Hello everyone,
My requirements are simple: 24V (single-ended) supply, 8 V/V gain. I'm not sure why this is being such a pain.
I need a 0-20V output. I have a DAC that provides 0-2.5V so I need a simple x8 gain stage to bring this to 0-20V. My supply is a fixed 24V. The attached schematic shows that I'm trying to use a simple non-inverting design. The op-amp is an L272A - this was chosen for its high supply voltage capabilities.
The circuit works great, and is linear from around 0.3 to 20V. But when I get down to around 0.3V or so, the output won't go to zero, it levels off at about 0.2V. The DAC output is correct, and linear all the way to zero.
Can someone help me understand why this is happening? I've done a lot of research and feel that it may have to do with Vos, the input offset voltage of the op amp. Is it my design or op-amp selection?
Thanks,
Jake
My requirements are simple: 24V (single-ended) supply, 8 V/V gain. I'm not sure why this is being such a pain.
I need a 0-20V output. I have a DAC that provides 0-2.5V so I need a simple x8 gain stage to bring this to 0-20V. My supply is a fixed 24V. The attached schematic shows that I'm trying to use a simple non-inverting design. The op-amp is an L272A - this was chosen for its high supply voltage capabilities.
The circuit works great, and is linear from around 0.3 to 20V. But when I get down to around 0.3V or so, the output won't go to zero, it levels off at about 0.2V. The DAC output is correct, and linear all the way to zero.
Can someone help me understand why this is happening? I've done a lot of research and feel that it may have to do with Vos, the input offset voltage of the op amp. Is it my design or op-amp selection?
Thanks,
Jake