CN100527576C - Power switching circuit - Google Patents
Power switching circuit Download PDFInfo
- Publication number
- CN100527576C CN100527576C CNB2006100718258A CN200610071825A CN100527576C CN 100527576 C CN100527576 C CN 100527576C CN B2006100718258 A CNB2006100718258 A CN B2006100718258A CN 200610071825 A CN200610071825 A CN 200610071825A CN 100527576 C CN100527576 C CN 100527576C
- Authority
- CN
- China
- Prior art keywords
- power switch
- switch circuit
- circuit
- transducer
- power
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The invention relates to a power switch circuit (2000), wherein when the power supply is connected, first connecting the MOSFET (Q1) with large conductive resistance; after preset time, connecting MOSFET (Q2) with lower conductive resistance; therefore, the invention can use simple structure to restrain the impact current when connecting the power supply. And the invention can be used in battery power supply.
Description
Technical field
The present invention relates to power switch circuit, in detail, relate to also corresponding to battery supply etc., cheap and suitably prevent the power switch circuit of impulse current.
Background technology
As the power switch circuit of equipment,, flowing through under the situation of big electric current in the past, transistor need flow through many base currents, so efficient reduces, if when using relay, reliability mechanically becomes problem.
Therefore, in recent years, use power MOSFET (field-effect transistor: Field EffectTransistor) more.Like this, use power MOSFET, power MOSFET can low-voltage be controlled, and conducting resistance is low, efficient is high.
But because conducting resistance is low, otherwise therefore, when the electric capacity of the capacitor of load-side was big, by the MOS switch conduction, the result flow through big impulse current.Thereby, in primary power source, for example used under the situation of AA alkaline battery, because internal resistance is big, the problem that therefore exists the power circuit of secondary side to stop owing to pressure drop.In addition, at secondary side, exist because this big electric current, the circuit overcurrent protection action of power circuit big inconvenient situation such as still stops at last.
Therefore, proposed a kind ofly to make the work of MOSFET grid voltage by bias current circuit in the past, connect resistance in advance and limit impulse current, then, the MOSFET that is connected in parallel is connected the switching power circuit (with reference to patent documentation 1) of the Current Control parts that pass through the conducting of CR delay circuit.
In addition, proposed a kind of two MOSFET that are connected in parallel in the past, a side had been connected limiting resistance, at first made the MOSFET conducting that has been connected limiting resistance, and then, made the impulse current of the MOSFET conducting that is not connected resistance prevent circuit (with reference to patent documentation 2).
And then, proposed a kind ofly to the power supply limiting resistance that is connected in series in the past, begin to connect controlling resistance by the action/non-action of voltage detecting circuit, then, make the impulse current of MOSFET conducting prevent circuit (with reference to patent documentation 3).
No. 2671568 communique of [patent documentation 1] special permission
[patent documentation 2] spy opens flat 7-5937 communique
[patent documentation 3] spy opens the 2003-189464 communique
But in above-mentioned prior art, the scope of application is defined, and usability is poor, and this is external needs on the impulse current to prevent to improve effectively.
Promptly, in the prior art of patent documentation 1 and patent documentation 3 records, exist because resistance is connected in series to power supply, therefore can be connected the secondary side of power supply, but be connected to the primary side of battery, non-operating current is many, is difficult to be applied to portable equipment, the scope of application is defined, the problem of usability difference.
In addition, in the prior art of patent documentation 2 records,, improve for the problem of patent documentation 1 and patent documentation 3, but need bias current circuit, need be used to drive the driving voltage of this bias current circuit by MOSFET is connected resistance.In addition, this bias current circuit is for example under the low input about two joint AA alkaline batteries, it is difficult that driving becomes, or by because bias current circuit itself, not only need become the power supply of big load in addition, and the impulse current when starting for this power supply itself do not take any countermeasure, and the problem of big impulse current takes place when therefore having starting.
Summary of the invention
Therefore the object of the present invention is to provide a kind of impulse current during with suitable and simple STRUCTURE DEPRESSION power connection, also can be applied to the power switch circuit of battery supply simultaneously.
The power switch circuit of the invention of the present invention's record is by reaching above-mentioned purpose to get off, be connected between power supply and the load, carry out the conduction and cut-off action, thereby carry out in the power switch circuit that this power supply stops the supply/supply of this load, the MOS transistor that MOS transistor that conducting resistance is big and conducting resistance are little is connected in parallel, when power connection, after the MOS transistor conducting that described conducting resistance is big, through after the stipulated time, make the little MOS transistor conducting of described conducting resistance.
Following mode (1)～(8) are the optimal ways of power switch circuit of the present invention.In addition, so long as not special contradiction, the combination arbitrarily of then (1)～(8) all is the mode of power switch circuit of the present invention.
(1) load described in the described power switch circuit is a capacity load.
(2) power supply described in the described power switch circuit is a battery supply, and described power switch circuit is the load switch (load switch) of this battery supply.
(3) in the described power switch circuit, the MOS transistor that described conducting resistance is big is the p channel MOS transistor, and the MOS transistor that described conducting resistance is little is the n channel MOS transistor.
(4) described power switch circuit has the DC-DC transducer, the MOS transistor that described conducting resistance is little, and its grid voltage applies via the DC-DC transducer.
(5) the included power supply of the shared electric equipment of described DC-DC transducer DC-DC transducer has been used described power switch circuit in described electric equipment.
(6) described power switch circuit has the gate driving special circuit, the MOS transistor that described conducting resistance is little, and its grid voltage is transfused to via the gate driving special circuit.
(7) described gate driving special circuit comprises oscillating circuit, and grid voltage buck or boost grid to the little MOS transistor of described conducting resistance behind the assigned voltage is applied.
(8) described power switch circuit is that the included power supply of electric equipment of having used this power switch circuit uses the secondary side of DC-DC transducer to connect the load switch of usefulness.
According to power switch circuit of the present invention, when power connection, in the little MOS transistor of MOS transistor that the conducting resistance that is connected in parallel is big and conducting resistance, after at first that conducting resistance is the big MOS transistor conducting, after the process stipulated time, the impulse current can suppress power turn-on with suitable and simple structure the time makes the little MOS transistor conducting of conducting resistance, so also can be applied to battery supply simultaneously.
Description of drawings
Fig. 1 is the major part frame assumption diagram of digital camera of having used first embodiment of power switch circuit of the present invention.
Fig. 2 is the circuit structure diagram of the power switch circuit of Fig. 1.
Fig. 3 is the circuit structure diagram of power switch circuit of digital camera of having used second embodiment of power switch circuit of the present invention.
Fig. 4 (a)～Fig. 4 (g) is the action timing diagram of each major part of the power switch circuit of Fig. 3.
Fig. 5 is the circuit structure diagram of power switch circuit of digital camera of having used the 3rd embodiment of power switch circuit of the present invention.
Fig. 6 is the circuit structure diagram of power switch circuit of digital camera of having used the 4th embodiment of power switch circuit of the present invention.
Fig. 7 (a)～Fig. 7 (g) is the action timing diagram of each major part of the power switch circuit of Fig. 6.
Fig. 8 is the circuit structure diagram of power switch circuit of digital camera of having used the 5th embodiment of power switch circuit of the present invention.
Fig. 9 is the circuit structure diagram of power switch circuit of digital camera of having used the 6th embodiment of power switch circuit of the present invention.
Figure 10 is the circuit structure diagram of power switch circuit of digital camera of having used the 7th embodiment of power switch circuit of the present invention.
Embodiment
Below, explain the preferred embodiments of the present invention based on accompanying drawing.In addition, below Xu Shu embodiment is a preferred embodiment of the present invention, has therefore added technical desirable various qualifications, but scope of the present invention just is not limited to these modes as long as be not particularly limited the record of the meaning of the present invention in the following description.
