请教sigma delta AD的参考电平电路怎么做
时间：10-02
整理：3721RD
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sdm的Fs=1M，OSR=1024，参考电平要怎么考虑啊?有没有什么好的资料可以参考，谢谢
Fs=1M，OSR=1024, 这么牛?
做什么用啊? OSR=1024 ?
sdm本身不是我做的，我就负责做两个参考电平
做什么用，这个不方便说啊
最简单的用电源电压，一切ok
This is a tricky question. If the SDM has a moderate dynamic range, the Vref can be generated on chip. Using a bandgap reference to drive a fully-differential amplifier will give Vhigh and Vlow, and therefore the Vref. The design of the fully-differential amplifier with minimum power requires a bit of knowledge. There is a document from Analog Device talking about this.
If your SDM has a very high SNDR, say >100dB, then Vref is good to be off-chip. Just my two cents.
小编找到正确答案了吗?我也正有这个问题要问呢。
小编找到正确答案了吗?我也正有这个问题要问呢。
不懂！
输入信号500Hz带宽
通常bandgap做出来的Vref低频噪声抑制比较好，应该不难做
BG + fully-differential OPA is ok.