Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
  • H02M1/00—Details of apparatus for conversion
  • H02M1/36—Means for starting or stopping converters

Definitions

• the invention relates to the field of converters with low input voltage, low power.
• the invention also relates to the field of analog monolithic integrated circuits for electronics, and more particularly to so-called switching voltage converters: these are devices which, connected to a source of variable voltage over a wide range, for example of 0.5 V to 15 V, are able to generate a fixed regulated voltage, for example 3.3 V, for the supply of electronic circuits.
• Applications of low-voltage converters include the power supply of so-called communicating objects and nomadic objects.
• These converters provide suitable voltages for the supply of electronic circuits from different configurations of batteries or batteries.
• SII-IC see Another manufacturer is MAXIM •
• MAXIM MAXIM •
• Another problem is to be able to use these sources until almost complete discharge, and in any case less than 0.9 V.
• the threshold voltage for the operation of known converters comes from the physics of active devices implanted in integrated circuits (MOS type transistors). We seek to have devices with lower input voltage.
• the invention relates to a DC voltage conversion device comprising DC / DC converter means, characterized in that further comprises additional means for supplying energy or voltage forming an energy or voltage reservoir for supplying the DC / DC converter with a starting voltage.
• an energy reservoir for example a rechargeable battery
• an energy reservoir is used to supply the converter with the voltage it needs at startup.
• the voltage of this tank can be coupled to means, for example an electronic architecture, to "start” the converter.
• the converter can, in turn, after starting, recharge the energy reservoir with its output voltage greater than the voltage of the energy tank.
• low input voltages for example between 10 mV and 0.1 V or 0.5 V to be able to start a converter, these low input voltages being compensated by the supply of the reservoir energy or complementary energy supply means.
• the converter will, in turn, be able to generate a fixed regulated voltage, for example 3.3 V, for the supply of electronic circuits.
• the invention also proposes a watch circuit comprising means for comparing an input voltage with a threshold value, means for activating the comparison means, and means for maintaining the level of the result of the comparison when the comparison means are disabled.
• the standby circuit preferably has an extremely low power consumption, in case the converter should remain in the standby position for a long time.
• FIG. 1 represents a device according to the invention
• FIG. 2 represents an embodiment of standby means
• FIG. 3 represents an embodiment of converter and charge regulation means
• FIGS. 4A-4D and 5A-5C illustrate an exemplary embodiment of the invention
• FIG. 6 represents an example of a micro-battery.
• Block 2 "dc / dc converter” comprises an up-converter filter, for example in pulse modulation.
• Means 4 form a watch circuit for a threshold detection.
• a clock circuit 6 After detection of this source, a clock circuit 6 is triggered. If not are implemented means 7 internal supply, or forming energy reservoir, for example a battery or micro ⁇ internal battery. These means 7 make it possible to start the converter 2 when the input voltage Ve is insufficient.
• Vbatt or Vdd indicates that the converter 2 is powered either by the means 7 or by Vdd, the selection being made by means of switching means.
• Vout usable externally by an external electronic circuit.
• This voltage supplied by the converter can also be used internally, for example to recharge the means 7 for their next use, especially if they were discharged when starting the converter 2. This recharge can be done using load control means 8.
• FIG. 1 One embodiment of the standby circuit means 4 is illustrated in FIG. 1
• These means are powered by the input voltage supplied by the means 7 or by the output voltage Vdd. They make it possible to detect, for example by comparing the input voltage Ve with a threshold S1 of reference voltage, when this input voltage is sufficiently high, or greater than the threshold S1, to be able to start the converter 2.
• This threshold is the minimum operating voltage (40 mV for example).
• this circuit 4 did not exist one could be in a situation where the means 7 (the energy reservoir) would be completely discharged and the system could then only start for input voltages Ve greater than, for example, example, 0.8 V.
• the monitoring of the input voltage can be done in a sampled or periodic manner.
• the idle circuit comprises, for example, means 12 which make it possible, by means of a comparator 121, to compare the input voltage Ve with a reference voltage VREF supplied by means 120. generating such a reference voltage. This comparison can be periodically activated by an ACT activation signal.