[embodiment 1]
Fig. 1 and Fig. 2 are the figure of first embodiment of expression power switch circuit of the present invention, and Fig. 1 is the major part frame assumption diagram of digital camera 1 of having used first embodiment of power switch circuit of the present invention.
In Fig. 1, digital camera 1 comprises: comprise focus lens system 201, zoom-lens system 202, aperture 203, the lens combination 2 of shutter 204 grades, electric system 210, drive system 220, TG (Timing Generator, timing generator) portion 301, CCD (charge coupled cell) 302, CDS (correlated double sampling) circuit 303, variable gain amplifier (AGC amplifier) 304, A/D converter 305, IPP (Image Pre-Processor, the image preprocessor) 306, RAM (internal storage) 307, DCT (Discrete Cosine Transform, discrete cosine transform) 308, encoder (huffman encoder/decoder) 309, MCC (Memory Card Controller, memory card controller) 310, card 311, PC card (comprising storage card etc.) 312, PERCOM peripheral communication driver 313, controller 4, flash memory (EEPROM) 401, controller A/D converter 402, controller D/A converter 403, system bus 404, photoflash lamp 5, LCD drive circuit 601, LCD display part 602, auxiliary light modulation 603, fill-in light lamp drive circuit 604, DC-DC transducer 7, battery A701, battery B702, AC adapter 703, sound enlarging section 8, microphone 901, loud speaker 802, earphone 803, operating portion 9, release switch 901, pattern input part 902, vibrating motor driver 1001, vibrating motor 1002 etc.
Above-mentioned electric system 210 comprises focusing motor 211, zoom motor 212, aperture motor 213 and fast door motor 214.Drive system 220 comprises focusing motor driver 221, zoom motor driver 222, aperture motor driver 223 and shutter motor driver 224.
Aperture 203 and shutter 204 constitute mechanical mechanism, use mechanical shutter.In addition, in the present embodiment,, be provided with aperture 203 and shutter 204 respectively, but also can have aperture function and shutter function with a mechanism as mechanical mechanism.The focus lens system 201 and the zoom-lens system 202 of lens combination 2 for example are made of lens of variable focal length.
Focus on motor driver 221 and control focusing motor 211 according to the control signal of coming self-controller 4, focus lens system 201 is moved to optical axis direction, zoom motor driver 222 is according to coming the control signal of self-controller 4 to control zoom motor 212, and zoom-lens system 202 is moved to optical axis direction.In addition, aperture motor driver 223 bases come the control signal of self-controller 4 to drive aperture 203, and set f-number, and shutter motor driver 224 makes shutter 204 carry out shutter action according to coming the control signal of self-controller 4 to drive fast door motor 214.
CCD (charge coupled cell) 302 will be the signal of telecommunication (simulated image data) via the image transitions of lens combination 2 inputs, and output to CDS circuit 303.303 pairs of picture signals (simulated image data) from the CCD302 input of CDS (correlated double sampling) circuit are carried out the low noise processing for CCD type imaging apparatus, and output to AGC amplifier 304.In addition, 304 pairs in AGC amplifier is proofreaied and correct by the level that CDS circuit 303 has carried out the signal of correlated double sampling, and outputs to A/D converter 305.In addition, AGC amplifier 304 passes through via built-in D/A converter AGC amplifier 304 to be set setting datas (control voltage), thereby sets correct level.A/D converter 305 will be converted to DID via the simulated image data from CCD302 of AGC amplifier 304 inputs, and output to IPP306.That is, the output signal of CCD302 is via CDS circuit 303 and AGC amplifier 304, or by A/D converter 305, is transformed to digital signal with the sample frequency (for example, the integral multiple of the subcarrier frequency of NTSC signal) of the best.In addition, be divided into aberration (Cb, Cr) and brightness (Y) and apply data processing such as various signal processing, treatment for correcting and image compression/extension process for DID as IPP306, the DCT308 of Digital Signal Processing portion and encoder 309 from A/D converter 305 inputs.DCT308 and encoder 309 for example carry out the huffman coding/decoding etc. of one way of the image compression/expansion of the orthogonal transform/inverse orthogonal transformation of one way of image compression/expansion of Joint Photographic Experts Group and Joint Photographic Experts Group.In addition, IPP306 detects the brightness data (Y) of G view data, the AE evaluation of estimate corresponding with brightness data (Y) that 4 output preliminary examinations are measured to controller.Represent the to be taken brightness (lightness) of body of this AE evaluation of estimate.And then, IPP306 in the reference color temperature of setting, the AWB corresponding with each brightness data (Y) of R, G, B view data (Auto WhiteBalance, Automatic white balance) evaluation of estimate to each controller 4 output.This AWB evaluation of estimate represent to be taken color component of body.
Timing generator (TG) 301 generates various timing signals based on horizontal-drive signal and vertical synchronizing signal from the IPP306 input.
The interim storage of MCC310 is compressed processed images, and carries out the record of PC card 312 and reading from the image of PC card 312 via card 311.
PC card (exterior storage medium) 312 for example uses storage card etc., writes or the image of reading number camera 1 photography.
PERCOM peripheral communication for example is used for communicating with the communication protocol of standards such as USB, IEEE1394 and outside unit with driver 313, be connected with PC (personal computer) 1101 grades, carry out the exchange of data, can be connected with PC1101 or AC adapter 703 via the communication/power supply adaptor 1102 that can be connected, and can carry out the exchange of electric power or communication with camera 1.
Flash lamp circuit 5 flashes under the control of controller 4.Battery A701, battery B702 for example use Ni-MH battery, lithium ion battery, NI-G (NiCd) battery, alkaline battery etc., according to circumstances different, supply with the supply voltage of AC adapter 703, via power switch circuit 2000 and DC-DC transducer 7 and load switch 2000a internal feed supply voltage to digital camera 1.
7 pairs of electric power from power switch circuit 2000 of DC-DC transducer carry out supplying to after DC-DC changes the each several part of digital camera 1.
Controller (control device) 4 for example comprises CPU (Central Processing Unit, CPU), ROM (Read Only Memory, read-only memory), RAM (Random AccessMemory, random access memory), A/D converter, D/A converter etc., CPU is according to the indication from the indication of operating portion 9 or not shown external action such as remote controller, according to the control program that is stored among the ROM, RAM as the service area, is carried out the control of the each several part of digital camera 1.In addition, A/D converter, D/A converter etc. also can be located at the outside of controller 4, in this case, sets with D/A converter 403 with A/D converter 402, controller as controller.
Specifically, the control of action or AF action, demonstration etc. is adjusted in photograph action, automatic exposure (AE) action, Automatic white balance (AWB) of controller 4, and, use built-in A/D converter to carry out the assurance of analog information as being used for one of information input part of various controls.In addition, built-in A/D converter is changed thereby carry out A/D by comparing with reference voltage.In addition, controller 4 uses D/A converter in order to simulate output, and then, for example, carry out the control signal of IPP306 and controller 4 or the exchange of data via system bus 404.
In addition, the view data that controller 4 carries out logging mode in PC card 312 of the Imagery Data Recording that will obtain being taken body shooting, will be recorded in the PC card 312 is being reproduced the reproduction mode that shows, the monitoring picture of shooting directly is being presented at various mode treatment such as monitoring mode on the LCD display part 602 on the LCD display part 602, and in reproduction mode or monitoring mode, display mode as the situation of display image on LCD display part 602, according to the selection of operating portion 9, carry out the mode treatment of fixed mode and outer light adaptation pattern.
Record the various parameters or the data of digital camera in the flash memory 401.
The amplification of the analog signal of microphone 801, loud speaker 802 and earphone 803 is carried out in sound enlarging section 8 with D/A converter 403 with A/D converter 402 or controller via controller.In addition,, be not limited to loud speaker 802, for example, also can use buzzer of sounding a buzzer etc. based on the not shown output of controller 4 as the voice output parts.
