44 ics 1-1-3 dc/dc converter ics electrical characteristics unit v mv/ ? % khz mv mv a ma a a v a v % nsec ? ? 1 b s b n f u f s reference voltage temperature coefficient of reference voltage efficiency oscillation frequency line regulation load regulation overcurrent protection starting current quiescent circuit current 1 quiescent circuit current 2 ss pin outflow current at low voltage open voltage en pin inflow current on threshold voltage maximum on duty minimum on time thermal protection start temperature thermal protection return hysteresis (ta=25 c, v in =12v, v o =3.3v, and io=1.0a, unless otherwise specified) ratings min. typ. max. 0.784 0.800 0.816 ?.05 90 400 500 600 50 50 3.1 6.0 6 10 61014 3.0 50 100 0.7 1.4 2.1 90 150 151 165 20 *: pin 8 is the ss pin. soft start at power on can be performed with a capacitor connected to this pin. the ss pin is pulled up to the power supply in the ic, so applying the external voltage is prohibited. $ p o e j u j p o t 5 b ? u p ? 7 * / 7 u p 7 * p u p " 7 & |