MC74ACT245DTG

Overview

The MC74ACT245DTG is an octal bidirectional transceiver with three-state outputs manufactured by onsemi. It operates within a supply voltage range of 4.5 V to 5.5 V and features TTL-compatible inputs. The device provides non-inverting buffers with a propagation delay of up to 9.0 ns at 5.0 V. It supports a maximum output current of 24 mA for both sourcing and sinking. The component is housed in a TSSOP-20 package and functions across an ambient temperature range from -40°C to +85°C.

Feature Summary

• TTL-compatible input thresholds allow direct interfacing with standard logic families
• Bidirectional data path controlled by a single Transmit/Receive pin
• High drive capability with 24 mA source and sink currents at both ports

Applications

• Bus-oriented memory and instrument control systems
• Clock drivers and bus transceivers
• Bidirectional data flow applications requiring high impedance states

Procurement Notes

Verify the specific ordering suffix 'DTG' corresponds to the TSSOP-20 package configuration. Confirm that the procurement specification requires the ACT logic family, which mandates a 4.5 V to 5.5 V supply voltage, rather than the AC family. Ensure environmental compliance requirements match the lead-free designation indicated by the suffix.

Selection Notes

Select this part when a wide operating voltage range is not required but TTL compatibility is necessary. The ACT series offers faster switching speeds compared to standard AC devices at 5.0 V. Consider the TSSOP-20 package dimensions if board space is constrained relative to the SOIC-20 alternative.

Part Context

This component belongs to the MC74AC245/MC74ACT245 family of octal bus transceivers. The ACT variant specifically integrates TTL-compatible input structures while maintaining CMOS output characteristics. This combination facilitates seamless integration between different logic families in mixed-voltage digital systems.

Replacement Considerations

MC74ACT245DWG (SOIC-20 package)

FAQ

What determines the direction of data flow?

The Transmit/Receive (T/R) input determines the direction. A HIGH level enables data transfer from port A to port B, while a LOW level enables transfer from port B to port A.

How does the Output Enable (OE) pin function?

When the OE input is HIGH, both port A and port B are disabled and placed in a High Z state, effectively isolating the device from the bus.