3-to-8 decoder/demultiplexer for automotive and industrial buses
The Texas Instruments SN74HCS138DYYR is a single 3-to-8 line decoder/demultiplexer from the 74HCS family, qualified to AEC-Q100 for automotive applications. It accepts three binary address inputs and drives one of eight active-low outputs low, with a single active-low enable and two active-high enables for cascading. The part operates across a 2V to 6V supply range, covering 3.3V and 5V logic rails without translation, and is rated for -40°C to 125°C ambient — suited for under-hood ECUs, industrial motor drives, and outdoor telecom line cards where temperature cycling is a given.
SOT-23-16 Thin — board-area fit
Housed in a 16-pin thin SOT-23 variant (SOT-23-16 Thin), this decoder fits dense layouts on automotive ECU inner layers. Surface-mount only; no through-hole option exists.
Output drive and enable logic
Each output sources or sinks 7.8 mA — enough to drive CMOS logic inputs or a low-current indicator LED directly. The three enable inputs (one active-low, two active-high) let you daisy-chain multiple devices without external gating for address expansion beyond 8 lines.
Lifecycle and sourcing posture
Listed as Active and current-production. No direct factory second-source is listed.