Methods and apparatus for dynamically reconfiguring a charge pump during output transients
Methods and apparatus are described for dynamically controlling a charge pump system including a plurality of charge pump stages, with each charge pump stage coupled between an input voltage V IN at an input voltage node and an output voltage V OUT at an output voltage node. In particular, the configuration of the charge pump stages may be dynamically controlled during a transition on V OUT from a first voltage to a second voltage to improve the circuit's transient response.
1 . A method for controlling a charge pump system comprising a plurality of charge pump stages, each charge pump stage coupled between an input voltage V IN at an input voltage node and an output voltage V OUT at an output voltage node, the method comprising:
changing a configuration of the charge pump stages during a transition on V OUT from a first voltage to a second voltage.
2 . The method of claim 1 , wherein changing the configuration comprises coupling one of the charge pump stages to the input voltage node and the output voltage node to increase V OUT to a first intermediate voltage between the first and second voltages.
3 . The method of claim 1 , wherein changing the configuration comprises coupling a first plurality of the charge pump stages to the input voltage node and the output voltage node to increase V OUT to a first intermediate voltage between the first and second voltages.
4 . The method of claim 3 , wherein changing the configuration further comprises coupling a second plurality of the charge pump stages to the input voltage node and the output voltage node to increase V OUT to a second intermediate voltage between the first and second voltages.
5 . The method of claim 1 , wherein changing the configuration comprises coupling one of the charge pump stages to the input voltage node and the output voltage node during a first time interval during the transition on V OUT from the first voltage to the second voltage.
6 . The method of claim 1 , wherein changing the configuration comprises coupling a first plurality of the charge pump stages to the input voltage node and the output voltage node during a first time interval during the transition on V OUT from the first voltage to the second voltage.
7 . The method of claim 6 , wherein changing the configuration further comprises coupling a second plurality of the charge pump stages to the input voltage node and the output voltage node during a second time interval during the transition on V OUT from the first voltage to the second voltage.
8 . The method of claim 1 , wherein changing the configuration comprises controlling a number of the charge pump stages coupled to the input voltage node and the output voltage node during the transition on V OUT from the first voltage to the second voltage.
9 . The method of claim 1 , wherein changing the configuration comprises controlling a frequency of a clock signal supplied to the charge pump stages during the transition on V OUT from the first voltage to the second voltage.
10 . The method of claim 9 , wherein controlling the clock frequency comprises providing a first clock signal at a first frequency to the charge pump stages to increase V OUT to a first intermediate voltage between the first and second voltages.
11 . The method of claim 10 , wherein controlling the clock frequency further comprises providing a second clock signal at a second frequency to the charge pump stages to increase V OUT to a second intermediate voltage between the first and second voltages.
12 . The method of claim 9 , wherein controlling the clock frequency comprises providing a first clock signal at a first frequency to the charge pump stages during a first time interval during the transition on V OUT from the first voltage to the second voltage.
13 . The method of claim 9 , wherein controlling the clock frequency further comprises providing a second clock signal at a second frequency to the charge pump stages during a second time interval during the transition on V OUT from the first voltage to the second voltage.
14 . The method of claim 1 , wherein:
the charge pump system supplies an output current I OUT at the output voltage node; and
changing the configuration maximizes the output current I OUT during a transition on V OUT from a first voltage to a second voltage.
15 . The method of claim 1 , wherein
the charge pump system receives an input current I IN at the input node, and supplies an output current I OUT at the output voltage node; and
changing the configuration limits input current I IN requirements.
16 . The method of claim 1 , wherein changing the configuration comprises:
coupling a first plurality of the charge pump stages in series during a first time interval during the transition on V OUT from the first voltage to the second voltage; and
coupling a second plurality of the charge pump stages in series during a second time interval during the transition on V OUT from the first voltage to the second voltage.
17 . A charge pump system comprising a plurality of charge pump stages, each charge pump stage coupled between an input voltage V IN at an input voltage node and an output voltage V OUT at an output voltage node, the charge pump system comprising:
means for dynamically controlling a configuration of the charge pump stages during a transition on V OUT from a first voltage to a second voltage.
18 . The system of claim 17 , wherein the means for dynamically controlling comprises means for coupling one of the charge pump stages to the input voltage node and the output voltage node to increase V OUT to a first intermediate voltage between the first and second voltages.
19 . The system of claim 17 , wherein the means for dynamically controlling comprises means for coupling a first plurality of the charge pump stages to the input voltage node and the output voltage node to increase V OUT to a first intermediate voltage between the first and second voltages.
20 . The system of claim 19 , wherein the means for dynamically controlling further comprises means for coupling a second plurality of the charge pump stages to the input voltage node and the output voltage node to increase V OUT to a second intermediate voltage between the first and second voltages.
21 . The system of claim 17 , wherein the means for dynamically controlling comprises means for coupling one of the charge pump stages to the input voltage node and the output voltage node during a first time interval during the transition on V OUT from the first voltage to the second voltage.
22 . The system of claim 17 , wherein the means for dynamically controlling comprises means for coupling a first plurality of the charge pump stages to the input voltage node and the output voltage node during a first time interval during the transition on V OUT from the first voltage to the second voltage.
23 . The system of claim 22 , wherein the means for dynamically controlling further comprises means for coupling a second plurality of the charge pump stages to the input voltage node and the output voltage node during a second time interval during the transition on V OUT from the first voltage to the second voltage.
24 . The system of claim 17 , wherein the means for dynamically controlling comprises means for controlling a number of the charge pump stages coupled to the input voltage node and the output voltage node during the transition on V OUT from the first voltage to the second voltage.
25 . The system of claim 17 , wherein the means for dynamically controlling comprises means for controlling a frequency of a clock signal supplied to the charge pump stages during the transition on V OUT from the first voltage to the second voltage.
26 . The system of claim 25 , wherein the means controlling the clock frequency comprises means for providing a first clock signal at a first frequency to the charge pump stages to increase V OUT to a first intermediate voltage between the first and second voltages.
27 . The system of claim 25 , wherein the means for controlling the clock frequency further comprises means for providing a second clock signal at a second frequency to the charge pump stages to increase V OUT to a second intermediate voltage between the first and second voltages.
28 . The system of claim 25 , wherein the means for controlling the clock frequency comprises means for providing a first clock signal at a first frequency to the charge pump stages during a first time interval during the transition on V OUT from the first voltage to the second voltage.
29 . The system of claim 25 , wherein the means for controlling the clock frequency further comprises means for providing a second clock signal at a second frequency to the charge pump stages during a second time interval during the transition on V OUT from the first voltage to the second voltage.
30 . The system of claim 17 , wherein:
the charge pump system supplies an output current I OUT at the output voltage node; and
the means for dynamically controlling maximizes the output current I OUT during a transition on V OUT from a first voltage to a second voltage.
31 . The system of claim 17 , wherein
the charge pump system receives an input current I IN at the input node, and supplies an output current I OUT at the output voltage node; and
the means for dynamically controlling limits input current I IN requirements.
32 . The system of claim 17 , wherein the means for changing the configuration comprises:
means for coupling a first plurality of the charge pump stages in series during a first time interval during the transition on V OUT from the first voltage to the second voltage; and
means for coupling a second plurality of the charge pump stages in series during a second time interval during the transition on V OUT from the first voltage to the second voltage.