Features:
- The 74HC139 is a high-speed CMOS integrated circuit that provides two independent 1-of-4 Decoders/Demultiplexers.
- It is a versatile component commonly used in digital logic systems for decoding or routing signals.
- The 74HC139 decodes two binary weighted address inputs (nA0, nA1) to four mutually exclusive outputs (nY0 to nY3).
- Each decoder features an enable input (nE).
- When (nE) is HIGH all outputs are forced HIGH.
- The enable input can be used as the data input for a 1-to-4 demultiplexer application.
- Inputs include clamp diodes.
- This enables the use of current limiting resistors to interface inputs to voltages in excess of VCC.
- High-Speed Operation: Operates with a propagation delay of only a few nanoseconds, depending on supply voltage and load conditions.
- Wide Operating Voltage Range: Compatible with both 3.3V and 5V logic levels, typically ranging from 2V to 6V.
- Standard CMOS Logic: Fully compatible with TTL input levels for ease of integration in mixed-logic systems.
- Independent Operation: Two separate decoders/demultiplexers in one package.
- Active Low Outputs: Outputs are active low, which is standard for many digital logic applications.
- Enable Input: Each decoder can be individually enabled or disabled to conserve power or manage functionality.
- Low Power Consumption: Ideal for battery-powered devices or systems with strict power requirements.
Pin Assignments:

Specifications:
| Datasheet | 74HC139 |
| Product Type: | Decoders & Demultiplexes |
| Series: | 74HC |
| Model | 74HC139 |
| Technology: | CMOS |
| Logic Type: | Decoders/Demultiplexes |
| Number of Input Lines: | 2 Input |
| Number of Output Lines: | 4 Output |
| Number of Circuits: | 2 Circuit |
| Package/Case: | DIP-16 |
| Mounting Style: | Through Hole |
| Supply Voltage – Min: | 2 V |
| Supply Voltage – Max: | 6 V |
| High Level Output Current: | – 5.2 mA |
| Low Level Output Current: | 5.2 mA |
| Maximum Clock Frequency: | 28 MHz |
| Operating Supply Voltage: | 2 V to 6 V |
| Output Current: | – 4 mA, 4 mA |
| Supply Current – Max: | 80 µA |
| Propagation Delay Time: | 44 ns |
| Operating Temperature: | – 40 °C to + 85 °C |
Applications:
- Memory Address Decoding.
- Data Routing and Selection.
- Signal Multiplexing and Demultiplexing.
- Logic Function Generation.
- Digital Communication Systems.


