An input buffer using a frequency dependent impedance circuit to compensate for nonlinearity in low frequency is shown. In a pseudo-differential architecture, a frequency-dependent impedance circuit is coupled between the drain of a positive input transistor of the flipped voltage follower and the drain of a negative input transistor of the flipped voltage follower. In a single-ended architecture, the frequency-dependent impedance circuit is coupled between the drain of an input transistor of the flipped voltage follower and an alternating current ground. The frequency-dependent impedance circuit includes a capacitor.