Power manager controlling supply of driving voltages preventing display panel damage

1 . A power manager, comprising:

a first driving voltage generator which supplies a first driving voltage to a first power line, wherein the first driving voltage generator includes:

a first driving voltage converter which generates the first driving voltage by converting an input voltage supplied from an exterior;

a first comparator which compares the voltage of the first power line and a first reference voltage; and

a first determiner which outputs a first shutdown signal to the first driving voltage converter in response to an output signal of the first comparator; and

a second driving voltage generator which supplies a second driving voltage to a second power line, wherein a voltage level of the second driving voltage is lower than a voltage level of the first driving voltage,

wherein, during an initial driving period in which the first driving voltage is supplied to the first power line and before the second driving voltage is supplied to the second power line, the second driving voltage generator senses a voltage of the second power line, and a supply of the first driving voltage is controlled based on the voltage of the second power line,

wherein the initial driving period includes a pre-charge period and during the pre-charge period the first driving voltage has a first voltage level that is equal to an input voltage of the first driving voltage generator and after the pre-charge period the first driving voltage generator increases the first driving voltage to a second voltage level that is greater than the first voltage level,

wherein the first determiner outputs the first shutdown signal when the voltage of the first power line is less than the first reference voltage,

wherein the first comparator is active solely during the pre-charge period, and

wherein the first comparator is activated by a first sensing signal during at least a part of the pre-charge period and is deactivated at an end of the pre-charge period.

2 . The power manager of claim 1 , wherein the second driving voltage generator includes:

a second driving voltage converter which generates the second driving voltage by converting an input voltage supplied from the exterior;

a second comparator which compares the voltage of the second power line and a second reference voltage; and

a second determiner which outputs a second shutdown signal to the first driving voltage generator in response to an output signal of the second comparator.

3 . The power manager of claim 2 , wherein the second driving voltage converter includes:

a third transistor connected between a second input terminal which receives the input voltage and a second intermediate node, wherein the third transistor operates in response to a third control signal;

a second inductor connected between the second intermediate node and a ground node; and

a fourth transistor connected between the second intermediate node and the second power line, wherein the fourth transistor operates in response to a fourth control signal.

4 . The power manager of claim 2 , wherein the second comparator is activated during at least a part of the initial driving period and deactivated after the initial driving period.

5 . The power manager of claim 2 , wherein the second determiner outputs the second shutdown signal when the voltage of the second power line is greater than or equal to the second reference voltage.

6 . The power manager of claim 2 , wherein the first driving voltage generator stops the supply of the first driving voltage in response to the second shutdown signal.

7 . The power manager of claim 1 , wherein, during the pre-charge period the first driving voltage generator senses a voltage of the first power line, and controls the supply of the first driving voltage based on the voltage of the first power line.

8 . The power manager of claim 7 , wherein the first driving voltage converter includes:

a first inductor connected between a first input terminal which receives the input voltage and a first intermediate node;

a first transistor connected between the first intermediate node and a ground node, wherein the first transistor operates in response to a first control signal; and

a second transistor connected between the first intermediate node and the first power line, wherein the second transistor operates in response to a second control signal.

9 . The power manager of claim 7 , wherein the first driving voltage converter stops a generation of the first driving voltage in response to the first shutdown signal.

10 . A method of driving a power manager, the method comprising:

supplying a first driving voltage to a first power line;

sensing a voltage of a second power line during an initial driving period in which the first driving voltage is supplied to the first power line and before a second driving voltage is supplied to a second power line, wherein a voltage level of the second driving voltage is lower than a voltage level of the first driving voltage;

controlling a supply of the first driving voltage based on the voltage of the second power line;

sensing a voltage of the first power line during a pre-charge period in which the first driving voltage having a first voltage level is supplied to the first power line and before the first driving voltage having a second voltage level higher than the first voltage level is supplied to the first power line;

controlling the supply of the first driving voltage based on the voltage of the first power line; and

outputting a first shutdown signal when the voltage of the first power line is less than a first reference voltage,

wherein the initial driving period includes a pre-charge period and during the pre-charge period the first driving voltage has a first voltage level that is equal to an input voltage of the first driving voltage generator and after the pre-charge period the first driving voltage generator increases the first driving voltage to a second voltage level that is greater than the first voltage level,

wherein comparing the voltage of the first power line and the first reference voltage is performed by a first comparator that is active solely during the pre-charge period, and

wherein the first comparator is activated by a first sensing signal during at least a part of the pre-charge period and is deactivated at an end of the pre-charge period.

11 . The method of claim 10 , wherein controlling the supply of the first driving voltage based on the voltage of the second power line includes:

comparing the voltage of the second power line and a second reference voltage; and

stopping the supply of the first driving voltage when the voltage of the second power line is greater than or equal to the second reference voltage.

12 . The method of claim 11 , further comprising:

supplying the second driving voltage to the second power line when the voltage of the second power line is less than the second reference voltage.

13 . The method of claim 10 , wherein controlling the supply of the first driving voltage based on the voltage of the first power line includes:

comparing the voltage of the first power line and the first reference voltage; and

stopping the supply of the first driving voltage when the voltage of the first power line is less than the first reference voltage.

14 . A display device, comprising:

a display panel which includes a pixel;

a scan driver which supplies a scan signal to the pixel;

a data driver which supplies a data signal to the pixel; and

a power manager which supplies a first driving voltage and a second driving voltage to the pixel, wherein a voltage level of the second driving voltage is lower than a voltage level of the first driving voltage,

wherein the power manager includes:

a first driving voltage generator which supplies the first driving voltage to the pixel through a first power line; and

a second driving voltage generator which supplies the second driving voltage to the pixel through a second power line,

wherein, during an initial driving period in which the first driving voltage is supplied to the first power line and before the second driving voltage is supplied to the second power line, the second driving voltage generator senses a voltage of the second power line, and a supply of the first driving voltage is controlled based on the voltage of the second power line,

wherein the initial driving period includes a pre-charge period and the during pre-charge period the first driving voltage has a first voltage level that is equal to an input voltage of the first driving voltage generator and after the pre-charge period the first driving voltage generator increases the first driving voltage to a second voltage level that is greater than the first voltage level,

wherein a first determiner of the first driving voltage generator outputs a first shutdown signal when the voltage of the first power line is less than a first reference voltage,

wherein the first driving voltage generator includes a first comparator that is active solely during the pre-charge period, and

wherein the first comparator is activated by a first sensing signal during at least a part of the pre-charge period and is deactivated at an end of the pre-charge period.

15 . The display device of claim 14 , wherein, during the pre-charge period the first driving voltage generator senses a voltage of the first power line, and controls the supply of the first driving voltage based on the voltage of the first power line.

16 . The display device of claim 14 , wherein the pixel includes:

a driving transistor connected between the first power line and a first node, wherein the driving transistor operates in response to a voltage of a second node;

a switching transistor connected between a data line 103 which transmits the data signal and the second node, wherein the switching transistor operates in response to the scan signal;

a storage capacitor connected between the first power line and the second node; and

a light emitting diode connected between the first node and the second power line.