Vibrating motor driver 1001 moves by the control signal of coming self-controller 4, drives the vibrating motor 1002 of parts of display unit by way of caution, by vibrating motor 1002 vibration takes place and warns demonstration.
Then, above-mentioned power switch circuit 2000 is constituted by circuit as illustrated in fig. 2, by the control of controller 4, carries out ON/OFF (connection/shutoff) action, to internal load 3000 supplying electric currents of digital camera 1.In addition, in Fig. 2, the 705th, with the cell voltage power supply of the AC adapter 703 of Fig. 1, battery A701, battery B702 general name.
Respectively from the lead-out terminal input of the controller 4 of Fig. 1 power control signal Sa and the power control signal Sb as signal (voltage), this power control signal Sa, Sb are generally open (open) or ' H ' level (high level: with the roughly the same voltage of supply voltage) to the grid of MOSFETQ1 and MOSFETQ2.
And p channel mosfet Q1 uses the big MOSFET of conduction impedance, and p channel mosfet Q2 uses the little MOSFET of conducting resistance.MOSFETQ1 and MOSFETQ2 are connected in parallel, and are connected in series in simultaneously between cell voltage power supply 705 and the load 3000.
The effect of present embodiment then, is described.In the digital camera 1 of present embodiment, when not shown mains switch is connected, 4 pairs of power switch circuits 2000 of controller separate predetermined distance and export power control signal Sa of ' L ' level (low level) and the power control signal Sb of ' L ' level successively, thereby prevent big impulse current, carry out supply simultaneously the electric power of load 3000.
Promptly, when the mains switch of digital camera 1 is connected, controller 4, is about to the power control signal Sa of MOSFETQ1 is switched to ' L ' and output from ' H ' at first to the power control signal Sa of big p channel mosfet Q1 output ' L ' level of conducting resistance for power switch circuit 2000.
In the power switch circuit 2000, the power control signal Sa that is transfused to the big MOSFETQ1 of conducting resistance is when ' H ' level switches to ' L ' level, this MOSFETQ1 conducting, the electric power that beginning is supplied with from cell voltage power supply 705 load 3000 via the big MOSFETQ1 of conducting resistance.
Thereby by the condenser capacitance that exists in the load 3000 etc., the impulse current that takes place in the time of can limiting power connection begins the supply of electric power simultaneously.
Then, the power control signal Sb of p channel mosfet Q2 output ' L ' level that the conducting resistance in 4 pairs of power switch circuits 2000 of controller is little is about to the power control signal Sb of MOSFETQ2 is switched to ' L ' and output from ' H '.
In the power switch circuit 2000, the power control signal Sb that is transfused to the little MOSFETQ2 of conducting resistance is when ' H ' level switches to ' L ' level, this MOSFETQ2 conducting begins by little MOSFETQ2 of the conducting resistance that is connected in parallel with MOSFETQ1 and the electric power that load 3000 is supplied with from cell voltage power supply 705.This load 3000 supplied with the electric current I 2 that flows through among the electric current I 1 that flows through among the MOSFETQ1 and the MOSFETQ2 and electric current (I1+I2).
Thereby, can reduce the loss of the electric power that conducting resistance causes, simultaneously to load 3000 supply capabilities.
Like this, the power switch circuit 2000 of the digital camera 1 of present embodiment is when power turn-on, among the little MOSFETQ2 of MOSFETQ1 that the conducting resistance that is connected in parallel is big and conducting resistance, after at first that conducting resistance is the big MOSFETQ1 conducting, through after the stipulated time, make the little MOSFETQ2 conducting of conducting resistance.
Thereby the impulse current in the time of can be with suitable and simple STRUCTURE DEPRESSION power connection also can be applicable to battery supply simultaneously.
In addition, the power switch circuit 2000 of present embodiment also can suitably be controlled impulse current as the load switch of the cell voltage power supply 705 of digital camera 1 in battery-driven electric equipment.
[embodiment 2]
Fig. 3 and Fig. 4 are the figure of second embodiment of expression power switch circuit of the present invention, and Fig. 3 is the major part circuit structure diagram of power switch circuit 2010 of digital camera of having used second embodiment of power switch circuit of the present invention.
In addition, present embodiment is applicable to digital camera and the power switch circuit 2000 same with the digital camera 1 of above-mentioned first embodiment, in the explanation of present embodiment, to giving prosign and omit its detailed explanation with the same structure division of above-mentioned first execution mode, simultaneously for not shown part, as required, former state uses the symbol that uses in the explanation of first embodiment to describe.
In Fig. 3, power switch circuit 2010 is connected in parallel to above-mentioned same big p channel mosfet Q1 and the little n channel mosfet Q3 of conducting resistance of conducting resistance between cell voltage power supply 705 and load 3000, between the gate-to-drain of p channel mosfet Q1, connect the resistance R 1 of the grid voltage be used to take place MOSFETQ1, or between the gate-to-drain of n channel mosfet Q3, be connected with the resistance R 3 of the grid voltage that is used to take place MOSFETQ3.
To the input of the grid of n channel mosfet Q3:, thereby and then feed back and the power control signal Sb that comes self-controller 4 is carried out voltage control has been carried out voltage transformation in order to make the little n channel mosfet Q3 conducting of conducting resistance power control signal Sb ' by resistance R 4, R5 via DC-DC transducer 7.
In addition, power switch circuit 2010 is connected with smoothing circuit 2011 between the MOSFETQ1 that is connected in parallel and MOSFETQ3 and load 3000, smoothing circuit 2011 comprises capacitor C1, smmothing capacitor C2, inductor L1, rectifier diode D1 and switching transistor Tr1 etc.
Then, like this, obtain the voltage higher than the voltage of cell voltage power supply 705 by smoothing circuit 2011, this voltage is applied to load 3000.In this case, in order to make the little n channel mosfet Q3 conducting of conducting resistance, the grid of the n of the power control signal Sb former state of self-controller 4 input in the future channel mosfet Q3, therefore in the future the power control signal Sb of self-controller 4 via the grid of DC-DC transducer 7 as power control signal Sb ' input n channel mosfet Q3.That is, because under the situation of p channel mosfet, grid voltage need be lower than source voltage, otherwise but under the situation of n channel mosfet, need high grid voltage.In addition, be identical magnitude of voltage to MOSFETQ3 grid voltage that applies and the voltage that load 3000 is applied.
The effect of present embodiment then, is described.In the digital camera 1 of present embodiment, when not shown mains switch is connected, the power control signal Sa of 4 pairs of power switch circuits of controller, 2010 output ' L ' level, simultaneously DC-DC transducer 7 is exported the control signal of control smoothing circuits 2011, and then, the power control signal Sb of ' L ' level is postponed predetermined distance and output successively than power control signal Sa, thereby prevent big impulse current, carry out supply simultaneously the electric power of load 3000.
Promptly, when the mains switch of digital camera 1 is opened, shown in Fig. 4 (a), controller 4 is for power switch circuit 2010, at first the big p channel mosfet Q1 of conducting resistance is exported the power control signal Sa of ' L ' level, that is, will switch to ' L ' and export from ' H ' the power control signal Sa of MOSFETQ1.
In the power switch circuit 2010, the power control signal Sa of the big MOSFETQ1 of input conducting resistance is when ' H ' level switches to ' L ' level, the MOSFETQ1 conducting, shown in Fig. 4 (b), pass through the big MOSFETQ1 of conducting resistance from cell voltage power supply 705, smoothing circuit 2011 is supplied with the electric power of the voltage Vfi of rising lentamente, in inductor L1, accumulate electric charge.
By this work, because when power connection, load directly is not connected with power supply, and the impulse current that takes place during restriction power turn-ons such as condenser capacitance that therefore can be by existing in the load 3000 begins the supply of electric power simultaneously.
Then, shown in Fig. 4 (c), the power control signal Sb of 4 pairs of DC-DC transducers of controller, 7 output ' L ' level, DC-DC transducer 7 becomes operating state.The DC-DC transducer 7 that becomes operating state makes transistor Tr 1 conducting certain hour shown in Fig. 4 (d), emit the electric charge that is stored among the inductor L1.By emitting of this electric charge, be applied in the grid of MOSFETQ3, MOSFETQ3 conducting by the voltage of resistance R 4 and R5 dividing potential drop.
Promptly, shown in Fig. 4 (d), power switch circuit 2010 is by coming the control signal of self-controller 4, from the switch motion of the conduction and cut-off of DC-DC transducer 7 control switch transistor Tr 1, thereby emit the electric charge of charging in inductor L1, by rectifier diode D1 rectification.On the other hand, the rectifier diode D1 of resistance R 5 side apply by smmothing capacitor C2 level and smooth voltage Vfo, the voltage Vfo that applies in the rectifier diode D1 of this resistance R 5 side is by resistance R 5 and resistance R 4 dividing potential drops, shown in Fig. 4 (g), as the not shown error amplifier (error AMP) in the branch pressure voltage Vfb input DC-DC transducer 7.Error amplifier will be compared by the branch pressure voltage Vfb of resistance R 5 and resistance R 4 dividing potential drops and the reference voltage in the DC-DC transducer 7, thereby the duty ratio of the conduction and cut-off of control switch transistor T R1, carry out FEEDBACK CONTROL, so that branch pressure voltage Vfb equates with reference voltage.
And, according to the conduction and cut-off of switching transistor Tr1, shown in Fig. 4 (e), repeat accumulating and emit to the electric charge of inductor L1.In this case, the long more electric charge of then emitting from inductor L1 of the ON time of switching transistor Tr1 is many more, and the output voltage of inductor L1 is high more.In addition, in Fig. 4 (e), come figure is put down in writing with same magnitude of voltage for convenience.
And, in the power switch circuit 2010, at the power control signal Sb ' of the little n channel mosfet Q3 of input conducting resistance when ' H ' level switches to ' L ' level, the MOSFETQ3 conducting, shown in Fig. 4 (b), (f), apply the voltage of controlling by DC-DC transducer 7 via 2011 pairs of loads 3000 of smoothing circuit.
Thereby, can reduce the loss of the electric power that conducting resistance causes, simultaneously to load 3000 supply capabilities.
Like this, the MOSFETQ1 that the power switch circuit 2010 of the digital camera 1 of present embodiment is big with conducting resistance is made as p channel MOS transistor (MOSFET), and the MOSFETQ3 that conducting resistance is little is made as n channel MOS transistor (MOSDFET).
Thereby, can make the little MOSFETQ3 conducting resistance of conducting resistance lower, and can further reduce power loss.
In addition, in the power switch circuit 2010 of present embodiment, the grid voltage of the MOSFETQ3 that conducting resistance is little applies via DC-DC transducer 7.
Thereby, can make the little MOSFETQ3 conducting resistance of conducting resistance lower, and can further reduce power loss.
And then the power supply that the power switch circuit 2010 of present embodiment comprises digital camera 1 generates with the DC-DC transducer 7 shared grid power supplies of making power switch circuit 2010 uses the DC-DC transducer.Thereby, can make power switch circuit 2010 cheapnesss.
In addition, in the power switch circuit 2010 of present embodiment,, also can suitably suppress impulse current even load 3000 is a capacity load.
[embodiment 3]
Fig. 5 is the major part circuit structure diagram of power switch circuit 2020 of digital camera of having used the 3rd embodiment of power switch circuit of the present invention.
In addition, present embodiment is applied to the digital camera same with the digital camera 1 of above-mentioned first embodiment, in addition, be applied to the power switch circuit same with the power switch circuit 2010 of above-mentioned second embodiment, in the explanation of present embodiment, for with above-mentioned first embodiment or the same structure division of second embodiment, give prosign and omit its detailed explanation, simultaneously for not shown part, as required and former state uses the symbol that uses in the explanation of first embodiment to describe.
In Fig. 5, in the power switch circuit 2020, between cell voltage power supply 705 and load 3000, above-mentioned same big p channel mosfet Q1 and the little n channel mosfet Q3 of conducting resistance of conducting resistance is connected in parallel, between the gate-to-drain of p channel mosfet Q1, be connected with the resistance R 1 of the grid voltage that is used to take place MOSFETQ1, and between the gate-to-drain of n channel mosfet Q3, be connected with the resistance R 3 of the grid voltage that is used to take place MOSFETQ3.
Grid for n channel mosfet Q3, the power control signal Sb of input self-controller 4 in future is via DC-DC transducer 7, and then by resistance R 4, R5 feedback back by voltage control, thereby be carried out the power control signal Sb ' of voltage transformation in order to make the Q3 conducting of n channel mosfet.
In addition, in the power switch circuit 2020, between the MOSFETQ1 that is connected in parallel and MOSFETQ3 and load 3000, be connected with smoothing circuit 2011.
And, in the power switch circuit 2020, and then with the big p channel mosfet Q1 of the conducting resistance little p channel mosfet Q4 of conducting resistance that is connected in parallel, between the gate-to-drain of this p channel mosfet Q4, be connected with the resistance R 6 of the grid voltage that is used to take place MOSFETQ4.The grid input power control signal Sc of 4 couples of these MOSFETQ4 of slave controller.In addition, be identical magnitude of voltage to MOSFETQ3 grid voltage that applies and the voltage that load 3000 is applied.
The effect of present embodiment then, is described.In the digital camera 1 of present embodiment, when not shown mains switch is connected, the power control signal Sa of 4 pairs of power switch circuits of controller, 2020 output ' L ' level, export the power control signal Sc of ' L ' level simultaneously, simultaneously DC-DC transducer 7 is exported the power control signal Sc of ' L ' level, and then to the control signal of DC-DC transducer 7 output control smoothing circuits 2011, then with the power control signal Sb of ' L ' level than power control signal Sa, Sc postpones predetermined distance and output successively, thereby prevent big impulse current, carry out simultaneously the electric power of load 3000 is supplied with.
Promptly, when the mains switch of digital camera 1 is connected, controller 4 is for power switch circuit 2020, at first the big p channel mosfet Q1 of conducting resistance is exported the power control signal Sa of ' L ' level, be about to the power control signal Sa of MOSFETQ1 is switched to ' L ' and output from ' H ', to the power control signal Sc of little p channel mosfet Q4 output ' L ' level of conducting resistance, be about to the power control signal Sc of MOSFETQ4 is switched to ' L ' and output from ' H ' simultaneously.
In the power switch circuit 2020, the power control signal Sa that is transfused to the big MOSFETQ1 of conducting resistance is when ' H ' level switches to ' L ' level, this MOSFETQ1 conducting, the electric power that beginning is supplied with from cell voltage power supply 705 smoothing circuit 2011 via the big MOSFETQ1 of conducting resistance, in addition, the power control signal Sc of the little MOSFETQ4 of input conducting resistance is when ' H ' level switches to ' L ' level, the MOSFETQ4 conducting will supply to smoothing circuit 2011 by the little MOSFETQ4 of conducting resistance from the electric power of cell voltage power supply 705.
As mentioned above, smoothing circuit 2011 by diode D1 and capacitor C2 make by the control signal of coming self-controller 4 become load 3000 that the DC-DC transducer 7 of operate condition controlled to apply electric current level and smooth.
