Overview
The MC74AC138DTR2G, produced by onsemi, is a high-speed 1-of-8 decoder/demultiplexer. This device is particularly suited for high-speed bipolar memory chip select address decoding. It features three binary weighted input addresses (A0, A1, A2) and provides eight mutually exclusive active-LOW outputs (O0-O7). The device also includes multiple input enables, allowing for easy parallel expansion to higher-order decoders such as 1-of-24 or 1-of-32 decoders using multiple MC74AC138/74ACT138 devices and an inverter if necessary.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| VCC (DC Supply Voltage) | 2.0 to 6.0 | V |
| VI (DC Input Voltage) | -0.5 to VCC + 0.5 | V |
| VO (DC Output Voltage) | -0.5 to VCC + 0.5 | V |
| IO (DC Output Sink/Source Current) | -50 to 50 | mA |
| TSTG (Storage Temperature Range) | -65 to 150 | °C |
| TA (Operating Ambient Temperature Range) | -40 to 85 | °C |
| tPLH (Propagation Delay An to On) | 6.5 to 10.5 | ns (at VCC = 5.0 V) |
| tPHL (Propagation Delay An to On) | 6.0 to 10.5 | ns (at VCC = 5.0 V) |
| IOH (Output Current - High) | -24 | mA |
| IOL (Output Current - Low) | 24 | mA |
| Package Type | TSSOP-16 |
Key Features
- Demultiplexing Capability: The device can function as an 8-output demultiplexer.
- Multiple Input Enable: Allows for easy parallel expansion to higher-order decoders.
- Active LOW Mutually Exclusive Outputs: Ensures that only one output is active at a time.
- Outputs Source/Sink 24 mA: High current drive capability.
- TTL Compatible Inputs (ACT138): Compatible with TTL logic levels.
- Pb-Free Packages: Available in lead-free packages, compliant with environmental regulations.
Applications
- High-Speed Bipolar Memory Chip Select Address Decoding: Ideal for applications requiring fast address decoding in memory systems.
- Demultiplexing: Can be used as a demultiplexer by utilizing the enable inputs as data and strobe signals.
- Parallel Expansion: Can be expanded to higher-order decoders such as 1-of-24 or 1-of-32 decoders.
- General Logic Circuits: Useful in various digital logic circuits requiring decoding and demultiplexing functions.
Q & A
- What is the primary function of the MC74AC138DTR2G?
The primary function is to act as a high-speed 1-of-8 decoder/demultiplexer.
- What are the input and output configurations of the MC74AC138DTR2G?
The device has three binary weighted input addresses (A0, A1, A2) and eight mutually exclusive active-LOW outputs (O0-O7).
- How can the MC74AC138DTR2G be expanded for higher-order decoding?
It can be expanded to a 1-of-24 or 1-of-32 decoder using multiple MC74AC138/74ACT138 devices and an inverter if necessary.
- What is the output current capability of the MC74AC138DTR2G?
The outputs can source or sink up to 24 mA.
- Is the MC74AC138DTR2G compatible with TTL logic levels?
Yes, the ACT138 version is TTL compatible.
- What is the operating temperature range of the MC74AC138DTR2G?
The operating temperature range is -40°C to 85°C.
- What is the propagation delay of the MC74AC138DTR2G?
The propagation delay ranges from 6.5 to 10.5 ns at VCC = 5.0 V.
- What package type is the MC74AC138DTR2G available in?
The device is available in a TSSOP-16 package.
- Is the MC74AC138DTR2G available in Pb-free packages?
Yes, it is available in Pb-free packages.
- What are some common applications of the MC74AC138DTR2G?
Common applications include high-speed bipolar memory chip select address decoding, demultiplexing, and general logic circuits.
