We have been experimenting with the Touchstone semi TS1001 ultra-low power, low voltage op-amp demo board, and the results are in.
For our tests, the board inverting op-amp circuit was powered by a solar cell from a calculator with two 0.5v zener in series. The total supply was about 950mV, well below the operating range of most op-amps. It consumes 1.3 micro watts when the input is driven by an 1Khz 500mV square wave.
From our initial testing we found a usable bandwidth of about 1KHz, this op-amp appears best suited for low power sensors. Replicating a sine wave (blue signal) up to about 850hz is possible, any further and you end up with a more triangular wave as shown above (yellow signal).
Keep reading for more before and after signal comparisons.
This first capture shows that there is an input(yellow) offset of about +160mV.
This capture shows the rise time is about 460uS, the falling times are similar to the rising time.
Zooming in an 20uS delay can be seen above.
Replicating a sine wave up to about 850hz is possible(above) ,any further and you end up with a more triangular wave.(bottom)
Overall the TS1001 is suited for low speed sensor applications where the voltage being input is fairly stable and not expected to have a full-scale change in less than 500 micro seconds.