74HC238D

The 74HC238D is a high-speed CMOS 3-to-8 line decoder/demultiplexer manufactured by Toshiba. It is part of the 74HC (High-speed CMOS) series, which is known for its low power consumption and high-speed operation. Below is a detailed description of the 74HC238D:

General Features:

• Functionality: The 74HC238D takes three binary inputs (A0, A1, A2) and decodes them into one of eight outputs (Y0 to Y7). It can also be used as a demultiplexer, directing a single input signal to one of the eight outputs based on the binary input.
• Active Low Outputs: The outputs are active low, meaning that when a specific input combination is applied, the corresponding output goes low (0), while all other outputs remain high (1).
• Enable Inputs: The device includes three enable inputs (G1, G2A, G2B) that control the operation of the decoder. The outputs are enabled only when G1 is high and both G2A and G2B are low.
• High-Speed Operation: The 74HC238D is designed for high-speed applications, with typical propagation delays in the range of nanoseconds, making it suitable for fast digital circuits.
• Low Power Consumption: As a CMOS device, it consumes significantly less power compared to traditional TTL logic families, making it ideal for battery-operated devices and energy-efficient applications.

Pin Configuration:

• The 74HC238D typically comes in a 16-pin dual in-line package (DIP) or surface mount package (SOIC). The pin configuration includes:
  • Inputs: A0, A1, A2 (3 input pins for binary selection)
  • Enable Pins: G1, G2A, G2B (3 enable pins to control the operation)
  • Outputs: Y0 to Y7 (8 output pins)
  • VCC: Power supply pin (typically +2V to +6V)
  • GND: Ground pin

Electrical Characteristics:

• Supply Voltage (VCC): The device operates within a supply voltage range of 2V to 6V.
• Input Voltage Levels: The input high voltage (VIH) and input low voltage (VIL) levels are defined to ensure proper logic level recognition.
• Output Drive Capability: The outputs can typically sink or source a certain amount of current, allowing them to drive other logic inputs or loads directly.

Applications:

• Data Routing: The 74HC238D can be used in applications where data needs to be routed to different destinations based on control signals.
• Memory Address Decoding: It is commonly used in memory address decoding applications, where specific memory locations are activated based on the binary address inputs.
• Signal Demultiplexing: The device can serve as a demultiplexer, directing a single input signal to one of several outputs based on the select lines.

Summary:

The 74HC238D from Toshiba is a versatile and efficient 3-to-8 line decoder/demultiplexer that is well-suited for a variety of digital logic applications. Its combination of high-speed performance, low power consumption, and ease of use makes it a popular choice in modern electronic designs.