A series of decoders, multiplexers, and demultiplexers of 74LS series low-power Schottky logic ICs. The 74LS series uses bipolar junction technology, coupled with Schottky diode clips to achieve the same operating speed as the original 74TTL series, but with much lower power consumption.These devices contain three independent 3-input and gates. The SN74LS138N is characterized for operation from 0°C to 70°C.
The Schottky-clamped TTL MSI circuits are designed to be used in high-performance memory decoding or data-routing applications requiring very short propagation delay times,these decoders can be used to 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.This means that the effective system delay introduced by the Schottky-clamped system decoder is negligible.The LS138N decode one of eight lines dependent on the conditions at the three binary select inputs and the three enable inputs .Two active-low and one active-high enable inputs reduce the need for external gates or inverts when expanding.A 24-line decoder can be implemented without external inverters and a 32-line decoder requires only one inverter .An enable input can be used as a data input for demultiplexing applications. All of these decoder/demultiplexers feature fully buffered inputs ,each of which represents only one normalized load to its driving circuit.All inputs are clamped with high-performance Schottky diodes to suppress line-ringing and to simplify system design.

?Demultiplexing Capability
?Multiple Input Enable for Easy Expansion
?Typical Power Dissipation of 32 mW
?Active Low Mutually Exclusive Outputs
?Input Clamp Diodes Limit High Speed Termination Effects