The LTC1998 is a micropower comparator and a precision adjustable reference in a 6-pin SOT-23 package that is optimized for lithium-ion low battery detection circuits. The LTC1998 features a voltage detection circuit with an adjustable threshold voltage and hysteresis. The threshold voltage can be programmed from 2.5V to 3.25V with two external resistors. A 10mV to 750mV hysteresis can be added with a third external resistor. A proprietary internal architecture maintains 1% threshold voltage accuracy over temperature with low cost 1% external resistors.