The analytical noise model of HgCdTe focal plane array (FPA) pixel based on capacitive transimpedance amplifier (CTIA) is presented. It allows to evaluate the noise-equivalent power (NEP) and input dynamic range (IDR) of short-wavelength infrared HgCdTe FPA. The noise model takes into account the following noise mechanisms: photodiode shot noise due to fluctuations of the radiation flux and dark current, thermal noises of a photodiode and a unit cell of a silicon readout integrated circuit (ROIC), reset noise, 1/f noises of a photodiode and an ROIC unit cell. The theoretical dependencies of NEP and IDR for p-on-n HgCdTe FPA with sensitivity in 2–3 μm band operating at 170 K are presented.