Other Parts Discussed in Thread: OPA333
Tool/software:
From the detailed ref design, we can see how to implement V, I measurements. From the schematic block diagram (Figure 1) we see V mode and I mode sensor data is fed to a programmable gain amplifier / ADC chain in the MCU . From the MCU datasheet, it is seen that V+/V- outputs from an OPA333 op-amp is fed to MCU pins SD0P0/SD0N0 and I+/I- outputs from a similar op-amp is fed to pins SD1P0/SD2P0. It is noted that that SD24_B is a multiple-input multiple-converter sigma-delta analog-to-digital conversion module. There are possibly 0-7 (eight) such modules, in the TIDA ref design, SD2P0/SD2N0 are shown tied to ground and the rest of the input pairs not shown.
- I would like to implement a resistance measuring function. Is there an application note relevant to this design for this function? A DMM is kind of useful when it can measure V, I, R on the bench.
- Is it recommended to implement a separate R measurement front end and feed it into the SD24_B ?
- Is it possible to use existing V, I sensor telemetry to calculate R at all in this ref design without additional elements?
- If a seperate R measurement front end has to be designed, are there any COTS semiconductor elements available from TI ?
- Given existing ref design, if simultaneous V, I measurements are possible (are they?) is there a suggested design methodology to design a four-wire Kelvin Method resistance measurement feature?
- Can we get an evaluation MCU to program with source code of firmware with rights to add the new feature to it? What are the restrictions/licensing fees on using TI developed firmware?
