[0001] The present invention relates to industrial process control and monitoring systems. More specifically, the present invention relates to wireless field devices used in industrial process control and/or monitoring systems.
[0002] Industrial processes are used in many industries to process or transport various materials. Industrial processes are implemented in, for example, oil refineries, food manufacturing facilities, paper pulp manufacturing facilities, etc.
[0003] Operation of an industrial process typically requires the monitoring of process variable. Example process variables include temperature, pressure, flow rate, level, etc. A process variable transmitted is used to measure a process variable and transmit information of the measured process variable to a central location. This information can used to monitor the process and can be used to control the process. For example, a valve can be adjusted using another type of field device, a control device, based upon a measured flow rate. _
[0004] Traditionally, process variable transmitters have communicated with a central location using a wired connection. An example of a wired connection is a two wire process control loop in a current loop through the loop is representative of a measured process variable. Other communication techniques include transmitting digital information on the process control loop. The same two wire process control loop can be used to provide power to the field device.
[0005] Wireless field devices are used to measure process variables and communicate with another location and do not require the wired connection described above. One wireless communication technique uses a mesh network configuration. One example communication protocol is the Wireless HART(R) communication protocol in accordance with the IEC 62591 Standard. One benefit of a wireless device is that it does not require wires to be extended from a central control location to the field device. A further reduction in wiring can be achieved if the field device includes an internal power supply such as a battery. However, if the field device is battery operated, the device will cease operation if its power source is depleted.
U.S. Patent Publication No. 2008/280568 is directed to an adapter for coupling to a process control transmitter in an industrial process. The adapter comprises an I/O circuitry coupled to a process control loop, and includes a power supply circuitry which in turn includes a capacitor. A current is used to charge capacitor, and the voltage across the capacitor is set using a voltage clamp set at a predetermined voltage. A converter is configured as a step up converter and provides a regulated voltage output to a low dropout regulator. The output of the low dropout regulator is also set at a predetermined voltage value. During operation, the voltage on the capacitor will decrease and the converter via the low dropout regulator provides a stable voltage to the transmitter.
Document US 2009 / 0 102 449 A1 discloses a power supply device with a boost converter and with a buck converter. Document US 2010 / 0 156 175 A1 discloses a DC/DC boost converter with a bypass feature.
Therefore, it is often desirable to take steps to reduce power consumption in the field device in order to extend the life of the power source.
[0006] The present patent application provides a wireless industrial process field device for use in controlling or monitoring a process variable of an industrial process with the features of claim 1. Furthermore, the present patent application provides a method with the features of claim 9.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007]
Figure 1 is a simplified diagram of a industrial process control or monitoring system including a wireless field device.
Figure 2 is simplified block diagram of the wireless field device of Figure 1.
Figure 3 is a simplified schematic diagram showing a power supply of the wireless field device of Figure 1 in accordance with one example embodiment of the present invention.
DETAILED DESCRIPTION
[0008] The present invention provides a power supply circuit for a wireless field device such as a process variable transmitter or process controller. The power supply circuit includes a boost converter and a Low Drop Out (LDO) regulator which can be selectively used to power circuitry of the field device. The combination of LDO and boost converter is used to increase the battery life. A comparator is used to switch between the boost and LDO.
[0009] Figure 1 is a simplified diagram of an industrial process control or monitoring system 100 in which a field device such as process field device 102 interfaces with a process fluid 108 through a process interface element 104. The process fluid 108 is contained in, for example, process piping 106. The field device 102 can be configured as a process variable transmitter, in which the process interface element 104 can comprise a sensor to sense a process variable of the process fluid 108. Examples include temperature, flow rate, level, etc.
[0010] Process field device 102 communicates with another location, such as location 110, over wireless communication link 112. Location 110 includes communication circuitry 114 coupled to an antenna 116 which is used to establish communication link 112. Location link 110 can, for example, be a central control room or the like in which operation of the process is monitored or controlled. The wireless communication link 112 can be in accordance with any of the communication protocol technique or standard. One example is the Wireless HART® communication protocol in accordance with the IEC 62591 Standard.
