Example embodiments relate to a voltage converter having a power switching unit, an analog-digital converting (ADC) unit, a digital low pass filter (LPF), an error value (EV) calculator, and a switching signal generator. The power switching unit may generate an output voltage by switching between an output terminal and one of the power voltage and the ground voltage in response to a switching signal. The ADC unit may output a converted power level signal and a converted output level signal. The EV calculator may generate an EV by comparing a low pass filtered power level signal and a low pass filtered output level signal output from the digital LPF, and an output set value. The switching signal generator may generate the switching signal for adjusting a time interval during which the output terminal is connected to one of the power voltage and the ground voltage.