Power consumption reduction in medical devices employing just-in-time clock

• US 6,167,303 A
• Filed: 04/09/1999
• Issued: 12/26/2000
• Est. Priority Date: 04/29/1998
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Thompson, David L.
• Primary Examiner(s): Getzow, Scott M.
• Application Number:
  US09/289,471
• Time in Patent Office: 627 Days
• Field of Search: 607/2, 607/9, 607/3, 607/16, 607/27
• US Class Current: 607/2
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• CPC Class Codes: A61N 1/37276 characterised by means for reducing power consumption during telemetry
• CPC Class Codes: A61N 1/378 Electrical supply

Abstract

Power consumption in medical and battery powered devices is reduced through the use and operation of a data monitor which measures, senses or detects signals, inputs or outputs in a medical device before they are input to a principal or main digital signal processor, controller or microprocessor. In response to detecting or measuring such a signal which meets certain amplitude, frequency and/or phase characteristics, the data monitor directs or controls clock or voltage supply circuits to increase or decrease clock frequency, or to increase or decrease the voltage provided to certain circuits within the medical device. The clock frequencies and/or voltages so employed are tailored to reduce the amount of power consumed by the medical device while preserving computational performance.

Claims

1. A method device, comprising:

at least one circuit operable to perform at least one function and having at least one of a first input and a first output connected thereto for receiving or outputting, respectively, a first input signal or a first output signal;

a clock source for providing clock signals at a plurality of clock frequencies, the clock source being operatively connected to control the at least one circuit at a clock frequency such that substantially the entire predetermined time period is used to perform the at least one function, the function being completed just prior to the subsequent time period;

a processing device having a second input for receiving at least one of the first input signal and the first output signal, the first input signal or first output signal being input to the second input before or after having been subjected to any one of preliminary signal conditioning, filtering, amplification and logic processing, and

a monitor circuit connected between the second input and the first input or first output, the monitor circuit being operable to at least one of measure, sense and detect at least one predetermined characteristic of the first input signal or the first output signal, the monitor circuit being connected to the clock source and being operable, in response to at least one of measuring, sensing and detecting the at least one predetermined characteristic, to cause the clock source to increase or decrease the clock frequency.

2. The device of claim 1, wherein the at least one circuit further comprises at least a first logic circuit for performing a first function and a second logic circuit for performing a second function, the first logic circuit being operable to perform the first function during a first predetermined time period and the second logic circuit being operable to perform the second function during a second predetermined time period, each of the first and second logic circuits being operated at a different clock frequency such that substantially the entire respective first and second predetermined time periods are used by the respective first and second logic circuits to perform the respective first and second functions.

3. The device of claim 2, wherein the first predetermined time period and the second predetermined time period are time periods based on physiological events.

4. The device of claim 3, wherein at least one of the first and second time periods is a time period associated with a cardiac event and is selected from the group consisting of a blanking interval, an upper rate interval, an escape interval, a refractory interval, and a pulse generator/programmer handshake.

5. The device of claim 1, wherein the processing device is operable to perform a plurality of functions, each of the plurality of functions being performed during an associated predetermined time period prior to a subsequent time period in which another of the plurality of functions is performed, the processing device being operable to perform each of two or more functions of the plurality of functions at a different clock frequency such that substantially the entire associated predetermined time period for each function is used to perform the functions prior to the subsequent time period in which another of the plurality of functions is performed.

6. The device of claim 5, wherein the associated predetermined time periods are time periods based on physiological events.

7. The device of claim 6, wherein at least one of the associated time periods is a time period associated with a cardiac event and is selected from the group consisting of a blanking interval, an upper rate interval, an escape interval, a refractory interval, and a pulse generator/programmer handshake.

8. The device of claim 1, wherein the device further includes one or more supply voltage sources to provide one or more supply voltages, the one or more supply voltage sources being operatively connected to the at least one circuit such that a supply voltage is applied to at least a portion of the at least one circuit as a function of the clock frequency applied to the at least portion of the at least one circuit.

9. The device of claim 8, wherein the at least one circuit comprises at least a first logic circuit for performing a first function and a second logic circuit for performing a second function, wherein each of the first and second logic circuits is operated at a different clock frequency, and further wherein each of the logic circuits has a different supply voltage applied thereto by the one or more voltage sources based on the different clock frequencies used to control the first and second logic circuits.

