Overview
The SN74LVC138A, produced by Texas Instruments, is a 3-line to 8-line decoder/demultiplexer designed for high-performance applications. This device operates within a voltage range of 2.7 V to 3.6 V, making it suitable for various memory-decoding and data-routing tasks. It is particularly useful in high-speed memory systems where minimal propagation delay times are crucial. The SN74LVC138A features two active-low enable inputs and one active-high enable input, reducing the need for external gates or inverters in system expansion.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage Range (VCC) | 2 | 3.6 | V | |
| Input Voltage Range (VI) | -0.5 | 6.5 | V | |
| Output Voltage Range (VO) | -0.5 | VCC + 0.5 | V | |
| High-Level Input Voltage (VIH) | 2 | V | ||
| Low-Level Input Voltage (VIL) | 0.8 | V | ||
| Propagation Delay Time (tpd) | 5.8 | ns | ||
| Operating Free-Air Temperature (TA) | -55 | 125 | °C | |
| Continuous Output Current (IO) | ±50 | mA |
Key Features
- Operates from 2 V to 3.6 V, with inputs accepting voltages up to 5.5 V.
- ESD protection exceeds 2000 V per MIL-STD-883, Method 3015, and 200 V using the Machine Model.
- Maximum propagation delay time of 5.8 ns at 3.3 V.
- Typical output ground bounce (VOLP) less than 0.8 V and output VOH undershoot greater than 2 V at VCC = 3.3 V and TA = 25°C.
- Supports mixed 3.3-V/5-V system environments.
- Controlled baseline, one assembly/test site, and one fabrication site for reliability.
- Available in military temperature range (-55°C to 125°C) and extended product life cycle.
Applications
The SN74LVC138A is designed for high-performance memory-decoding or data-routing applications. It is particularly useful in high-speed memory systems where fast enable circuits are employed. The device minimizes system decoding delays, making it suitable for applications requiring very short propagation delay times.
- High-speed memory systems.
- Data-routing applications.
- Mixed 3.3-V/5-V system environments.
- Defense, aerospace, and medical applications due to its controlled baseline and extended product life cycle.
Q & A
- What is the operating voltage range of the SN74LVC138A?
The SN74LVC138A operates from 2 V to 3.6 V.
- What is the maximum propagation delay time of the SN74LVC138A at 3.3 V?
The maximum propagation delay time is 5.8 ns at 3.3 V.
- What level of ESD protection does the SN74LVC138A offer?
The device offers ESD protection exceeding 2000 V per MIL-STD-883, Method 3015, and 200 V using the Machine Model.
- Can the SN74LVC138A be used in mixed 3.3-V/5-V system environments?
Yes, the device supports mixed 3.3-V/5-V system environments.
- What are the typical output ground bounce and VOH undershoot values at VCC = 3.3 V and TA = 25°C?
The typical output ground bounce (VOLP) is less than 0.8 V, and the output VOH undershoot is greater than 2 V.
- What are the key applications of the SN74LVC138A?
The device is used in high-speed memory systems, data-routing applications, and mixed 3.3-V/5-V system environments. It is also suitable for defense, aerospace, and medical applications.
- What is the operating free-air temperature range of the SN74LVC138A?
The operating free-air temperature range is -55°C to 125°C.
- Does the SN74LVC138A have any special features for reliability?
Yes, it has a controlled baseline, one assembly/test site, and one fabrication site, along with an extended product life cycle.
- What types of packages are available for the SN74LVC138A?
The device is available in SOIC (D package) and TSSOP (PW package) options.
- How many output lines does the SN74LVC138A have?
The device has 8 output lines.
