Texas Instruments
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MM74C949N

MM74C949N

Product Overview

  • Category: Integrated Circuit (IC)
  • Use: Encoder/Decoder
  • Characteristics: Low-power, high-performance, versatile
  • Package: DIP (Dual In-line Package)
  • Essence: Converts parallel data to serial and vice versa
  • Packaging/Quantity: Available in tubes of 25 units

Specifications

  • Supply Voltage: 4.5V to 5.5V
  • Operating Temperature: -40°C to +85°C
  • Input/Output Logic Levels: TTL compatible
  • Number of Pins: 16
  • Data Rate: Up to 2 Mbps

Detailed Pin Configuration

  1. VCC: Supply voltage
  2. GND: Ground
  3. A0: Address input bit 0
  4. A1: Address input bit 1
  5. A2: Address input bit 2
  6. A3: Address input bit 3
  7. A4: Address input bit 4
  8. /CS: Chip select input
  9. /RD: Read enable input
  10. /WR: Write enable input
  11. D0: Data input/output bit 0
  12. D1: Data input/output bit 1
  13. D2: Data input/output bit 2
  14. D3: Data input/output bit 3
  15. D4: Data input/output bit 4
  16. D5: Data input/output bit 5

Functional Features

  • Parallel-to-serial and serial-to-parallel conversion
  • Addressable operation for multiple devices on the same bus
  • Bidirectional data transfer capability
  • Built-in chip select and read/write control signals
  • TTL compatible logic levels for easy integration with other ICs

Advantages and Disadvantages

Advantages: - Low power consumption - High-speed data transfer - Versatile addressing options - Compact DIP package for easy PCB integration

Disadvantages: - Limited number of addressable devices on the bus - Requires external components for voltage regulation and protection

Working Principles

The MM74C949N is an encoder/decoder IC that facilitates parallel-to-serial and serial-to-parallel data conversion. It operates by receiving parallel data through its input pins (D0-D5) and converting it into a serial data stream. Conversely, it can receive a serial data stream and convert it back into parallel data. The address inputs (A0-A4) allow multiple devices to be connected on the same bus, each with a unique address. The chip select (/CS), read enable (/RD), and write enable (/WR) signals control the data transfer operations.

Detailed Application Field Plans

The MM74C949N finds applications in various fields, including:

  1. Communication Systems: Used in data communication protocols where parallel data needs to be transmitted over a serial interface.
  2. Industrial Automation: Enables efficient data transfer between microcontrollers and peripheral devices.
  3. Automotive Electronics: Facilitates communication between different electronic modules within a vehicle.
  4. Consumer Electronics: Integrated into devices requiring serial data transmission, such as remote controls and digital displays.

Detailed and Complete Alternative Models

  1. SN74LS148: 8-line to 3-line priority encoder
  2. CD4028B: BCD-to-decimal decoder
  3. MC145027: Remote control encoder/decoder
  4. HT12E/HT12D: Encoder/decoder pair for RF remote control systems

These alternative models offer similar functionality to the MM74C949N and can be considered based on specific application requirements.

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Seznam 10 běžných otázek a odpovědí souvisejících s aplikací MM74C949N v technických řešeních

Sure! Here are 10 common questions and answers related to the application of MM74C949N in technical solutions:

  1. Q: What is MM74C949N? A: MM74C949N is a programmable keyboard/display interface IC that can be used to interface a microcontroller or microprocessor with a keyboard and display.

  2. Q: What are the key features of MM74C949N? A: Some key features of MM74C949N include a 16-key keyboard matrix, 8-segment LED display driver, debounce circuitry, and programmable scan timing.

  3. Q: How can MM74C949N be used in technical solutions? A: MM74C949N can be used in various technical solutions where a microcontroller or microprocessor needs to interface with a keyboard and display, such as in embedded systems, industrial control panels, or electronic appliances.

  4. Q: How does MM74C949N handle keyboard scanning? A: MM74C949N uses a matrix scanning technique to detect key presses. It scans each row and column of the keyboard matrix to determine which keys are pressed.

  5. Q: Can MM74C949N support multiple keyboards? A: Yes, MM74C949N has provisions for connecting multiple keyboards by cascading additional ICs, allowing support for multiple input devices.

  6. Q: Does MM74C949N have built-in debounce circuitry? A: Yes, MM74C949N includes debounce circuitry to eliminate contact bounce and ensure accurate key detection.

  7. Q: Can MM74C949N drive different types of displays? A: MM74C949N is specifically designed to drive 8-segment LED displays. It may require additional circuitry or interfacing components to drive other types of displays.

  8. Q: How can MM74C949N be programmed? A: MM74C949N can be programmed using external control signals from a microcontroller or microprocessor. The programming involves setting the scan timing and configuring other parameters.

  9. Q: What is the power supply requirement for MM74C949N? A: MM74C949N typically operates on a 5V power supply, but it may have a wide voltage range depending on the specific variant.

  10. Q: Are there any application notes or reference designs available for MM74C949N? A: Yes, the manufacturer of MM74C949N usually provides application notes and reference designs that can help in understanding and implementing the IC in various technical solutions.

Please note that the answers provided here are general and may vary based on the specific datasheet and documentation of MM74C949N.