SN54AHC138 and SN74AHC138 are 3-line to 8-line decoders/demultiplexers designed specifically for high-speed memory decoders and data-transmission systems. They incorporate three enable inputs to simplify cascading and/or data reception. They have latch-up performance exceeding 250 mA, and ESD protection exceeding 2000 V human-body model, 200 V machine model, and 1000 V charged-device model.
The SN54AHC138 and SN74AHC138 are 3‑line to 8‑line decoder/demultiplexer devices designed for high‑performance memory‑decoding and data‑routing applications. They feature three enable inputs that simplify external logic and can be used as data inputs for demultiplexing. The devices operate over a supply voltage range of 2 V to 5.5 V and provide low propagation delay for fast memory systems.
The datasheet includes ordering information for multiple package types (PDIP, SOIC, TSSOP, etc.), electrical characteristics such as input‑high voltage (VIH) 2 V to 5.5 V, output‑low current up to –8 mA, and thermal data for each package. Mechanical drawings and pin‑out diagrams are provided, along with an important notice about product warranties and usage conditions.
| Input voltage range (VI) | 0 V to 5.5 V |
|---|---|
| Operating temperature range | -55 °C to 125 °C (PDIP) / -40 °C to 85 °C (SOIC) |
It has three enable inputs that can be used to simplify external logic or as data inputs for demultiplexing.