The MAX9691/MAX9692/MAX9693 are ultra-fast ECL comparators capable of very short propagation delays. Their design maintains the excellent DC matching characteristics normally found only in slower comparators. The MAX9691/MAX9692/MAX9693 have differential inputs and complementary outputs that are fully compatible with ECL-logic levels. Output current levels are capable of driving 50 terminated transmission lines. The ultra-fast operation makes signal processing possible at frequencies in excess of 600MHz. The MAX9692/MAX9693 feature a latch-enable (LE) function that allows the comparator to be used in a sample-hold mode. When LE is ECL high, the comparator functions normally. When LE is driven ECL low, the outputs are forced to an unambiguous ECL-logic state, dependent on the input conditions at the time of the latch input transition. If the latch-enable function is not used on either of the two comparators, the appropriate LE input must be connected to ground; the companion LE input must be connected to a high ECL logic level. These devices are available in SO, QSOP, and tiny MAX packages for added space savings.