The ALS139 are dual 2-line to 4-line decoders/demultiplexers designed for use in high-performance memory-decoding or datarouting applications requiring very short propagation delay times. In high-performance memory systems, these devices can minimize the effects of system decoding. When employed with high-speed memories utilizing a fast-enable circuit, the delay times of these decoders and the enable time of the memory are usually less than the typical access time of the memory. Therefore, the effective system delay introduced by the Schottky-clamped system decoder is negligible.