Overview
The SN74HC138N is a 3-line to 8-line decoder/demultiplexer integrated circuit produced by Texas Instruments. It is designed for high-performance memory-decoding or data-routing applications that require very short propagation delay times. This device is particularly useful in high-speed memory systems where it can minimize the effects of system decoding, ensuring that the delay times introduced by the decoders are negligible when used with fast enable circuits and high-speed memories.
Key Specifications
| Parameter | Value |
|---|---|
| Package Type | PDIP (N), SOIC (D), SSOP (DB), SO (NS), TSSOP (PW), CDIP (J), CFP (W), LCCC (FK) |
| Number of Pins | 16 |
| Operating Temperature Range | -40°C to 85°C |
| Operating Voltage Range | 2 V to 6 V |
| Propagation Delay Time (tpd) | Typical 15 ns |
| Output Drive | ±4 mA at 5 V |
| Input Current | Maximum 1 µA |
| Power Consumption | Maximum 80 µA ICC |
| Enable Inputs | One active high, two active low |
Key Features
- Targeted specifically for high-speed memory decoders and data-transmission systems.
- Wide operating voltage range (2 V to 6 V).
- Outputs can drive up to 10 LSTTL loads.
- Low power consumption, maximum 80 µA ICC.
- Typical propagation delay time of 15 ns.
- ±4 mA output drive at 5 V.
- Low input current of maximum 1 µA.
- Active low outputs (selected output is low).
- Incorporate three enable inputs to simplify cascading or data reception.
Applications
- LED Displays.
- Servers.
- White Goods.
- Power Infrastructure.
- Building Automation.
- Factory Automation.
Q & A
- What is the primary function of the SN74HC138N?
The SN74HC138N is a 3-line to 8-line decoder/demultiplexer designed for high-performance memory-decoding or data-routing applications.
- What is the operating voltage range of the SN74HC138N?
The operating voltage range is from 2 V to 6 V.
- What is the typical propagation delay time of the SN74HC138N?
The typical propagation delay time is 15 ns.
- How many enable inputs does the SN74HC138N have?
The device has one active high enable and two active low enable inputs.
- What is the maximum power consumption of the SN74HC138N?
The maximum power consumption is 80 µA ICC.
- What types of packages are available for the SN74HC138N?
The device is available in PDIP, SOIC, SSOP, SO, TSSOP, CDIP, CFP, and LCCC packages.
- What is the operating temperature range of the SN74HC138N?
The operating temperature range is from -40°C to 85°C.
- Can the SN74HC138N drive multiple LSTTL loads?
Yes, the outputs can drive up to 10 LSTTL loads.
- What are some common applications of the SN74HC138N?
Common applications include LED displays, servers, white goods, power infrastructure, building automation, and factory automation.
- How does the SN74HC138N minimize system decoding delays in high-speed memory systems?
The device minimizes system decoding delays by ensuring that its propagation delay times and the enable time of the memory are usually less than the typical access time of the memory.
