JP4296472B2 - Information processing apparatus and power supply circuit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an information processing apparatus. as well as Power supply times On the road For example, it can be applied to a notebook computer. According to the present invention, a capacitor main body made of a multilayer ceramic capacitor is floated from the substrate and surface-mounted, so that the multilayer ceramic capacitor can be applied to a ripple capacitor to sufficiently suppress vibration noise caused by the multilayer ceramic capacitor.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, notebook personal computers, which are portable information processing devices, have been designed to mount components with high density by surface mounting to reduce the overall shape. For example, a multilayer ceramic capacitor is applied to a ripple capacitor in an input line of a DC-DC converter that requires a high withstand voltage and a large capacity.
[0003]
In such a multilayer ceramic capacitor, since the dielectric material is a ceramic which is an electrostrictive material, the thickness changes according to a change in voltage due to a ripple. That is, as shown in FIG. 4, a multilayer ceramic capacitor is connected to a predetermined power source, and as shown in FIG. 5A, an AC voltage V1 biased by a predetermined DC voltage DC is applied by the power source. In the multilayer ceramic capacitor, when the thickness of one dielectric layer is changed by σ according to the voltage change according to the applied voltage, and the number of dielectric layers of the multilayer ceramic capacitor is n, FIG. As shown in (B), it is confirmed that the thickness changes by n × σ as a whole.
[0004]
As a result, when the multilayer ceramic capacitor is applied to a ripple capacitor of a DC-DC converter, there is a drawback in that the thickness changes according to the ripple component, and the substrate vibrates due to the change in thickness.
[0005]
For this reason, in the conventional notebook personal computer, the switching frequency of the DC-DC converter is set to a frequency sufficiently higher than the audible frequency band so that the vibration of the board cannot be perceived by the user. .
[0006]
On the other hand, in Japanese Patent Application Laid-Open No. 2002-232110, by changing the phase of the applied voltage so that the phase of the ripple component differs by 180 degrees with respect to the multilayer ceramic capacitors arranged close to each other, There has been proposed a method of canceling vibrations of a laminated ceramic capacitor arranged on the substrate, thereby preventing the vibration of the substrate due to such a change in the thickness of the multilayer ceramic capacitor.
[0007]
On the other hand, in the latest processor mounted on such a computer, overall power consumption is reduced by frequently setting the power saving mode. That is, in such a computer, when a task is generated, the power consumption mode is raised from the power saving mode to the normal operation mode, the power consumption is increased, the processing related to the task is executed, and then the operation mode is switched to the power saving mode to reduce the power consumption. It is getting used to reducing. In such a computer, such switching of the operation mode is abruptly performed to effectively avoid a decrease in processing speed.
[0008]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-232110
[0009]
[Problems to be solved by the invention]
Incidentally, in the operation mode switching related to such a power saving mode in the computer, naturally, large and steep fluctuations in power consumption occur. In addition, a task that is a trigger for switching the operation mode may occur periodically, such as a key scan, and in this generation cycle, not only the program related to the task but also the operating environment of the computer It varies depending on the setting environment.
[0010]
As a result, it has been found that when a computer is configured with such a latest processor, a ripple is generated due to the frequency of the audible frequency band, and the vibration sound of the board due to this ripple is perceived unpleasantly by the user.
[0011]
As one method for solving this problem, for example, it is conceivable to apply the method disclosed in Japanese Patent Application Laid-Open No. 2002-232110. However, the task generation cycle varies depending on various conditions, so in practice, the applied voltage of the multilayer ceramic capacitor can be set to the desired phase against the ripple caused by such task generation cycle. Therefore, there is a problem that this method cannot be applied.
[0012]
Such a processor that frequently switches to the power saving mode may be widely applied not only to computers but also to various information processing apparatuses such as PDAs (Personal Digital Assistants) and mobile phones. It is considered that similar problems occur not only in computers but also in these information processing apparatuses. Further, in these information processing apparatuses, it is considered that such vibration sound further causes discomfort to the user because it is quieter than a computer.
[0013]
The present invention has been made in consideration of the above points, and an information processing apparatus capable of sufficiently suppressing vibration noise caused by the multilayer ceramic capacitor by applying the multilayer ceramic capacitor to a ripple capacitor. as well as Power supply times The road It is what we are going to propose.
[0014]
[Means for Solving the Problems]
In order to solve such a problem, in the first aspect of the present invention, the power consumption is increased by the trigger, the process corresponding to the trigger is executed, and then the power consumption is decreased. An arithmetic processing circuit and a power supply circuit that inputs at least the power of the battery and supplies power to the arithmetic processing circuit. Capacitor that eliminates ripple caused by power consumption changes And the capacitor is Capacitor body with multilayer ceramic capacitor When, The capacitor body is lifted from the board, and the capacitor body is connected to the land of the board so as to have a terminal for surface mounting.
[0015]
In the invention of claim 4, At least from the battery, After executing the processing corresponding to the trigger by starting up the power consumption by the trigger, apply it to the power supply circuit that supplies power to the load that reduces the power consumption, On the input side of the battery power supply, Capacitor that eliminates ripple caused by power consumption changes Is placed and the capacitor is Capacitor body with multilayer ceramic capacitor When, The capacitor main body is floated from the substrate, and the capacitor main body is connected to the land of the substrate so as to have a terminal for surface mounting.
[0017]
According to the configuration of claim 1 If The change of the multilayer ceramic capacitor due to the pull can be prevented from directly propagating to the substrate, and accordingly, the vibration noise caused by the multilayer ceramic capacitor can be sufficiently suppressed by applying the multilayer ceramic capacitor to the ripple capacitor.
[0018]
According to the configuration of claim 4 If The change of the multilayer ceramic capacitor due to the pull can be prevented from directly propagating to the substrate, and accordingly, the vibration noise caused by the multilayer ceramic capacitor can be sufficiently suppressed by applying the multilayer ceramic capacitor to the ripple capacitor.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
[0021]
(1) Configuration of the embodiment
FIG. 2 is a block diagram showing a power supply system of the notebook personal computer according to the embodiment of the present invention. In the computer 1, when the AC adapter 2 is connected, the computer 1 is operated by the power source of the AC adapter 2 and the battery 3 is charged by the power source of the AC adapter 2. Further, when the AC adapter 2 is not connected, the battery 3 is operated by the power source.
[0022]
For this reason, in this computer 1, the power supply by the AC adapter 2 is connected to the main power supply line L 1 via the switch circuit 4, thereby switching the switch circuit 4 to the on state by the connection of the AC adapter 2. The power can be supplied to the main power supply line L1. Further, when the power supply of the battery 3 is connected to the main power supply line L1 via the switch circuits 5 and 6, and thus operates by the connection of the AC adapter 2, the main power supply line L1 of these switch circuits 5 and 6 is used. The switch circuit 5 on the near side is switched to the OFF state so that the battery 3 can be disconnected from the main power supply line L1.
[0023]
In the computer 1, a power source for charging the battery 3 is generated from the power source supplied to the main power source line L1 by the power source circuit 7A, and this power source for charging is supplied between the switch circuits 5 and 6 on the battery 3 side. It is made like that. Thus, in the computer 1, the power supply of the AC adapter 2 is supplied to the main power supply line L 1, the switch circuit 6 on the side close to the battery 3 is turned on, and the battery 3 is charged by the charging power source. The switch circuit 6 can be switched off to stop charging. In the case of operating with the power supply of the battery 3, the operation of the power supply circuit 7A is controlled to stop, and the switch circuits 5 and 6 are switched on so that the power of the battery 3 can be supplied to the main power supply line L1. ing.
[0024]
In the computer 1, power supply circuits 7B to 7E for supplying power to each unit are connected to the main power supply line L1. Here, the power supply circuit 7B generates and outputs a power supply of voltage 2.5 [V] from the power supply of the main power supply line L1, and the power supply circuit 7F outputs a voltage 2.5 [V] output from the power supply circuit 7B. A power supply having a voltage of 1.25 [V] is generated and output from the power supply. In the computer 1, power of 2.5 [V] and 1.25 [V] is supplied to a memory or the like. The power supply circuit 7C generates and outputs power supplies of voltages 5 [V] and 3.3 [V] from the power supply of the main power supply line L1, and the computer 1 outputs these voltages 5 [V] and 3.3 [V]. ] Is supplied to a logic IC, a hard disk device (HDD), a CD (Compact Disc) drive, a DVD (Digital Video Disk) drive, and the like.
[0025]
The power supply circuit 7D generates and outputs power supplies of voltages 1.8 [V] and 1.2 [V] from the power supply of the main power supply line L1, and the power supply circuit 7G outputs the voltages of 1.8 [V]. A power supply with a voltage of 1.5 [V] is generated from the power supply and output. The computer 1 supplies power of these voltages 1.8 [V], 1.2 [V], and 1.5 [V] to an integrated circuit such as a chip set or a video chip. The power supply circuit 7E generates and outputs a power supply of voltage 1.5 [V] from the power supply of the main power supply line L1, and the power supply circuit 7G supplies the power supply of voltage 1.5 [V] to the central processing unit or the like. It is made to supply. In this embodiment, a processor that frequently switches to the power saving mode is applied to the central processing unit. With this, mainly in the power supply circuit 7E that supplies power to the central processing unit, the operation mode is switched. The power consumption is greatly changed.
[0026]
Among these power supply circuits 7A to 7G, the power supply circuit 7G is constituted by a series regulator, whereas the other power supply circuits 7A to 7F are constituted by DC-DC converters by switching regulators. .
[0027]
FIG. 3 is a block diagram showing a DC-DC converter according to these power supply circuits 7A to 7F. In the power supply circuits 7A to 7F, a plurality of DC-DC converters are provided according to the number of output systems, and are substantially the same except that the setting differs depending on the output voltage of each system. Thus, in the following description, the configuration of the DC-DC converter 10 will be described, and individual descriptions of the power supply circuits 7A to 7F will be omitted.
[0028]
In the DC-DC converter 10, a series circuit of field effect transistors 11 and 12 is connected between the main power supply line L 1 and the ground, and the field effect transistors 11 and 12 are complementarily controlled by the control circuit 14. It is designed to operate on and off. The DC-DC converter 10 is configured such that the midpoint voltage of the connection between the field effect transistors 11 and 12 is output via the inductor 13, and a smoothing capacitor 15 is provided at the output terminal of the inductor 13. ing. Here, the smoothing capacitor 15 is a small-sized, high-capacity functional polymer capacitor, which can reduce the overall shape.
[0029]
In the DC-DC converter 10, the control circuit 14 controls the on / off timing of the field effect transistors 11 and 12 by a pulse width modulation method with a frequency higher than the audible frequency according to the output terminal voltage V0 of the inductor 13, As a result, the output terminal voltage V0 is held at the predetermined voltage described above. Accordingly, the DC-DC converter 10 responds to the on / off operation of the field effect transistors 11 and 12 at the input terminal of the series circuit including the field effect transistors 11 and 12 and further according to the change in the timing of the on / off operation. In this embodiment, a ripple capacitor 16 that removes such a ripple is arranged at the input end. One or three ripple capacitors 16 are provided in each of the power supply circuits 7A to 7E.
[0030]
FIG. 1 is a perspective view showing the ripple capacitor 16. The ripple capacitor 16 is formed by attaching terminals 18A and 18B to both ends of a capacitor body 17 composed of a surface mount type chip capacitor. Here, the capacitor body 17 is a multilayer ceramic capacitor, and the width W, the height H, and the length L are approximately 2.5 [mm], 2.7 [mm], and 3.5 [mm], respectively. It is formed by body shape. The capacitor body 17 is formed with electrodes 17A and 17B on both end faces in the longitudinal direction and portions surrounding the periphery by a predetermined length from both end faces, whereby the electrodes 17A and 17B are attached without the terminals 18A and 18B being attached. 17B can be surface-mounted by soldering to the substrate.
[0031]
The terminals 18A and 18B are held at both end surfaces of the capacitor body 17 in the longitudinal direction, formed so that the tip protrudes from one side surface of the capacitor body 17, and the protruded tip is bent at a substantially right angle toward the inside. Thus, the cross section L is formed in a letter shape. As a result, the ripple capacitor 16 can be surface-mounted on the substrate by being soldered to the substrate by the bent portion at the tip. Further, the capacitor body 17 can be floated from the surface of the substrate by surface mounting in this way, so that the vibration due to the ripple of the capacitor body 17 does not directly propagate to the substrate.
[0032]
Further, the terminals 18A and 18B are thus formed so as to be held at both end faces in the longitudinal direction and not to protrude to both side faces, and thus can be mounted with the same component spacing as when the capacitor body 17 is surface-mounted. It is made like that.
[0033]
Further, the terminals 18A and 18B are formed so that the size of the bent portion at the tip thereof is substantially the same as the size of the corresponding surface of the electrodes 17A and 17B of the capacitor body 17, so that the capacitor body 17 is mounted. When vibration sound is generated from the substrate, the ripple capacitor 16 is mounted in place of the capacitor body 17 without changing the pattern shape, so that vibration sound can be prevented. In this embodiment, the length E of the bent portion is set to 0.7 [mm].
[0034]
Further, the terminals 18A and 18B are soldered by reflow, and even if the solder used for the soldering wraps around the side surface of the capacitor main body 17, the capacitor main body 17 is sufficient to prevent direct contact of the solder with the capacitor main body 17. On the contrary, even if this ripple capacitor 16 is mounted instead of the capacitor body 17, the dimension in the height direction is not greatly changed from that when the capacitor body 17 is mounted. A length D protruding to the substrate side is set. In this embodiment, the protruding length D is set to 0.3 [mm] so as to satisfy these conditions.
[0035]
Further, the terminals 18A and 18B are held by being soldered to the end surface of the capacitor body 17 with a high melting point solder having a sufficiently high melting point temperature as compared with the soldering temperature in the reflow. Even when the terminals 18A and 18B are connected by a technique and soldered by reflow and mounted on the substrate, the terminals 18A and 18B are prevented from falling off from the end face of the capacitor body 17.
[0036]
Further, the terminals 18A and 18B hold the capacitor body 17 so as to float from the substrate in this way so that the vibration of the capacitor body 17 does not directly propagate to the substrate, and further the vibration of the capacitor body 17 also via the terminals 18A and 18B. Is formed of a predetermined material so as not to propagate to the substrate. Specifically, the terminals 18A and 18B are, for example, a solder-plated rinsei copper plate or a tin-plated copper plate.
[0037]
Thus, the power supply circuits 7A to 7E are formed by surface mounting such as the ripple capacitor 16 and the integrated circuit constituting the control circuit 14.
[0038]
(2) Operation of the embodiment
In the above configuration, in the computer 1 (FIG. 2), when the AC adapter 2 is connected, the power of the AC adapter 2 is supplied to the main power line L1 via the switch circuit 4, and the main power line The charging power generated by the power circuit 7A from the power source L1 is supplied to the battery 3 via the switch circuit 6, and the battery 3 is charged. Further, when the AC adapter 2 is not connected, the power of the battery 3 is supplied to the main power supply line L1. In the computer 1, the power supply supplied to the main power supply line L1 generates power necessary for the operation of each unit in each of the power supply circuits 7A to 7G, and operates by this power supply to execute various processes.
[0039]
In the computer 1, among the power generated by these power supply circuits 7 </ b> A to 7 </ b> G, the power generated by the power supply circuit 7 </ b> E is supplied to the central processing unit. After the operation is started and the processing related to the task is executed, the operation is switched to the power saving mode. Thereby, in this computer 1, after starting up power consumption by the trigger by a task and performing the process corresponding to this trigger, power consumption is lowered, and as a result, the trigger concerning such a task is repeated, In this repetition cycle, the power consumption is large and sharply changed, and a frequency ripple due to the audible frequency band is generated in the power supply line L1 of the power supply circuit 7E.
[0040]
In the power supply circuit 7E (FIG. 3), among the ripples due to such power consumption changes, on the output side, the ripples are suppressed by the smoothing capacitor 15 by the functional polymer capacitor, and voltage fluctuations related to the ripples are controlled. It is suppressed by the control of the field effect transistors 11 and 12 by the circuit 14.
[0041]
However, in this type of computer 1, the main power supply line L1 cannot be formed short enough with a sufficient pattern width because of its small size, and the operation mode switching in such a central processing unit is steep. A ripple corresponding to such a change in power consumption occurs not only on the output side of the power supply circuit 7E but also on the input side of the power supply circuit 7E.
[0042]
In the power supply circuit 7E, such a ripple is suppressed by the ripple capacitor 16 that is a multilayer ceramic capacitor. However, in the multilayer ceramic capacitor, the thickness changes due to such a ripple, and eventually, it vibrates according to the ripple. In this embodiment (FIG. 1), the ripple capacitor 16 is a monolithic ceramic capacitor. The capacitor body 17 and the capacitor body 17 are floated from the substrate, and the capacitor body 17 is connected to the land of the substrate to be surface-mounted. By having 18A and 18B, it is possible to prevent direct contact between the capacitor body 17 and the substrate, thereby preventing a change in the thickness of the capacitor body 17 from directly propagating to the substrate. Vibration noise can be sufficiently suppressed.
[0043]
In addition, since the terminals 18A and 18B are formed of a predetermined material, it is possible to prevent the propagation of vibration through the terminals 18A and 18B, and it is possible to sufficiently suppress the vibration noise.
[0044]
The capacitor body 17 is a surface mount component that can be used as a single unit, and the size of the bent portion on the tip side of the terminals 18A and 18B corresponds to the terminals 18A and 18B related to the surface mounting of the capacitor body 17. Since the terminals 18A and 18B are formed and held so as not to protrude to both sides, the capacitor main body 17 is surface-mounted and vibration noise is generated from the board. When this occurs, the ripple capacitor 16 can be mounted in place of the capacitor body 17 without changing the pattern shape to prevent vibration noise, and thus measures against vibration noise can be taken quickly. .
[0045]
Further, even if the terminals 18A and 18B are soldered by reflow and the solder used for the soldering wraps around the side surface of the capacitor main body 17, the capacitor main body 17 is sufficient to prevent the direct contact of the solder with the capacitor main body 17. The vibration of the capacitor main body 17 can be prevented from propagating to the substrate via the solder, and the vibration noise can be sufficiently suppressed.
[0046]
Further, the terminals 18A and 18B are soldered and held on the end face of the capacitor body 17 with a high melting point solder having a sufficiently high melting point temperature as compared with the soldering temperature in reflow, and soldered by reflow and mounted on the substrate. Even in this case, the terminals 18A and 18B can be prevented from falling off from the end face of the capacitor body 17, and the occurrence of defective products can be effectively avoided.
[0047]
As a result, in the power supply circuit 7E, it is possible to effectively avoid the generation of vibration noise related to the switching of the operation mode of the central processing unit.
[0048]
Thus, when the power consumption changes steeply and greatly in the power supply circuit 7E as described above, the main power supply line L1 cannot be formed short with a sufficient pattern width because the power supply circuit 7E is formed small, and in such a central processing unit. It has been found that ripples are generated on the input side in the other power supply circuits 7A to 7D and 7F due to the steep switching of the operation mode. In particular, the ripple capacitor 16 is surface-mounted through the terminals 18A and 18B, so that the impedance is higher than that of the prior art, and thus the other power supply circuits 7A to 7D, 7F are higher than the conventional one. The ripple on the input side increases, and it has been found that even in these other power supply circuits 7A to 7D, 7F, vibration noise is generated if they are configured in the same manner as in the prior art.
[0049]
However, in this embodiment, also in such other power supply circuits 7A to 7D, 7F, the ripple capacitor 16 that is the sound source of the vibration sound is configured to be the same as the ripple capacitor 16 in the power supply circuit 7E. Therefore, generation of vibration noise can be sufficiently prevented also in these other power supply circuits 7A to 7D, 7F.
[0050]
Thus, in this embodiment, a computer with low power consumption and no generation of vibration noise can be provided.
