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CD74HC138MT
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CD74HC138MT

Product Overview

  • Category: Integrated Circuit
  • Use: Decoding/Demultiplexing
  • Characteristics: High-speed, CMOS technology
  • Package: TSSOP (Thin Shrink Small Outline Package)
  • Essence: 3-to-8 line decoder/demultiplexer
  • Packaging/Quantity: Tape and Reel, 2500 units per reel

Specifications

  • Supply Voltage Range: 2V to 6V
  • High-Level Input Voltage: 2V
  • Low-Level Input Voltage: 0.8V
  • High-Level Output Current: -4mA
  • Low-Level Output Current: 4mA
  • Maximum Operating Frequency: 50MHz
  • Propagation Delay Time: 13ns

Detailed Pin Configuration

The CD74HC138MT has a total of 16 pins, which are assigned as follows:

  1. GND (Ground)
  2. A0 (Address Input 0)
  3. A1 (Address Input 1)
  4. A2 (Address Input 2)
  5. E1 (Enable Input 1)
  6. Y0 (Output 0)
  7. Y1 (Output 1)
  8. Y2 (Output 2)
  9. Y3 (Output 3)
  10. Y4 (Output 4)
  11. Y5 (Output 5)
  12. Y6 (Output 6)
  13. Y7 (Output 7)
  14. E2 (Enable Input 2)
  15. VCC (Positive Power Supply)
  16. GND (Ground)

Functional Features

The CD74HC138MT is a high-speed CMOS integrated circuit that functions as a 3-to-8 line decoder/demultiplexer. It takes three address inputs (A0, A1, A2) and two enable inputs (E1, E2) to generate eight outputs (Y0-Y7). The decoder/demultiplexer selects one of the eight outputs based on the input address lines.

Advantages and Disadvantages

Advantages: - High-speed operation - Wide supply voltage range - Low power consumption - Compact TSSOP package - Easy to use and integrate into circuits

Disadvantages: - Limited number of address inputs - Output current limitations - Not suitable for high-voltage applications

Working Principles

The CD74HC138MT operates by decoding the binary address inputs (A0-A2) and enabling one of the eight outputs (Y0-Y7) based on the selected address. The enable inputs (E1, E2) control the operation of the decoder/demultiplexer. When both enable inputs are low, all outputs are disabled. When either enable input is high, the decoder/demultiplexer is enabled, and the selected output is determined by the address inputs.

Detailed Application Field Plans

The CD74HC138MT finds applications in various fields, including:

  1. Digital Electronics: Used for address decoding in microprocessors, memory systems, and digital circuits.
  2. Communication Systems: Used for channel selection and signal routing in multiplexers and demultiplexers.
  3. Industrial Automation: Used for controlling multiple devices based on address inputs.
  4. Automotive Electronics: Used for decoding signals in automotive control systems.
  5. Consumer Electronics: Used in remote control systems, audio/video equipment, and home automation.

Detailed and Complete Alternative Models

  1. 74LS138: TTL version of the decoder/demultiplexer with similar functionality.
  2. CD4514: 4-to-16 line decoder/demultiplexer with additional features.
  3. SN74HC238: 3-to-8 line decoder/demultiplexer with active-low outputs.

These alternative models offer similar decoding/demultiplexing functionality with slight variations in specifications and package options.

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10個與CD74HC138MT在技術方案中應用相關的常見問題與解答

Sure! Here are 10 common questions and answers related to the application of CD74HC138MT in technical solutions:

  1. Q: What is CD74HC138MT? A: CD74HC138MT is a 3-to-8 line decoder/demultiplexer integrated circuit (IC) that can be used to decode binary information and select one of eight outputs based on the input signals.

  2. Q: What is the voltage supply range for CD74HC138MT? A: CD74HC138MT operates with a voltage supply range of 2V to 6V.

  3. Q: How many inputs does CD74HC138MT have? A: CD74HC138MT has three input pins, A0, A1, and A2, which are used to provide the binary input to select one of the eight outputs.

  4. Q: What is the maximum output current of CD74HC138MT? A: The maximum output current of CD74HC138MT is typically around 4mA.

  5. Q: Can CD74HC138MT be used as a demultiplexer? A: Yes, CD74HC138MT can be used as a demultiplexer by providing the appropriate input signals to select one of the eight outputs.

  6. Q: What is the propagation delay of CD74HC138MT? A: The propagation delay of CD74HC138MT is typically around 15ns.

  7. Q: Can CD74HC138MT be cascaded to increase the number of outputs? A: Yes, multiple CD74HC138MT ICs can be cascaded together to increase the number of outputs by connecting the enable (E1, E2, E3) and input (A0, A1, A2) pins in series.

  8. Q: What is the power dissipation of CD74HC138MT? A: The power dissipation of CD74HC138MT is typically around 20mW.

  9. Q: Can CD74HC138MT be used in high-speed applications? A: Yes, CD74HC138MT is designed for high-speed operation and can be used in various applications that require fast decoding or demultiplexing.

  10. Q: What are some common applications of CD74HC138MT? A: CD74HC138MT is commonly used in digital systems, address decoding, memory selection, data routing, and other applications where binary information needs to be decoded and selected among multiple outputs.

Please note that these answers are general and may vary depending on specific datasheet specifications and application requirements.