  We present the results obtained from timing and spectral studies of Be/X-ray
binary pulsar EXO 2030+375 using observations with the Large Area Xenon
Proportional Counters and Soft X-ray Telescope of AstroSat, at various phases
of its Type-I outbursts in 2016, 2018, and 2020. The pulsar was faint during
these observations as compared to earlier observations with other
observatories. At the lowest luminosity of 2.5$\times$10$^{35}$ erg s$^{-1}$ in
0.5--30 keV energy range, $\approx$41.3 s pulsations were clearly detected in
the X-ray light curves. This finding establishes the first firm detection of
pulsations in EXO 2030+375 at an extremely low mass accretion rate to date. The
shape of the pulse profiles is complex due to the presence of several narrow
dips. Though pulsations were detected up to $\sim$80 keV when the source was
brighter, pulsations were limited up to $\sim$25 keV during the third AstroSat
observation at lowest source luminosity. A search for quasi-periodic
oscillations in 2$\times$10$^{-4}$ Hz to 10 Hz yielded a negative result.
Spectral analysis of the AstroSat data showed that the spectrum of the pulsar
was steep with a power-law index of $\sim$2. The values of photon-indices at
observed low luminosities follow the known pattern in sub-critical regime of
the pulsar.
