74ACT125TTR

Buffers, Drivers, Receivers, Transceivers Overview

The STMicroelectronics 74ACT125TTR is a quad bus buffer with three-state outputs, manufactured using advanced sub-micron silicon gate and double-layer metal wiring C2MOS technology. It operates within a supply voltage range of 4.5V to 5.5V. The device features high-speed performance with a typical propagation delay of 5ns at VCC = 5V. It provides symmetrical output impedance with minimum drive currents of 24mA for both high and low states. The inputs are compatible with TTL levels, requiring a minimum high-level input voltage (VIH) of 2V and having a maximum low-level input voltage (VIL) of 0.8V. Quiescent supply current is typically 4μA at 25°C.

Buffers, Drivers, Receivers, Transceivers Feature Summary

• Advanced CMOS fabrication utilizing sub-micron silicon gate and double-layer metal wiring C2MOS technology for enhanced speed and density.
• High-speed operation capability designed for driving 50Ω transmission lines with balanced propagation delays.
• Robust protection circuits integrated on all inputs and outputs to provide immunity against static discharge up to 2KV ESD.
• Direct interface compatibility allowing connection between High-Speed CMOS systems and TTL, NMOS, or CMOS output voltage levels.

Buffers, Drivers, Receivers, Transceivers Applications

• Bus-oriented memory and address drivers
• Clock drivers and buffering
• Transceiver applications in communication systems

Buffers, Drivers, Receivers, Transceivers Procurement Notes

Verify the specific package type required, as the 74ACT125 series is available in DIP, SOP, and TSSOP configurations. Confirm that the design environment supports the specified operating temperature range of -55°C to 125°C. Ensure that power supply decoupling meets the requirements for the dynamic output current capabilities. Check for any specific ordering suffixes if tape and reel packaging is mandatory for the assembly process.

Buffers, Drivers, Receivers, Transceivers Selection Notes

Select this component when interfacing high-speed CMOS logic with TTL-compatible loads requiring strong drive capability. The symmetrical output impedance makes it suitable for applications demanding consistent signal integrity in both high and low states. Consider the 5ns propagation delay for timing-critical bus architectures. Verify that the 2V minimum VIH requirement aligns with the source logic family being used.

Buffers, Drivers, Receivers, Transceivers Part Context

This part belongs to the 74ACT logic family, which represents an evolution from standard 74HC devices by offering improved noise margins and faster switching speeds while maintaining CMOS power efficiency. The 'TTR' suffix indicates the device is supplied in a Tape and Reel format within a TSSOP-14 package. It serves as a direct functional replacement for the older 74S125 and 74LS125 families in terms of pinout and function, but with significantly higher performance characteristics.

Buffers, Drivers, Receivers, Transceivers Replacement Considerations

Public confirmed substitute part numbers include 74ACT125PW,118 from Nexperia USA Inc., SN74ACT125PWR from Texas Instruments, and MC74ACT125ADTR2G from onsemi. These alternatives maintain pin and function compatibility with the original 74ACT125 specification.

Buffers, Drivers, Receivers, Transceivers FAQ

What is the maximum quiescent supply current for the 74ACT125?

The maximum quiescent supply current (ICC) is 4μA at 25°C and increases to a maximum of 80μA across the full operating temperature range of -55°C to 125°C.

How does the 74ACT125 handle static discharge?

All inputs and outputs are equipped with protection circuits that provide 2KV ESD immunity and protection against transient excess voltage.

Is the 74ACT125 compatible with standard TTL logic levels?

Yes, the device is designed to interface directly with TTL, NMOS, and CMOS output voltage levels, featuring a minimum high-level input voltage (VIH) of 2V and a maximum low-level input voltage (VIL) of 0.8V.