10. The device of claim 8, wherein the processing device is operable to perform a plurality of functions, each of at least two of the plurality of functions is performed at a different clock frequency, and the supply voltage applied to the processing device by the one or more voltage sources is adjusted such that a first supply voltage is provided to the processing device during performance of one of the at least two functions and a second supply voltage is provided to the processing device during performance of the other function, wherein the first and second supply voltages are applied to the processing device based on the different clock frequencies used to control the processing device.

11. The device of claim 1, wherein at least a portion of the at least one circuit comprises circuitry of a type selected from the group consisting of a CMOS circuit, a CML circuit, an SOS circuit, an SOI circuit, a BICMOS circuit and an NMOS circuit.

12. The device of claim 1, wherein the device is an hermetically sealed implantable medical device.

13. The device of claim 12, wherein the implantable medical device is selected from the group consisting of an implantable stimulator, an implantable nerve stimulator, an implantable pacemaker, an IPG, an implantable cardioverter, an implantable PCD, an implantable defibrillator, an implantable ICD and an implantable drug pump.

14. The device of claim 1, wherein the at least one circuit further comprises one or more analog circuits operable to perform at least one function.

15. The device of claim 14, wherein the one or more analog circuits include at least one of an atrial sense amplifier, a ventricular sense amplifier, a T-wave amplifier, one or more bandpass filters, one or more detection circuits, one or more sensor amplification circuits, one or more physiological signal amplification circuits, one or more output circuits, a battery monitor circuit, and a power on reset circuit.

16. The device of claim 14, wherein the one or more analog circuits include at least one amplifier circuit for amplifying the one or more analog signals.

17. The method of claim 1, wherein the one or more circuits further comprise one or more digital circuits operable to perform at least one function.

18. The device of claim 17, wherein the device further includes means for adjusting the back gate bias of at least one of the one or more digital circuits.

19. The device of claim 1, wherein the processing device comprises one or more of a microprocessor, a microcomputer, a controller, a microcontroller, a processor, a controller, a memory, a digital signal processor, a digital controller timer circuit, a central processing unit (CPU) and an Application Specific Integrated Circuit (ASIC).

20. The device of claim 19, wherein the at least one circuit further comprises one or more analog circuits operable to perform at least one function and the processing device receives data representative of the one or more analog signals.

21. The device of claim 1, further comprising a power source for applying a first fixed supply voltage to at least portions of the at least one circuit.

22. The device of claim 21, further comprising a voltage generation circuit having the first fixed supply voltage supplied thereto, the voltage generation circuit generating at least a second fixed supply voltage for application to at least portions of the at least one circuit, the second fixed supply voltage being greater than the first fixed supply voltage.

23. The device of claim 22, wherein the voltage generation circuit is a charge pump circuit for generating the second fixed supply voltage based on the first fixed supply voltage.

24. The device of claim 21, wherein the first supply voltage ranges between about 0.8 volts and about 1.5 volts.

25. The device of claim 22, wherein the second supply voltage ranges between about +/-2.0 volts and about +/-3.0 volts.

26. The device of claim 1, wherein the at least one circuit further comprises one or more analog circuits, one or more digital circuits, and a level shifter to translate signals between the one or more analog circuits and the one or more digital circuits.

27. The device of claim 1, wherein the monitor circuit employs an adaptive control algorithm to determine whether or not a measured, sensed or detected signal meets the at least one predetermined characteristic.

28. The device of claim 1, wherein the at least one predetermined characteristic is defined in respect of at least one of the sign, polarity, slope, rate of change, amplitude, frequency and phase of the measured, sensed or detected signal.

29. The device of claim 1, wherein the first input or the first output is selected from the group consisting of an output of a comparator, an output of a clock source, an output of a clock, an output of a supply voltage source, an output of an activity sensor, an output of a telemetry circuit, a sensing input from a pacing lead, and a sensing input from a defibrillating lead.

30. The device of claim 1, wherein the first input signal or the first output signal is representative of information selected from the group consisting of a sensed normal intrinsic sensed event, a sensed premature atrial contraction (PAC), a sensed premature ventricular contraction (PVC'"'"'s), sensed atrial and/or ventricular tachycardia, sensed atrial and/or ventricular flutter, sensed atrial and/or ventricular fibrillation, sensed noise, sensed electromagnetic interference, a sensed muscle signal, a sensed far-field R-wave (FFRW), a sensed antegrade P-wave and a sensed retrograde P-wave.

