A semiconductor memory apparatus includes: a compensation voltage input node; a core voltage generator configured to generate a core voltage using an external power source voltage and supply the core voltage to the compensation voltage input node; a compensation controlling unit configured to generate a compensation control signal to determine power compensation, in response to a refresh signal; a power compensating unit configured to selectively supply the external power source voltage to the compensation voltage input node in response to the compensation control signal; and a power supply unit configured to supply a voltage at the compensation voltage input node or the external power source voltage to a sense-amp driver in response to a first power control signal or a second power control signal.