Overview
The MC74AC138DG, 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 is available in Pb-free packages and supports various operating conditions, making it versatile for different applications.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC (Supply Voltage) | 2.0 | 5.0 | 6.0 | V |
| VIN (DC Input Voltage) | 0 | - | VCC | V |
| VOUT (DC Output Voltage) | 0 | - | VCC | V |
| TA (Operating Ambient Temperature Range) | -40 | - | 85 | °C |
| IOH (Output Current - High) | - | - | -24 | mA |
| IOL (Output Current - Low) | - | - | 24 | mA |
| tPLH (Propagation Delay An to On) | 6.5 | - | 10.5 | ns |
| tPHL (Propagation Delay An to On) | 6.0 | - | 10.0 | ns |
| Package Type | - | - | SOIC-16 | - |
Key Features
- Demultiplexing Capability: The device can function as an 8-output demultiplexer by using one of the active LOW Enable inputs as the data input and the other Enable inputs as strobes.
- Multiple Input Enable for Easy Expansion: Allows parallel expansion to a 1-of-24 decoder using three devices or a 1-of-32 decoder using four devices and one inverter.
- Active LOW Mutually Exclusive Outputs: All outputs are HIGH unless E1 and E2 are LOW and E3 is HIGH.
- Outputs Source/Sink 24 mA: Capable of sourcing or sinking up to 24 mA per output.
- TTL Compatible Inputs (ACT138): The ACT138 version has TTL compatible inputs.
- Pb-Free Packages: Available in Pb-free packages, ensuring compliance with environmental regulations.
Applications
- High-Speed Bipolar Memory Chip Select Address Decoding: Ideal for decoding addresses in high-speed memory applications.
- Demultiplexing: Can be used as an 8-output demultiplexer for data routing and selection.
- Decoder Expansion: Can be expanded to create higher-order decoders such as 1-of-24 or 1-of-32 decoders.
- General Digital Logic Circuits: Suitable for various digital logic applications requiring decoding and demultiplexing functions.
Q & A
- What is the primary function of the MC74AC138DG?
The primary function of the MC74AC138DG is to act as a high-speed 1-of-8 decoder/demultiplexer.
- What are the operating voltage ranges for the MC74AC138DG?
The operating voltage ranges are from 2.0 V to 6.0 V.
- How many outputs does the MC74AC138DG have?
The device has eight mutually exclusive active-LOW outputs (O0-O7).
- Can the MC74AC138DG be expanded to create higher-order decoders?
Yes, it can be expanded to create 1-of-24 or 1-of-32 decoders using multiple devices and an inverter.
- What is the maximum output current for the MC74AC138DG?
The outputs can source or sink up to 24 mA.
- Is the MC74AC138DG available in Pb-free packages?
Yes, the device is available in Pb-free packages.
- What is the propagation delay for the MC74AC138DG?
The propagation delay ranges from 6.5 ns to 10.5 ns depending on the conditions.
- What are the typical applications of the MC74AC138DG?
It is typically used in high-speed bipolar memory chip select address decoding, demultiplexing, and general digital logic circuits.
- What package types are available for the MC74AC138DG?
The device is available in SOIC-16 and TSSOP-16 packages.
- What is the operating temperature range for the MC74AC138DG?
The operating temperature range is from -40°C to 85°C.