• the means 4 produce a trigger signal S of the converter 2, for example by means of the control of the clock 6
• the converter 2 is then supplied directly by the voltage reserve 7.
• the means 4 only allow the tank 7 to deliver its voltage when the input voltage Ve is above this threshold value.
• the crossing of the threshold value indicates an increase in the input voltage, a criterion according to which the power supply of the converter can be reasonably triggered by the means 7.
• the means 7 would be disconnected again to no longer power the converter. They will also be disconnected if the voltage Vdd generated by the converter 2 during operation exceeds another threshold value, for example about 1 Volt.
• the means 10 generate an activation signal ACT.
• Means 10 include, for example, means 101 generating a current reference, means 102 oscillators and means 103 for shaping the ACT signal.
• Means 14 make it possible to maintain the level of the result of the comparison when the means 12 are deactivated, in particular between two ACT activation signals.
• These means comprise, for example, a digital flip-flop, for example a flip-flop D.
• the means 10 and 14 can operate continuously; they are then preferably designed so as to consume as little as possible.
• a current of the order of a few tens of nanoamperes makes it possible to generate the activation signal ACT, under 2V, and to maintain the level of current consumption (in the means 14) at approximately some nano-amps, which is compatible with the use of a micro-battery 7 power supply as a reservoir of energy.
• the authorized consumption for the means 12 of comparison is even lower than the activation of this block is frequent.
• comparing means 12 can consume 2 ⁇ A and be activated for one second every hour.
• the reference the reference
• FIG. 3 represents an embodiment of the converter means 2 and the charging means 8.
• the means 2 converters may comprise means 20 forming a lift filter with means 22 for regulating Vdd (for example control means by pulse modulation or pulse density control associated with a PID control type Proportional Integral Derivative ").
• the means 22 may send, via the means 24, a signal to a switch 25, which signal will close or open this switch.
• the means 20 further comprise an inductor 26 L and a capacitor 28 C, these two components being external.
• the component Rc represents an external circuit to be powered with the output voltage Vdd of the converter means 20.
• a clock signal formed by clock circuit means 6 (FIG. 1) is supplied to the regulation means 22 under the control of the means 4, as explained above.
• This clock signal makes it possible to trigger the means 22, and thus the power supply of the converter either with the external voltage Ve or with the voltage of the means 7.
• the regulator 22 makes it possible to reach the desired voltage. It can also advantageously, when Vdd reaches a predefined threshold S2, disconnect the means 7, the DC / DC converter then being powered by V DD .
• the means 8 are charging means, in current, means 7, for example a micro-battery during operation of the device.
• the means 8 are adapted to the maximum current available at the output. Indeed, like any electronic circuit, they are designed to work under pre-established conditions: they are said to be "adapted". They include, for example, a current mirror. In this FIG. 3, the mention “Vbatt or Vdd” indicates that the means 8, 22 are powered either by the means 7 or by Vdd, the selection being made by means of switching means.
• a device such as that of FIG. 1 implements energy reserve means 7 for starting the converter means if the input voltage Ve is insufficient.
• they can then be recharged by the latter, whose output voltage Vdd is higher than its input voltage.
• These means 7 are for example a battery, or a micro-battery, as in the example illustrated above in connection with FIG.
• a micro-battery can be made using processes comparable to those presented by 2_0jL_ JL ht ⁇ LL. Such methods make it possible to produce batteries which supply a voltage of 2 to 2.5 V.
• Such a micro-battery is for example represented in FIG.
• the battery comprises a silicon substrate 50, a platinum current collector 52, a titanium sulfide electrode 54, a LIPON ("lithium phosphate oxynitride") electrolyte 55 and a lithium metal electrode 56.
• the layers are deposited by PVD technique on the substrate and total about 10 micrometers thick. On the surface, the micro-battery is about a few mm2.
• the battery can be an integral part of the manufacturing process of the integrated circuit; it is invisible to the user.
• the means 7 may, by construction (for example by choice of the materials of the architecture), be made in such a way as to have a negligible self-discharge rate. In this case, they can be loaded as soon as they are built, and wait for the activation of the standby circuit 4, in the event that an input voltage Ve is insufficient.
• the latter triggers the operation of the converter 2 if, and only if, there is a voltage Ve usable at its input, or uses the energy reservoir 7 to start the converter.
