MC74VHC1GT126DT1

Overview

The MC74VHC1GT126DT1 is a single-gate noninverting 3-state buffer from the VHC logic family, manufactured by onsemi. It operates within a supply voltage range of 2.0 V to 5.5 V and features TTL-level input thresholds. The device provides high noise immunity through a buffered three-stage internal circuit and includes over-voltage tolerant inputs and outputs up to 5.5 V. It supports partial power down protection via IOFF and offers source/sink currents of 8 mA at 3.0 V. Typical propagation delay is 3.5 ns at 5 V with a 15 pF load.

Feature Summary

• Single-channel noninverting buffer with 3-state output capability for bus holding or signal isolation
• TTL-compatible input thresholds allowing direct interfacing with 5 V circuits while operating at lower voltages
• Over-voltage tolerant I/O structures protect against voltage mismatches during hot insertion or battery backup scenarios
• IOFF feature enables partial power down protection by limiting leakage current when VCC is zero

Applications

• Bus-oriented communications systems requiring signal buffering and isolation
• Clock distribution networks where low propagation delay and stable output are critical
• Memory and microcontroller interfaces utilizing 3-state control for data line management
• Consumer electronics and portable devices benefiting from low power consumption and small footprint packages

Procurement Notes

Verify the specific package suffix corresponds to the required mechanical form factor, as the DT1 designation implies a specific tape and reel shipping configuration. Confirm that the GT variant matches the system's input threshold requirements, distinguishing it from the standard G version which uses CMOS thresholds. Ensure the -Q suffix is not present if automotive qualification or unique site control is not required for the application.

Selection Notes

Select this component when a single-channel buffer with TTL input compatibility is needed in a compact surface-mount package. The VHC series offers faster switching speeds compared to standard HC logic while maintaining CMOS power efficiency. Consider the SC-74A or similar available packages based on board space constraints. Verify that the 8 mA drive strength meets the load requirements of the destination circuitry without exceeding maximum ratings.

Part Context

This part belongs to the MC74VHC1G126/MC74VHC1GT126 family of single noninverting buffers. The 'GT' suffix indicates TTL input thresholds, whereas the 'G' suffix denotes CMOS thresholds. The device is available in multiple tiny footprint packages including SC-88A, SC-74A, SOT-953, and UDFN6 variants. It is designed for applications requiring high density and low power operation in portable electronic equipment.

Replacement Considerations

MC74VHC1G126DT1G serves as a functional equivalent but utilizes CMOS input thresholds instead of TTL levels. MC74VHC1GT125DBVT1G is a compatible alternative offering an inverted output polarity rather than non-inverting. Designers must verify pinout compatibility and electrical characteristics such as input threshold voltages and drive strength when substituting these parts.