Patent ID: 8274305

Claim:
A linear voltage generating device for testing performance of a power supply, comprising: a comparator circuit for receiving a pulse width modulation (PWM) signal, and comparing the PWM signal with a reference voltage to output a filtered PWM signal; an analog to digital (A/D) conversion circuit for receiving the filtered PWM signal, and converting the filtered PWM signal to a linear digital signal; and an amplifier circuit for receiving the linear digital signal, and outputting an amplified linear digital signal to an electric load electrically coupled to the power supply; wherein the amplifier circuit comprises a second amplifier, and a fourth resistor; a non inverting input terminal of the second amplifier is adapted to receive the linear digital signal; an inverting input terminal of the second amplifier is electrically coupled to an output terminal of the second amplifier via the fourth resistor; the second amplifier output terminal is adapted to output the amplified linear digital signal; a voltage level of the second amplifier output terminal is equal to a voltage level of the second amplifier non inverting input terminal; and a current of the second amplifier output terminal is amplified.