Overview
The CD74HCT138MT is a high-speed CMOS logic 3-to-8 line decoder/demultiplexer integrated circuit manufactured by Texas Instruments. This device is part of the 74HCT series, which is known for its compatibility with TTL (Transistor-Transistor Logic) inputs and its low power consumption. The CD74HCT138MT is designed to decode three binary inputs into one of eight mutually exclusive outputs, making it suitable for applications such as memory address decoding, data routing, and I/O port or memory selection.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Manufacturer | Texas Instruments | |
| Category | Integrated Circuits (ICs) - Logic - Signal Switches, Multiplexers, Decoders | |
| Package | 16-SOIC (0.154", 3.90mm Width) | |
| Series | 74HCT | |
| Type | Decoder/Demultiplexer | |
| Circuit | 1 x 3:8 | |
| Current - Output High, Low | 4mA, 4mA | mA |
| Voltage Supply Source | Single Supply | |
| Voltage - Supply | 4.5 V ~ 5.5 V | V |
| Operating Temperature | -55°C ~ 125°C | °C |
| Mounting Type | Surface Mount | |
| Propagation Delay | 35 ns (max at VCC = 5V, CL = 50pF) | ns |
| Input Leakage Current | ±0.1 µA (max at VCC = 5.5V) | µA |
Key Features
- Decoder/Demultiplexer Functionality: The CD74HCT138MT can decode three binary inputs into one of eight mutually exclusive outputs, making it ideal for memory address decoding and data routing applications.
- Three Enable Inputs: The device includes three strobe inputs (G2, G1, and G0) that simplify cascading and facilitate demultiplexing. When any input strobe is active, all outputs are forced into the high state for the '138 function.
- TTL Input Compatibility: The HCT series is compatible with TTL input logic, allowing for direct interface with TTL systems.
- Low Power Consumption: The CMOS technology used in this device ensures significant power reduction compared to LSTTL logic ICs.
- Wide Operating Temperature Range: The device operates over a wide temperature range of -55°C to 125°C, making it suitable for various environmental conditions.
- High Noise Immunity: The device has high noise immunity, with NIL = 30% and NIH = 30% of VCC at VCC = 5V.
Applications
- Memory Address Decoding: The CD74HCT138MT is well-suited for memory address decoding in digital systems.
- Data Routing: It can be used to route data in complex digital circuits, ensuring that data is directed to the correct output.
- I/O Port or Memory Selection: The device can act as an I/O port or memory selector, enabling the selection of specific outputs based on input conditions.
- Digital Switching Circuits: It can be used in various digital switching circuits where decoding and demultiplexing are required.
Q & A
- What is the primary function of the CD74HCT138MT?
The primary function of the CD74HCT138MT is to decode three binary inputs into one of eight mutually exclusive outputs, acting as a 3-to-8 line decoder/demultiplexer.
- What is the operating voltage range of the CD74HCT138MT?
The operating voltage range of the CD74HCT138MT is from 4.5 V to 5.5 V.
- What is the maximum propagation delay of the CD74HCT138MT?
The maximum propagation delay of the CD74HCT138MT is approximately 35 ns at VCC = 5V and CL = 50pF.
- Is the CD74HCT138MT compatible with TTL inputs?
Yes, the CD74HCT138MT is compatible with TTL input logic, allowing for direct interface with TTL systems.
- What is the operating temperature range of the CD74HCT138MT?
The operating temperature range of the CD74HCT138MT is from -55°C to 125°C.
- How many enable inputs does the CD74HCT138MT have?
The CD74HCT138MT has three enable inputs (G2, G1, and G0) that simplify cascading and facilitate demultiplexing.
- What is the package type of the CD74HCT138MT?
The CD74HCT138MT comes in a 16-SOIC (Small Outline Integrated Circuit) package.
- Is the CD74HCT138MT RoHS compliant?
Yes, the CD74HCT138MT is RoHS compliant.
- What are some common applications of the CD74HCT138MT?
The CD74HCT138MT is commonly used in memory address decoding, data routing, I/O port or memory selection, and various digital switching circuits.
- What is the maximum output current of the CD74HCT138MT?
The maximum output current of the CD74HCT138MT is 4 mA for both high and low output states.
