MC54/74HC138A is the upgraded version of MC54/74HC138, which supports LSTTL output. This chip can decode three-bit address into eight outputs, and supports three selection functions: decoding, cascading and selection.
The MC54/74HC138A is a 1‑of‑8 decoder/demultiplexer that converts a three‑bit address into one of eight active‑low outputs. It features three chip‑select inputs (two active‑low, one active‑high) and is pin‑compatible with the LS138, allowing easy replacement in existing designs.
The device operates from 2.0 V to 6.0 V, can drive up to 10 LSTTL loads, and includes protection against static discharge. It is offered in ceramic, plastic, SOIC, and TSSOP packages, each with specified power dissipation and temperature limits.
| Output Drive Capability | 10 LSTTL Loads |
|---|---|
| Operating Voltage Range | 2.0 V to 6.0 V |
| Maximum Supply Voltage (Voc) | -0.5 V to +7.0 V |
| Input Current per Pin | +20 mA |
| Output Current per Pin | +25 mA |
| Power Dissipation (Plastic DIP) | 750 mW |
| Storage Temperature Range | -65 °C to +150 °C |
It can drive up to 10 LSTTL loads.
The recommended operating voltage is from 2.0 V to 6.0 V.
It provides eight active‑low outputs (Y0‑Y7).
The device can tolerate a supply voltage from –0.5 V to +7.0 V.