[0011] Figure 2 is a simplified block diagram of process field device 102. As illustrated in Figure 2, a microprocessor 200 is coupled to the process interface element 104 through process circuitry 202. Process circuitry 202 can comprise, for example, an amplifier, analog to digital converter, etc. In such a configuration, a digital representation of a sensed process variable is provided to the microprocessor 200. Microprocessor 200 operates in accordance with instructions stored in memory 204 and couples to wireless communication circuitry 206. The wireless communication circuitry 206 couples to an antenna 208 which is linked to the communication link 112 shown in Figure 1. Using this configuration, the transmitter 102 can receive or transmit information on the communication link 112. An optional local input/output (I/O) circuit 210 is shown. For example, I/O circuit 210 can be used by an operator to locally control the transmitter 102. Figure 2 also illustrates a power supply 220 coupled to a power storage element 222. Power supply 220 is used to provide power to circuitry of the process variable 102 from power storage element 222 as discussed below in more detail. Power storage element 222 may comprise any appropriate device which is capable of storing sufficient power as desired. Examples include a battery, a rechargeable battery, an electrical capacitor, including a bulk or "super" capacitor.
[0012] The various circuit components of process field device 102 are configured to operate based upon a stable power source. For example, a stable power supply of 3.0 volts may be required. However, the voltage provided by power storage element 222 may vary from between 2.0 to 3.7 volts during its change or discharge cycle. In such a configuration, a "Buck-Boost" converter is typically used in which a single converter is used to both boost a DC voltage to obtain a desired output voltage as well as decrease a DC voltage to obtain the desired output voltage. However, the Buck-Boost converter consumes additional power from the power storage element thereby shortening battery life.
[0013] During operation, the process field device 102 senses a process variable using a process variable sensor such as process interface element 104. Microprocessor 200 is used to control operation of the process field device 102 and transmit information related to the sensed process variable on communication link 112 using wireless communication circuitry 206. In order to increase the life of power storage element 222, the circuitry of process field device 102 may enter a "sleep" or reduced power mode. Typically, the process field device 102 may operate in a reduced power mode more than 90% of the time. In such a configuration, the circuitry only requires tens of microwatts of power for operation. For example, the wireless communication circuitry 206 can be turned off or idled, the speed of microprocessor 200 can be reduced, the process circuitry 202 can be disabled, etc. During active times, this circuitry is powered up and the power requirements may go as high as tens of milliwatts. When the power storage element 220 voltage is above 3.0 volts, the power supply circuitry 220 must reduce the voltage to 3.0 volts for powering the circuitry of the field device 102. Similarly, when the power storage element 220 voltage dips below 3.0 volts, the power supply 220 circuitry must boost the voltage to 3.0 volts to properly power the field device 102 circuitry. Prior art techniques have used "Buck-Boost" converter. However, the quiescent power draw of such a "Buck-Boost" circuit may be tens of microwatts which will significantly reduce the life of the power storage element 222.
[0014] Figure 3 is a simplified block diagram of power supply circuitry 220 in accordance with one example embodiment of the present invention. Power supply circuitry 220 includes a boost converter 240 and an LDO (low drop out) or "LDO" converter 242. Boost converter 240 and LDO converter 242 can operate in accordance with standard techniques. For example, the boost converter can comprise a switched-mode or other step-up power supply. The boost converter 240 is configured to receive a voltage from power storage element 222 which is less than 3 volts and provide an output voltage which is regulated 3.0 volts. Similarly, the LDO converter 242 is configured to receive a voltage from the power storage element 222 which is greater than 3 volts and provide a regulated output which is 3.0 volts. An analog switch 244 is configured to selectively couple either the output from converter 240 or the output from converter 242 to bulk capacitor(s) 246. This output is used to provide power to circuitry of the process field device 102. Operation of the analog switch 244 is controlled by a comparator 248 which has a threshold set to the desired switch over point in the output voltage of power storage element 222, i.e. 3.0 volts. The comparator 250 is also used to control operation of boost converter 240 whereby boost converter 240 is turned "toff" if the battery voltage is greater than the desired threshold. This saves power because the boost converter 240 operates only when its functioning is required. A diode 252 is connected across the analog switch 244 and bulk capacitor(s) 246 and operates to provide a power supply voltage to circuitry of the process field device 102 during the switching transition and improves the settling time of the boost converter 240.
