SNJ54LS138J

The SNJ54LS138J from Motorola Semiconductor is a Schottky-clamped TTL MSI circuit designed for high-performance memory decoding or data-routing applications. It decodes one of eight lines based on three binary select inputs and three enable inputs. The device features three enable inputs, two active-low and one active-high, which simplify cascading and data reception, reducing the need for external gates or inverters. This makes it suitable for implementing larger decoders without additional components.

Designed for high-speed operation, the SNJ54LS138J is particularly useful in memory systems where minimizing decoding delay is critical. Its propagation delay is typically less than the access time of high-speed memories, ensuring negligible system delay. The part belongs to the LS technology family and operates across a wide temperature range of -55°C to 125°C, making it suitable for military applications.

Each input is fully buffered, presenting only one normalized load to the driving circuit. High-performance Schottky diodes are integrated to suppress line-ringing and simplify system design. The SNJ54LS138J is available in a CDIP (J) 16-pin package. An enable input can also serve as a data input for demultiplexing tasks.