Diodes Incorporated 74HC138T16-13

Overview

74HC138T16-13 from Diodes Incorporated is a high-speed CMOS 3-to-8 line decoder/demultiplexer with active-low outputs, three binary address inputs (A0–A2), and three enable inputs (E1, E2 low-active; E3 high-active). It operates from 2.0V to 6.0V, sinks/sources 8 mA at 4.5V, and features Schmitt-trigger inputs for noise immunity. Used in memory chip select decoding and peripheral demultiplexing.

For engineers reviewing the 74HC138T16-13 datasheet, 74HC138T16-13 pinout, 74HC138T16-13 application, or 74HC138T16-13 equivalent, key selection criteria include enable logic configuration (E1/E2 low + E3 high), propagation delay (12–45 ns over voltage/temperature), output drive capability (±4 mA at 4.5V), and TSSOP-16 thermal performance.

Technical Context

The 74HC138T16-13 implements combinational logic decoding with strict enable hierarchy: all outputs go high unless E1 = L, E2 = L, and E3 = H. Its internal NAND-based architecture ensures deterministic one-hot active-low output selection per 3-bit address.

Input Schmitt triggers provide hysteresis (typ. 0.9 V at VCC = 4.5V), enabling robust operation with slow or noisy address/enable signals. Output stage uses standard CMOS push-pull drivers-no open-drain or level-shifting functionality.

Key Specifications

Pinout & Package

TSSOP-16 package: 4.9 mm × 6.4 mm body, 0.65 mm pitch, 1.08 mm max height, exposed pad not present, RoHS-compliant lead-free finish.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 3-to-8 decoder applications.

Compared with SN74HC138N and MC74HC138ADR2G, the 74HC138T16-13 offers superior noise immunity via Schmitt inputs and space-saving TSSOP-16 packaging-ideal for compact industrial controllers where trace length and EMI are concerns.

Availability

74HC138T16-13 is available at Aetrix Electronics and suitable for memory chip select decoding, peripheral demultiplexing, and industrial I/O expansion requiring stable component supply, consistent parametric performance, and long-term manufacturability.

Supply support for 74HC138T16-13 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability, energy-efficient components for industrial, computing, and consumer markets.

The 74HC138T16-13 belongs to Diodes' HC logic family-designed for low-power, noise-immune digital interfacing in space-constrained embedded systems operating across wide temperature and voltage ranges.

FAQ

What is the minimum supply voltage for guaranteed operation of the 74HC138T16-13?

The 74HC138T16-13 is fully specified down to 2.0 V, with guaranteed VIH ≥1.5 V and VOL ≤0.1 V at that rail. Below 2.0 V, propagation delay increases sharply and output drive degrades-operation below 2.0 V is not characterized or recommended.

Can E1, E2, and E3 be tied together for simplified enable control?

No-E1 and E2 are active-low while E3 is active-high; tying them together creates a logical conflict. To simplify enable logic, tie E1 and E2 to GND and drive only E3, or use an inverter to generate complementary signals for cascaded decoding.

Does the 74HC138T16-13 support hot insertion or live enable toggling?

Yes-the device has no power-on reset or internal state machine; outputs respond immediately to valid enable/address transitions. However, ensure all inputs are within VIH/VIL thresholds before asserting enables to avoid transient glitches.

How does the Schmitt-trigger input affect timing measurements?

Schmitt-trigger hysteresis delays input threshold crossing but does not alter propagation delay specs (tPLH/tPHL), which are measured from 50% input to 50% output. The hysteresis improves noise margin without increasing worst-case timing uncertainty.