We started doing the first tests with AFE3 for the MIO168 module. Unlike AFE1 where all four analog inputs share the same GND, here we have two fully isolated channels for which TI isolators with DC/DC converters were used.
The first input (AIN1) is voltage only, the
AMC3330 is used and has two ranges: ±50 V and ±450 V so it will allow measurement of AC mains up to 320 Vrms. The second input (AIN2) is current only,
AMC3301 is used and also has two ranges: ±1 A and ±10 A. This in combination with the remaining two inputs which are combined voltage/current as in the case of AFE1, and with simultaneous A/D conversion I expect that there could be a usable solution for measuring input power, output power and the efficiency of AC/DC and DC/DC converters, battery chargers, etc.

I have to say that the mentioned isolators look very promising. Here we come to one interesting detail: the problem of measuring large currents (e.g. over 4 A) where the TCR of the current shunt is very pronounced. I have already discussed this with @Kleinstein and complained that the ROHM of 0R010 (GMR100HTBFA10L0) used with a TCR of only ±20 ppm/K does not seem to be good enough. After all it’s just an SMT component in the 2512 packaging so that shouldn’t come as a surprise. I tested it on AFE1 where I have it on AIN3 and AIN4 inputs. I use the same with AFE3 on the AIN2 and AIN4 inputs with the difference that behind the one on AIN2 is the already mentioned AMC3301.
A thing that is interesting and I don't know how to interpret at the moment: when measuring a current of 5 A at the AIN4 input in a period of 15 minutes, I have a drift of +6 mA. However when measuring the same current on AIN2 (with AMC3301) in the same period and using the same current shunt I have a 0 mA drift!
The first thing that comes to my mind is that the current shunt (R11) on AIN2 is better cooled because there is more copper on the PCB. However, this is not true. The traces to the shunt (R32) on the AIN4 are longer, so there is more copper to keep it cooler. Perhaps this drift should not be attributed to the current shunt at all but to some other component. The schematics (which does not include the latest changes but is relevant to the prototype I am testing is attached).