The 74LS series of integrated circuits (ICs) was one of the most popular logic families of transistor-transistor logic (TTL) logic chips. 74LS series is a bipolar, low-power Schottky IC. The 74LS138, decode one of eight lines dependent on the conditions at the three binary select inputs and the three enable inputs. Two active-low and one active-high enable inputs to reduce the need for external gates or inverters when expanding
- Decodes One-of-Eight Lines Based Upon the Select Inputs
- Inputs Clamped with Schottky Diodes
- Designed for Memory Decoders and Data Transmission Systems
- Operating Temperature up to 70°C
- Standard TTL Switching Voltages
|Supply Voltage||4.75 – 5.25Vdc|
|Maximum Clock Frequency||40Mhz|
|Power Dissipation||2mW/gate @100kHz|
|Minimum Output Current||8mA|
|Fan Out (TTL Loads)||20|
74LS138 Pinout Diagram
74LS138 Pin Description
|Pin No||Pin Name||Description|
|1||A0||Data Input Select Pin|
|2||A1||Data Input Select Pin|
|3||A2||Data Input Select Pin|
- Decoders are used to input data to a specified output line as is done in addressing core memory where input data is to be stored in a specified memory location.
- It is used in code conversions.
- In high-performance memory systems, this decoder can be used to minimize the effects of system decoding
74LS138 Alternative Equivalent
Download 74LS138 3 to 8 Decoder/Demultiplexer Datasheet from the link given below.