Apparatus and method controlling peak to peak ripple of charge pump output voltage

1 . An apparatus controlling peak-to-peak ripple in an output voltage, the apparatus comprising:

a feedback mechanism configured to generate a feedback voltage in response to the output voltage;

a pump regulator configured to compare the feedback voltage and a reference voltage to generate a control voltage;

a voltage control unit configured to generate a multi-phase clock signal in response to the control voltage;

a charge pump unit configured to generate the output voltage in response to the multi-phase clock signal and an input supply voltage;

a low voltage detector configured to generate a control signal and detect whether the input supply voltage has a first voltage level or a second voltage level, wherein the second voltage level is greater than the first voltage level; and

an input supply voltage adjustment circuit configured to adjust a level of the input supply voltage in response to the control signal,

wherein the input supply voltage adjustment circuit includes a first circuit component and a second circuit component,

and wherein the second circuit component is configured to reduce the input supply voltage and pass the reduced input supply voltage to the charge pump unit in response to detecting that the input supply voltage has the second voltage level, and

wherein the first circuit component is in parallel with the second circuit component.

2 . The apparatus of claim 1 , wherein the low voltage detector is configured to compare the input supply voltage with the reference voltage and to generate the control signal based on a result of the comparison.

3 . The apparatus of claim 1 , wherein the input supply voltage adjustment circuit comprises:

a selecting component configured to dynamically adjust the level of the input supply voltage by selecting between the first circuit component and the second circuit component in response to the control signal.

4 . The apparatus of claim 1 , wherein

upon detecting that the input supply voltage has the first voltage level, the low voltage detector is further configured to generate the control signal such that the first circuit component is turned ON, and

the input supply voltage is passed directly to the charge pump unit when the first circuit component is turned ON.

5 . The apparatus of claim 1 , wherein

upon detecting that the input supply voltage has the second voltage level, the low voltage detector is further configured to generate the control signal such that the first circuit component is turned OFF, and

the input supply voltage is passed to the charge pump unit through the second circuit component when the first circuit component is turned OFF.

6 . The apparatus of claim 1 , wherein the first circuit component includes at least one of a power switch and a first voltage-controlled resistor.

7 . The apparatus of claim 6 , wherein the second circuit component includes at least one of a diode and a second voltage-controlled resistor.

8 . The apparatus of claim 1 , wherein the output voltage is a programming voltage used to program a memory cell of a memory device.

9 . The apparatus of claim 1 , wherein the charge pump unit includes multiple charge pump stages.

10 . An apparatus controlling peak-to-peak ripple in an output voltage, the apparatus comprising:

a charge pump unit configured to generate the output voltage in response to an input supply voltage;

a low voltage detector configured to generate a control signal and detect whether the input supply voltage has a first voltage level or a second voltage level, wherein the second voltage level is greater than the first voltage level; and

an input supply voltage adjustment circuit configured to adjust a level of the input supply voltage in response to the control signal,

wherein the input supply voltage adjustment circuit includes a first circuit component and a second circuit component,

wherein the second circuit component is configured to reduce the input supply voltage and pass the reduced input supply voltage to the charge pump unit in response to detecting that the input supply voltage has the second voltage level, and

wherein the first circuit component is in parallel with the second circuit component.

11 . The apparatus of claim 10 , wherein the input supply voltage adjustment circuit comprises:

a selecting component, configured to dynamically adjust the level of the input supply voltage by selecting between the first circuit component and the second circuit component in response to the control signal.

12 . The apparatus of claim 10 , wherein

upon detecting that the input supply voltage has the first voltage level, the low voltage detector is further configured to generate the control signal such that the first circuit component is turned ON, wherein the input supply voltage is passed directly to the charge pump unit without level adjustment when the first circuit component is turned ON, and

upon detecting that the input supply voltage has the second voltage level, the low voltage detector is further configured to generate the control signal such that the first circuit component is turned OFF, wherein the input supply voltage is passed to the charge pump unit through the second circuit component when the first circuit component is turned OFF.

13 . A method controlling peak-to-peak ripple in an output voltage generated by a charge pump unit, the method comprising:

generating a control signal using a low voltage detector in response to an input supply voltage;

adjusting, by an input supply voltage adjustment circuit, a level of the input supply voltage to generate a defined input supply voltage; and

generating the output voltage in response to the defined input supply voltage wherein generating the control signal using the low voltage detector in response to the input supply voltage comprises

detecting whether the input supply voltage has a first voltage level or a second voltage level, wherein the second voltage level is greater than the first voltage level,

wherein the input supply voltage adjustment circuit includes a first circuit component and a second circuit component,

wherein the second circuit component is configured to reduce the input supply voltage and pass the reduced input supply voltage to the charge pump unit as the defined input supply voltage, and

wherein the first circuit component is in parallel with the second circuit component.

14 . The method of claim 13 , wherein adjusting the level of the input supply voltage to generate the defined input supply voltage includes selecting between the first circuit component and the second circuit component in response to the control signal.

15 . The method of claim 13 , wherein the generating of the control signal using the low voltage detector in response to the input supply voltage comprises:

upon detecting that the input supply voltage has the first voltage level, generating the control signal such that a first circuit component is turned ON to directly pass the input supply voltage to the charge pump unit without level adjustment, else

upon detecting that the input supply voltage has the second voltage level, generating the control signal such that the first circuit component is turned OFF to pass the input supply voltage to the charge pump unit through a second circuit component with level adjustment.

16 . The method of claim 13 , wherein the first circuit component includes at least one of a power switch and a first voltage-controlled resistor, and the second circuit component includes at least one of a diode and a second voltage-controlled resistor.

17 . The method of claim 13 , further comprising:

applying the output voltage as a programming voltage to a memory cell of a memory device.

18 . The method of claim 13 , further comprising:

generating a feedback voltage in response to the output voltage;

comparing the feedback voltage with a reference voltage to generate a control voltage; and

generating a multi-phase clock signal in response to the control voltage,

wherein the generating of the output voltage is further in response to the multi-phase clock signal.