The actual switching frequency will be high - perhaps 1.5MHz. It would be good if you can see what the frequency actually is. I don't think anyone has actually measured it yet. It is almost certainly between 1MHz and 2MHz and it will probably be most noticeable at a high load.
It is. I attached pictures of the actual switching.
One of the other things I am interested to see is how quickly the converter wakes. If you switch a high load on suddenly, how low does the voltage drop?
I don't even have a clue how much current the Batteriser can output yet so I don't know if a high current is 100mA or 1A. Due to the very low quiescent current, the wake up circuitry may be very slow, and if the voltage can drop to zero when the load is switched on, that would be a pretty big disaster.
I attached pictures with around 100mA, 500mA and 1A load.
This last waveform shows how the batteriser switches, which is 7 times in this instance during the rising edge. After that de DC-DC converter goes to sleep, because the output voltage got to high.
During the rising edge, between the spikes you see little dents. That is clearly the point where the inductor is charged. The dents are slightly less then 1 us apart, which gives a switching frequency of 1.2Mhz or so.
Try zooming in further on the rising edge, and is should become clearer.
Thanks for clearing that up, my knowledge of switching converters seems to be capable of improvement.
Here I zoomed into the actual switching, which happenes indeed with around 1.2MHz with no load.
another picture, just a bit more zoomed in.
Under load (500mA)
Wake up time with 100mA load ~40µs
500mA, also around 40µs
fully recovered after around 100µs
1A load, 33µs wake up time, dropping down to 750mV
fully recovered after around 60µs but it is struggling to keep up the voltage, idling at around 1.2V (sorry, forgot to move the horizontal cursor..)
judging from those curves, can we assume that 1A load is to much and even 500mA is near the border of "to much"?