Thereby, under the situation that load 3000 weighs, in the internal resistance of cell voltage power supply 705, cause the output voltage pressure drop by load current, can prevent to be reduced to below the voltage of DC-DC transducer 7 work, the big MOSFETQ1 conducting of conducting resistance simultaneously, thereby the impulse current that takes place in the time of can limiting power turn-on by the condenser capacitance that exists in the load 3000 etc. begins the supply of electric power simultaneously.
Then, the power control signal Sb of 4 pairs of DC-DC transducers of controller, 7 output ' L ' level is about to power control signal Sb and switches to ' L ' and output from ' H '.The grid input of the n channel mosfet Q3 that 7 pairs of conducting resistance of DC-DC transducer are little utilizes the power control signal Sb that comes self-controller 4 carries out the power control signal Sb ' that voltage control has been carried out voltage transformation by the feedback of R4, R5.
In the power switch circuit 2020, at the power control signal Sb ' of the little n channel mosfet Q3 of input conducting resistance when ' H ' level switches to ' L ' level, the MOSFETQ3 conducting applies the voltage of being controlled by DC-DC transducer 7 to load 3000 via smoothing circuit 2011.
Thereby, can reduce the loss of the electric power that conducting resistance causes, simultaneously to load 3000 supply capabilities.
[embodiment 4]
Fig. 6 and Fig. 7 are the figure of the 4th embodiment of expression power switch circuit of the present invention, and Fig. 6 is the major part circuit structure diagram of power switch circuit 2030 of digital camera of having used the 4th embodiment of power switch circuit of the present invention.
In addition, present embodiment is applied to the digital camera same with the digital camera 1 of above-mentioned first embodiment, in addition, be applied to the power switch circuit same with the power switch circuit 2010 of above-mentioned second embodiment, in the explanation of present embodiment, for with above-mentioned first embodiment or the same structure division of second embodiment, give prosign and omit its detailed explanation, simultaneously for not shown part, as required and former state uses the symbol that uses in the explanation of first embodiment to describe.
In Fig. 6, in the power switch circuit 2030 of present embodiment, between cell voltage power supply 705 and load 3000, the p channel mosfet Q6 that p channel mosfet Q5 that the conducting resistance that is connected in parallel is big and conducting resistance are little, between the gate-to-drain of p channel mosfet Q5, be connected with the resistance R 7 of the grid voltage that is used to take place MOSFETQ5, and between the gate-to-drain of p channel mosfet Q6, be connected with the resistance R 8 of the grid voltage that is used to take place MOSFETQ6.
Grid for p channel mosfet Q6, the power control signal Sb of input self-controller 4 in future is via DC-DC transducer 7, and then by resistance R 4, R5 feedback back by voltage control, thereby be carried out the power control signal Sb ' of voltage transformation in order to make the little p channel mosfet Q6 conducting of conducting resistance.
In addition, in the power switch circuit 2030, between the MOSFETQ5 that is connected in parallel and MOSFETQ6 and load 3000, be connected with smoothing circuit 2031, smoothing circuit 2031 comprises the switching transistor Tr2 of capacitor C1, smmothing capacitor C2, inductor L2, rectifier diode D2 and positive-negative-positive, and negative supply takes place.
In the smoothing circuit 2031, by coming the control signal of self-controller 4, the conduction and cut-off of DC-DC transducer 7 control switch transistor Tr 2, thereby in inductor L2 negative voltage takes place, by for the reverse rectifier diode D2 rectification of load 3000, and by smmothing capacitor C2 level and smooth after, negative direct current power is supplied with in load 3000.
And, like this, in smoothing circuit 2031, load 3000 is being supplied with under the situation of negative voltage, in order to make the little p channel mosfet Q6 conducting of conducting resistance, the grid of the p of the power control signal Sb former state of self-controller 4 input in the future channel mosfet Q6, therefore the power control signal Sb of self-controller 4 imports the grid of p channel mosfet Q6 via DC-DC transducer 7 as power control signal Sb ' in the future.In addition, be identical magnitude of voltage to MOSFET6 grid voltage that applies and the voltage that load 3000 is applied.
The effect of present embodiment then, is described.In the digital camera 1 of present embodiment, when not shown mains switch is connected, the power control signal Sa of 4 pairs of power switch circuits of controller, 2030 output ' L ' level, simultaneously DC-DC transducer 7 is exported the control signal of control smoothing circuits 2031, and then, the power control signal Sb of ' L ' level is postponed predetermined distance and output successively than power control signal Sa, thereby prevent big impulse current, carry out supply simultaneously the electric power of load 3000.
Promptly, when the mains switch of digital camera 1 is opened, shown in Fig. 7 (a), controller 4 is for power switch circuit 2030, at first the big p channel mosfet Q5 of conducting resistance is exported the power control signal Sa of ' L ' level, that is, will switch to ' L ' and export from ' H ' the power control signal Sa of MOSFETQ5.
In the power switch circuit 2030, the power control signal Sa of the big MOSFETQ5 of input conducting resistance is when ' H ' level switches to ' L ' level, the MOSFETQ5 conducting, shown in Fig. 7 (b), pass through the big MOSFETQ5 of conducting resistance from cell voltage power supply 705, smoothing circuit 2031 is supplied with the electric power of the voltage Vfi of rising lentamente, in inductor L2, accumulate electric charge.
By this work, because when power connection, power supply directly is not connected with load is instantaneous, and the impulse current that takes place during restriction power turn-ons such as condenser capacitance that therefore can be by existing in the load 3000 begins the supply of electric power simultaneously.
Then, shown in Fig. 7 (c), the power control signal Sb of 4 pairs of DC-DC transducers of controller, 7 output ' L ' level is about to power control signal Sb and switches to ' L ' and output from ' H '.DC-DC transducer 7 shown in Fig. 7 (e), thereby to the input of the grid of the little p channel mosfet Q6 of conducting resistance in the future the power control signal Sb of self-controller 4 use by the feedback of resistance R 4, R5 and carry out the power control signal Sb ' that voltage control has been carried out voltage transformation.
Promptly, shown in Fig. 7 (d), power switch circuit 2030 is by coming the control signal of self-controller 4, from the switch motion of the conduction and cut-off of DC-DC transducer 7 control switch transistor Tr 2, thereby emit the electric charge of charging in inductor L2, by rectifier diode D2 rectification.On the other hand, the rectifier diode D2 of resistance R 5 side apply by smmothing capacitor C2 level and smooth voltage Vfo, the voltage Vfo that applies in the rectifier diode D2 of this resistance R 5 side is by resistance R 5 and resistance R 4 dividing potential drops, shown in Fig. 7 (g), as the not shown error amplifier (error AMP) in the branch pressure voltage Vfb input DC-DC transducer 7.Error amplifier will be compared by the branch pressure voltage Vfb of resistance R 5 and resistance R 4 dividing potential drops and the reference voltage in the DC-DC transducer 7, thereby the duty ratio of the conduction and cut-off of control switch transistor Tr 2, carry out FEEDBACK CONTROL, so that branch pressure voltage Vfb equates with reference voltage.
And, according to the conduction and cut-off of switching transistor Tr2, shown in Fig. 7 (e), repeat accumulating and emit to the electric charge of inductor L2.In this case, the long more electric charge of then emitting from inductor L2 of the ON time of switching transistor Tr2 is many more, and the output voltage of inductor L2 is high more.In addition, in Fig. 7 (e), come figure is put down in writing with same magnitude of voltage for convenience.
And, in the power switch circuit 2030, at the power control signal Sb ' of the little p channel mosfet Q6 of input conducting resistance when ' H ' level switches to ' L ' level, the MOSFETQ6 conducting, shown in Fig. 7 (b), (f), apply the voltage of controlling by DC-DC transducer 7 via 2031 pairs of loads 3000 of smoothing circuit.
Thereby, can reduce the loss of the electric power that conducting resistance causes, simultaneously to load 3000 supply capabilities.
