Abstract:
A three-phase voltage tripler includes first, second, and third capacitive elements and a switching module. The switching module selectively switches connections among the capacitive elements and between the capacitive elements and a reference voltage during first, second, and third periods. The switching module charges the first capacitive element to a first voltage level during the first period, the second capacitive element to a second voltage level during the second period, and the third capacitive element to a third voltage level during the third period. The third voltage level is greater than the second voltage level and the second voltage level is greater than the first voltage level.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Application No. 60/790,731, filed on Apr. 10, 2006. The disclosure of the above application is incorporated herein by reference in its entirety. 

   FIELD 
   The present disclosure relates to power supply circuits, and more particularly to voltage tripler circuits. 
   BACKGROUND 
   The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. 
   Circuits in many electrical and electronic devices can be powered by batteries. Referring now to  FIGS. 1A-1B , a battery  10  may output a voltage V dd  to a circuit generally called a load  12 . The load  12  may draw varying amounts of current from the battery  10 . The voltage V dd  may vary depending on the amount of current drawn by the load  12 . Additionally, V dd  may decrease over time as shown by line  20  in  FIG. 1B  as the battery  10  gets used. 
   When the load  12  instantaneously draws a large amount of current from the battery  10 , V dd  may drop or dip momentarily before returning to a value that is less than or equal to V dd . Momentary drops in V dd  are called voltage spikes in V dd . The amount of drop in V dd  may be proportional to the amount of current instantaneously drawn by the load  12 . 
   For example, the drop in V dd  may be small (i.e., the voltage spike may be small) as shown at  22  when the amount of current instantaneously drawn is small. On the other hand, the drop in V dd  may be large (i.e., the voltage spike may be large) as shown at  24  when the amount of current instantaneously drawn is large. 
   Thus, voltage spikes in V dd  momentarily decrease V dd . When voltage spikes decrease V dd  below a threshold voltage V threshold , a reset may be triggered that resets the load  12  as shown at  26  and  28 . Large voltage spikes may trigger the reset even when the battery  10  is relatively new as shown at  26 . On the other hand, small voltage spikes may easily trigger the reset when the battery  10  gets relatively old as shown at  28 . Thus, limiting the drops or voltage spikes in V dd  may minimize triggers that reset the load  12  and may increase life of the battery  10 . 
   SUMMARY 
   A three-phase voltage tripler comprises first, second, and third capacitive elements and a switching module. The switching module selectively switches connections among the capacitive elements and between the capacitive elements and a reference voltage during first, second, and third periods. The switching module charges the first capacitive element to a first voltage level during the first period, the second capacitive element to a second voltage level during the second period, and the third capacitive element to a third voltage level during the third period. The third voltage level is greater than the second voltage level and the second voltage level is greater than the first voltage level. 
   In another feature, the first voltage level is approximately equal to the reference voltage, the second voltage level is approximately equal to two times the first voltage level, and the third voltage is approximately equal to three times the first voltage level. 
   In another feature, the switching module comprises a plurality of switches and a clock module that generates clock signals that selectively control the plurality of switches. 
   In another feature, the plurality of switches comprise first, second, and third transistors. The first transistor has a first terminal that communicates with the reference voltage, a control terminal, and a second terminal that communicates with a first end of the first capacitive element. The second transistor has a first terminal that communicates with the second terminal of the first transistor, a control terminal, and a second terminal that communicates with a first end of the second capacitive element. The third transistor has a first terminal that communicates with the second terminal of the second transistor, a control terminal, and a second terminal that communicates with a first end of the third capacitive element. The clock module selectively biases the first, second, and third transistors during the first, second, and third periods. 
   In another feature, substantially the same peak current is drawn during the first, second, and third periods from a source of the reference voltage when the three-phase voltage tripler supplies a predetermined load current. 
   In another feature, during the first period, a first end of the first capacitive element communicates with the reference voltage and a second end of the first capacitive element communicates with a common voltage. 
   In another feature, during the second period, the first end of the first capacitive element communicates with a first end of the second capacitive element, the second end of the first capacitive element communicates with the reference voltage, and a second end of the second capacitive element communicates with the common voltage. 
   In another feature, during the third period, the first end of the second capacitive element communicates with a first end of the third capacitive element, the second end of the second capacitive element communicates with the reference voltage, and a second end of the third capacitive element communicates with the common voltage. 
   In still other features, a method comprises arranging first, second, and third capacitive elements and selectively switching connections among the capacitive elements and between the capacitive elements and a reference voltage during first, second, and third periods. The method further comprises charging the first capacitive element to a first voltage level during the first period, the second capacitive element to a second voltage level during the second period, and the third capacitive element to a third voltage level during the third period. The third voltage level is greater than the second voltage level and the second voltage level is greater than the first voltage level. 
   In another feature, the first voltage level is approximately equal to the reference voltage, the second voltage level is approximately equal to two times the first voltage level, and the third voltage is approximately equal to three times the first voltage level. 
   In another feature, the method further comprises arranging a plurality of switches, generating clock signals that selectively control the plurality of switches, and communicating among the capacitive elements, the switches, and the reference voltage based on the clock signals. 
   In another feature, the method further comprises including first, second, and third transistors in the switches, wherein each of the transistors has first, second, and control terminals. The method further comprises communicating between the first terminal of the first transistor and the reference voltage and communicating between the second terminal of the first transistor and a first end of the first capacitive element. The method further comprises communicating between the first terminal of the second transistor and the second terminal of the first transistor and communicating between the second terminal of the second transistor and a first end of the second capacitive element. The method further comprises communicating between the first terminal of the third transistor and the second terminal of the second transistor and communicating between the second terminal of the third transistor and a first end of the third capacitive element. The method further comprises communicating the clock signals to the control terminals of the transistors and selectively biasing the transistors during the first, second, and third periods. 
   In another feature, the method further comprises drawing substantially the same peak current during the first, second, and third periods from a source of the reference voltage when supplying a predetermined load current. 
   In another feature, the method further comprises communicating during the first period between a first end of the first capacitive element and the reference voltage, and between a second end of the first capacitive element and a common voltage. 
   In another feature, the method further comprises communicating during the second period between the first end of the first capacitive element and a first end of the second capacitive element, between the second end of the first capacitive element and the reference voltage, and between a second end of the second capacitive element and the common voltage. 
   In another feature, the method further comprises communicating during the third period between the first end of the second capacitive element and a first end of the third capacitive element, between the second end of the second capacitive element and the reference voltage, and between a second end of the third capacitive element and the common voltage. 
   In still other features, a three-phase voltage tripler comprises first, second, and third capacitive means for providing capacitance and switching means for selectively switching connections among the capacitive means and between the capacitive means and a reference voltage during first, second, and third periods. The switching means charges the first capacitive means to a first voltage level during the first period, the second capacitive means to a second voltage level during the second period, and the third capacitive means to a third voltage level during the third period. The third voltage level is greater than the second voltage level and the second voltage level is greater than the first voltage level. 
   In another feature, the first voltage level is approximately equal to the reference voltage, the second voltage level is approximately equal to two times the first voltage level, and the third voltage is approximately equal to three times the first voltage level. 
   In another feature, the switching means comprises a plurality of switches and clock means for generating clock signals that selectively control the plurality of switches. 
   In another feature, the plurality of switches comprise first, second, and third transistors. The first transistor has a first terminal that communicates with the reference voltage, a control terminal, and a second terminal that communicates with a first end of the first capacitive means. The second transistor has a first terminal that communicates with the second terminal of the first transistor, a control terminal, and a second terminal that communicates with a first end of the second capacitive means. The third transistor has a first terminal that communicates with the second terminal of the second transistor, a control terminal, and a second terminal that communicates with a first end of the third capacitive means. The clock means selectively biases the first, second, and third transistors during the first, second, and third periods. 
   In another feature, substantially the same peak current is drawn during the first, second, and third periods from a source of the reference voltage when the three-phase voltage tripler supplies a predetermined load current. 
   In another feature, during the first period, a first end of the first capacitive means communicates with the reference voltage and a second end of the first capacitive means communicates with a common voltage. 
   In another feature, during the second period, the first end of the first capacitive means communicates with a first end of the second capacitive means, the second end of the first capacitive means communicates with the reference voltage, and a second end of the second capacitive means communicates with the common voltage. 
   In another feature, during the third period, the first end of the second capacitive means communicates with a first end of the third capacitive means, the second end of the second capacitive means communicates with the reference voltage, and a second end of the third capacitive means communicates with the common voltage. 
   Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: 
       FIG. 1A  is a functional block diagram of a battery-operated circuit according to the prior art; 
       FIG. 1B  is a graph of output voltage of a battery relative to time showing voltage spikes generated by peak current drawn by a load according to the prior art; 
       FIG. 2A  is a functional block diagram of a two-phase voltage tripler; 
       FIG. 2B  is a schematic of a two-phase voltage tripler; 
       FIG. 2C  is a schematic of the two-phase voltage tripler of  FIG. 2B  operating in charging phase; 
       FIG. 2D  is a schematic of the two-phase voltage tripler of  FIG. 2B  operating in transfer phase; 
       FIG. 2E  is a graph of supply current drawn by the two-phase voltage tripler of  FIG. 2B  relative to time in charging and transfer phases while maintaining a substantially constant load current; 
       FIG. 3A  is a functional block diagram of a three-phase voltage tripler according to the present disclosure; 
       FIG. 3B  is a schematic of a three-phase voltage tripler according to the present disclosure; 
       FIG. 3C  is a schematic of the three-phase voltage tripler of  FIG. 3B  operating in charging phase; 
       FIG. 3D  is a schematic of the three-phase voltage tripler of  FIG. 3B  operating in transfer phase; 
       FIG. 3E  is a schematic of the three-phase voltage tripler of  FIG. 3B  operating in pumping phase; 
       FIG. 3F  is a graph of supply current drawn by the three-phase voltage tripler of  FIG. 3B  relative to time in charging, transfer, and pumping phases while maintaining a substantially constant load current; 
       FIG. 4  is a graph of supply current drawn by the two-phase voltage tripler of  FIG. 2B  and by the three-phase voltage tripler of  FIG. 3B  relative to time while maintaining a substantially constant load current; 
       FIG. 5A  is a schematic of an exemplary implementation of the three-phase voltage tripler of  FIG. 3B ; 
       FIG. 5B  is a timing diagram of various clock signals generated by a clock generator module to implement the three-phase voltage tripler of  FIG. 3B ; 
       FIG. 6  is a flowchart of a method for implementing the three-phase voltage tripler of  FIG. 3B ; 
       FIG. 7A  is a functional block diagram of a hard disk drive; 
       FIG. 7B  is a functional block diagram of a digital versatile disk (DVD); 
       FIG. 7C  is a functional block diagram of a high definition television; 
       FIG. 7D  is a functional block diagram of a vehicle control system; 
       FIG. 7E  is a functional block diagram of a cellular phone; 
       FIG. 7F  is a functional block diagram of a set top box; and 
       FIG. 7G  is a functional block diagram of a media player. 
   

   DETAILED DESCRIPTION 
   The following description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the term module, circuit and/or device refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical or. It should be understood that steps within a method may be executed in different order without altering the principles of the present disclosure. 
   Voltage triplers are circuits that triple an output voltage of a voltage source. Referring now to  FIGS. 2A-2E , a two-phase voltage tripler (tripler)  50  triples an output voltage V dd  of a battery  10  as shown in  FIG. 2A . The tripler  50  outputs a voltage equal to 3V dd  to a load  12 . The output voltage V dd  of the battery  10  is the supply voltage of the tripler  50 . 
   The tripler  50  comprises two input capacitors CP 1  and CP 2 , a storage capacitor C pump , and seven switches S 1  through S 7  as shown in  FIG. 2B . The tripler  50  operates in cycles. Each cycle comprises two phases: a charging phase and a charge transfer phase (i.e., a transfer phase). In the charging phase, switches S 1  through S 4  are closed, and switches S 5  through S 7  are open. The tripler  50  operates as shown in  FIG. 2C . Specifically, capacitors CP 1  and CP 2  are connected in parallel to V dd . Both CP 1  and CP 2  charge to V dd . 
   In the transfer phase, switches S 1  through S 4  are opened and switches S 5  through S 7  are closed as shown in  FIG. 2D . Specifically, capacitors CP 1  and CP 2  are connected in series. Charges stored in CP 1  and CP 2  in the charging phase are transferred to the storage capacitor C pump . Additionally, one end of CP 1 , which was connected to a common voltage in the charging phase, is now connected to V dd . Thus, the voltage at a second end of CP 1 , which is connected to CP 2 , is 2V dd , and V pump =3V dd . 
   Let I o  denote a load current drawn by the load  12  from the battery  10 . To maintain the load current substantially constant at I o , the tripler  50  transfers an average charge equal to 3*I o *(2t) from V dd  to V pump  in each cycle as shown at  30  in  FIG. 2E , where 2t is a period of one cycle, and t is a period of one phase. 
   Specifically, the charge transferred in the charging phase from V dd  to each of CP 1  and CP 2  is equal to 2*I o *(t), where t is a period of the charging phase. In the transfer phase, an additional charge equal to 2*I o *(t) is transferred from V dd  to CP 1 , where t is the period of the transfer phase. 
   If a current equal to 2I o  is used to charge each of CP 1  and CP 2  in the charging phase, a supply current drawn by the tripler  50  from the battery  10  in the charging phase is equal to 2I o +2I o =4I o . Additionally, a supply current equal to 2I o  is drawn by the tripler  50  from the battery  10  to charge CP 1  in the transfer phase. Thus, a total supply current equal to 3I o  is drawn from the battery  10  in one cycle of the tripler  50  to maintain the load current substantially constant at I o . 
   A peak current I pk  is an instantaneous value of the supply current drawn by the tripler  50  from the battery  10  at the beginning of each phase. I pk  is mathematically obtained as follows. For the charging phase, (½)*I pk *(t)=2*I o *(2t) gives I pk =8I o . Similarly, for the transfer phase, (½)*I pk *(t)=I o *(2t) gives I pk =4I o . The supply current is in fact exponential. However, a linear approximation of the supply current is shown for illustrative purposes at  40  in  FIG. 2E . 
   Thus, to supply a substantially constant load current I o , the tripler  50  instantaneously draws I pk =8*I o , in the charging phase and I pk =4*I o  in the transfer phase from the battery  10 . The inequality in I pk  may generate voltage spikes of different amplitudes in the supply voltage of the tripler  50  although an average supply current drawn by the tripler  50  from the battery  10  during each cycle does not change. 
   The present disclosure discloses a three-phase voltage tripler that draws a substantially equal peak current in each phase and that draws a lower peak current in each phase than the two-phase voltage tripler  50 . Consequently, voltage spikes in a supply voltage of the three-phase voltage tripler are substantially uniform in each cycle. Additionally, an amplitude of the voltage spikes in the supply of the three-phase voltage tripler is less than the amplitude of the voltage spikes in the supply of the two-phase voltage tripler  50 . 
   Referring now to  FIGS. 3A-3F , a three-phase voltage tripler (voltage tripler)  100  triples an output voltage of a power supply. For example, the voltage tripler  100  may be used to triple an output voltage V dd  of a battery  10  as shown in  FIG. 3A . The voltage tripler  100 , in turn, outputs a voltage equal to 3V dd  to a load  12 . The output voltage V dd  of the battery  10  is the supply voltage of the voltage tripler  100 . 
   The voltage tripler  100  comprises two input capacitors CP 1  and CP 2 , a storage capacitor C pump , and seven switches S 1  through S 7  as shown in  FIG. 3B . The voltage tripler  100  operates in continuous cycles. Each cycle comprises three phases: a charging phase, a charge transfer phase (i.e., a transfer phase), and a pumping phase. CP 1  is charged in the charging phase, and CP 2  is charged in the transfer phase as follows. 
   In the charging phase, switches S 1  and S 2  are closed, and switches S 3  through S 7  are open. The capacitor CP 1  charges to V dd  as shown in  FIG. 3C . In the transfer phase, switches S 1  and S 2  are opened, and switches S 3  through S 5  are closed while switches S 6  and S 7  are still open. Capacitors CP 1  and CP 2  are connected in series as shown in  FIG. 3D . Charge stored in CP 1  in the charging phase is transferred from CP 1  to CP 2 . Additionally, one end of CP 1 , which was connected to a common voltage in the charging phase, is now connected to V dd . Thus, both CP 1  and CP 2  charge to 2V dd . 
   In the pumping phase, switches S 3  through S 5  are opened, and switches S 6  and S 7  are closed while switches S 1  and S 2  are still open. The voltage tripler  100  operates as shown in  FIG. 3E . Charge stored in CP 2  in the transfer phase is transferred to the storage capacitor C pump . Additionally, one end of CP 2 , which was connected to the common voltage in the transfer phase, is now connected to V dd . Thus, V pump =3*V dd . 
   Let I o  denote a load current drawn by the load  12  from the battery  10 . To maintain the load current substantially constant at I o , the voltage tripler  100  transfers an average charge equal to 3*I O *(3t) from V dd  to V pump  in each cycle as shown at  130  in  FIG. 3F , where 3t is a period of one cycle, and t is a period of one phase. 
   Specifically, the charge transferred in the charging phase from V dd  to CP 1  is equal to 3*I o *(t), where t is a period of the charging phase. In the transfer phase, an additional charge equal to 3*I o *(t) is transferred from V dd  to CP 2 , where t is the period of the transfer phase. Finally, in the pumping phase, an additional charge equal to 3*I o *(t) is transferred from V dd  to C pump . Thus, V pump =3*V dd . 
   If a current equal to 3I o  is used to charge each of CP 1 , CP 2 , and C pump  in the respective phases, a supply current drawn by the voltage tripler  100  from the battery  10  in each of the three phases is substantially equal to 3I o . Consequently, an instantaneous value of the supply current or a peak current I pk  drawn by the voltage tripler  100  from the battery  10  at the beginning of each phase is also equal in each of the three phases. 
   I pk  is mathematically obtained as follows. For each phase, (½)*I pk *(t)=3*I o *(t) gives I pk =6I o . Thus, to supply a substantially constant load current I o , the voltage tripler  100  instantaneously draws I pk =6I o  in each phase from the battery  10 . The supply current is in fact exponential. However, a linear approximation of the supply current is shown for illustrative purposes at  140  in  FIG. 3F . 
   Referring now to  FIG. 4 , to supply a substantially constant load current I o , the three-phase voltage tripler  100  draws less peak current from the battery  10  than the two-phase voltage tripler  50 . Additionally, unlike the two-phase voltage tripler  50 , which draws unequal peak currents in charging and transfer phases, the three-phase voltage tripler  100  draws substantially equal peak current in each phase. 
   Consequently, the supply voltage of the three-phase voltage tripler  100  may have lower voltage spikes than the supply voltage of the two-phase voltage tripler  50 . Additionally, the voltage spikes in the output voltage of the three-phase voltage tripler  100  may be substantially uniform. Thus, the battery  10  may last longer when the three-phase voltage tripler  100  is used than when the two-phase voltage tripler  50  is used. Finally, input decoupling capacitors used in the three-phase voltage tripler  100  may be smaller than the input decoupling capacitors used in the two-phase voltage tripler  50  for the same ripple in the supply voltage. 
   Referring now to  FIGS. 5A-5B , an exemplary voltage tripler circuit  150  that implements the three-phase voltage tripler  100  comprises a clock module  152 , three PMOS transistors (switches) M 1 , M 2 , and M 3 , and three capacitors CP 1 , CP 2 , and C pump . Although PMOS transistors are shown, NMOS transistors or other components capable of performing a switching operation may be used instead. 
