An analog control system configured to operate a converter in an electric vehicle battery charging system is provided. The analog control system includes a pulse width modulation (PWM) output unit that is configured to output a PWM signal to the converter and an integrated control unit that is configured to sense an input voltage and an output voltage of the converter. The analog control system may be implemented on a printed circuit board having a first ground voltage stage connected to the PWM output unit, a second ground voltage stage separated from the first ground voltage stage by a first predetermined interval and connected to the integrated control unit. A filtering unit is disposed between the first ground voltage stage and the second ground voltage stage to pass an output signal of a predetermined band from the PWM unit to the integrated control unit.