1
\$\begingroup\$

I am using a Raspberry Pi and a Adafruit MCP4725 to control a mass flow controller, as well as powering the DAC, and I am meeting the bare minimum of current to control it with the Adafruit MCP4725. The voltage range is fine. Is there a way to up the current available, even just a little?

\$\endgroup\$
  • 2
    \$\begingroup\$ Welcome to EE.SE, Michael. It's a good idea to link to the datasheet rather than the ad page for the device. It's three links away otherwise. It would also be a good idea to explain in the question what the output specifications of the MCP4725 chip are and what the mass flow controller requires. Otherwise you're asking rather a lot of your readers to follow all the links, read the datasheets and try to figure out what your requirements are. \$\endgroup\$ – Transistor Aug 19 at 20:28
  • \$\begingroup\$ Without knowing the exact details of your problem, I suggest you google "unity gain buffer" or "unity gain amplifier" and take it from there. \$\endgroup\$ – Peter Jennings Aug 19 at 20:56
3
\$\begingroup\$

A good way is the voltage follower circuit. Select an opamp with a low voltage offset, and rail to rail. Make sure the current of the opamp is higher than what the mass flow controller input needs. Vcc is set to near the DAC output (you could go higher if the mass flow controller output will allow.

Make sure bypass capacitors are used on the Vcc terminals.

enter image description here

\$\endgroup\$
  • \$\begingroup\$ This is what I thought I was going to have to do, was wanting to know if there was a different or better option out there. \$\endgroup\$ – Michael H. Aug 19 at 22:47
  • \$\begingroup\$ There isn't, you can get a breakout board or I think spark fun or adafruit have some opamps on a board \$\endgroup\$ – Voltage Spike Aug 19 at 23:24

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.