The 74LS138 decodes one of eight lines dependent on the conditions at the three binary select inputs and the three enable inputs. It is intended to function in high-performance memory-decoding or data-routing applications, requiring very short propagation delay times. The output of the IC always comes in TTL which makes it easy to work with other TTL devices and microcontrollers. The IC 74LS138 is smaller in size and it has a much faster speed which makes it reliable in every kind of device.
What is a Decoder/Demultiplexer?
A Demultiplexer is a data distributor, it takes one single input data line and distributes it to any one of a number of individual output lines one at a time. Demultiplexing is the process of converting a signal containing multiple analog or digital signals backs into the original and separate signals.
74LS138 Pinout
74LS138 Pin Configuration
| Pin No | Pin Name | Description |
|---|---|---|
| 1 | A0 | Address Input Pin A0 |
| 2 | A1 | Address Input Pin A1 |
| 3 | A2 | Address Input Pin A2 |
| 4 | E1′ | Active Low Enable Input E1′ |
| 5 | E2′ | Active Low Enable Input E2′ |
| 6 | E3 | Active high Enable Input E3 |
| 7 | O7′ | Active Low Output pin O7 |
| 8 | GND | Ground Pin |
| 9 | O6′ | Active Low Output pin O6 |
| 10 | O5′ | Active Low Output pin O5 |
| 11 | O4′ | Active Low Output pin O4 |
| 12 | O3′ | Active Low Output pin O3 |
| 13 | O2′ | Active Low Output pin O2 |
| 14 | O1′ | Active Low Output pin O1 |
| 15 | O0′ | Active Low Output pin O0 |
| 16 | Vcc | Chip Supply Voltage |
74LS138 Features & Specifications
- Technology Family: LS
- Rating: Catalog
- Supply voltage: 1.0V to 5.5V
- Frequency at nominal voltage: 35 MHz
- Typical propagation delay: 21nS
- Low power consumption: 32mW
- Operating temperature: -40ºC to +125ºC
- ESD protection
- Balanced propagation delays
- Designed specifically for high speed
- Channels (#): 1
- Configuration: 3:8
- Product type: Standard
Applications
- Serves the function of Speed synchronization of multiple motors in industries
- Also used in War field flying robot with a night vision flying camera
- Robotic vehicle with the metal detector
You can download this Datasheet for 74LS138 1-To-8 Decoder/Demultiplexer from the link given below:
See Also: 74LS94 4-Bit Serial In-Out Shift Register IC | 74LS48 BCD-to-7 Segment Decoder/Driver IC | 74LS28 Quad 2–Input NOR Buffer IC