31. The device of claim 1, wherein the first input signal or the first output signal is representative of information selected from the group consisting of a sensed complete memory data dump, a sensed selected memory location uplink, a detected re-transmission in a noisy environment, sensed telemetry distance, transmission power, receiver sensitivity, bit error rate (BER), and an amount of data telemetered or received.

32. The device of claim 1, wherein the first input signal or the first output signal is representative of information selected from the group consisting of a sampling rate, an activity rate response signal, a cardiac acceleration signal, and an oxygen saturation signal.

33. The device of claim 1, wherein the first input signal or the first output signal is representative of a sensed intra-circuit block activity per unit time.

34. The device of claim 1, wherein the first input signal or the first output signal is representative of information selected from the group consisting of a sensed number of operand codes processed per unit time and a sensed type of operand codes processed per unit time.

35. The device of claim 1, wherein the first input signal and the first output signal is representative of information selected from the group consisting of a sensed telemetry data format, sensed telemetry data movement, sensed Direct Memory Access (DMA) of an intra-cardiac electrogram, an analog-to-digital converter sample rate, and an analog-to-digital converter conversion rate.

36. The device of claim 1, wherein the first input signal or the first output signal is representative of information selected from the group consisting of sensed activity along a bus, sensed activity within a controller, sensed activity within a microcontroller, sensed activity within a microprocessor, and sensed activity within a digital signal processor.

37. The device of claim 1, wherein the first input signal or the first output signal is representative of information selected from the group consisting of a timed wakeup, an alarmed wakeup, a sensed interrupt for rate response calculation, a sensed completion of a diagnostic enable window, and a sensed acquisition of diagnostic data.

38. The method of claim 1, wherein the monitor circuit comprises a device selected from the group consisting of a microprocessor, a microcomputer, a controller, a microcontroller, a processor, a controller, a memory, a digital signal processor, a digital controller timer circuit, a central processing unit (CPU) and an Application Specific Integrated Circuit (ASIC).

39. The device of claim 1, wherein the monitor circuit is operable to execute an adaptive control algorithm.

40. The device of claim 39, wherein the adaptive control algorithm permits at least some operating parameters of the medical device to be adjusted on the fly on the basis of the measured, sensed or detected first input signal or the first output signal.

41. The device of claim 1, wherein the monitor circuit further measures, senses or detects data moving along at least one data bus.

42. The device of claim 1, wherein the monitor circuit is programmable.

43. The device of claim 1, wherein the monitor circuit is programmable with an adaptive control algorithm.

44. The device of claim 1, wherein the monitor circuit comprises a programmable digital signal processor capable of having an adaptive control algorithm programmed therein.

45. The device of claim 44, wherein the digital signal processor is capable of carrying out adaptive filtering on the measured, sensed or detected first input signal or first output signal.

46. The device of claim 45, wherein the digital signal processor is programmable to be capable of discriminating between or detecting at least one of supraventricular tachycardia (SVT), atrial fibrillation (AF), atrial flutter (AFL), ventricular tachycardia (VT), ventricular fibrillation (VF), ventricular flutter (VFL), premature atrial contractions (PAC'"'"'s), premature ventricular contractions (PVC'"'"'s), signal-to-noise ratio of intrinsic cardiac signals, electromagnetic interference (EMI) and myopotentials.

47. The device of claim 1, further comprising one or more supply voltage sources operable to provide a plurality of different supply voltages, at least one supply voltage of the plurality of different supply voltages being operatively connected to at least a first circuit of the at least one circuit, at least one different supply voltage being operatively connected to at least a second circuit of the at least first circuit.

48. The device of claim 47, wherein the clock source is operatively connected to control each of first and second circuits at different clock frequencies.

49. The device of claim 47, wherein the at least one supply voltage of the plurality of different supply voltages operatively connected to the first circuit is applied based on the clock frequency used for controlling operation of the first circuit, and further wherein the at least one different supply voltage operatively connected to the second circuit is applied based on the clock frequency used for controlling operation of the second circuit.

50. The device of claim 1, wherein the at least one circuit comprises a plurality of circuits and a particular circuit of the plurality of circuits performs at least a first and second function, one or more supply voltage sources being operatively connected to the particular circuit, the one or more supply voltage sources comprising a supply voltage source and a voltage regulator connected to the supply voltage source, the voltage regulator adjusting the supply voltage source such that a first supply voltage applied to the particular circuit for performance of the first function differs from a second supply voltage applied to the particular circuit for performance of the second function.

