Overview
The SN74HCT138NE4 is a 3-line to 8-line decoder/demultiplexer produced by Texas Instruments. This device is designed for high-performance memory-decoding and data-routing applications, particularly where short propagation delay times are crucial. It operates within a voltage range of 4.5 V to 5.5 V, making it compatible with TTL (Transistor-Transistor Logic) systems. The SN74HCT138NE4 is part of the 74HCT series, known for its low power consumption and high-speed capabilities.
Key Specifications
| Parameter | Min | Nom | Max | Unit |
|---|---|---|---|---|
| VCC (Supply Voltage) | 4.5 | 5 | 5.5 | V |
| VIH (High-level Input Voltage) | 2 | 2 | 2 | V |
| VIL (Low-level Input Voltage) | 0.8 | 0.8 | 0.8 | V |
| TA (Operating Free-air Temperature) | -40 | 85 | °C | |
| tpd (Propagation Delay Time) | 17 | 49 | ns | |
| IOH (Output High Current) | -4 | -4 | mA | |
| IOL (Output Low Current) | 4 | 4 | mA | |
| ICC (Supply Current) | 8 | 80 | μA | |
| Package | 16-PDIP |
Key Features
- Operating voltage range of 4.5 V to 5.5 V, compatible with TTL systems.
- Outputs can drive up to 10 LSTTL loads.
- Low power consumption, with a maximum supply current (ICC) of 80 μA.
- Typical propagation delay time (tpd) of 17 ns at 5 V.
- ±4-mA output drive at 5 V.
- Low input current of 1 μA max.
- Inputs are TTL-Voltage compatible.
- Designed specifically for high-speed memory decoders and data transmission systems.
- Incorporate three enable inputs to simplify cascading and/or data reception.
Applications
The SN74HCT138NE4 is primarily used in high-performance memory-decoding and data-routing applications. It is particularly useful in systems that require very short propagation delay times, such as:
- High-speed memory systems where it can minimize the effects of system decoding.
- Data transmission systems that require fast enable circuits).
- Other applications where TTL compatibility and low power consumption are essential.
Q & A
- What is the operating voltage range of the SN74HCT138NE4?
The operating voltage range is 4.5 V to 5.5 V).
- What is the typical propagation delay time of the SN74HCT138NE4?
The typical propagation delay time is 17 ns at 5 V).
- How many LSTTL loads can the outputs of the SN74HCT138NE4 drive?
The outputs can drive up to 10 LSTTL loads).
- What is the maximum supply current (ICC) of the SN74HCT138NE4?
The maximum supply current is 80 μA).
- What is the package type of the SN74HCT138NE4?
The package type is 16-PDIP (Plastic Dual In-Line Package)).
- What are the operating temperature ranges for the SN74HCT138NE4?
The operating temperature range is -40°C to 85°C).
- Can the SN74HCT138NE4 be used in high-speed memory systems?
Yes, it is designed specifically for high-speed memory-decoding and data-routing applications).
- How many enable inputs does the SN74HCT138NE4 have?
The device incorporates three enable inputs).
- What is the input current of the SN74HCT138NE4?
The input current is 1 μA max).
- Is the SN74HCT138NE4 compatible with TTL systems?
Yes, the inputs are TTL-Voltage compatible).
