High-Impedance Buffer

Jordan1x — Wed, 10 Dec 2025 22:06:22 GMT

Hi everyone,

I’m working on a small digital logic project and I’m considering using a 74HCT1G126GV as a buffer/line driver. The part is a single-channel buffer with 3-state output and a supply range of 2–5.5 V, so it’s ideal for mixed-voltage logic interfaces. The datasheet is here.

My plan is to place the 74HCT1G126 between a microcontroller output and a shared bus or external module. Because the output can be disabled (tri-state), I can avoid bus conflicts when multiple devices share the same lines. It’s also useful for isolating noisy parts of a circuit or for level shifting/helping drive loads that the MCU can’t handle directly.

Before I build, I have a few questions and I’d love your input:

Is it okay to rely on the 74HCT1G126’s 3-state behavior for shared-bus applications, or are there timing or leakage pitfalls I should watch out for? For mixed-voltage interfacing (e.g. 5 V logic driving 3.3 V), how reliable is the HCT buffer in real-life use? Any known gotchas regarding signal integrity or margins? When placing this buffer on a PCB, what layout practices would you recommend (trace routing, decoupling, pull-ups/pull-downs for high-Z)?

Thanks in advance!

topic High-Impedance Buffer in Other NXP Products

High-Impedance Buffer