51. The device of claim 50, wherein the first supply voltage and the second supply voltage are determined on the basis of the clock frequency used to control the particular circuit during the performance of the first function and the clock frequency used to control the particular circuit during the performance of the second function, respectively.

52. The device of claim 50, wherein the device further includes means for adjusting the back gate bias of at least one of the first and second circuits based on the supply voltage applied to the at least one circuit.

53. The device of claim 1, wherein the device further comprises:

a multiplexer for receiving a plurality of analog signals; and

an analog to digital converter for converting one or more of the analog signals to digital signals and applying such digital signals to the processing device.

54. A method of conserving power in a medical device, comprising:

providing at least one circuit operable to perform at least one function and having at least one of a first input and a first output connected thereto for receiving or outputting, respectively, a first input signal or a first output signal;

providing a clock source for providing clock signals at a plurality of clock frequencies, the clock source being operatively connected to control the at least one circuit at a clock frequency such that substantially the entire predetermined time period is used to perform the at least one function, the function being completed just prior to the subsequent time period.

providing a processing device having a second input for receiving at least one of the first input signal and the first output signal, the first input signal or first output signal being input to the second input before or after having been subjected to any one of preliminary signal conditioning, filtering, amplification and logic processing, and

providing a monitor circuit connected between the second input and the first input or first output, the monitor circuit being operable to at least one of measure, sense and detect at least one predetermined characteristic of the first input signal or the first output signal, the monitor circuit being connected to the clock source and being operable, in response to measuring, sensing or detecting the at least one predetermined characteristic, to cause the clock source to increase or decrease the clock frequency.

55. The method of claim 54, wherein providing the at least one circuit further comprises providing at least a first logic circuit for performing a first function and providing a second logic circuit for performing a second function, the first logic circuit being operable to perform the first function during a first predetermined time period and the second logic circuit being operable to perform the second function during a second predetermined time period.

56. The method of claim 55, further comprising operating each of the first and second logic circuits at different clock frequencies such that substantially the entire respective first and second predetermined time periods are used by the respective first and second logic circuits to perform the respective first and second functions.

57. The method of claim 54, wherein the first predetermined time period and the second predetermined time period are time periods based on physiological events.

58. The method of claim 57, wherein providing at least one of the first and second time periods comprises selecting a time period from the group consisting of a blanking interval, an upper rate interval, an escape interval, a refractory interval, and a pulse generator/programmer handshake.

59. The method of claim 54, further comprising operating the processing device to perform a plurality of functions, each of the plurality of functions being performed during an associated predetermined time period prior to a subsequent time period in which another of the plurality of functions is performed, the processing device performing each of two or more functions of the plurality of functions at different clock frequencies such that substantially the entire associated predetermined time period for each function is used to perform the functions prior to the subsequent time period in which another of the plurality of functions is performed.

60. The method of claim 59, wherein the associated predetermined time periods are time periods based on physiological events.

61. The method of claim 60, wherein providing at least one of the associated time periods comprises selecting a time period selected from the group consisting of a blanking interval, an upper rate interval, an escape interval, a refractory interval, and a pulse generator/programmer handshake.

62. The method of claim 54, further comprising providing one or more supply voltage sources to provide one or more supply voltages, the one or more supply voltage sources being operatively connected to the at least one circuit such that a supply voltage is applied to at least a portion of the at least one circuit as a function of the clock frequency applied to the at least portion of the at least one circuit.

63. The method of claim 62, wherein providing the at least one circuit further comprises providing at least a first logic circuit for performing a first function and providing a second logic circuit for performing a second function, each of the first and second logic circuits being operated at different clock frequencies, each of the logic circuits having a different supply voltage applied thereto by the one or more voltage sources based on the different clock frequencies used to control the first and second logic circuits.

64. The method of claim 63, further comprising operating the processing device to perform a plurality of functions, each of at least two of the plurality of functions being performed at different clock frequencies, the supply voltage applied to the processing device by the one or more voltage sources being adjusted such that a first supply voltage is provided to the processing device during performance of one of the at least two functions and a second supply voltage is provided to the processing device during performance of the other function, the first and second supply voltages being applied to the processing device based on the different clock frequencies used to control the processing device.

65. The method of claim 54, further comprising hermetically sealing the medical device for implantation within a mammalian.

66. The method of claim 65, further comprising selecting the medical device from the group consisting of an implantable stimulator, an implantable nerve stimulator, an implantable pacemaker, an IPG, an implantable cardioverter, an implantable PCD, an implantable defibrillator, an implantable ICD and an implantable drug pump.

