Currents from {TAIL ~ the sources} selected by the switches are combined, and the total current is mirrored to {HEAD ~ the charge pump} 
Currents from { TAIL ~ the sources } selected by the switches are combined , and the total current is mirrored to { HEAD ~ the charge pump }
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD