如说你的
the sample hold settling error is about 1/A for flip around structure.
If opamp open loop gain is not large enough , then there are somes errors of S/H output compared with the input signal.
however, if you can make sure the low gain will not induce distortion(THD),
the S/H is also OK for application, which just attenuate the amplitude of signal instead of signal degeneration.
For the MDACs, the open loop gain should be high enough because the signal will be mutiplied by 2, quantilized and minus/plus the reference voltage. Every stage error will be accumulated. the equivalent input error should be no more than 1/2LSB. |
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