A buck converter circuit provides the output voltage responsive to the boosted input voltage from the capacitor pump circuit in the first mode of operation and provides the output voltage responsive to the input voltage in a second mode of operation when {HEAD ~ the input voltage} is above {TAIL ~ the desired voltage level} 
is above
A buck converter circuit provides the output voltage responsive to the boosted input voltage from the capacitor pump circuit in the first mode of operation and provides the output voltage responsive to the input voltage in a second mode of operation when { HEAD ~ the input voltage } is above { TAIL ~ the desired voltage level }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL