  We introduce a new experimental effort at Jefferson Lab (JLab) to precisely
measure the ratios of charged pion electroproduction in Semi-Inclusive Deep
Inelastic Scattering (SIDIS) from $^2$D, $^3$He, and $^3$H targets
\cite{c12-21-004}. This conditionally approved experiment (C12-21-004) aims to
run in Hall-B using the standard CLAS12 configuration and a new target system
developed for the approved quasi-elastic experiment (E12-20-005). In this
data-driven study, we will measure the cross-sections as a function of ($x$,
$Q^2$, $z$, $P_T$) to allow the extraction of the unpolarized parton
distribution functions (PDFs), transverse momentum distributions (TMDs) and
fragmentation functions (FFs) in A = 3 nuclei. By using super-ratios of pion
yields of SIDIS off light nuclei over a wide $x_B$ range, we search for
evidence of a flavor dependence in the EMC effect, giving us new insights into
the effect of the nuclear environment on valance quarks. Double-ratios between
A = 3 mirror nuclei can provide a direct measurement of the d/u ratios at large
x due to their similar and well-understood nuclear corrections. With the
utilization of mirror nuclei and the large kinematic range, and high precision
of CLAS12, we will be able to maintain the sensitivity to the underlying
physics but dramatically decrease the nuclear uncertainties due to attenuation
and hadronization in heavy nuclei targets.
