3 VIN 1 P-Drive SGND 11 SenseSense+ 8 7 Adjustable Version VFB 9 14 N-Drive - 12 PGND V Sleep + + Q S - VTH2 VTH1 R 25-150 mV C S + - + - T ITH 6 13 k G + 4 CT + Off-Time Control VIN SenseVFB 5 pF VOS Shutdown 10 100 k 1.25 V Reference 5 INTVCC LTC1148-FD fig 4 The functional block diagram of Linear Technology's synchronous step-down switching regulator LTC1148. (Figure courtesy of Linear Technology.) September 2014 z IEEE PowEr ElEctronIcs MagazInE 13