[0015] When the power required by the circuitry of the field device is low, the loss through the LDO converter 242 will be larger when compared to the other circuitry. This can be seen in Equation 1.
Equation shows that for low load currents, the power loss is less than when compared to a traditional Buck-Boost converter. As a basis for comparison, a power supply in accordance with Figure 3 was tested and compared to a traditional Buck-Boost converter. Table 1 is a tabulation of experimental results for different loads applied to a traditional Buck-Boost converter and the parallel LDO/ boost converter configuration shown in Figure 3:
Table 1
Test Number | Buck-Boost Converter | LDO and Boost Converter (Fig. 3) | Increase in battery life (%) |
Average Current (uA) | Battery life (Years) | Average Current (uA) | Battery life (Years) |
1 |
117.84 |
15.02 |
98.07 |
18.04 |
20.15% |
2 |
130.72 |
13.54 |
108.33 |
16.33 |
20.67% |
3 |
107.46 |
16.47 |
89.57 |
19.76 |
19.97% |
4 |
218.79 |
8.09 |
181.76 |
9.73 |
20.37% |
5 |
192.64 |
9.18 |
156.24 |
11.32 |
23.30% |
6 |
180.38 |
9.81 |
151.61 |
11.67 |
18.98% |
[0016] Although the discussion above is directed specifically to the process interface element 104 as comprising a process variable sensor, in some configurations the process interface 105 comprises a control element which is used to control operation of the process in response to an output from microprocessor 200.
1. A wireless industrial process field device (102) for use in controlling or monitoring a process variable of an industrial process, comprising:
a process device circuitry (202) with a process interface circuit configured to measure or control the process variable of the industrial process with a process interface element (104);
a wireless communication circuitry (206) configured for wireless communication;
a power storage element (222) having a voltage output; and
a power supply circuitry (220) configured to provide power to the process device circuitry (202) from the power storage element (222) at an output voltage, the power supply circuitry (220) comprising:
a low drop out (LDO) voltage regulator (242) configured to reduce a voltage of the power storage element (222) when the voltage output of the power storage element (222) is above a threshold, and provide the reduced voltage to the process device circuitry (202);
a boost converter (240) configured to increase the voltage of the power storage element (222) when the voltage output of the power storage element (222) is below the threshold, and provide the increased voltage to the process device circuitry (202);
characterized by the power supply circuitry (220) comprising:
a comparator (248) configured to turn
the boost converter (240) off if the voltage output from the power storage element (222) is greater than the threshold; and
an analog switch responsive to an output from the comparator to connect an output of the low drop out (LDO) voltage regulator to the process device circuitry if the voltage output from the power storage element is greater than the threshold and further configured to connect an output of the boost converter to the process device circuitry if the voltage output from the power storage element is less than the threshold.
2. The wireless industrial process field device (102) of claim 1 wherein the comparator (248) is responsive to the voltage output of the power storage element (222).
3. The wireless industrial process field device (102) of claim 2 wherein the comparator (248) compares the threshold to the voltage output of the power storage element (222).
4. The wireless industrial process field device (102) of claim 3 wherein the comparator (248) couples the boost converter (240) to the process device circuitry (202) if the voltage output is less than the threshold, and/or
wherein the comparator (248) couples the low drop out voltage regulator (242) to the process device circuitry (202) if the voltage output is greater than the threshold.
5. The wireless industrial process field device (102) of claim 1 wherein an output of the comparator (248) is coupled to the boost converter (240).