[embodiment 5]
Fig. 8 is the major part circuit structure diagram of power switch circuit 2040 of digital camera of having used the 5th embodiment of power switch circuit of the present invention.
In addition, present embodiment is applied to the digital camera same with the digital camera 1 of above-mentioned first embodiment, in addition, be applied to the power switch circuit same with the power switch circuit 2010 of above-mentioned second embodiment, in the explanation of present embodiment, for with above-mentioned first embodiment or the same structure division of second embodiment, give prosign and omit its detailed explanation, simultaneously for not shown part, as required and former state uses the symbol that uses in the explanation of first embodiment to describe.
In Fig. 8, in the power switch circuit 2040 of present embodiment, between cell voltage power supply 705 and load 3000 or DC-DC transducer 7, the n channel mosfet Q3 that p channel mosfet Q1 that the conducting resistance that is connected in parallel is big and conducting resistance are little, between the gate-to-drain of p channel mosfet Q1, be connected with the resistance R 1 of the grid voltage that is used to take place MOSFETQ1, and between the gate-to-drain of n channel mosfet Q3, be connected with the resistance R 3 of the grid voltage that is used to take place MOSFETQ3.
Connected jointly between the grid of the source side of p channel mosfet Q1 and n channel mosfet Q3 and n channel mosfet Q3, be connected with the DC-DC translation function portion 2042 that constitutes by pnp transistor Tr 3 and multi-resonant oscillating circuit 2041, above-mentioned capacitor C1, smmothing capacitor C2, the smoothing circuit 2011 that constitutes by inductor L1 and rectifier diode D1, by the constant voltage circuit 2043 that resistance R 9 and Zener diode ZD1 constitute, the power control signal Sa that comes self-controller 4 of the grid of input MOSFETQ1 is branched after imported the base stage of the transistor Tr 3 of DC-DC translation function portions 2042 by resistance R 10.
Multi-resonant oscillating circuit 2041 is common multi-resonant oscillating circuits, comprises two transistor Tr 4, Tr5, two capacitor C3, C4 and four resistance R 11, R12, R13, R14.
The effect of present embodiment then, is described.In the digital camera 1 of present embodiment, when not shown mains switch is connected, the power control signal Sa of 4 pairs of power switch circuits of controller, 2040 output ' L ' level, simultaneously the transistor Tr 3 of DC-DC translation function portion 2042 is imported, grid as the little n channel mosfet Q3 of the power control signal Sd input conducting resistance that has postponed by this DC-DC translation function portion 2042, smoothing circuit 2011 and constant voltage circuit 2043, thereby prevent big impulse current, carry out simultaneously the electric power of load 3000 or DC-DC transducer 7 is supplied with.
Promptly, when the mains switch of digital camera 1 is connected, controller 4, is about to the power control signal Sa of MOSFETQ1 is switched to ' L ' and output from ' H ' to the power control signal Sa of big p channel mosfet Q1 output ' L ' level of conducting resistance for power switch circuit 2040.
In the power switch circuit 2040, the power control signal Sa that is transfused to the big MOSFETQ1 of conducting resistance is when ' H ' level switches to ' L ' level, the MOSFETQ1 conducting, the electric power that beginning is supplied with from cell voltage power supply 705 DC-DC translation function portion 2042 via the big MOSFETQ1 of conducting resistance is branched after by the transistor Tr 3 of resistance R 10 input DC-DC translation function portions 2042 from the power control signal Sa of above-mentioned controller 4.DC-DC translation function portion 2042 is supplied to electric power via MOSFETQ1 from cell voltage power supply 705, when transistor Tr 3 is passed through power control signal Sa conducting, the voltage of multi-resonant oscillating circuit 2041 pulsing shapes, by this pulse, by smoothing circuit 2011 voltage higher than cell voltage power supply 705 taking place, makes the low n channel mosfet Q3 conducting of conducting resistance via constant voltage circuit 2043.
Like this, the power switch circuit 2040 of the digital camera 1 of present embodiment comprises the multi-resonant oscillating circuit 2041 as oscillating circuit, grid voltage is boosted or is depressured to the grid that is applied to the little MOSFETQ3 of conducting resistance behind the assigned voltage.
Thereby by the condenser capacitance that exists in the load 3000 etc., the impulse current that takes place in the time of can limiting power connection, and begin the supply of electric power simultaneously reduces the loss of the electric power that conducting resistance causes simultaneously, and to load 3000 supply capabilities.
[embodiment 6]
Fig. 9 is the major part circuit structure diagram of power switch circuit 2050 of digital camera of having used the 6th embodiment of power switch circuit of the present invention.
In addition, present embodiment is applied to the digital camera same with the digital camera 1 of above-mentioned first embodiment, in addition, be applied to the power switch circuit same with the power switch circuit 2010 of above-mentioned second embodiment, in the explanation of present embodiment, for with above-mentioned first embodiment or the same structure division of second embodiment, give prosign and omit its detailed explanation, simultaneously for not shown part, as required and former state uses the symbol that uses in the explanation of first embodiment to describe.
In Fig. 9, in the power switch circuit 2050 of present embodiment, between cell voltage power supply 705 and load 3000 or DC-DC transducer 7, the n channel mosfet Q3 that p channel mosfet Q1 that the conducting resistance that is connected in parallel is big and conducting resistance are little, between the gate-to-drain of p channel mosfet Q1, be connected with the resistance R 1 of the grid voltage that is used to take place MOSFETQ1, and between the gate-to-drain of n channel mosfet Q3, be connected with the resistance R 3 of the grid voltage that is used to take place MOSFETQ3.
Connected jointly between the grid of the source side of p channel mosfet Q1 and n channel mosfet Q3 and n channel mosfet Q3, be connected with the DC-DC translation function portion 2052 that constitutes by pnp transistor Tr 3 and intermittent oscillation circuit 2051, above-mentioned capacitor C1, the smoothing circuit 2011 that constitutes by smmothing capacitor C2 and rectifier diode D1, by the constant voltage circuit 2043 that resistance R 9 and Zener diode ZD1 constitute, the power control signal Sa that comes self-controller 4 of the grid of input MOSFETQ1 is branched after imported the base stage of the transistor Tr 3 of DC-DC translation function portions 2052 by resistance R 10.
And, voltage after the output of the AC portion that will be separated by the capacitor C6 of intermittent oscillation circuit 2051 is stablized by the diode D1 rectification of smoothing circuit 2011 and by constant voltage circuit 2043 outputs to the grid of the little n channel mosfet Q3 of conducting resistance, makes n channel transistor MOSFETQ3 conducting.
In addition, as integral body, work as the gate driving special circuit that is used to apply the grid voltage higher than cell voltage power supply 705 except DC-DC translation function portion 2052, smoothing circuit 2011 and the power failure volt circuit 2043 of the circuit of the load 3000 of n channel mosfet Q3 purpose.
The effect of present embodiment then, is described.In the digital camera 1 of present embodiment, when not shown mains switch is connected, the power control signal Sa of 4 pairs of power switch circuits of controller, 2050 output ' L ' level, simultaneously the transistor Tr 3 of DC-DC translation function portion 2052 is imported, grid as the little n channel mosfet Q3 of the power control signal Sd input conducting resistance that has postponed by this DC-DC translation function portion 2052, smoothing circuit 2011 and constant voltage circuit 2043, thereby prevent big impulse current, carry out simultaneously the electric power of load 3000 or DC-DC transducer 7 is supplied with.
Promptly, when the mains switch of digital camera 1 is connected, controller 4, is about to the power control signal Sa of MOSFETQ1 is switched to ' L ' and output from ' H ' to the power control signal Sa of big p channel mosfet Q1 output ' L ' level of conducting resistance for power switch circuit 2050.
