On Mon, 15 Mar 2010 09:53:51 +0800, "Xiaofan Chen" said:

> One potential issue with the circuit is at low output current value,
> then the common-mode voltage seen by the op amp is near
> ground potential, a Rail-to-Rail type is required in this
> application if no negative power supply is used and the requirement
> of accuracy is higher. In this case, it may not matter as the
> accuracy requirement is not that high.

The LM358 has a PNP input stage and is fully valid to the negative rail.
Input voltage is only limited near the positive rail for this opamp.

Cheers,

Bob

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