Is it better to run CC2650, CC2640, CC1350 or CC1310 SoCs from Texas Instruments keeping in mind ultra low power and utilizing energy harvesting at 1.8V (but consume larger current) or at higher voltages (like 3.3V ) but consume lesser current?
Well, it depends. The performance will be similar because the core runs at 1.6V !!. It is important to note that the power consumption will be same but you can definitely play around with voltages. However for small energy harvesting devices and space constrained applications it might be a constraint that you don’t get higher voltages like 3.3V. For example, a supercapacitor will discharge from lets say 5V to 1.8V. In that case you are effectively using the capacity from 5V to 3.3V only(C*(V2-V1)), however if you run at 1.8V then you will use its capacity from 5v to 1.8V(which is more than 5V to 3.3V). But you can say that in this case its current consumption is larger. True. But you need to understand and take into consideration the worst case scenarios and edge cases like when the node is sleeping. Then the current consumption is same so voltage will play an important factor and keep your node active(ON) for a larger time!!.
However if you think about it then it is unclear that, although the core is running at 1.6V then suppose at 3.3V if the TX current is 5.5mA then why should it consume more current at 1.8V. I believe that the core consumes effectively the same current, what is happening here is the load that is called the antenna. It needs to radiate a certain amount of energy so that the data actually reaches a receiver at a respectable distance. Hence more current consumption at lesser voltage? Is this theory correct? Please comment below.