Winsu
Full Member level 3
Hi All,
I trying to do Howland current pump circuit, to get an output current depending o the input voltage to the non-inverting op amp input. The Howland current pump circuit hasn't been an issue. The problem is that I was planning to feed the Howland circuit with an op amp follower circuit to isolate the input of the Howland circuit. It didn't work quite well first try as the voltage at the output of the follower circuit was dropping unexpectedly. The reason is that the op amp chosen can't not draw enough current , so the voltage drops. The simulation is working now fine with a universal op amp from LT spice which doesn't have physical limitations.
I'm finding difficult to find an op amp that can draw enough out put current for my application. I would need something that can draw at least 25mA, when the op amp is connected from 0V to 15V.My real problem I that I don't know what parameters to look at to choose an op amp suitable for what I need. Anyone can advice please?
Below is the LTspice simulation:
I trying to do Howland current pump circuit, to get an output current depending o the input voltage to the non-inverting op amp input. The Howland current pump circuit hasn't been an issue. The problem is that I was planning to feed the Howland circuit with an op amp follower circuit to isolate the input of the Howland circuit. It didn't work quite well first try as the voltage at the output of the follower circuit was dropping unexpectedly. The reason is that the op amp chosen can't not draw enough current , so the voltage drops. The simulation is working now fine with a universal op amp from LT spice which doesn't have physical limitations.
I'm finding difficult to find an op amp that can draw enough out put current for my application. I would need something that can draw at least 25mA, when the op amp is connected from 0V to 15V.My real problem I that I don't know what parameters to look at to choose an op amp suitable for what I need. Anyone can advice please?
Below is the LTspice simulation: