JP2008148509A - Electronic equipment and power supply method for electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow all batteries except one battery of a plurality of batteries to be replaceable even during the operation of electronic equipment while preventing effects caused by mutual noise or the like between circuits caused by a power supply circuit. <P>SOLUTION: Electronic equipment is provided with a power supply control part 202 that has voltage detection parts 301, 302 for detecting an output voltage of a first battery 106 for supplying power to an analog circuit 211 and an output voltage of a second battery 107 for supplying power to a digital circuit 212, respectively. The power supply control part 202 has a switch circuit 303 that connects a first power supply path 307 from the first battery 106 and a second power supply path 308 from the second battery 107 or separates them from each other corresponding to each voltage detection value of the voltage detection parts 301, 302. When the voltage detection parts 301, 302 detect temporary voltage drops, the first and second power supply paths 307, 308 from the first and second batteries 106, 107 are separated from each other so as to prevent effects caused by noise between circuits. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electronic device such as a mobile phone having a plurality of circuit blocks, each of which is a battery, and a power supply method for the electronic device.

  An electronic circuit has a plurality of signals such as an analog circuit (analog part) that handles a continuously changing signal, that is, an analog signal, and a digital circuit (digital part) that operates according to a combination of a state with or without a voltage or current. Divided into circuits. In recent years, with the remarkable development of digital circuit technology, digital circuits have been adopted to control circuits that handle analog quantities. For example, in a television receiver, an analog video signal and an audio signal are extracted from broadcast radio waves received by a tuner. An electronic tuner and an electronic audio amplifier are employed, and these are controlled by a digital circuit. . Further, in mobile phones that have been rapidly spreading in recent years, analog circuits and digital circuits such as a telephone number registration function, a display function, and an e-mail transmission / reception function are used together in addition to transmission / reception of telephones.

  Thus, in many electronic devices, analog circuits and digital circuits are used in combination, and portable electronic devices such as handy terminals and portable audio players are no exception.

  However, in conventional electronic devices, power is supplied from the same battery to analog circuits such as video circuits and audio circuits that operate based on analog signals and digital circuits such as control circuits that control systems that operate based on digital signals. It has become. That is, even in an electronic device having a plurality of batteries, power is supplied to both the analog unit and the digital unit from a single system battery in which these batteries are connected in series. For this reason, in the conventional portable electronic device, both the analog unit and the digital unit are affected by mutual noise and the like via the power supply circuit.

  In particular, a TV tuner, an audio output unit, and the like consume a large amount of power (consumption current) and have large fluctuations in consumption current compared to a digital circuit. For this reason, when the remaining battery level is low due to power consumption due to long-time operation, the power supply voltage is greatly reduced due to the sudden increase in current consumption of the analog unit that occurs when the TV reception function is turned on. . Then, the voltage supplied to the digital unit becomes lower than the operating voltage of the digital circuit, the digital unit malfunctions, and the system becomes unstable.

Therefore, as disclosed in Patent Document 1, in order to prevent the influence of mutual noise between the analog unit and the digital unit generated through the power supply circuit and to stabilize the operation of the system control unit, A configuration using a power supply that individually supplies a digital unit is known.
JP 2002-354691 A

  However, according to the above-described conventional technology, there are unsolved problems such as mutual noise between circuit blocks occurring between the analog unit and the digital unit, and battery replacement being impossible during the operation of the electronic device.

  The present invention prevents an influence due to mutual noise between a plurality of circuit blocks, and enables replacement of all batteries except at least one of the plurality of batteries during operation of the electronic apparatus. It is another object of the present invention to provide a power supply method for electronic equipment.

  An electronic apparatus according to the present invention includes a first circuit block, a first battery, a first power supply path for supplying power of the first battery to the first circuit block, a second circuit block, and a second battery. A second power supply path for supplying power of the second battery to the second circuit block, a first voltage detector for detecting an output voltage of the first battery, and detecting an output voltage of the second battery. Interconnection and separation between the first power supply path and the second power supply path are alternately performed according to a voltage detection value by the second voltage detection section and the first or second voltage detection section. Interconnecting means.

  A first battery and a second battery are provided corresponding to the first circuit block and the second circuit block, and the power of the second battery is supplied to the second circuit block through the second power supply path. Is supplied to the first circuit block through the first power supply path. Usually, the first power supply path and the second power supply path are interconnected by the interconnection means. When the output voltage of one battery greatly decreases due to fluctuations in current consumption, the second power supply path and the first power supply path are temporarily separated, and the second circuit block and the first circuit block are separated. Avoid the effects of mutual noise and the like that occur between them.

  For example, when there is a large fluctuation in current consumption on the first circuit block side, the fluctuation of the power supply voltage in the second circuit block can be prevented, and the operation of the system control unit etc. on the second circuit block side can be stabilized. Can do. Further, when there is little influence due to mutual noise or the like, the first power supply path and the second power supply path are connected in parallel, so that only the power of one battery is consumed more and more, so-called depletion of the battery is prevented. be able to.

  Furthermore, when the output voltage of one of the first battery and the second battery falls below the operable lower limit voltage of the electronic device, the interconnection between the first power supply path and the second power supply path is resumed. In this way, when an electronic device with a plurality of batteries supplying power to a plurality of circuit blocks is used, or when two systems of batteries are used in parallel, even if one battery is removed due to battery replacement, etc. It does not lead to. Therefore, the battery can be replaced while the electronic device is operating.

  The best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing a portable electronic device (mobile phone) according to an embodiment. The electronic device 100 includes a power-on button 102, a power-off button 103, an infrared communication function, and a function for reproducing audio recorded on a memory card (audio reproduction function). In addition, the electronic device 100 includes a display unit 104 having a size of several inches in the upper part of the front surface. In the present embodiment, a liquid crystal panel is used.

  On the surface of the electronic device 100, a power-on button 102 and a power-off button 103 constituting a power switch unit are disposed. By operating the power-on button 102 and the power-off button 103, the power of the electronic device 100 is turned on. It can be turned on and off. A system key 105 is provided below the display unit 104, and a menu screen for selecting a function can be displayed on the display unit 104 by operating the system key 105.

  The electronic device 100 includes a square first battery 106 and a second battery 107 made of lithium ions or the like. The first battery 106 and the second battery 107 are arranged in parallel with each other. The terminals of the batteries 106 and 107 are brought into close contact with the power supply terminal of the electronic device 100 by the elastic force of the spring provided in the power supply terminal portion (not shown) of the electronic device 100, as in a normal portable audio player. It is.

  The electronic device 100 is provided with an earphone jack (not shown) serving as an acoustic output unit, so that sound (sound) can be output by headphones or earphones via the earphone jack. The electronic device 100 is provided with an interface for mounting a memory card serving as an external storage device. When a memory card that records sound or a memory card that records images or information is attached to this interface, it is possible to reproduce sound, display images, or view information.

  FIG. 2 is a block diagram illustrating a main part of the electronic device 100. The electronic device 100 includes a CPU 201, and the CPU 201 performs power control such as turning off the power of the electronic device 100 when the output voltages of the first battery 106 and the second battery 107 become a predetermined value or less. The power control unit 202 is controlled.

  When the power-on button 102 is manually operated, the power control unit 202 supplies power to each circuit constituting the electronic device 100 as a switching connection unit that starts supplying power from the battery. In other words, the printer unit 203 and the interface unit 204 constituting the analog circuit (first circuit block) 211 are connected to the first output side of the power supply control unit 202. The second output side of the power supply control unit 202 is connected to an audio / image decoder 205, a liquid crystal controller 206, a display unit (liquid crystal panel) 104, and the like constituting a digital circuit (second circuit block) 212. It is. The CPU 201 controls the power control unit 202, the printer unit 203, the interface unit 204, the audio / image decoder 205, the liquid crystal controller 206, and the like. The interface unit 204 is an interface circuit for connecting to an external connection device that is a secondary load, and operates in accordance with communication standards such as USB, IEEE 1394, IEEE 802.3, IEEE 802.11 series, IrDA, and the like.

  Further, a memory card interface (memory card I / F) 207, a RAM 208, a flash memory 209, a display control unit 210, and the like are connected to the CPU 201 via a bus. The memory card I / F 207 is loaded with a memory card that records audio / image data. The CPU 201 can read audio / image data recorded as digital data on the memory card via the memory card I / F 207 and write it to the flash memory 209. These are also supplied with power from the second output side of the power control unit 202, but are not shown.

  In some cases, the power supply control unit 202 integrates outputs from both the first battery 106 and the second battery 107 and supplies them to both the digital circuit 212 and the analog circuit 211. In some cases, the power supply control unit 202 supplies the output from the first battery 106 to the analog circuit 211 and supplies the output from the second battery 107 to the digital circuit 212. In some cases, the power supply control unit 202 selects the output of either the first battery 106 or the second battery 107 and supplies it to both the digital circuit 212 and the analog circuit 211. The power supply control unit 202 receives a switching signal (not shown) for performing these switching operations from the CPU 201.

  FIG. 3 shows the configuration of the power control unit 202. The first power supply path 307 and the second power supply path 308 having switches 305 and 306 connected when the power is turned on, and the interconnection and separation between them. And a switch circuit portion 303 which is an interconnection means for alternately performing the above. Usually, by turning on the switch circuit unit 303, the output of the first battery 106 and the output of the second battery 107 are integrated and supplied to both the analog circuit 211 and the digital circuit 212. In addition, it has conflict prevention units 309 and 310 that prevent problems such as backflow caused by the voltage difference between the first battery 106 and the second battery 107. Note that only one of the conflict prevention units 309 and 310 may be provided, or may be incorporated in each of the batteries 106 and 107.

  Furthermore, a voltage detection unit (first voltage detection unit) 301 connected in parallel to the first battery 106 and a voltage detection unit (second voltage detection unit) 302 connected in parallel to the second battery 107 are included. These voltage detection units 301 and 302 have a settable reference voltage, and when the input voltage is higher than the reference voltage (first threshold value), an “H” detection signal is output, and when the input voltage falls below the reference voltage. An “L” detection signal is output and transmitted to the CPU 201. A second threshold can also be set, and a similar detection signal is output from another output terminal. Note that these voltage detection units may be realized by using an A / D converter built in or connected to the CPU 201.

  FIG. 4 is a time chart for explaining the operation of the power control unit 202 of the electronic device 100 when an external connection device that is a secondary load is connected.

  Before the time point a in FIG. 4, the switch circuit unit 303 is on, and the first power supply path 307 and the second power supply path 308 are interconnected. At the time point b shown in FIG. 4, the CPU 201 sends a control signal for turning on a switch (not shown) in order to start supplying power to the externally connected device connected to the interface unit 204. Prior to that, the CPU 201 controls the switch circuit unit 303 to be turned off during a to c in FIG. In this way, the first power supply path 307 and the second power supply path 308 are disconnected, and an instantaneous voltage drop generated in the battery at the moment of starting to supply power to the externally connected device affects only the analog circuit 211, The influence on the digital circuit 212 can be blocked.

  In this way, while the generation of power supply noise is expected, the second power supply path 308 to the digital circuit 212 and the first power supply path 307 to the analog circuit 211 are separately supplied to supply power. It is possible to avoid the influence of mutual noise and the like generated through the circuit.

  In addition, the generation of power supply noise is not expected, but the response to the sudden drop in battery voltage is performed as follows. The voltage detection unit 301, the switch circuit unit 303 and the switches 305, 306 are all turned on, and the output voltage of at least one of the first battery 106 and the second battery 107 instantaneously falls below the first threshold value. When the CPU 302 detects this, the CPU 201 turns off the switch circuit unit 303. Thus, by separating the second power supply path 308 to the digital circuit 212 and the first power supply path 307 to the analog circuit 211, the influence of mutual noise and the like can be eliminated.

  The switch circuit unit 303 is turned off while the output voltage of at least one of the first battery 106 and the second battery 107 is lower than the first threshold, but the CPU 201 predicts a predetermined time or noise periodicity. It is desirable to extend the off state.

  Next, a description will be given of a case where the battery voltage drop is not instantaneous but the remaining battery power is reduced due to long-time power consumption.

  FIG. 5 is a flowchart for explaining the operation of detecting a decrease in the remaining battery level and switching the connection state of the batteries 106 and 107. When the power is turned on, in step S01, the CPU 201 determines whether or not the output voltage V1 of the first battery 106 is higher than the minimum operation voltage Vmin (second threshold) necessary for causing the electronic device 100 to perform a stable operation. This is determined using the voltage detector 301. As the second threshold value, it is preferable to select a value closer to the operation limit and set a voltage lower than the first threshold value, but it may be the same value as the first threshold value.

  When CPU 201 determines in step S01 that V1> Vmin, it proceeds to step S02 and determines whether or not output voltage V2 of second battery 107 is higher than Vmin using voltage detection unit 302. If V2> Vmin, the process returns to step S01. In this state, the switch circuit unit 303 and the switches 305 and 306 are all on, and the electronic device 100 continues to monitor the battery voltage while performing a normal operation.

