This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

OPA4350: Selection of OpAmps in Reference Design TIDA-01606

Part Number: OPA4350
Other Parts Discussed in Thread: TIDA-01606, , OPA4340

Dear TI,

I'm working on a project similar to TIDA-01606: 10-kW Three-level, Three-Phase Grid tie Inverter Reference Design for Solar String Inverters.

As I am not so familar with OpAmps and there are so many of them available, I wonder why exactly you chose the OPA4340 (current) and OPA4350 (voltage).

Could I relpace the OPA-devices for example with the TLV27x? Or would this lead to any performance degradation, because it has lower bandwidh and more noise leaving anything else unchanged?

Is the TLV27x also suitable to drive the ADC on the 28377D or a similar C2000 device.

I hope you can help me.

MK

  • In case of current sensing, the OPA4340 is used over the OPA4350 in the voltage-sensing path due to the former's lower bandwidth. The lower bandwidth helps to reduce accidental amplification of switching noise that might be picked up by long traces in the PCB.
    In addition to 10x higher input voltage offset (+/-5mV vs +/-0.5mV), 35nV/rt-Hz broadband noise of TLV27x is much higher than OPA4350 (5nV/rt-Hz) or OPA4340 (25nV/rt-Hz) thus you may expect degradation of performance but only you may decide whether this is acceptable.