• the energy reservoir 7 is then charged to start the converter, if the input voltage Ve is insufficient, for example in view of the comparison made by the means 12 described above.
• the means 7 can be loaded at the moment when the circuit is set up, for example on an electronic card, and at any convenient moment, either by starting the converter 2 with an input voltage Ve sufficient to exceed the threshold, and thus ensure the recharge of the means 7 by the output voltage of said converter, or by a specific charging input. This operation is all the more limited in time as the battery can be recharged quickly.
• the starting voltage of the means 2 can be delivered by something other than a battery, for example by a mechanical converter (for example by a compressed spring).
• the energy reservoir is for example a battery or a micro-battery, and is preferably rechargeable.
• the device may comprise, as explained above, a charging system powered by the output voltage of the converter.
• the battery or micro-battery is preferably integrated.
• FIGS. 4A-4D and 5A-5C presents a system as just described, with an input detection threshold S1 of 40 mV and a desired voltage Vdd of 1.2 V.
• the nominal voltage of the means 7 (here: a micro ⁇ battery) is 1.5 V.
• FIGS. 4A-4D represent the temporal evolution of the voltages, respectively, of the input voltage Ve, of the voltage at the terminals of the supply means 7, the supply voltage generated to the outside, the supply voltage of the means 4 and the means 2 (means of standby and converter).
• FIGS. 5A-5C show the time evolution of the currents, respectively, of the current consumed by the external circuit Rc, of the charging current of the battery (current entering the battery), and the current consumed on the battery (current leaving the battery).
• Part 1 (between 0 and tl): As long as the input has a power below a fixed threshold and a voltage below a fixed threshold S1 (here the threshold is 40 mV), only part of the standby means 4 operates (There is generation of the ACT activation signal and maintenance of the output level, the comparator operating periodically). The micro-battery 7 supplies the standby circuit only and the consumption is minimal.
• Part 2 (between t1 and t2):
• the DC-DC converter means 2 turn on.
• S 2 for example 1 V
• the micro-battery 7 continues to supply the entire circuit. Consumption is important, but for a short time.
• the DC / DC converter will "pump" on the battery, the voltage of which will drop (FIG. 4B), whereas the supply voltage Vdd generated to the outside (FIG. that is to say that the supply voltage of the standby circuit 4 and converter drops ( Figure 4D), Vdd can gradually take over.
• the invention therefore proposes a new device, for example of the monolithic integrated circuit type, making it possible to convert the voltage of energy sources towards a voltage usable by electronic circuits, capable of operating with extremely low input voltages, up to a few tens of mV.
• the invention allows the use of new energy sources, not used until now because of their low voltage.
• the device according to the invention is compatible with the integrated circuit industry; it can be integrated in the manufacturing process: the designer of electronic circuits does not have to worry about the assembly of new circuits more or less esoteric or difficult to implement.
• the invention does not increase the volume usually devolved to the function of the voltage conversion.
• the invention makes it possible to provide designers, and in particular electronics engineers, with a DC / DC converter that can handle extremely low input voltages, up to a few tens of mV.
• the described embodiment makes it possible to obtain a monolithic integrated circuit, with a architecture and circuits that manage the charging and providing an integrated micro-battery, which provides sufficient voltage to the transistors of a converter to operate.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Dc-Dc Converters (AREA)

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• 2004
  • 2004-07-13 FR FR0451519A patent/FR2873242B1/fr not_active Expired - Fee Related
• 2005
  • 2005-07-11 WO PCT/FR2005/050568 patent/WO2006008423A1/fr not_active Ceased
  • 2005-07-11 EP EP20050789993 patent/EP1774641B1/fr not_active Expired - Lifetime
  • 2005-07-11 AT AT05789993T patent/ATE509423T1/de not_active IP Right Cessation
  • 2005-07-11 JP JP2007520868A patent/JP4805925B2/ja not_active Expired - Fee Related
  • 2005-07-11 US US11/631,526 patent/US7642765B2/en not_active Expired - Fee Related
  • 2005-07-11 ES ES05789993T patent/ES2371443T3/es not_active Expired - Lifetime

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