   The clock module  152  generates clock signals that synchronize switching of transistors M 1 , M 2 , and M 3  and charging of capacitors CP 1 , CP 2 , and C pump  as shown in  FIG. 5B . That is, the clock signals sequence the charging, transition, and pumping phases of the voltage tripler circuit  150  as shown in  FIG. 5B . The sequence of the charging phase and the transfer phase may be exchangeable. 
   Specifically, the clock module  152  generates three clock signals clk-a, clk-b, and clk-c that bias the three PMOS switches M 1 , M 2 , and M 3 , respectively. The three PMOS switches M 1 , M 2 , and M 3  open and close at times determined by the three clock signals clk-a, clk-b, and clk-c, respectively. Additionally, the clock module  152  generates clock signals clk- 1  and clk- 2  that bias input capacitors CP 1  and CP 2  as shown in  FIG. 5B . 
   In the charging phase, clk-a biases M 1  to saturation. That is, switch M 1  is closed. Thus, a first plate of CP 1  is connected to V dd . clk-b and clk-c do not bias M 2  and M 3  to saturation, respectively. That is, switches M 2  and M 3  are open. Thus, CP 2  and C pump  do not communicate with CP 1  and/or V dd . clk- 1  and clk- 2  bias second plates of CP 1  and CP 2  to a common voltage, respectively. Thus, at the end of the charging phase, the first plate of CP 1  is charged to V dd  while the second plate of CP 1  is held at the common voltage by clk- 1 . 
   In the transfer phase, clk-a biases M 1  out of saturation. That is, switch M 1  is opened. Thus, V dd  is not connected to the first plate of CP 1 . clk-b biases M 2  to saturation. That is, switch M 2  is closed. Thus, the first plate of CP 1  is connected to a first plate of CP 2 . Charge stored in CP 1  is transferred to CP 2 . Additionally, clk- 1  biases the second plate of CP 1  to V dd  while clk- 2  still holds the second plate of CP 2  at the common voltage. Thus, the first plate of CP 2  is charged to 2V dd  at the end of the transfer phase. Since clk-c still does not bias M 3  to saturation (i.e., since switch M 3  is still open), C pump  is not yet connected to CP 2 , CP 1 , or V dd . 
   In the pumping phase, clk-c biases M 3  to saturation. That is, switch M 3  is closed. clk-b biases M 2  out of saturation (i.e., switch M 2  is opened) while clk-a still keeps M 1  out of saturation (i.e., switch M 1  is still open). Thus, the first plate of CP 2  is connected to the first plate of C pump . Charge stored in CP 2  is transferred to C pump . Additionally, clk- 2  biases the second plate of CP 2  to V dd . Thus, the first plate of C pump  is charged to 3V dd  at the end of the pumping phase, and V pump =3V dd . That is, V pump  or an output voltage of the voltage tripler circuit  150  equals three times the output voltage V dd  of a power supply or a battery  10 . 
   Referring now to  FIG. 6 , a method  200  for reducing and regulating voltage spikes in a three-phase voltage tripler  100  begins at step  202 . A first end of a first input capacitor CP 1  is connected to a supply voltage V dd  of a power source such as a battery  10  and a second end of CP 1  is connected to a common node in a charging phase in step  204 . Whether the first end of CP 1  is charged to V dd  is determined in step  206 . Step  206  is repeated until charging time is reached. 
   When the first end of CP 1  is charged to V dd , the first end of CP 1  is disconnected from V dd  and is connected to a first end of a second input capacitor CP 2 , and the charge is transferred from the first end of CP 1  to the first end of CP 2  in a transfer phase in step  208 . The second end of CP 1  is disconnected from the common node and is connected to V dd , and a second end of CP 2  is connected to the common node during the transfer phase in step  210 . 
