Electronics > Beginners
Is OPA277 a good op amp for an electronic DC Load?
Prithul0218:
I am going to make a simple electronic DC load. It will be digital. I am probably going to use MCP4725 as the DAC and ADS1115 as the ADC. (cause these are available as module cheaply from China).
I will be using OPA277 to make a simple voltage sense circuit. I have a few of these OPA277s, so I was thinking if I could use it as the main MOSFET driver op amp as well. If not, suggest me decent through hole and fairly cheap op amp that will do a good job.
Feel free to suggest me anything else for the project.
Thanks.
Zero999:
It seems reasonable. The only issue might be its inputs need to be 2V away from either supply rail, for it to work properly. Refer to page 8 of the datasheet: Common-Mode Voltage Range.
http://www.ti.com/lit/ds/symlink/opa277.pdf
You've not posted a schematic, so there's no way of telling whether this is a problem or not.
Care needs to be taken with frequency compensation, to avoid oscillation, but this is true, irrespective of the choice of op-amp.
Kleinstein:
The strength of the OPA277 is more with a relatively low input bias and low offset. If there is a low offset, one might be better off with a lower noise, that has more of a bias, like OP27 or similar. If cheap is priority OP07 could be a good choice.
Prithul0218:
--- Quote from: Zero999 on January 17, 2019, 12:41:34 pm ---It seems reasonable. The only issue might be its inputs need to be 2V away from either supply rail, for it to work properly. Refer to page 8 of the datasheet: Common-Mode Voltage Range.
http://www.ti.com/lit/ds/symlink/opa277.pdf
You've not posted a schematic, so there's no way of telling whether this is a problem or not.
Care needs to be taken with frequency compensation, to avoid oscillation, but this is true, irrespective of the choice of op-amp.
--- End quote ---
Thanks. I have not designed the schematic yet. I have just made a simple LCD UI code and tested it. I will eventually select all the parts and start making the schematic. But here's a schematic that Scullcom Hobby Electronics made. I will use it as reference as I am just a hobbyist.
I don't have an oscilloscope and can not afford one right now. So, I can't really do much about the noise. I'll ignore it for now I guess. So other than that, OPA277 seems like a good candidate?
Prithul0218:
--- Quote from: Kleinstein on January 17, 2019, 12:57:31 pm ---The strength of the OPA277 is more with a relatively low input bias and low offset. If there is a low offset, one might be better off with a lower noise, that has more of a bias, like OP27 or similar. If cheap is priority OP07 could be a good choice.
--- End quote ---
Now I am getting a little bit confused. I already have OPA277 for the sense circuit that I'm going to copy from the schematic I attached in my reply above. I can afford OP27/OP07.
I do care about precision/accuracy. I will use one op amp as voltage follower for the current sense ADC input. Like U7D in the schematic above.
So, which one should I go for? OPA277(already have at home)/OP27/OP07?
Navigation
[0] Message Index
[#] Next page
Go to full version