Digital power supply circuit and liquid crystal driving device

1. A digital power supply circuit, comprising:

a power management module providing a digital supply voltage to a timing controller, the power management module having a first output terminal and an enable terminal, the first output terminal used for outputting the digital supply voltage, and the enable terminal used for controlling the power management module to be turned-on or turned-off; and

a controlling module, comprising:

an acquiring unit acquiring a rate of change of the digital supply voltage at an initial stage;

a comparing unit comparing the rate of change with a preset threshold value, so as to obtain a comparing result, thereby generating a control signal according to the comparing result; and

a voltage reducing unit pulling-down an input voltage of the enable terminal by using the control signal when the rate of change is greater than the preset threshold value, so as to turn-off the power management module;

wherein the acquiring unit comprises a first comparator and a capacitor, and the first comparator comprises a first input terminal, a second input terminal, and a second output terminal; the first input terminal is connected with the first output terminal through the capacitor, and the second input terminal is grounded; the first input terminal is also connected with the second output terminal; the second output terminal is used for outputting the rate of change of the digital supply voltage; and

the comparing unit comprises a second comparator which includes a third input terminal, a fourth input terminal, and a third output terminal; the preset threshold value is inputted into the third input terminal, and the fourth input terminal is connected with the second output terminal, and the third output terminal is used for outputting the control signal;

wherein the acquiring unit further comprises a second resistor, and a terminal of the second resistor is connected between the capacitor and the first input terminal, and another terminal of the second resistor is connected with the second output terminal.

2. The digital power supply circuit as claimed in claim 1 , wherein the acquiring unit further comprises a first resistor which is connected between the capacitor and the first output terminal.

3. The digital power supply circuit as claimed in claim 1 , wherein the voltage reducing unit comprises a control terminal, a fifth input terminal, and a fourth output terminal, and the fifth input terminal is connected with the enable terminal, the control terminal is connected with the third output terminal, and the fourth output terminal is grounded.

4. A digital power supply circuit, comprising:

a power management module providing a digital supply voltage to a timing controller, the power management module having a first output terminal and an enable terminal, the first output terminal used for outputting the digital supply voltage, and the enable terminal used for controlling the power management module to be turned-on or turned-off; and

a controlling module, comprising:

an acquiring unit acquiring a rate of change of the digital supply voltage at an initial stage;

a comparing unit comparing the rate of change with a preset threshold value, so as to obtain a comparing result, thereby generating a control signal according to the comparing result; and

a voltage reducing unit pulling-down an input voltage of the enable terminal by using the control signal when the rate of change is greater than the preset threshold value, so as to turn-off the power management module;

wherein the acquiring unit comprises a first comparator, and the first comparator comprises a first input terminal, a second input terminal, and a second output terminal;

the first input terminal is connected with the first output terminal, and the second input terminal is grounded; the first input terminal is also connected with the second output terminal; the second output terminal is used for outputting the rate of change of the digital supply voltage; and

wherein the acquiring unit further comprises a capacitor, a terminal of the capacitor is connected with the first output terminal, and another terminal of the capacitor is connected with the first input terminal.

5. The digital power supply circuit as claimed in claim 4 , wherein the acquiring unit further comprises a first resistor connected between the capacitor and the first output terminal.

6. The digital power supply circuit as claimed in claim 4 , wherein the acquiring unit further comprises a second resistor, and a terminal of the second resistor is connected between the capacitor and the first input terminal, and another terminal of the second resistor is connected with the second output terminal.

7. The digital power supply circuit as claimed in claim 4 , wherein the comparing unit comprises a second comparator which includes a third input terminal, a fourth input terminal, and a third output terminal; and

the preset threshold value is inputted into the third input terminal, and the fourth input terminal is connected with the second output terminal, and the third output terminal is used for outputting the control signal.

8. The digital power supply circuit as claimed in claim 7 , wherein the voltage reducing unit comprises a control terminal, a fifth input terminal, and a fourth output terminal, and the fifth input terminal is connected with the enable terminal, the control terminal is connected with the third output terminal, and the fourth output terminal is grounded.

9. A liquid crystal driving device, comprising:

a digital power supply circuit, comprising:

a power management module providing a digital supply voltage to a timing controller, the power management module having a first output terminal and an enable terminal, the first output terminal used for outputting the digital supply voltage, and the enable terminal used for controlling the power management module to be turned-on or turned-off; and

a controlling module, comprising:

an acquiring unit acquiring a rate of change of the digital supply voltage at an initial stage;

a comparing unit comparing the rate of change with a preset threshold value, so as to obtain a comparing result, thereby generating a control signal according to the comparing result; and

a voltage reducing unit pulling-down an input voltage of the enable terminal using the control signal when the rate of change is greater than the preset threshold value, so as to turn-off the power management module;

wherein the acquiring unit comprises a first comparator, and the first comparator comprises a first input terminal, a second input terminal, and a second output terminal;

the first input terminal is connected with the first output terminal, and the second input terminal is grounded; the first input terminal is also connected with the second output terminal; the second output terminal is used for outputting the rate of change of the digital supply voltage;

wherein the acquiring unit further comprises a capacitor, a terminal of the capacitor is connected with the first output terminal, and another terminal of the capacitor is connected with the first input terminal.

10. The liquid crystal driving device as claimed in claim 9 , wherein the acquiring unit further comprises a first resistor connected between the capacitor and the first output terminal.

11. The liquid crystal driving device as claimed in claim 9 , wherein the acquiring unit further comprises a second resistor, and a terminal of the second resistor is connected between the capacitor and the first input terminal, and another terminal of the second resistor is connected with the second output terminal.

12. The liquid crystal driving device as claimed in claim 9 , wherein the comparing unit comprises a second comparator which includes a third input terminal, a fourth input terminal, and a third output terminal; and

the preset threshold value is inputted into the third input terminal, and the fourth input terminal is connected with the second output terminal, and the third output terminal is used for outputting the control signal.

13. The liquid crystal driving device as claimed in claim 12 , wherein the voltage reducing unit comprises a control terminal, a fifth input terminal, and a fourth output terminal, and the fifth input terminal is connected with the enable terminal, the control terminal is connected with the third output terminal, and the fourth output terminal is grounded.