Overview
The MC74HC138ADG is a 1-of-8 decoder/demultiplexer integrated circuit produced by onsemi. It is identical in pinout to the LS138 and is designed to decode a three-bit address to one of eight active-low outputs. This device features three Chip Select inputs, two active-low and one active-high, which facilitate demultiplexing, cascading, and chip-selecting functions. The inputs are compatible with standard CMOS outputs and, with pullup resistors, they are also compatible with LSTTL outputs. The MC74HC138ADG is part of the HC138A series, known for its high-performance silicon-gate CMOS technology.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Operating Voltage Range | 2.0 to 6.0 | V |
| Output Drive Capability | 10 LSTTL Loads | |
| Input Current | 1.0 μA | |
| Maximum Propagation Delay (Input A to Output Y) | 27 to 135 ns | ns |
| Maximum Propagation Delay (CS1 to Output Y) | 22 to 110 ns | ns |
| Maximum Output Transition Time | 13 to 75 ns | ns |
| Maximum Input Capacitance | 10 pF | pF |
| Storage Temperature | -65 to +150 °C | °C |
| Junction Temperature Under Bias | -55 to +125 °C | °C |
| Package Type | SOIC-16 | |
| Moisture Sensitivity Level | 1 |
Key Features
- Decodes a three-bit address to one of eight active-low outputs.
- Three Chip Select inputs: two active-low and one active-high for demultiplexing, cascading, and chip-selecting functions.
- Inputs compatible with standard CMOS outputs; with pullup resistors, compatible with LSTTL outputs.
- Outputs directly interface to CMOS, NMOS, and TTL.
- High noise immunity characteristic of CMOS devices.
- In compliance with the requirements defined by JEDEC Standard No. 7A.
- Pb-Free packages available.
Applications
The MC74HC138ADG is versatile and can be used in various applications, including:
- Digital decoding and demultiplexing circuits.
- Data routing and selection in digital systems.
- Interface circuits between different logic families (CMOS, TTL, NMOS).
- Embedded systems requiring low power consumption and high noise immunity.
- Automotive and industrial control systems where robustness and reliability are crucial.
Q & A
- What is the primary function of the MC74HC138ADG?
The primary function of the MC74HC138ADG is to decode a three-bit address to one of eight active-low outputs, and it also serves as a demultiplexer.
- What are the operating voltage ranges for the MC74HC138ADG?
The operating voltage range for the MC74HC138ADG is from 2.0 to 6.0 volts.
- How many Chip Select inputs does the MC74HC138ADG have?
The MC74HC138ADG has three Chip Select inputs: two active-low and one active-high.
- What is the maximum propagation delay from input A to output Y?
The maximum propagation delay from input A to output Y ranges from 27 to 135 nanoseconds depending on the operating voltage.
- Is the MC74HC138ADG compatible with different logic families?
- What is the maximum input current for the MC74HC138ADG?
The maximum input current for the MC74HC138ADG is 1.0 microampere.
- What is the storage temperature range for the MC74HC138ADG?
The storage temperature range for the MC74HC138ADG is from -65 to +150 degrees Celsius.
- Does the MC74HC138ADG come in Pb-Free packages?
- What is the moisture sensitivity level of the MC74HC138ADG?
The moisture sensitivity level of the MC74HC138ADG is 1.
- What are some common applications of the MC74HC138ADG?