6. The wireless industrial process field device (102) of claim 5 wherein the comparator (248) disables operation of the boost converter (240) to thereby reduce power consumption if the low drop out voltage regulator (242) is coupled to the process device circuitry (202).
7. The wireless industrial process field device (102) of claim 1 including a bulk capacitor (246) coupled to the process device circuitry (202) configured to store power from the power supply circuitry (220).
8. The wireless industrial process field device (102) of claim 1 including a diode (252) configured to couple the low drop out voltage regulator (242) to the process device circuitry (202).
9. A method of powering a wireless industrial process field device (102) of the type used in controlling or monitoring a process variable of an industrial process, comprising:
providing a process device circuitry (202) configured to operate with a process interface element (104);
providing wireless communication circuitry (206) configured for wireless communication;
providing a voltage output from a power storage element (222);
coupling the process device circuitry (202) to an output of a low drop out (LDO) voltage regulator when the voltage output of the power storage element (222) is above a threshold, wherein the LDO voltage regulator (242) is configured to provide a reduced voltage formed by reducing the voltage output of the power storage element (222); and
selectively coupling the process device circuitry (202) to an output of a boost converter (240) when the voltage output of the power storage element (222) is below a threshold, wherein the boost converter (240) is configured to provide an increased voltage formed by increasing the voltage output of the power storage element (222);
characterized in
turning, by a comparator (248), the boost converter (240) off when the voltage output from the power storage element (222) is greater than the threshold, and
further characterized in controlling an analog switch responsive to an output from the comparator to connect an output of the low drop out (LDO) voltage regulator to the process device circuitry if the voltage output from the power storage element is greater than the threshold and further to connect an output of the boost converter to the process device circuitry if the voltage output from the power storage element is less than the threshold.
10. The method of claim 9 wherein selectively coupling comprises coupling the output of the boost converter (240) to the process device circuitry (202) if the output voltage is less than the voltage threshold.
11. The method of claim 10 including disabling operation of a boost converter (240) to thereby reduce power consumption if voltage output is above the threshold, and/or storing power in a bulk capacitor (246).
1. Drahtlos-Feldgerät für einen industriellen Prozess (102) zur Verwendung beim Steuern oder Überwachen einer Prozessvariable eines industriellen Prozesses, umfassend:
eine Prozessvorrichtungsschaltung (202) mit einer Prozessschnittstellenschaltung, die dafür ausgebildet ist, die Prozessvariable des industriellen Prozesses mit einem Prozessschnittstellenelement (104) zu messen oder zu steuern;
eine Drahtloskommunikationsschaltung (206), die für eine Drahtloskommunikation ausgebildet ist;
ein Energiespeicherelement (222) mit einem Spannungsausgang; und eine Stromversorgungsschaltung (220), die dafür ausgebildet ist, der Prozessvorrichtungsschaltung (202) Energie aus dem Energiespeicherelement (222) mit einer Ausgangsspannung zuzuführen, wobei die Stromversorgungsschaltung (220) Folgendes umfasst:
einen Low Drop Out (LDO)-Spannungsregler (242), der dafür ausgebildet ist, eine Spannung des Energiespeicherelements (222) zu reduzieren, wenn der Spannungsausgang des Energiespeicherelements (222) oberhalb einer Schwelle liegt, und die reduzierte Spannung in die Prozessvorrichtungsschaltung (202) einzuspeisen;
einen Boostwandler (240), der dafür ausgebildet ist, die Spannung des Energiespeicherelements (222) zu erhöhen, wenn der Spannungsausgang des Energiespeicherelements (222) unterhalb der Schwelle liegt, und die erhöhte Spannung in die Prozessvorrichtungsschaltung (202) einzuspeisen;
dadurch gekennzeichnet, dass die Stromversorgungsschaltung (220) Folgendes umfasst:
einen Komparator (248), der dafür ausgebildet ist, den Boostwandler (240) auszuschalten, wenn der Spannungsausgang von dem Energiespeicherelement (222) größer als die Schwelle ist; und
einen analogen Schalter, der auf ein Ausgangssignal von dem Komparator anspricht, um einen Ausgang des Low Drop Out (LDO)-Spannungsreglers mit der
Prozessvorrichtungsschaltung zu verbinden, wenn der Spannungsausgang von dem Energiespeicherelement größer ist als die Schwelle, und des Weiteren dafür ausgebildet ist, einen Ausgang des Boostwandlers mit der
Prozessvorrichtungsschaltung zu verbinden, wenn der Spannungsausgang von dem Energiespeicherelement kleiner ist als die Schwelle.
