Non-inverting amplifier and voltage supply circuit including the same

A voltage supply circuit, comprising:

• a digital-to-analog converter that generates an analog voltage according to a digital value;
• and
• at least one non-inverting amplifier that transfers an output voltage of the digital-to-analog converter,
• wherein the at least one non-inverting amplifier comprises:
• an operational amplifier that amplifies and outputs a difference between an input voltage and a voltage of a control node;
• an input resistor connected between a reference voltage port and the control node;
• and
• a feedback resistor connected to an output port of the operational amplifier and the control node,
• wherein the at least one non-inverting amplifier supplies a control current to the control node for controlling an offset voltage of the output port.

An apparatus for controlling an offset voltage of an operational amplifier having a non-inverting input port, an inverting input port, an output port, a feedback resistor coupled between the output port and the non-inverting input port, and an input resistor coupled between the non-inverting port and a reference voltage port, when an input voltage applied to the non-inverting input port of the non-inverting amplifier is substantially 0 V, the apparatus comprising:

• a control node coupled to the non-inverting port;
• and
• a plurality of current sources connectable in parallel,
• wherein each of the current sources is connected in series to a respective switch such that a switching operation controls each of the respective switches to supply a desired control current to the control node according to a decoded digital value comprising a sequence of digital bits, each digital bit being associated with an on-off condition of each of the respective switches.