In the power switch circuit 2050, the power control signal Sa that is transfused to the big MOSFETQ1 of conducting resistance is when ' H ' level switches to ' L ' level, the MOSFETQ1 conducting, the electric power that beginning is supplied with from cell voltage power supply 705 DC-DC translation function portion 2052 via the big MOSFETQ1 of conducting resistance is branched after by the transistor Tr 3 of resistance R 10 input DC-DC translation function portions 2052 from the power control signal Sa of above-mentioned controller 4.DC-DC translation function portion 2052 is supplied to electric power via MOSFETQ1 from cell voltage power supply 705, when transistor Tr 3 is passed through power control signal Sa conducting, the voltage of intermittent oscillation circuit 2051 pulsing shapes, by this pulse, by smoothing circuit 2011 voltage higher than cell voltage power supply 705 taking place, makes the low n channel mosfet Q3 conducting of conducting resistance via constant voltage circuit 2043.
Thereby by the condenser capacitance that exists in the load 3000 etc., the impulse current that takes place in the time of can limiting power connection, and begin the supply of electric power simultaneously reduces the loss of the electric power that conducting resistance causes simultaneously, and to load 3000 supply capabilities.
[embodiment 7]
Figure 10 is the major part circuit structure diagram of power switch circuit 2060 of digital camera of having used the 7th embodiment of power switch circuit of the present invention.
In addition, present embodiment is applied to the digital camera same with the digital camera 1 of above-mentioned first embodiment, in addition, be applied to the power switch circuit same with the power switch circuit 2010 of above-mentioned second embodiment, in the explanation of present embodiment, for with above-mentioned first embodiment or the same structure division of second embodiment, give prosign and omit its detailed explanation, simultaneously for not shown part, as required and former state uses the symbol that uses in the explanation of first embodiment to describe.
In Figure 10, in the power switch circuit 2060 of present embodiment, between cell voltage power supply 705 and load 3000 or DC-DC transducer 7, the n channel mosfet Q3 that p channel mosfet Q1 that the conducting resistance that is connected in parallel is big and conducting resistance are little, between the gate-to-drain of p channel mosfet Q1, be connected with the resistance R 1 of the grid voltage that is used to take place MOSFETQ1, and between the gate-to-drain of n channel mosfet Q3, be connected with the resistance R 3 of the grid voltage that is used to take place MOSFETQ3.
Connected jointly between the grid of the source side of p channel mosfet Q1 and n channel mosfet Q3 and n channel mosfet Q3, the amplifying circuit 2061 that is connected with the DC-DC translation function portion 2042 that is made of pnp transistor Tr 3 and multi-resonant oscillating circuit 2041, is made of capacitor C1～C13 and diode D3～D8, the power control signal Sa that comes self-controller 4 of the grid of input MOSFETQ1 are branched after by the base stage of the transistor Tr 3 of resistance R 10 input DC-DC translation function portions 2042.
Multi-resonant oscillating circuit 2041 is common multi-resonant oscillating circuit as mentioned above, comprises two transistor Tr 4, Tr5, two capacitor C3, C4 and four resistance R 11, R12, R13, R14.
Amplifying circuit 2061 is by capacitor C7 and multi-resonant oscillating circuit 2041 couplings, by repeat with take place by multi-resonant oscillating circuit 2041 and via the voltage of the pulse type of capacitor C7 input to each capacitor C8～C12 charging, simultaneously by the action of each diode D3～D8 rectification and the voltage that separated to each capacitor C8～C12 charging, thereby voltage is risen, and the voltage that will rise is imported the grid of the little n channel mosfet Q3 of conducting resistance.
The effect of present embodiment then, is described.In the digital camera 1 of present embodiment, during not shown power switch conducts, the power control signal Sa of 4 pairs of power switch circuits of controller, 2060 output ' L ' level, simultaneously the transistor Tr 3 of DC-DC translation function portion 2042 is imported, after postponing to amplify simultaneously by this DC-DC translation function portion 2042 and amplifying circuit 2061, grid as the little n channel mosfet Q3 of power control signal Sd input conducting resistance, thereby prevent big impulse current, use the MOSFET of low on-resistance simultaneously as MOSFETQ3, carry out the electric power of load 3000 or DC-DC transducer 7 is supplied with.
Promptly, when the mains switch of digital camera 1 is connected, controller 4 is about to the power control signal Sa of MOSFETQ1 is switched to ' L ' and output from ' H ' for the power control signal Sa of p channel mosfet Q1 output ' L ' level that conducting resistance is big in the power switch circuit 2060.
In the power switch circuit 2060, the power control signal Sa that is transfused to the big MOSFETQ1 of conducting resistance is when ' H ' level switches to ' L ' level, the MOSFETQ1 conducting, begin the electric power DC-DC translation function portion 2042 supplied with from cell voltage power supply 705 by the big MOSFETQ1 of conducting resistance, be branched after by the transistor Tr 3 of resistance R 10 input DC-DC translation function portions 2042 from the power control signal Sa of above-mentioned controller 4.DC-DC translation function portion 2042 is supplied to electric power via MOSFETQ1 from cell voltage power supply 705, when transistor Tr 3 is passed through power control signal Sa conducting, the voltage of multi-resonant oscillating circuit 2041 pulsing shapes, the voltage higher than cell voltage power supply 705 is taken place by amplifying circuit 2061 in this pulse-like voltage, make the lower n channel mosfet Q3 conducting of conducting resistance.
Thereby by the condenser capacitance that exists in the load 3000 etc., the impulse current that takes place in the time of can limiting power connection, and begin the supply of electric power simultaneously further reduces the loss of the electric power that conducting resistance causes simultaneously, and to load 3000 supply capabilities.
In addition, in the various embodiments described above, illustrated by coming the signal of self-controller 4, the situation of power switch circuit 2000,2010,2020,2030,2040,2050,2060 actions, but as power switch circuit, being not limited to by coming the signalizing activity of self-controller, also can serve as to trigger to move with other signal.
More than, specifically understand the invention that the present inventor finishes based on preferred embodiment, but the invention is not restricted to the foregoing description, in the scope that does not break away from its purport, certainly carry out various changes.
Utilizability on the industry, the dash current in the time of can being applied to suitably suppress power connection, with The time electronic equipments such as image recording structure such as digital camera, printer that drive with cell voltage power supply On-off circuit.
Claims (24)
1. power switch circuit, be connected between power supply and the load, carry out the conduction and cut-off action, thereby carry out this power supply the supply/supply of this load is stopped, it is characterized in that this power switch circuit has big MOS transistor and the little MOS transistor of conducting resistance of conducting resistance that is connected in parallel, when power connection, after the MOS transistor conducting that described conducting resistance is big,, make the little MOS transistor conducting of described conducting resistance through after the stipulated time.
2. power switch circuit as claimed in claim 1 is characterized in that described load is a capacity load.
3. as claim 1 or the described power switch circuit of claim 2, it is characterized in that described power supply is a battery supply, described power switch circuit is the load switch of this battery supply.
4. as claim 1 or the described power switch circuit of claim 2, it is characterized in that the MOS transistor that described conducting resistance is big is the p channel MOS transistor, the MOS transistor that described conducting resistance is little is the n channel MOS transistor.
5. power switch circuit as claimed in claim 3 is characterized in that, the MOS transistor that described conducting resistance is big is the p channel MOS transistor, and the MOS transistor that described conducting resistance is little is the n channel MOS transistor.
6. as claim 1 or the described power switch circuit of claim 2, it is characterized in that described power switch circuit has the DC-DC transducer, the MOS transistor that described conducting resistance is little, its grid voltage applies via the DC-DC transducer.
7. power switch circuit as claimed in claim 3 is characterized in that described power switch circuit has the DC-DC transducer, the MOS transistor that described conducting resistance is little, and its grid voltage applies via the DC-DC transducer.
