M74HCT138B1R

Product Overview

• Category: Integrated Circuit (IC)
• Use: Decoder/Demultiplexer
• Characteristics: High-Speed CMOS Logic, 3-to-8 Line Decoder/Demultiplexer
• Package: SO-16
• Essence: The M74HCT138B1R is a decoder/demultiplexer IC that converts a binary input into one of eight outputs.
• Packaging/Quantity: Available in tape and reel packaging with 2500 units per reel.

Specifications

• Logic Family: HCT
• Number of Inputs: 3
• Number of Outputs: 8
• Supply Voltage: 4.5V to 5.5V
• Operating Temperature Range: -40°C to +125°C
• Propagation Delay: 13 ns (typical)
• Output Current: ±6 mA
• Input Capacitance: 3 pF (typical)

Detailed Pin Configuration

The M74HCT138B1R has a total of 16 pins arranged as follows:

+---+--+---+ A2 --|1 +--+ 16|-- Vcc A1 --|2 15|-- Y7 A0 --|3 14|-- Y6 /E1 --|4 13|-- Y5 /E2 --|5 74HCT138B1R 12|-- Y4 /E3 --|6 11|-- Y3 Y0 --|7 10|-- Y2 Y1 --|8 9|-- GND +----------+

Functional Features

• Converts a 3-bit binary input to one of eight outputs.
• Active LOW enable inputs (/E1, /E2, /E3) allow for easy expansion and cascading of multiple ICs.
• High-speed operation with low power consumption.
• Schmitt trigger inputs provide hysteresis for improved noise immunity.

Advantages

• Compact and versatile decoder/demultiplexer solution.
• Wide operating voltage range allows compatibility with various systems.
• Fast propagation delay ensures quick response time.
• Low power consumption makes it suitable for battery-powered devices.
• Schmitt trigger inputs enhance noise immunity.

Disadvantages

• Limited number of inputs and outputs compared to higher-order decoders.
• Not suitable for applications requiring more complex decoding functions.

Working Principles

The M74HCT138B1R operates by decoding a 3-bit binary input (A2, A1, A0) and activating the corresponding output line (Y0-Y7). The active LOW enable inputs (/E1, /E2, /E3) control the operation of the decoder. When an enable input is set to LOW, the decoder is enabled, and the selected output line becomes active.

Detailed Application Field Plans

The M74HCT138B1R can be used in various applications, including:

1. Address decoding in microcontrollers and microprocessors.
2. Memory selection in RAM and ROM systems.
3. Data routing and selection in multiplexers.
4. Signal demultiplexing in communication systems.
5. Control signal generation in digital circuits.

Detailed and Complete Alternative Models

1. SN74LS138: Similar 3-to-8 line decoder/demultiplexer from Texas Instruments.
2. CD74HC238: 3-to-8 line decoder/demultiplexer from Texas Instruments with higher speed and lower power consumption.
3. MC14538B: CMOS dual 4-input multiplexer/3-line decoder from ON Semiconductor.

(Note: This list is not exhaustive and other alternative models may exist.)

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