2. Drahtlos- Feldgerät für einen industriellen Prozess (102) nach Anspruch 1, wobei der Komparator (248) auf den Spannungsausgang des Energiespeicherelements (222) anspricht.
3. Drahtlos- Feldgerät für einen industriellen Prozess (102) nach Anspruch 2, wobei der Komparator (248) die Schwelle mit dem Spannungsausgang des Energiespeicherelements (222) vergleicht.
4. Drahtlos- Feldgerät für einen industriellen Prozess (102) nach Anspruch 3, wobei der Komparator (248) den Boostwandler (240) mit der Prozessvorrichtungsschaltung (202) koppelt, wenn der Spannungsausgang kleiner ist als die Schwelle, und/oder
wobei der Komparator (248) den Low Drop Out-Spannungsregler (242) mit der Prozessvorrichtungsschaltung (202) koppelt, wenn der Spannungsausgang größer ist als die Schwelle.
5. Drahtlos- Feldgerät für einen industriellen Prozess (102) nach Anspruch 1, wobei ein Ausgang des Komparators (248) mit dem Boostwandler (240) gekoppelt ist.
6. Drahtlos- Feldgerät für einen industriellen Prozess (102) nach Anspruch 5, wobei der Komparator (248) den Betrieb des Boostwandlers (240) deaktiviert, um dadurch den Stromverbrauch zu senken, wenn der Low Drop Out-Spannungsregler (242) mit der Prozessvorrichtungsschaltung (202) gekoppelt ist.
7. Drahtlos- Feldgerät für einen industriellen Prozess (102) nach Anspruch 1, die einen Volumenkondensator (246) enthält, der mit der Prozessvorrichtungsschaltung (202) gekoppelt ist und dafür ausgebildet ist, Energie von der Stromversorgungsschaltung (220) zu speichern.
8. Drahtlos-Feldgerät für einen industriellen Prozess (102) nach Anspruch 1, die eine Diode (252) umfasst, die dafür ausgebildet ist, den Low Drop Out-Spannungsregler (242) mit der Prozessvorrichtungsschaltung (202) zu koppeln.
9. Verfahren zur Energieversorgung einer Drahtlos-Feldgeräts für einen industriellen Prozess (102) des Typs, der zum Steuern oder Überwachen einer Prozessvariable eines industriellen Prozesses verwendet wird, umfassend:
Bereitstellen einer Prozessvorrichtungsschaltung (202), die dafür ausgebildet ist, mit einem Prozessschnittstellenelement (104) zu arbeiten;
Bereitstellen einer Drahtloskommunikationsschaltung (206), die für eine Drahtloskommunikation ausgebildet ist;
Bereitstellen eines Spannungsausgangs von einem Energiespeicherelement (222);
Koppeln der Prozessvorrichtungsschaltung (202) mit einem Ausgang eines Low Drop Out (LDO)-Spannungsreglers, wenn der Spannungsausgang des Energiespeicherelements (222) oberhalb einer Schwelle liegt,
wobei der LDO-Spannungsregler (242) dafür ausgebildet ist, eine reduzierte Spannung bereitzustellen, die durch eine Reduzierung des Spannungsausgangs des Energiespeicherelements (222) gebildet wird; und
selektives Koppeln der Prozessvorrichtungsschaltung (202) mit einem Ausgang eines Boostwandlers (240), wenn der Spannungsausgang des Energiespeicherelements (222) unterhalb einer Schwelle liegt, wobei der Boostwandler (240) dafür ausgebildet ist, eine erhöhte Spannung bereitzustellen, die durch Erhöhen des Spannungsausgangs des Energiespeicherelements (222) gebildet wird;
gekennzeichnet durch Abschalten, durch einen Komparator (248), des Boostwandlers (240), wenn der Spannungsausgang von dem Energiespeicherelement (222) größer ist als die Schwelle, und des Weiteren gekennzeichnet durch Steuern eines analogen Schalters, der auf einen Ausgang von dem Komparator anspricht, um einen Ausgang des Low Drop Out (LDO)-Spannungsreglers mit der Prozessvorrichtungsschaltung zu verbinden, wenn der Spannungsausgang von dem Energiespeicherelement größer ist als die Schwelle, und des Weiteren einen Ausgang des Boostwandlers mit der Prozessvorrichtungsschaltung zu verbinden, wenn der Spannungsausgang von dem Energiespeicherelement kleiner ist als die Schwelle.
