antknee
New Member
I'm going to use an opamp, the LM675 fits the bill for my purpose and I've attached the datasheet. I've never made an opamp do anything useful as of yet so I'd like to ask some questions from the datasheet application hints. I will understand the concept if the notation is explained.
I will for simplicity just reproduce what the application hints say and then ask a question.
1) "The LM675 is designed to be stable at a closed loop gain of 10 or greater, as with any opamp the LM675 can be made to oscillate under certain situations"
I'd prefer the gain to be 5, do I have to use 10 for the circuit to be stable?
What is the difference between closed loop and open loop?
Oscillation is bad and to be avoided?
2) "When designing a pcb layout it is important to return the load ground, the output compensation ground and the low level grounds to the circuit board ground through separate paths"
I understand what this passage means, I just have no sense of how I should even begin to do this without fuss.
Thanks,
Antknee.
I will for simplicity just reproduce what the application hints say and then ask a question.
1) "The LM675 is designed to be stable at a closed loop gain of 10 or greater, as with any opamp the LM675 can be made to oscillate under certain situations"
I'd prefer the gain to be 5, do I have to use 10 for the circuit to be stable?
What is the difference between closed loop and open loop?
Oscillation is bad and to be avoided?
2) "When designing a pcb layout it is important to return the load ground, the output compensation ground and the low level grounds to the circuit board ground through separate paths"
I understand what this passage means, I just have no sense of how I should even begin to do this without fuss.
Thanks,
Antknee.