SN74AHCT125N quad channel non-inverting bus buffer with 3-state outputs

Description

Overview

The SN74AHCT125N from Texas Instruments is a quadruple non-inverting bus buffer featuring four independent logic channels with 3-state outputs. Each channel can pass a digital signal from its input to its output or disconnect its output by using the individual Output Enable (OE) control.

The AHCT logic family features TTL-compatible inputs, making the device particularly useful for interfacing lower-voltage logic signals with 5 V logic systems. The device operates from a 4.5 V to 5.5 V supply and is available in a through-hole 14-pin PDIP package.

Key Features

• Quadruple non-inverting bus buffer
• 4 independent logic channels
• 3-state outputs
• Individual Output Enable (OE) for each channel
• TTL-compatible CMOS inputs
• 4.5–5.5 V supply operation
• Up to ±8 mA output drive
• Through-hole DIP-14 / PDIP-14 package
• Suitable for digital signal buffering and logic-level interfacing
• High-impedance output state when disabled
• Designed for bus-oriented applications

Technical Specifications

TI currently lists the SN74AHCT125N as an active device in a 14-pin PDIP package with a −40°C to +125°C operating-temperature range.

Logic Operation

Each channel operates as a non-inverting buffer:

When OE is LOW, the output follows the input. When OE is HIGH, the output is placed into a high-impedance (Hi-Z) state, allowing multiple devices to share a common bus.

Pin Configuration

Power & Programming

• Supply voltage: 4.5–5.5 V
• Typical operation: 5 V
• No programming required.
• The device is controlled entirely through its digital inputs and Output Enable pins.
• A bypass capacitor should be placed close to the VCC and GND pins in practical PCB designs.
• Unused inputs should not be left floating; TI recommends tying unused inputs to VCC or GND.

Applications

• Digital bus buffering
• Logic signal buffering
• 3-state bus systems
• Microcontroller interfaces
• Logic-level interfacing
• Data bus isolation
• Memory and peripheral interfaces
• Signal distribution
• Digital control systems
• General-purpose 5 V logic circuits

What’s Included

• 1 × SN74AHCT125N Quad Non-Inverting Bus Buffer IC
• Package: DIP-14 / PDIP-14
• Through-hole

Notes

• The AHCT family uses TTL-compatible input thresholds, which makes it useful when interfacing logic signals to a 5 V system.
• Unlike a simple 74HC125, the 74AHCT125 should be powered from approximately 5 V within its specified operating range.
• The four channels are independently controlled through their respective OE inputs.
• When OE is HIGH, the corresponding output becomes high impedance rather than producing a logic HIGH or LOW.
• SN74AHCT125N is the TI PDIP-14 version; the same logic function is also available in other package variants.