According to the data sheet the LT1677 is a RRIO op amp whose output can get within a hundred mV of ground (or -Vs).Yes, though I don't know whether the LT1677 can get that close to ground.
A lot of people aren't aware of that, or overlook it. Syscompdesign.com has a writeup on curing circuit oscillation, and says this about emitter followers (emphasis mine):Emitter followers are a great way to make an oscillator though -- except in simulation.
I've been bitten by the emitter follower oscillation problem myself a few times when I wasn't paying attention...There are some situations that should be an immediate red flag to a circuit designer where oscillation is concerned.
– Emitter followers have a tendency to oscillate. This is counter-intuitive, because the voltage gain of an emitter follower is less than one. But the emitter follower *does* have power gain, and for certain phase conditions it will oscillate. The solution is a resistor in the base lead of the emitter follower: a few hundred ohms for a single emitter follower, about 5000 ohms for a darlington pair.
Not a problem. The actual input will be essentailly DC from a current shunt and will feed an ADC. Frequency response is not an issue.The disadvantage with the diode or the transistor at the output is that it prevents the op amp from pulling the load low, so the frequency response/slew-rate in the negative direction is limited by the load RC time-constant.
Then the diode or transistor should work, provided you don't need to go to the positive rail.Not a problem. The actual input will be essentailly DC from a current shunt and will feed an ADC. Frequency response is not an issue.
.. with a unipolar supply. They don't normally have that ability. With a bipolar supply, of course it is no problem. That is why I like splitting the unipolar supply in an asymmetric fashion.The offset. Of course.
But what I was alluding to, was the ability of a plain vanilla opamp to swing to zero volts.
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