74LCX126MX

Overview

The Fairchild Semiconductor 74LCX126MX is a low-voltage quad buffer featuring five-state outputs, designed for high-speed digital applications. It operates within a supply voltage range of 2.0V to 5.5V and supports 5V tolerant inputs and outputs, enabling seamless interfacing between 3.3V and 5V logic systems. The device utilizes advanced CMOS technology to achieve propagation delays as low as 5.2ns at VCC = 3.3V while maintaining low power consumption. Packaged in a 14-pin TSSOP or SOIC format, it includes independent output enable controls for each pair of buffers, facilitating data bus management and signal buffering in portable and battery-powered electronics.

Feature Summary

• Provides four non-inverting buffer channels with independent output enable functionality
• Supports 5V tolerant inputs and outputs for mixed-voltage system compatibility
• Utilizes advanced CMOS technology for high-speed operation and low static power consumption

Applications

• Portable consumer electronics requiring low voltage operation
• Battery-powered equipment and handheld devices
• High-speed data bus buffering and line driving
• Mixed-voltage interface circuits between 3.3V and 5V logic domains

Procurement Notes

Verify the specific suffix (e.g., MX vs MTC) against the manufacturer's current datasheet to confirm package type and tape-and-reel specifications. Ensure the component meets RoHS compliance requirements if mandated by your assembly process. Cross-reference the ordering code with ON Semiconductor, the successor to Fairchild Semiconductor, to confirm availability and any potential nomenclature changes due to corporate integration.

Selection Notes

Select this component when designing systems that require bidirectional or unidirectional buffering between different voltage domains without level shifting circuitry. The 5V tolerance feature allows direct connection to legacy 5V buses while operating from a lower 3.3V or 2.5V supply. Consider the propagation delay and output drive capability relative to your clock speeds and load capacitance requirements to ensure signal integrity in high-frequency applications.

Part Context

This part belongs to the 74LCX series, which represents low-voltage CMOS logic optimized for performance and power efficiency. The LCX family bridges the gap between older LVC and newer HCT/VHC families, offering robust 5V tolerance alongside sub-nanosecond switching speeds. It is widely used in modern embedded systems where power conservation and voltage translation are critical design constraints.

Replacement Considerations

Equivalent parts include the NXP/ON Semiconductor 74LCX126MTC and Toshiba TC74LCX125F. Verify pinout compatibility and electrical characteristics such as propagation delay and output current before substitution.