open-bldc/open-bldc-hardware

Find a replacement opamp

esden opened this issue · 2 comments

The currently used Opamp is the OPA335 from texas instruments.

Hopefully we can find something less expensive.

The requirements for the opamp are probably:

  • Low offset voltage
  • Speed faster then the targeted maximum PWM frequency to be able to sample the current on the phases (>30khz)
  • Rail to rail

Anything else?

Can anyone help with this search?

I haven't studied the design extensively to see if this would be a good fit, but based solely on the specs and cost, maybe the Analog Devices AD8538 would be a good fit?

Maybe a Intersil ISL28130? It a gain product of 400kHz enough?