[0051]
In the state where the ripple capacitor 16 is arranged in parallel on the test wiring pattern and a voltage of 16 [V] is applied, an electronic load connected in parallel to the ripple capacitor 16 has a frequency of 1.0 [kHz]. When the load sound was varied and the vibration noise was measured, the vibration noise was reduced by 15 [dB] (frequency: 12.5 [kHz]) at the maximum. This measurement is performed when the load current is changed from 1 [A] (duty ratio 80 [%]) to 3 [A] (duty ratio 20 [%]) by an electronic load.
[0052]
(3) Effects of the embodiment
According to the above configuration, the capacitor main body made of the multilayer ceramic capacitor is floated from the substrate and mounted on the surface, so that the multilayer ceramic capacitor can be applied to the ripple capacitor to sufficiently suppress the vibration noise caused by the multilayer ceramic capacitor.
[0053]
(4) Other embodiments
In the above-described embodiment, the case where the present invention is applied to the ripple capacitor of the power supply circuit using all DC-DC converters has been described. However, the present invention is not limited to this, and vibration noise is generated as necessary. You may make it apply only about the ripple capacitor of a power supply circuit.
[0054]
In the above-described embodiment, the case where the present invention is applied to the power supply circuit by the switching regulator has been described. However, the present invention is not limited to this and can be widely applied to the power supply circuit using the series regulator.
[0055]
In the above embodiment, the case where the present invention is applied to a notebook computer that is one of information processing apparatuses has been described. However, the present invention is not limited to this, and a so-called desktop computer, PDA, Power supply that can be widely applied to various information processing devices such as cellular phones, and further supplies power to a load that lowers power consumption after starting power consumption by triggering and executing processing corresponding to the trigger It can be widely applied to circuits.
[0056]
【The invention's effect】
As described above, according to the present invention, the multilayer ceramic capacitor is applied to the ripple capacitor and the vibration noise caused by the multilayer ceramic capacitor is sufficiently suppressed by surface mounting the capacitor body by the multilayer ceramic capacitor from the substrate. Can do.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a ripple capacitor according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a computer using the ripple capacitor of FIG. 1;
3 is a block diagram showing a power supply circuit of the computer of FIG.
FIG. 4 is a schematic diagram for explaining vibration sound by a multilayer ceramic capacitor.
FIG. 5 is a characteristic curve diagram showing a change in thickness due to a ripple.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Computer, 7A-7G ... Power supply circuit, 10 ... DC-DC converter, 11, 12 ... Field effect transistor, 13 ... Inductor, 14 ... Control circuit, 15 ... Smoothing capacitor, 16 ... ... Ripple capacitors

Claims (4)

An arithmetic processing circuit that raises power consumption by a trigger and executes processing corresponding to the trigger, and then lowers power consumption ;
A power supply circuit that inputs at least a battery power supply and supplies power to the arithmetic processing circuit;
The power supply circuit is
On the input side of the power source of the battery, a capacitor for removing ripples due to the change in the power consumption is provided,
The capacitor is
Capacitor body with multilayer ceramic capacitor ,
By floating the previous SL capacitor body from a substrate, that having a a terminal for surface mounting by connecting the capacitor body to the land of the substrate
Information processing apparatus. The capacitor body is
A rectangular shape with electrodes formed on both end faces in the longitudinal direction,
The terminal is
Ru metal plate der-shaped connection cross-section L by the high melting point solder to the electrodes of the capacitor body
The information processing apparatus according to 請 Motomeko 1. The capacitor body is
Ru capacitor der for surface mounting
The information processing apparatus according to 請 Motomeko 1. In a power supply circuit that receives power supply from at least a battery, raises power consumption by a trigger, executes processing corresponding to the trigger, and then supplies power to a load that lowers power consumption.
On the input side of the power supply of the battery, a capacitor for removing a ripple due to the change in the power consumption is disposed,
The capacitor is
Capacitor body with multilayer ceramic capacitor ,
By floating the previous SL capacitor body from a substrate, that having a a terminal for surface mounting by connecting the capacitor body to the land of the substrate
Power supply circuit.

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