  Characterizing charge noise is of prime importance to the semiconductor spin
qubit community. We analyze the echo amplitude data from a recent experiment
[Yoneda et al., Nat. Nanotechnol. 13, 102 (2018)] and note that the data shows
small but consistent deviations from a $1/f^\alpha$ noise power spectrum at the
higher frequencies in the measured range. We report the results of using a
physical noise model based on two-level fluctuators to fit the data and find
that it can mostly explain the deviations. While our results are suggestive
rather than conclusive, they provide what may be an early indication of a
high-frequency cutoff in the charge noise. The location of this cutoff, where
the power spectral density of the noise gradually rolls off from $1/f$ to
$1/f^2$, crucial knowledge for designing precise qubit control pulses, is given
by our fit of the data to be around 200 kHz.