   Whether the first end of CP 2  is charged to 2V dd  is determined in step  212 . Step  212  is repeated until transfer time is reached. When the first end of CP 2  is charged to 2V dd , the first end of CP 2  is disconnected from the first end of CP 1  and is connected to C pump , and the charge is transferred from the first end of CP 2  to C pump  in a pumping phase in step  214 . The second end of CP 2  is disconnected from the common node and is connected to V dd  in step  216 . Whether C pump  is charged to 3V dd  is determined in step  218 . Step  218  is repeated until pumping time is reached. Once C pump  is charged to 3V dd , the method  200  ends, and steps  204  through  218  are repeated. 
   Referring now to  FIGS. 7A-7G , various exemplary implementations of the three-phase voltage tripler  100  including the voltage tripler circuit  150  (hereinafter collectively referred to as the three-phase voltage tripler) are shown. Referring now to  FIG. 7A , the three-phase voltage tripler can be implemented in a power supply  403  of a hard disk drive  400 . In some implementations, a signal processing and/or control circuit  402  and/or other circuits (not shown) in the HDD  400  may process data, perform coding and/or encryption, perform calculations, and/or format data that is output to and/or received from a magnetic storage medium  406 . 
   The HDD  400  may communicate with a host device (not shown) such as a computer, mobile computing devices such as personal digital assistants, cellular phones, media or MP3 players and the like, and/or other devices via one or more wired or wireless communication links  408 . The HDD  400  may be connected to memory  409  such as random access memory (RAM), low latency nonvolatile memory such as flash memory, read only memory (ROM) and/or other suitable electronic data storage. 
   Referring now to  FIG. 7B , the three-phase voltage tripler can be implemented in a power supply  413  of a digital versatile disc (DVD) drive  410 . In some implementations, a signal processing and/or control circuit  412  and/or other circuits (not shown) in the DVD  410  may process data, perform coding and/or encryption, perform calculations, and/or format data that is read from and/or data written to an optical storage medium  416 . The signal processing and/or control circuit  412  and/or other circuits (not shown) in the DVD  410  may also perform other functions such as encoding and/or decoding and/or any other signal processing functions associated with a DVD drive. 
   The DVD drive  410  may communicate with an output device (not shown) such as a computer, television or other device via one or more wired or wireless communication links  417 . The DVD  410  may communicate with mass data storage  418  that stores data in a nonvolatile manner. The mass data storage  418  may include a hard disk drive (HDD). The HDD may have the configuration shown in  FIG. 7A . The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. The DVD  410  may be connected to memory  419  such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. 
   Referring now to  FIG. 7C , the three-phase voltage tripler can be implemented in a power supply  423  of a high definition television (HDTV)  420 . The HDTV  420  receives HDTV input signals in either a wired or wireless format and generates HDTV output signals for a display  426 . In some implementations, signal processing circuit and/or control circuit  422  and/or other circuits (not shown) of the HDTV  420  may process data, perform coding and/or encryption, perform calculations, format data and/or perform any other type of HDTV processing that may be required. 
   The HDTV  420  may communicate with mass data storage  427  that stores data in a nonvolatile manner such as optical and/or magnetic storage devices. At least one HDD may have the configuration shown in  FIG. 7A  and/or at least one DVD may have the configuration shown in  FIG. 7B . The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″The HDTV  420  may be connected to memory  428  such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. The HDTV  420  also may support connections with a WLAN via a WLAN network interface  429 . 
   Referring now to  FIG. 7D , the three-phase voltage tripler may be implemented in a power supply  433  of a control system of a vehicle  430 . In some implementations, a powertrain control system  432  receives inputs from one or more sensors such as temperature sensors, pressure sensors, rotational sensors, airflow sensors and/or any other suitable sensors and/or that generates one or more output control signals such as engine operating parameters, transmission operating parameters, and/or other control signals. 
   A control system  440  may likewise receive signals from input sensors  442  and/or output control signals to one or more output devices  444 . In some implementations, the control system  440  may be part of an anti-lock braking system (ABS), a navigation system, a telematics system, a vehicle telematics system, a lane departure system, an adaptive cruise control system, a vehicle entertainment system such as a stereo, DVD, compact disc and the like. Still other implementations are contemplated. 