67. The method of claim 54, wherein providing the at least one circuit further comprises providing one or more analog circuits operable to perform at least one function.

68. The method of claim 67, wherein providing the one or more analog circuits includes selecting the one or more analog circuits from the group consisting of an atrial sense amplifier, a ventricular sense amplifier, a T-wave amplifier, one or more bandpass filters, one or more detection circuits, one or more sensor amplification circuits, one or more physiological signal amplification circuits, one or more output circuits, a battery monitor circuit, and a power on reset circuit.

69. The method of claim 54, wherein providing the at least one circuit further comprises providing one or more digital circuits operable to perform at least one function.

70. The method of claim 69, further comprising including means for adjusting the back gate bias of at least one of the one or more digital circuits.

71. The method of claim 54, wherein providing the processing device comprises providing one or more of a microprocessor, a microcomputer, a controller, a microcontroller, a processor, a controller, a memory, a digital signal processor, a digital controller timer circuit, a central processing unit (CPU) and an Application Specific Integrated Circuit (ASIC).

72. The method of claim 71, wherein providing the at least one circuit further comprises providing one or more analog circuits operable to perform at least one function and the processing device receives data representative of the one or more analog signals.

73. The method of claim 54, further comprising providing a power source for applying a first fixed supply voltage to at least portions of the at least one circuit.

74. The method of claim 73, further comprising providing a voltage generation circuit having the first fixed supply voltage supplied thereto, the voltage generation circuit generating at least a second fixed supply voltage for application to at least portions of the at least one circuit, the second fixed supply voltage being greater than the first fixed supply voltage.

75. The method of claim 74, wherein providing the voltage generation circuit further comprises providing a charge pump circuit for generating the second fixed supply voltage based on the first fixed supply voltage.

76. The method of claim 73, wherein the first supply voltage ranges between about 0.8 volts and about 1.5 volts.

77. The method of claim 74, wherein the second supply voltage ranges between about +/-2.0 volts and about +/-3.0 volts.

78. The method of claim 54, wherein providing the at least one circuit further comprises providing one or more analog circuits, providing one or more digital circuits, and providing a level shifter to translate signals between the one or more analog circuits and the one or more digital circuits.

79. The method of claim 54, wherein providing the monitor circuit further comprises providing an adaptive control algorithm in the monitor circuit to determine whether or not a measured, sensed or detected signal meets the at least one predetermined characteristic.

80. The method of claim 54, wherein the at least one predetermined characteristic is defined in respect of at least one of the sign, polarity, slope, rate of change, amplitude, frequency and phase of the measured, sensed or detected signal.

81. The method of claim 54, wherein providing the first input or the first output further comprises selecting the first input or the first output from the group consisting of an output of a comparator, an output of a clock source, an output of a clock, an output of a supply voltage source, an output of an activity sensor, an output of a telemetry circuit, a sensing input from a pacing lead, and a sensing input from a defibrillating lead.

82. The method of claim 54, wherein the first input signal or the first output signal is representative of information selected from the group consisting of a sensed normal intrinsic sensed event, a sensed premature atrial contraction (PAC), a sensed premature ventricular contraction (PVC'"'"'s), sensed atrial and/or ventricular tachycardia, sensed atrial and/or ventricular flutter, sensed atrial and/or ventricular fibrillation, sensed noise, sensed electromagnetic interference, a sensed muscle signal, a sensed far-field R-wave (FFRW), a sensed antegrade P-wave and a sensed retrograde P-wave.

83. The method of claim 54, wherein the first input signal or the first output signal is representative of information selected from the group consisting of a sensed complete memory data dump, a sensed selected memory location uplink, a detected re-transmission in a noisy environment, sensed telemetry distance, transmission power, receiver sensitivity, bit error rate (BER), and an amount of data telemetered or received.

84. The method of claim 54, wherein the first input signal or the first output signal is representative of information selected from the group consisting of a sampling rate, an activity rate response signal, a cardiac acceleration signal, and an oxygen saturation signal.

85. The method of claim 54, wherein the first input signal or the first output signal is representative of a sensed intra-circuit block activity per unit time.

86. The method of claim 54, wherein the first input signal or the first output signal is representative of information selected from the group consisting of a sensed number of operand codes processed per unit time and a sensed type of operand codes processed per unit time.

