74LS245 DIP Octal Bidirectional Bus Transceiver with Non-Inverting 3-State Outputs
The 74LS245 is a high speed TTL integrated circuit designed for 8-bit asynchronous bidirectional communication between data buses. This device features eight non-inverting transceivers with 3-state outputs, making it one of the most widely used components for interfacing microprocessors with memory and peripheral devices. It allows for the efficient transfer of a full byte of data while providing the ability to isolate buses to prevent signal contention.
The IC is controlled by two primary inputs: the Direction (DIR) pin and the Output Enable (G) pin. The DIR input determines the direction of data flow (from Bus A to Bus B or from Bus B to Bus A), while the active-low G input enables the device or places all sixteen I/O pins into a high-impedance state. The 74LS245 is engineered with high-current drive capabilities, ensuring it can handle the high-capacitance loads found in complex bus-oriented systems and backplanes.
KEY FEATURES
- 8-bit bidirectional data transfer in a single 20-pin package
- Non-inverting 3-state outputs for direct bus interfacing
- Dedicated Direction control and Output Enable inputs
- High-current sink and source capability for driving heavy bus loads
- Low power Schottky technology for high speed and reliability
- Standard 20 pin dual in line package
SPECIFICATIONS
- Supply Voltage 4.75V to 5.25V
- Operating Temperature 0 to 70 Celsius
- Logic Type TTL Low Power Schottky
- Typical Propagation Delay 12ns
- High Level Output Current -15mA
- Low Level Output Current 24mA
- Input Voltage High 2.0V Minimum
INTERFACES
- A1 to A8 Bidirectional data port A
- B1 to B8 Bidirectional data port B
- DIR Direction control input (High A to B, Low B to A)
- G BAR Output enable input active low
- VCC Positive supply voltage
- GND Ground reference
