These devices are fully specified for partial-power-down applications using I_off. The I_off circuitry disables the outputs, preventing damaging current backflow through the devices when they are powered down. The SN74LV21A devices perform the Boolean function Y = A • B • C • D in positive logic. These dual 4-input positive-AND gates are designed for 2-V to 5.5-V V_CC operation.