87. The method of claim 54, wherein the first input signal and the first output signal is representative of information selected from the group consisting of a sensed telemetry data format, sensed telemetry data movement, sensed Direct Memory Access (DMA) of an intra-cardiac electrogram, an analog-to-digital converter sample rate, and an analog-to-digital converter conversion rate.

88. The method of claim 54, wherein the first input signal or the first output signal is representative of information selected from the group consisting of sensed activity along a bus, sensed activity within a controller, sensed activity within a microcontroller, sensed activity within a microprocessor, and sensed activity within a digital signal processor.

89. The method of claim 54, wherein the first input signal or the first output signal is representative of information selected from the group consisting of a timed wakeup, an alarmed wakeup, a sensed interrupt for rate response calculation, a sensed completion of a diagnostic enable window, and a sensed acquisition of diagnostic data.

90. The method of claim 54, wherein providing the monitor circuit further comprises providing selecting the monitor circuit from the group consisting of a microprocessor, a microcomputer, a controller, a microcontroller, a processor, a controller, a memory, a digital signal processor, a digital controller timer circuit, a central processing unit (CPU) and an Application Specific Integrated Circuit (ASIC).

91. The method of claim 54, wherein the monitor circuit is operable to execute an adaptive control algorithm.

92. The method of claim 91, wherein the adaptive control algorithm permits at least some operating parameters of the medical device to be adjusted on the fly on the basis of the measured, sensed or detected first input signal or the first output signal.

93. The method of claim 54, wherein the monitor circuit further measures, senses or detects data moving along at least one data bus.

94. The method of claim 54, further comprising programming the monitor circuit.

95. The method of claim 94, further comprising programming the monitor circuit with an adaptive control algorithm.

96. The method of claim 54, wherein providing the monitor circuit further comprises providing a programmable digital signal processor capable of having an adaptive control algorithm programmed therein.

97. The method of claim 96, wherein the digital signal processor is capable of carrying out adaptive filtering on the measured, sensed or detected first input signal or first output signal.

98. The method of claim 97, wherein the digital signal processor is programmable to be capable of discriminating between or detecting at least one of supraventricular tachycardia (SVT), atrial fibrillation (AF), atrial flutter (AFL), ventricular tachycardia (VT), ventricular fibrillation (VF), ventricular flutter (VFL), premature atrial contractions (PAC'"'"'s), premature ventricular contractions (PVC'"'"'s), signal-to-noise ratio of intrinsic cardiac signals, electromagnetic interference (EMI) and myopotentials.

99. The method of claim 54, further comprising providing one or more supply voltage sources operable to provide a plurality of different supply voltages, operatively connecting at least one supply voltage of the plurality of different supply voltages to at least a first circuit of the at least one circuit, and operatively connecting at least one different supply voltage to at least a second circuit of the at least first circuit.

100. The method of claim 99, further comprising operatively connecting the clock source to control each of first and second circuits at different clock frequencies.

101. The method of claim 99, wherein applying the at least one supply voltage of the plurality of different supply voltages to the first circuit is based on the clock frequency used for controlling operation of the first circuit, and further wherein applying the at least one different supply voltage to the second circuit is based on the clock frequency used for controlling operation of the second circuit.

102. The method of claim 54, wherein providing the at least one circuit comprises providing a plurality of circuits and providing a particular circuit of the plurality of circuits to perform at least first and second functions, one or more supply voltage sources being operatively connected to the particular circuit, the one or more supply voltage sources comprising a supply voltage source and a voltage regulator connected to the supply voltage source, the voltage regulator adjusting the supply voltage source such that a first supply voltage applied to the particular circuit for performance of the first function differs from a second supply voltage applied to the particular circuit for performance of the second function.

103. The device of claim 102, wherein the first supply voltage and the second supply voltage are determined on the basis of the clock frequency used to control the particular circuit during the performance of the first function and the clock frequency used to control the particular circuit during the performance of the second function, respectively.

104. The method of claim 54, further comprising at least one of measuring, sensing and detecting the first input signal or the first output signal.

105. The method of claim 104, further comprising at least one of measuring, sensing and detecting the at least one predetermined characteristic.

106. The method of claim 105, further comprising, in response to at least one of measuring, sensing and detecting the at least one predetermined characteristic, causing the clock source to increase the clock frequency.

107. The method of claim 105, further comprising, in response to at least one of measuring, sensing and detecting the at least one predetermined characteristic, causing the clock source to decrease the clock frequency.