When the input voltage VIN 602 is much lower than the output voltage VOUT 604, {HEAD ~ the buck boost converter} is running in {TAIL ~ a pure boost mode} of operation 
is running in
When the input voltage VIN 602 is much lower than the output voltage VOUT 604 , { HEAD ~ the buck boost converter } is running in { TAIL ~ a pure boost mode } of operation
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH