Overview
The SN74LS138NSR is a 3-line to 8-line decoder/demultiplexer integrated circuit manufactured by Texas Instruments. This Schottky-clamped TTL MSI circuit is designed for high-performance applications, particularly in memory decoding and data-routing systems. It features three binary select inputs and three enable inputs, which simplify cascading and data reception. The device is available in a 16-pin SOP (NS) package and operates over a temperature range of 0°C to 70°C.
Key Specifications
| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Part Number | SN74LS138NSR |
| Package | 16-SO (Small Outline) |
| Operating Temperature Range | 0°C to 70°C |
| Voltage Supply | 4.75 V to 5.25 V |
| Current - Output High, Low | 400µA, 8mA |
| Enable Inputs | Three (two active-low, one active-high) |
| Select Inputs | Three binary select inputs |
| Line Configuration | 3:8 |
| Mounting Type | Surface Mount |
Key Features
- High-Speed Operation: Designed for high-speed memory decoding and data-routing applications with very short propagation delay times.
- Schottky-Clamped: Features Schottky diodes to suppress line-ringing and simplify system design.
- Enable Inputs: Three enable inputs (two active-low and one active-high) reduce the need for external gates or inverters when expanding the decoder.
- Fully Buffered Inputs: Each input represents only one normalized load to its driving circuit.
- Demultiplexing Capability: An enable input can be used as a data input for demultiplexing applications.
Applications
- Memory Decoding: Used in high-performance memory systems to minimize system decoding delays.
- Data Transmission Systems: Suitable for applications requiring fast data routing and decoding.
- High-Speed Digital Systems: Ideal for systems that require short propagation delay times and high performance.
Q & A
- What is the primary function of the SN74LS138NSR?
The SN74LS138NSR is a 3-line to 8-line decoder/demultiplexer, designed to decode one of eight lines based on the conditions at the three binary select inputs and the three enable inputs.
- What package types are available for the SN74LS138NSR?
The SN74LS138NSR is available in a 16-pin SOP (NS) package.
- What is the operating temperature range of the SN74LS138NSR?
The operating temperature range is from 0°C to 70°C.
- What are the voltage supply requirements for the SN74LS138NSR?
The voltage supply range is from 4.75 V to 5.25 V.
- How many enable inputs does the SN74LS138NSR have?
The device has three enable inputs (two active-low and one active-high).
- What is the purpose of the Schottky diodes in the SN74LS138NSR?
The Schottky diodes are used to suppress line-ringing and simplify system design.
- Can the SN74LS138NSR be used for demultiplexing applications?
- What are some common applications of the SN74LS138NSR?
- How does the SN74LS138NSR simplify cascading and data reception?
- What is the significance of the 'LS' in the part number SN74LS138NSR?
