TXS0206: How long PCB trace (6 mile width) can be driver by TXS0206 output?

Hi Thomas,

TXS doesn't provide active drive, however, provides momentary AC drive through its one-shot edge acceleration circuitry.

All the drive will come from the host( from high to low) and through the internal pullup resistor (low to high).

Hi Thomas,

Short answer - I'd try to stay under 20 cm.

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Long answer

Do you know the board material? (FR4? ε_r = 4.2?)

Is there a ground plane? What about the board thickness (d)?

How thick is the copper? 1 oz?

For line capacitance:

C = ε₀ ε_r A / d

A = width * length

We recommend to keep the load capacitance below 70pF, but it's really best to keep it as low as possible. Assuming some #'s from my questions above -- using FR4 material at 62 mil thickness (d), and keeping the trace capacitance low (7pF):

* converting all units to m instead of mil to match the ε₀ units:

C = 7pF = 4.2 * 8.854 * 10^-12 * 0.0001524 * length / 0.0015748

length (7pF) = 1.95m

That's just calculating capacitance, however. Next up would be problems associated with resistivity:

1 oz copper is said to have ~ 0.5 mΩ of resistance per square.  That means that 1m of 6 mil trace should give a resistance of:

1m/(6mil) * 0.5mΩ = 3.28 Ω. it doesn't look like this would be an issue for quite some distance.

You also will see some inductance due to line length - this is best calculated using one of the online calculators avialable.. I don't know of a simple/quick way like the above solutions.

Other problems show up due to transmission line effects... which will start to occur around 20cm.  This is the most restrictive value on the list, so I would go with that as the maximum length.

Generally speaking, I'd recommend keeping traces as short as possible, and make sure to round corners to prevent reflections and current flow issues.