10. Verfahren nach Anspruch 9, wobei das selektive Koppeln umfasst, den Ausgang des Boostwandlers (240) mit der Prozessvorrichtungsschaltung (202) zu koppeln, wenn die Ausgangsspannung kleiner ist als die Spannungsschwelle.
11. Verfahren nach Anspruch 10, das umfasst, den Betrieb eines Boostwandlers (240) zu deaktivieren, um dadurch den Stromverbrauch zu senken, wenn ein Spannungsausgang oberhalb der Schwelle liegt, und/oder Energie in einem Volumenkondensator (246) zu speichern.
1. Appareil de terrain de procédé industriel sans fil (102) destiné à être utilisé pour commander ou surveiller une variable de processus d'un procédé industriel, comprenant :
un circuit de dispositif de processus (202) avec un circuit d'interface de processus configuré pour mesurer ou commander la variable de processus du procédé industriel avec un élément d'interface de processus (104) ;
un circuit de communication sans fil (206) configuré pour une communication sans fil ;
un élément de stockage d'énergie (222) ayant une sortie de tension ; et
un circuit d'alimentation en courant (220) configuré pour fournir de l'énergie au circuit de dispositif de processus (202) à partir de l'élément de stockage d'énergie (222) à une tension de sortie, le circuit d'alimentation en courant (220) comprenant :
un régulateur de tension à faible perte de niveau (LDO) (242) configuré pour réduire une tension de l'élément de stockage d'énergie (222) lorsque la sortie de tension de l'élément de stockage d'énergie (222) est supérieure à un seuil, et fournir la tension réduite au circuit de dispositif de processus (202) ;
un convertisseur d'amplification (240) configuré pour augmenter la tension de l'élément de stockage d'énergie (222) lorsque la sortie de tension de l'élément de stockage d'énergie (222) est inférieure au seuil, et fournir la tension augmentée au circuit de dispositif de processus (202) ;
caractérisé en ce que le circuit d'alimentation en courant (220) comprend :
un comparateur (248) configuré pour désactiver le convertisseur d'amplification (240) si la sortie de tension de l'élément de stockage d'énergie (222) est supérieure au seuil ; et
un commutateur analogique sensible à une sortie du comparateur pour connecter une sortie du régulateur de tension à faible perte de niveau (LDO) au circuit de dispositif de processus si la sortie de tension de l'élément de stockage d'énergie est supérieure au seuil, et configuré en outre pour connecter une sortie du convertisseur d'amplification au circuit du dispositif de procédé si la sortie de tension de l'élément de stockage d'énergie est inférieure au seuil.
2. Appareil de terrain de procédé industriel sans fil (102) selon la revendication 1, dans lequel le comparateur (248) est sensible à la sortie de tension de l'élément de stockage d'énergie (222).