8. power switch circuit as claimed in claim 4 is characterized in that described power switch circuit has the DC-DC transducer, the MOS transistor that described conducting resistance is little, and its grid voltage applies via the DC-DC transducer.
9. power switch circuit as claimed in claim 6 is characterized in that, the included power supply of the shared electric equipment of described DC-DC transducer DC-DC transducer has been used described power switch circuit in described electric equipment.
10. power switch circuit as claimed in claim 7 is characterized in that, the included power supply of the shared electric equipment of described DC-DC transducer DC-DC transducer has been used described power switch circuit in described electric equipment.
11. power switch circuit as claimed in claim 8 is characterized in that, the included power supply of the shared electric equipment of described DC-DC transducer DC-DC transducer has been used described power switch circuit in described electric equipment.
12. as claim 1 or the described power switch circuit of claim 2, it is characterized in that described power switch circuit has the gate driving special circuit, the MOS transistor that described conducting resistance is little, its grid voltage is transfused to via the gate driving special circuit.
13. power switch circuit as claimed in claim 3 is characterized in that, described power switch circuit has the gate driving special circuit, the MOS transistor that described conducting resistance is little, and its grid voltage is transfused to via the gate driving special circuit.
14. power switch circuit as claimed in claim 4 is characterized in that, described power switch circuit has the gate driving special circuit, the MOS transistor that described conducting resistance is little, and its grid voltage is transfused to via the gate driving special circuit.
15. power switch circuit as claimed in claim 12 is characterized in that, described gate driving special circuit comprises oscillating circuit, and grid voltage buck or boost grid to the little MOS transistor of described conducting resistance behind the assigned voltage is applied.
16. power switch circuit as claimed in claim 13 is characterized in that, described gate driving special circuit comprises oscillating circuit, and grid voltage buck or boost grid to the little MOS transistor of described conducting resistance behind the assigned voltage is applied.
17. power switch circuit as claimed in claim 14 is characterized in that, described gate driving special circuit comprises oscillating circuit, and grid voltage buck or boost grid to the little MOS transistor of described conducting resistance behind the assigned voltage is applied.
18. power switch circuit as claimed in claim 1 is characterized in that, described power switch circuit is that the included power supply of electric equipment of having used this power switch circuit uses the secondary side of DC-DC transducer to connect the load switch of usefulness.
19. power switch circuit as claimed in claim 2 is characterized in that, described power switch circuit is that the included power supply of electric equipment of having used this power switch circuit uses the secondary side of DC-DC transducer to connect the load switch of usefulness.
20. power switch circuit as claimed in claim 4 is characterized in that, described power switch circuit is that the included power supply of electric equipment of having used this power switch circuit uses the secondary side of DC-DC transducer to connect the load switch of usefulness.
21. power switch circuit as claimed in claim 6 is characterized in that, described power switch circuit is that the included power supply of electric equipment of having used this power switch circuit uses the secondary side of DC-DC transducer to connect the load switch of usefulness.
22. power switch circuit as claimed in claim 8 is characterized in that, described power switch circuit is that the included power supply of electric equipment of having used this power switch circuit uses the secondary side of DC-DC transducer to connect the load switch of usefulness.
23. power switch circuit as claimed in claim 9 is characterized in that, described power switch circuit is that the included power supply of electric equipment of having used this power switch circuit uses the secondary side of DC-DC transducer to connect the load switch of usefulness.
24. power switch circuit as claimed in claim 11 is characterized in that, described power switch circuit is that the included power supply of electric equipment of having used this power switch circuit uses the secondary side of DC-DC transducer to connect the load switch of usefulness.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP079624/05 | 2005-03-18 | ||
| JP2005079624 | 2005-03-18 | ||
| JP028256/06 | 2006-02-06 | ||
| JP046346/06 | 2006-02-23 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1841874A CN1841874A (en) | 2006-10-04 |
| CN100527576C true CN100527576C (en) | 2009-08-12 |
Family
ID=37030758
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2006100718258A Expired - Fee Related CN100527576C (en) | 2005-03-18 | 2006-03-16 | Power switching circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100527576C (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8183713B2 (en) * | 2007-12-21 | 2012-05-22 | Qualcomm Incorporated | System and method of providing power using switching circuits |
| GB2480648B (en) * | 2010-05-26 | 2013-02-20 | Ge Aviat Systems Ltd | Measuring transient electrical activity in aircraft power distribution systems |
| CN102403752A (en) * | 2011-04-12 | 2012-04-04 | 王晓秋 | Discharging control circuit for storage battery and control method thereof |
| CN102904329B (en) * | 2011-07-29 | 2016-04-20 | 富泰华工业（深圳）有限公司 | Electric power management circuit |
| CN104158595B (en) * | 2014-07-21 | 2017-02-15 | 武汉中元华电科技股份有限公司 | Processing method of power supply circuit for reducing optical fiber module power consumption in power equipment |
| KR101755823B1 (en) * | 2015-08-12 | 2017-07-07 | 현대자동차주식회사 | Charging device for eco-friendly vehicle and control method of the same |
| JP6617571B2 (en) * | 2016-01-14 | 2019-12-11 | 富士電機株式会社 | Semiconductor switching element gate drive circuit |
| CN107181295A (en) * | 2017-05-10 | 2017-09-19 | 上海空间电源研究所 | A kind of space integration battery discharging on-off circuit |
| TWI645639B (en) * | 2017-11-09 | 2018-12-21 | 海韻電子工業股份有限公司 | Redundant isolating switch control circuit |
| CN111614896A (en) * | 2020-05-12 | 2020-09-01 | 上海创功通讯技术有限公司 | Camera control circuit, terminal and control method |
-
2006
- 2006-03-16 CN CNB2006100718258A patent/CN100527576C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN1841874A (en) | 2006-10-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100527576C (en) | Power switching circuit | |
| US20080055419A1 (en) | Digital camera using an indicating device to indicate a plurality of functions | |
| CN103873749A (en) | Imaging device and announcing method | |
| JP4851201B2 (en) | Power switch circuit | |
| JP2013240267A (en) | Power source switching device and electronic device | |
| KR20060082547A (en) | Apparatus for charging secondary battery in digital image processing apparatus using a charger for cellular phone, and a digital image processing apparatus using the same | |
| JP2004343909A (en) | Power supply circuit and electronic equipment | |
| JP2003116031A (en) | Information recorder/reproducer | |
| JP4359032B2 (en) | Power supply device and digital camera equipped with the power supply device | |
| JP2004023965A (en) | Inrush current prevented power circuit and portable image processor | |
| JP4227491B2 (en) | Power supply circuit for digital camera | |
| EP1617283B1 (en) | Motor driving apparatus, digital camera, and motor controlling method | |
| JP4719371B2 (en) | Imaging apparatus and control method thereof | |
| JPH0453368A (en) | Data storage device for video camera | |
| KR101255206B1 (en) | Control circuit for strobo charging and photographing device comprising the same | |
| JP2003169239A (en) | Digital camera | |
| JP4356875B2 (en) | Imaging device and illumination device thereof | |
| KR101086406B1 (en) | Camera executing reduced power on sequence | |
| KR100702953B1 (en) | Apparatus for charging battery in mobile device using charger for cellular phone and a mobile device using the apparatus | |
| JP3837000B2 (en) | Power supply circuit device | |
| JP3757511B2 (en) | Digital still camera | |
| JP4040921B2 (en) | Digital camera | |
| JP2005252615A (en) | Digital camera | |
| JP2016208207A (en) | Imaging apparatus | |
| JP2004347379A (en) | Voltage measuring apparatus and voltage measuring method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090812 Termination date: 20150316 |
|
| EXPY | Termination of patent right or utility model |