What is the difference between the normal buffer and the clock buffer?

Clock buffers are designed to maintain a clean and balanced clock signal—so they have equal rise and fall times, which helps avoid duty cycle distortion. We usually place them in higher metal layers and give them higher drive strength to handle longer distances and higher fanouts. On the other hand, normal buffers, or data buffers, are more relaxed in terms of timing—so you don’t need perfect symmetry in rise/fall times. They’re typically smaller and use less power, which is fine for most signal paths that don’t need such precision.

if you're dealing with clock trees, you must use clock buffers because they’re specially built to handle the strict timing requirements. You get more stability with clock buffers due to their reduced delay variations across different process, voltage, and temperature (PVT) conditions.

I once made the mistake of using a regular buffer in part of a clock tree, and we ended up with timing violations due to pulse width issues. We never do that now. For regular data paths, though, you can stick with normal buffers since you don’t need such tight control over signal balance and delay.

clock buffers are like premium highways for timing signals: balanced, wide, and built for speed. I usually go for clock buffers when I need consistent rise and fall times, especially when the clock is driving many flip-flops. We also place clock buffers with their pins accessible in higher metal layers to align with clock routing. But if you’re just buffering a data line or a control signal, a normal buffer does the job and saves area and power. So I’d say it really depends on what signal you’re handling.