Voltage regulator and display device

A voltage regulator for outputting a pixel power supply voltage supplied to pixels of a display panel, the voltage regulator comprising:

• a voltage divider configured to generate a feedback voltage by dividing the pixel power supply voltage;
• an error amplifier configured to generate an amplifier output voltage by comparing a reference voltage and the feedback voltage;
• a first transistor including a gate connected to a gate of a pass transistor, a first terminal for receiving a power supply voltage, and a second terminal;
• a first resistor including a first terminal connected to the second terminal of the first transistor, and a second terminal;
• a first capacitor including a first electrode connected to the second terminal of the first resistor, and a second electrode connected to an amplifier output node at which the amplifier output voltage is output;
• a second transistor including a gate connected to the amplifier output node, a first terminal connected to the gate of the pass transistor, and a second terminal for receiving a ground voltage;
• a variable current source connected between a line for transferring the power supply voltage and the gate of the pass transistor;
• and
• the pass transistor including the gate connected to the gate of the first transistor and the first terminal of the second transistor, a first terminal for receiving an input voltage, and a second terminal connected to an output node at which the pixel power supply voltage is output.

A display device comprising:

• a display panel including a plurality of pixels;
• a data driver configured to provide data signals to the plurality of pixels;
• a scan driver configured to provide scan signals to the plurality of pixels;
• an emission driver configured to provide emission signals to the plurality of pixels;
• a controller configured to control the data driver, the scan driver and the emission driver;
• and
• a voltage regulator configured to supply a pixel power supply voltage to the plurality of pixels, the voltage regulator comprising:
• a voltage divider configured to generate a feedback voltage by dividing the pixel power supply voltage;
• an error amplifier configured to generate an amplifier output voltage by comparing a reference voltage and the feedback voltage;
• a variable phase compensating circuit configured to adjust the amplifier output voltage according to a load current;
• a source follower buffer configured to generate a control voltage by buffering the adjusted amplifier output voltage;
• and
• a pass transistor configured to output, as the pixel power supply voltage, an input voltage based on the control voltage.