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. 74LS245 octal bus transceiver is designed for asynchronous two-way communication between data buses. The control function implementation minimizes external timing requirements.

74LS245 Features
- Tri-State Outputs Drive Bus Lines Directly
- PNP Inputs Reduce DC Loading on Bus Lines
- Hysteresis Inputs
- Designed for use as Bus Oriented Transmitters/Receivers
- Standard TTL Switching Voltages
74LS245 Specifications
Supply Voltage | 4.75 – 5.25Vdc |
Maximum Clock Frequency | 40Mhz |
Power Dissipation | 2mW/gate @100kHz |
Minimum Output Current | 8mA |
Propagation Delay | 10nS |
Fan Out (TTL Loads) | 20 |
74LS245 Pinout Diagram

74LS245 Pin Description
Pin No | Pin Name | Description |
1 | DIR | Controls signal direction; Low = Bx to Ax, High = Ax to Bx |
2 | A1 | Channel 1, (A) side |
3 | A2 | Channel 2, (A) side |
4 | A3 | Channel 3 Of Transceiver (A) |
5 | A4 | Channel 4 Of Transceiver (A) |
6 | A5 | Channel 5 Of Transceiver (A) |
7 | A6 | Channel 6 Of Transceiver (A) |
8 | A7 | Channel 7 Of Transceiver (A) |
9 | A8 | Channel 8 Of Transceiver (A) |
10 | GND | Ground |
11 | B8 | Channel 8 Of Transceiver (B) |
12 | B7 | Channel 7 Of Transceiver (B) |
13 | B6 | Channel 6 Of Transceiver (B) |
14 | B5 | Channel 5 Of Transceiver (B) |
15 | B4 | Channel 4 Of Transceiver (B) |
16 | B3 | Channel 3 Of Transceiver (B) |
17 | B2 | Channel 2 Of Transceiver (B) |
18 | B1 | Channel 1 Of Transceiver (B) |
19 | OE’ | Enable Output Active Low |
20 | VCC | Positive Supply |
Applications
- Transmit the data in the form of voice or data or video over the wireless medium.
74LS245 Alternative Equivalent
74LS243
Download 74LS245 Octal Bus Transceiver Tri-State Datasheet from the link given below.