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