SG3544

The SG3544 was designed to provide all the operational features of the SG1543/ 2543/3543 devices but with the added advantage of uncommitted inputs to the voltage sensing comparators. This allows monitoring of voltage levels less than 2.5 volts by dividing down the internal reference supply.

In all other respects, the SG3544 series is identical to the SG1543 series. The SG3544 contain all the functions necessary to monitor and control the output of a sophisticated power supply system. Over-voltage sensing with provision to trigger an external SCR "crowbar" shutdown; an under-voltage circuit which can be used to monitor either the output or sample the input line voltage; and a third op amp/comparator usable for current sensing are all included in this IC, together with an independent, accurate reference generator.

The voltage-sensing input comparators of SG3544 are identical and can be used with threshold levels from zero volts to (V_IN - 3V). Each has approximately 25mv of hysteresis which is offset so the switching differential threshold is zero on the noninverting input for rising levels and zero on the inverting input for falling signals. All other operating characteristics of SG3544 are as described in the SG1543 data sheet and application note.