Overview
The SN74HC139N is a dual 2-line to 4-line decoder/demultiplexer produced by Texas Instruments. This component is specifically designed for high-performance memory-decoding and data-routing applications that require very short propagation delay times. It features two independent 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 | Min | Nom | Max | Unit |
|---|---|---|---|---|
| Supply Voltage (VCC) | 2 | 5 | 6 | V |
| High-Level Input Voltage (VIH) | 1.5 (VCC=2V), 3.15 (VCC=4.5V), 4.2 (VCC=6V) | V | ||
| Low-Level Input Voltage (VIL) | 0.5 (VCC=2V), 1.35 (VCC=4.5V), 1.8 (VCC=6V) | V | ||
| Input Transition Rise/Fall Time | 1000 (VCC=2V), 500 (VCC=4.5V), 400 (VCC=6V) | ns | ||
| Operating Free-Air Temperature | -40 | 85 | °C | |
| Propagation Delay Time (tpd) | 10 | ns | ||
| Output Drive at 5 V | ±4 | mA | ||
| Low Input Current | 1 | μA | ||
| Continuous Output Current | ±25 | mA |
Key Features
- Targeted specifically for high-speed memory decoders and data-transmission systems.
- Wide operating voltage range of 2 V to 6 V.
- Outputs can drive up to 10 LSTTL loads.
- Low power consumption, 80-μA max ICC.
- Typical propagation delay time of 10 ns.
- ±4-mA output drive at 5 V.
- Low input current of 1 μA max.
- Incorporate two enable inputs to simplify cascading and/or data reception.
Applications
The SN74HC139N is particularly useful in high-performance memory systems and data-routing applications. It can be employed in systems requiring fast enable circuits, where the delay time of the decoders and the enable time of the memory are critical. This component is also suitable for demultiplexing applications, where the active-low enable input can be used as a data line.
Q & A
- What is the primary function of the SN74HC139N?
The SN74HC139N is a dual 2-line to 4-line decoder/demultiplexer, designed for high-performance memory-decoding and data-routing applications.
- What is the operating voltage range of the SN74HC139N?
The operating voltage range is from 2 V to 6 V.
- How many LSTTL loads can the outputs of the SN74HC139N drive?
The outputs can drive up to 10 LSTTL loads.
- What is the typical propagation delay time of the SN74HC139N?
The typical propagation delay time is 10 ns.
- What is the maximum output drive current at 5 V?
The maximum output drive current at 5 V is ±4 mA.
- What is the maximum low input current?
The maximum low input current is 1 μA.
- How many enable inputs does the SN74HC139N have?
The SN74HC139N has two enable inputs to simplify cascading and/or data reception.
- What are the typical applications of the SN74HC139N?
The SN74HC139N is used in high-performance memory systems and data-routing applications, including demultiplexing.
- What is the operating temperature range of the SN74HC139N?
The operating temperature range is from -40°C to 85°C.
- What is the maximum continuous output current?
The maximum continuous output current is ±25 mA.