   The powertrain control system  432  may communicate with mass data storage  446  that stores data in a nonvolatile manner. The mass data storage  446  may include optical and/or magnetic storage devices for example hard disk drives HDD and/or DVDs. At least one HDD may have the configuration shown in  FIG. 7A  and/or at least one DVD may have the configuration shown in  FIG. 7B . The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. 
   The powertrain control system  432  may be connected to memory  447  such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. The powertrain control system  432  also may support connections with a WLAN via a WLAN network interface  448 . The control system  440  may also include mass data storage, memory and/or a WLAN interface (all not shown). 
   Referring now to  FIG. 7E , the three-phase voltage tripler can be implemented in a power supply  453  of a cellular phone  450  that may include a cellular antenna  451 . In some implementations, the cellular phone  450  includes a microphone  456 , an audio output  458  such as a speaker and/or audio output jack, a display  460  and/or an input device  462  such as a keypad, pointing device, voice actuation and/or other input device. Signal processing and/or control circuits  452  and/or other circuits (not shown) in the cellular phone  450  may process data, perform coding and/or encryption, perform calculations, format data and/or perform other cellular phone functions. 
   The cellular phone  450  may communicate with mass data storage  464  that stores data in a nonvolatile manner such as optical and/or magnetic storage devices for example hard disk drives HDD and/or DVDs. At least one HDD may have the configuration shown in  FIG. 7A  and/or at least one DVD may have the configuration shown in  FIG. 7B . The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″The cellular phone  450  may be connected to memory  466  such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. The cellular phone  450  also may support connections with a WLAN via a WLAN network interface  468 . 
   Referring now to  FIG. 7F , the three-phase voltage tripler can be implemented in a power supply  483  of a set top box  480 . The set top box  480  receives signals from a source such as a broadband source and outputs standard and/or high definition audio/video signals suitable for a display  488  such as a television and/or monitor and/or other video and/or audio output devices. Signal processing and/or control circuits  484  and/or other circuits (not shown) of the set top box  480  may process data, perform coding and/or encryption, perform calculations, format data and/or perform any other set top box function. 
   The set top box  480  may communicate with mass data storage  490  that stores data in a nonvolatile manner. The mass data storage  490  may include optical and/or magnetic storage devices for example hard disk drives HDD and/or DVDs. At least one HDD may have the configuration shown in  FIG. 7A  and/or at least one DVD may have the configuration shown in  FIG. 7B . The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″The set top box  480  may be connected to memory  494  such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. The set top box  480  also may support connections with a WLAN via a WLAN network interface  496 . 
   Referring now to  FIG. 7G , the three-phase voltage tripler can be implemented in a power supply  503  of a media player  500 . In some implementations, the media player  500  includes a display  507  and/or a user input  508  such as a keypad, touchpad and the like. In some implementations, the media player  500  may employ a graphical user interface (GUI) that typically employs menus, drop down menus, icons and/or a point-and-click interface via the display  507  and/or user input  508 . The media player  500  further includes an audio output  509  such as a speaker and/or audio output jack. The signal processing and/or control circuits  504  and/or other circuits (not shown) of the media player  500  may process data, perform coding and/or encryption, perform calculations, format data and/or perform any other media player function. 
   The media player  500  may communicate with mass data storage  510  that stores data such as compressed audio and/or video content in a nonvolatile manner. In some implementations, the compressed audio files include files that are compliant with MP3 format or other suitable compressed audio and/or video formats. The mass data storage may include optical and/or magnetic storage devices for example hard disk drives HDD and/or DVDs. At least one HDD may have the configuration shown in  FIG. 7A  and/or at least one DVD may have the configuration shown in  FIG. 7B . The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. 
   The media player  500  may be connected to memory  514  such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. The media player  500  also may support connections with a WLAN via a WLAN network interface  516 . Still other implementations in addition to those described above are contemplated. 
   Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification and the following claims.