Overview
The SN74ALS139DR is a dual 2-line to 4-line decoder/demultiplexer produced by Texas Instruments. This component is designed for high-performance applications, particularly in memory-decoding and data-routing systems. It features two individual 2-line to 4-line decoders in a single package, making it ideal for minimizing system decoding delays in high-speed memory systems.
Key Specifications
| Parameter | Unit | Min | Typ | Max |
|---|---|---|---|---|
| Supply Voltage (VCC) | V | 4.5 | 5 | 5.5 |
| High-Level Input Voltage (VIH) | V | 2 | ||
| Low-Level Input Voltage (VIL) | V | 0.7 | ||
| High-Level Output Current (IOH) | mA | -0.4 | ||
| Low-Level Output Current (IOL) | mA | 4 | 8 | |
| Operating Free-Air Temperature | °C | 0 | 70 | |
| Propagation Delay Time (tPLH, tPHL) | ns | 3 | 17 | |
| Package Type | SOIC-16 |
Key Features
- High-performance Schottky-clamped inputs to suppress line ringing and simplify system design.
- Two enable inputs to simplify cascading and/or data reception.
- Fully buffered inputs, each representing only one normalized load to its driving circuit.
- Active-low enable (G) input can be used as a data line in demultiplexing applications.
- Available in various package options including SOIC, PDIP, and LCCC.
- Compliant with RoHS and Green standards.
Applications
- High-speed memory-decoding systems.
- Data-routing applications requiring short propagation delay times.
- Demultiplexing applications where the enable input can be used as a data line.
- General-purpose decoding and demultiplexing in digital systems.
Q & A
- What is the primary function of the SN74ALS139DR?
The SN74ALS139DR is a dual 2-line to 4-line decoder/demultiplexer designed for high-performance memory-decoding and data-routing applications.
- What are the operating temperature ranges for the SN74ALS139DR?
The SN74ALS139DR operates from 0°C to 70°C.
- What is the supply voltage range for the SN74ALS139DR?
The supply voltage range is from 4.5V to 5.5V.
- What types of packages are available for the SN74ALS139DR?
The component is available in SOIC-16, PDIP, and LCCC packages.
- What is the significance of the active-low enable input?
The active-low enable input can be used as a data line in demultiplexing applications.
- How does the SN74ALS139DR minimize system decoding delays?
It minimizes system decoding delays by having very short propagation delay times, especially when used with high-speed memories and fast-enable circuits.
- Is the SN74ALS139DR RoHS compliant?
Yes, the SN74ALS139DR is RoHS and Green compliant.
- What are the typical propagation delay times for the SN74ALS139DR?
The typical propagation delay times (tPLH, tPHL) are 3 to 17 ns.
- What are the high-level and low-level output currents for the SN74ALS139DR?
The high-level output current (IOH) is -0.4 mA, and the low-level output current (IOL) is 4 to 8 mA.
- What are the high-level and low-level input voltage thresholds for the SN74ALS139DR?
The high-level input voltage (VIH) is 2 V, and the low-level input voltage (VIL) is 0.7 V.