3. Appareil de terrain de procédé industriel sans fil (102) selon la revendication 2, dans lequel le comparateur (248) compare le seuil à la sortie de tension de l'élément de stockage d'énergie (222).
4. Appareil de terrain de procédé industriel sans fil (102) selon la revendication 3, dans lequel le comparateur (248) couple le convertisseur d'amplification (240) au circuit de dispositif de processus (202) si la sortie de tension est inférieure au seuil et/ou
dans lequel le comparateur (248) couple le régulateur de tension à faible perte de niveau (242) au circuit de dispositif de processus (202) si la sortie de tension est supérieure au seuil.
5. Appareil de terrain de procédé industriel sans fil (102) selon la revendication 1, dans lequel une sortie du comparateur (248) est couplée au convertisseur d'amplification (240).
6. Appareil de terrain de procédé industriel sans fil (102) selon la revendication 5, dans lequel le comparateur (248) désactive le fonctionnement du convertisseur d'amplification (240) pour ainsi réduire la consommation d'énergie si le régulateur de tension à faible perte de niveau (242) est couplé au circuit de dispositif de processus (202).
7. Appareil de terrain de procédé industriel sans fil (102) selon la revendication 1, comprenant un condensateur massif (246) couplé au circuit de dispositif de processus (202) configuré pour stocker de l'énergie provenant du circuit d'alimentation en courant (220).
8. Appareil de terrain de procédé industriel sans fil (102) selon la revendication 1, comprenant une diode (252) configurée pour coupler le régulateur de tension à faible perte de niveau (242) au circuit de dispositif de processus (202).
9. Procédé d'alimentation en courant d'un apparteil de terrain de procédé industriel sans fil (102) du type utilisé pour commander ou surveiller une variable de processus d'un procédé industriel, comprenant de :
fournir un circuit de dispositif de processus (202) configuré pour fonctionner avec un élément d'interface de processus (104) ;
fournir un circuit de communication sans fil (206) configuré pour une communication sans fil ;
fournir une sortie de tension à partir d'un élément de stockage d'énergie (222) ;
coupler le circuit de dispositif de processus (202) à une sortie d'un régulateur de tension à faible perte de niveau (LDO) lorsque la sortie de tension de l'élément de stockage d'énergie (222) est supérieure à un seuil, le régulateur de tension LDO (242) étant configuré pour fournir une tension réduite formée en réduisant la sortie de tension de l'élément de stockage d'énergie (222) ; et
coupler sélectivement le circuit de dispositif de processus (202) à une sortie d'un convertisseur d'amplification (240) lorsque la sortie de tension de l'élément de stockage d'énergie (222) est inférieure à un seuil, dans lequel le convertisseur d'amplification (240) est configuré pour fournir une tension augmentée formée en augmentant la sortie de tension de l'élément de stockage d'énergie (222) ;
caractérisé par la désactivation, par un comparateur (248), du convertisseur d'amplification (240) lorsque la sortie de tension de l'élément de stockage d'énergie (222) est supérieure au seuil, et
caractérisé en coutre par la commande d'un commutateur analogique en réponse à une sortie du comparateur pour connecter une sortie du régulateur de tension à faible perte de niveau (LDO) au circuit de dispositif de processus si la sortie de tension de l'élément de stockage d'énergie est supérieure au seuil, et en outre pour connecter une sortie du convertisseur d'amplification au circuit du dispositif de procédé si la sortie de tension de l'élément de stockage d'énergie est inférieure au seuil.
10. Procédé selon la revendication 9, dans lequel le couplage sélectif comprend de coupler la sortie du convertisseur d'amplification (240) au circuit de dispositif de processus (202) si la tension de sortie est inférieure au seuil de tension.
11. Procédé selon la revendication 10, comprenant de désactiver le fonctionnement d'un convertisseur d'amplification (240) pour ainsi réduire la consommation d'énergie si la sortie de tension est supérieure au seuil, et/ou stocker de l'énergie dans un condensateur massif (246).