  We report on the analysis of the AstroSat dataset of the accreting
millisecond X-ray pulsar SAX J1808.4-3658, obtained during its 2019 outburst.
We found coherent pulsations at $\sim 401$ Hz and an orbital solution
consistent with previous studies. The 3-20 keV pulse profile can be well fitted
with three harmonically related sinusoidal components with background-corrected
fractional amplitude of $\sim 3.5 \%$, $\sim 1.2 \%$ and $\sim 0.37 \%$ for
fundamental, second and third harmonic, respectively. Our energy-resolved pulse
profile evolution study indicate a strong energy dependence. We also observed a
soft lag in fundamental and hard lag during its harmonic. The broadband
spectrum of SAX J1808.4-3658 can be well described with a combination of
thermal emission component with $kT \sim 1$ keV, a thermal Comptonization
($\Gamma \sim 1.67$) from the hot corona and broad emission lines due to Fe.