  If V1> Vmin is not satisfied in step S01, the CPU 201 proceeds to step S03 and determines whether V2> Vmin. If V2> Vmin is not satisfied, the CPU 201 performs a predetermined shutdown process and turns off the power (step S06). That is, when both the first battery 106 and the second battery 107 are below the minimum operating voltage Vmin necessary for stable operation of the electronic device 100, the necessary processing is completed and the switches 305 and 306 are switched. Turn off. As a result, it is possible to prevent the processing data stored in the RAM 208 or the like from being lost due to the system being reset during an important process, and to stabilize the system.

  On the other hand, if the determination in step S03 is V2> Vmin, the CPU 201 enables power supply from only the second battery 107 in step S05. Specifically, if the switch circuit unit 303 is off, the switch circuit unit 303 is turned on and the switch 305 is turned off, and then the process returns to step S01. Since the first battery 106 can be replaced in this state, the CPU 201 displays a message prompting the replacement of the first battery 106 on the display unit 104 or turns on a lamp provided for displaying the operation state. Alternatively, it is possible to prevent the noise associated with the replacement of the first battery 106 by the action of the conflict prevention unit 309 and to omit turning off the switch 305. As the contention prevention unit 309, a voltage stabilization circuit, a circuit including a backflow prevention diode, or the like can be applied.

  When the determination in step S01 is V1> min and the determination in step S02 is not V2> Vmin, the CPU 201 enables power supply from only the first battery 106 as shown in step S04. Specifically, if the switch circuit section 303 is off, the switch circuit section 303 is turned on and the switch 306 is turned off, and the process returns to step S01. In addition, since the second battery 107 can be replaced in this state, the CPU 201 displays a message prompting the replacement of the second battery 107 on the display unit 104 or turns on a lamp provided for displaying the operation state. Alternatively, it is possible to prevent the noise associated with the replacement of the second battery 107 by the action of the conflict prevention unit 310 and to omit turning off the switch 306.

  Any part or all of the above-described various processes performed by the CPU 201 may be changed to be performed by hardware.

  The present invention is not limited to application to a portable electronic device such as a mobile phone, but can be widely applied to various electronic devices having two or more circuit blocks on which a plurality of batteries are mounted.

It is a perspective view which shows the portable electronic device by one Embodiment. It is a block diagram explaining the principal part of the electronic device of FIG. It is a block diagram which shows the power supply control part of the electronic device of FIG. It is a figure explaining the timing of operation | movement of a power supply control part. It is a flowchart explaining operation | movement when a battery remaining charge falls.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Electronic device 102 Power-on button 103 Power-off button 104 Display part 105 System key 106 1st battery 107 2nd battery 201 CPU
202 Power control unit 211 Analog circuit 212 Digital circuit 301, 302 Voltage detection unit 303 Switch circuit unit 305, 306 Switch 307 First power supply path 308 Second power supply path

Claims (7)

  The first circuit block, the first battery, the first power supply path for supplying the power of the first battery to the first circuit block, the second circuit block, the second battery, and the power of the second battery A second power supply path that supplies the second circuit block, a first voltage detector that detects an output voltage of the first battery, a second voltage detector that detects an output voltage of the second battery, Interconnection means for alternately performing interconnection and separation between the first power supply path and the second power supply path in accordance with a voltage detection value by the first or second voltage detection unit. An electronic device characterized by that.   The interconnection means separates the first power supply path and the second power supply path when a voltage detection value by the first or second voltage detection unit falls below a first threshold. The electronic device according to claim 1.   The interconnect means interconnects the first power supply path and the second power supply path when a voltage detection value by the first or second voltage detection unit falls below a second threshold value. The electronic device according to claim 2, characterized in that:   The electronic device according to claim 3, wherein the second threshold is lower than the first threshold.   The first circuit block or the second circuit block includes an interface unit that supplies power to a secondary load, and the interconnection unit is configured to start supplying power to the secondary load by the interface unit. 5. The electronic apparatus according to claim 1, wherein the first power supply path and the second power supply path are separated from each other.   6. The electronic device according to claim 5, wherein the subsidiary load is an external connection device.   A first power supply path for supplying power of the first battery to the first circuit block; a second power supply path for supplying power of the second battery to the second circuit block; the first power supply path; and the second power supply path. In an electronic device power supply method comprising: an interconnection means for interconnecting a power supply path; and according to an output voltage of the first battery or an output voltage of the second battery, A method of supplying power to an electronic device, wherein the second power supply path is temporarily separated.

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