Overview
The SN74ALS138AN is a 3-line to 8-line decoder/demultiplexer designed by Texas Instruments for high-performance memory-decoding and data-routing applications. This device is optimized for very short propagation delay times, making it suitable for use in high-speed systems. It can be employed to minimize the effects of system decoding, particularly when used with high-speed memories that have fast enable circuits. The SN74ALS138AN operates within a temperature range of 0°C to 70°C, making it versatile for various environmental conditions.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC Supply Voltage | 4.5 | 5 | 5.5 | V |
| VIH High-Level Input Voltage | 2 | V | ||
| VIL Low-Level Input Voltage | 0.7 | V | ||
| IOH High-Level Output Current | -0.4 | mA | ||
| IOL Low-Level Output Current | 4 | 8 | mA | |
| TA Operating Free-Air Temperature | 0 | 70 | °C | |
| Package Type | PDIP (N) | |||
| Pins | 16 |
Key Features
- Designed specifically for high-speed memory decoders and data transmission systems.
- Incorporate three enable inputs to simplify cascading and/or data reception. Two active-low and one active-high enable inputs reduce the need for external gates or inverters when expanding.
- Package options include plastic small-outline (D) packages, ceramic chip carriers (FK), and standard plastic (N) and ceramic (J) 300-mil DIPs.
- Can be used to implement larger decoders without external inverters; for example, a 24-line decoder can be implemented without external inverters, and a 32-line decoder requires only one inverter.
Applications
- High-performance memory-decoding applications: The device is optimized for use in high-speed memory systems to minimize system decoding delays.
- Data-routing applications: Suitable for data-routing in high-speed systems where short propagation delay times are critical.
- Demultiplexing applications: An enable input can be used as a data input for demultiplexing, adding flexibility to the device's functionality.
Q & A
- What is the primary function of the SN74ALS138AN?
The SN74ALS138AN is a 3-line to 8-line decoder/demultiplexer designed for high-performance memory-decoding and data-routing applications.
- What is the operating temperature range of the SN74ALS138AN?
The device operates within a temperature range of 0°C to 70°C).
- What are the package options available for the SN74ALS138AN?
The device is available in plastic small-outline (D) packages, ceramic chip carriers (FK), and standard plastic (N) and ceramic (J) 300-mil DIPs).
- How many enable inputs does the SN74ALS138AN have?
The device has three enable inputs: two active-low and one active-high).
- Can the SN74ALS138AN be used for demultiplexing applications?
- What is the typical supply voltage for the SN74ALS138AN?
The typical supply voltage is 5 V, with a range of 4.5 V to 5.5 V).
- How many pins does the SN74ALS138AN have?
The device has 16 pins).
- What are the high-level and low-level output currents for the SN74ALS138AN?
The high-level output current is -0.4 mA, and the low-level output current is 4 mA to 8 mA).
- Can the SN74ALS138AN be used to implement larger decoders?
- What is the significance of the short propagation delay times in the SN74ALS138AN?
The short propagation delay times make the device suitable for high-speed systems, minimizing the effects of system decoding delays).
