Charge pump timing control

Abstract

Cycle timing of a charge pump is adapted according to monitoring of operating characteristics of a charge pump and/or peripheral elements coupled to the charge pump. In some examples, this adaptation provides maximum or near maximum cycle times while avoiding violation of predefine constraints (e.g., operating limits) in the charge pump and/or peripheral elements.

1 - 14 . (canceled) 
     
     
         15 . An apparatus comprising a charge pump having switch elements that are arranged to operate in a cycle from a plurality of cycles, each of which is associated with a different configuration of said switch elements, said switch elements being configured to switch according to a timing pattern and to provide charge-transfer paths between capacitive elements, and a controller, coupled to said charge pump, said controller comprising an output that provides a signal that selects a cycle from said plurality of cycles and a first sensor-input that accepts a sensor signal that characterizes operation of at least one of said charge pump and a peripheral circuit coupled to said charge pump, said controller being configured to adjust said timing pattern based at least in part on variation of said first sensor-input during operation of said charge pump. 
     
     
         16 . The apparatus of  claim 15 , wherein said first sensor-input receives, from a regulator that is coupled to an output of said charge pump, a signal indicative of an output voltage of said regulator. 
     
     
         17 . The apparatus of  claim 15 , wherein a converter that carries out switching operation according to a duty cycle is coupled to an output of said charge pump and wherein said first sensor-input is configured to receive a signal from said converter, said signal being indicative of said duty cycle. 
     
     
         18 . The apparatus of  claim 15 , wherein said controller is configured to adjust said timing pattern by determining a switching time, wherein said switching time determines an end to a cycle, wherein said controller selects said timing pattern at least in part based on variation of an input to said first sensor-input during a cycle. 
     
     
         19 . The apparatus of  claim 15 , wherein said first sensor-input comprises an output-voltage sensor-input that receives a signal that represents an output voltage of said charge pump and wherein said controller is configured to adjust said timing pattern according to variation in said signal. 
     
     
         20 . The apparatus of  claim 15 , wherein said controller is configured to receive, at said sensor input, a signal that represents an output voltage of said charge pump and wherein said controller is configured to adjust said timing pattern to maintain variation of said output voltage to be within a fixed range. 
     
     
         21 . The apparatus of  claim 15 , wherein said controller further comprises a second sensor-input that receives a signal that represents an output voltage of a regulator that is coupled to an output of said charge-pump and wherein said controller is configured to adjust said timing pattern to maintain a desired voltage margin between a voltage at said output of said charge pump and said output voltage of said regulator. 
     
     
         22 . The apparatus of  claim 15 , wherein said controller is configured to adjust said timing pattern by adjusting a switching frequency of said charge pump. 
     
     
         23 . The apparatus of  claim 15 , wherein said controller further comprises a second sensor-input, wherein said controller is configured to receive, at said first sensor-input, a first signal that represents an output voltage of said charge pump, and wherein said controller is configured to adjust said timing pattern to maintain variation of said output voltage to be within a range that depends on a second signal, said second signal being provided to said second sensor-input. 
     
     
         24 . The apparatus of  claim 15 , wherein said charge pump comprises a Dickson charge-pump. 
     
     
         25 . The apparatus of  claim 15 , wherein said charge pump comprises an output that is coupled to a regulator that carries out switching operation according to a duty cycle, wherein said first sensor-input is configured to receive a signal from said regulator, said signal being indicative of said duty cycle of said regulator. 
     
     
         26 . The apparatus of  claim 15 , wherein said controller is configured to receive, at said sensor input, a signal that represents an output voltage of said charge pump and wherein said controller is configured to adjust said timing pattern to maintain variation of said output voltage to be within a desired range. 
     
     
         27 . The apparatus of  claim 15 , wherein said first sensor-input accepts a sensor signal that characterizes operation of a peripheral circuit coupled to said charge pump, 
     
     
         28 . The apparatus of  claim 15 , wherein said first sensor-input comprises a converter sensor-input that receives, from a converter that is coupled to an output of said charge pump, a signal indicative of an output voltage of said converter. 
     
     
         29 . The apparatus of  claim 15 , wherein said first sensor-input is configured to receive a signal indicative of an operating characteristic of a regulator that is coupled to an output of said charge pump. 
     
     
         30 . The apparatus of  claim 15 , wherein said first sensor-input accepts a sensor signal that characterizes operation of said charge pump. 
     
     
         31 . The apparatus of  claim 15 , wherein said first sensor-input accepts a sensor signal that characterizes operation of a peripheral circuit coupled to said charge pump, said peripheral circuit comprising a current source. 
     
     
         32 . The apparatus of  claim 15 , wherein said first sensor-input is configured to receive a signal from a buck converter, said signal being indicative of a duty cycle of said buck converter. 
     
     
         33 . A method comprising operating a charge pump having switch elements that are arranged to operate in a cycle from a plurality of cycles, each of which is associated with a different configuration of said switch elements, said switch elements being configured to switch according to a timing pattern and to provide charge-transfer paths between capacitive elements, said method comprising selecting a cycle from said plurality of cycles based at least in part on a sensor signal that characterizes operation of at least one of said charge pump and a peripheral circuit coupled to said charge pump and adjusting said timing pattern based at least in part on variation of said first sensor-input during operation of said charge pump.