CN100353286C - Power supply circuit and electronic device - Google Patents
Power supply circuit and electronic device Download PDFInfo
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- CN100353286C CN100353286C CNB2005100986100A CN200510098610A CN100353286C CN 100353286 C CN100353286 C CN 100353286C CN B2005100986100 A CNB2005100986100 A CN B2005100986100A CN 200510098610 A CN200510098610 A CN 200510098610A CN 100353286 C CN100353286 C CN 100353286C
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Abstract
A power supply circuit, wherein a power supply in a backup system is operational effectively even when a normal power supply to be used at a normal operation is turned off, including an A power supply system for supplying a first voltage to a circuit unit at a normal operation and a backup B power supply system, which starts to operate instantly when the A power supply system becomes abnormal to supply the first voltage to the circuit unit; wherein the B power supply system includes a regulator for outputting a second voltage equivalent to the first voltage, and a feedback circuit for detecting a voltage to be applied to the circuit unit and feeding back the detected voltage to the regulator; and the regulator adjusts an output voltage thereof, so that the voltage to be applied to the circuit unit becomes the first voltage when the voltage detected by the feedback circuit is lower than the first voltage.
Description
Technical field
The present invention relates to power circuit and provide the electronic equipment of power by this power circuit, particularly, the electronic equipment that the present invention relates to have the power circuit of standby system and power is provided by this power circuit.
Background technology
In the electronic equipment such as digital equipment (electronics), get when unstable when closing (cut-out) power and power source voltage and electrorheological, in the time for example can't normally providing power because instantaneous voltage interrupts (temporary transient outage), following problems can appear perhaps.
(1) when the operating voltage of supply voltage step-down and electronic equipment assembly becomes inadequate, this electronic equipment can be out of control, for example because the program and the data value that read from the RAM of electronic equipment become unusually the or operation of CPU instability or the like that becomes in the electronic equipment.And abnormal information can be stored in the recording medium (for example flash memory and dish).
(2) flash memory etc. for example is EEPROM, so power supply must be held a period of time, and to carry out and write to preserve deal with data by receive instruction from the CPU as control module, described deal with data must be held when closing power.If power is not held during during this period of time, the data in then can defective flash memory etc.
For fear of this defective, even when closing power, also need before the operation of closing power is finished, the power supply be kept a period of time, handle with the preservation that is used for storer.
When closing power,, taked following measure in the prior art for the circuit in electronic equipment (for example storer and CPU) work prerequisite supplies to wish held voltage.
As shown in Figure 1, by by power supply 11 (for example 5V), be used for exporting the constant voltage source 12 of constant voltage (for example 2.5V) and circuit that circuit unit 13 (for example flash memory, CPU and RAM) constitutes provides the capacitor 14 with quite big electric capacity, even thereby after powered-down 11, capacitor 14 also can keep supply voltage one period schedule time, and this section schedule time is that the required time is backed up in processing.
But, in such power circuit, need externally provide capacitor 14 with large-scale capacitor device (being large capacitor).
Compare with circuit arrangement shown in Figure 1, circuit shown in Figure 2 has replacement power supply 11 and has the more power supply 15 and the capacitor 14 with big electric capacity of high current capacity, and this capacitor 14 is positioned at the output terminal of power supply 15.
But, in such power circuit, must provide power supply 15 with high current capacity, in addition, also must externally provide the capacitor with big electric capacity, i.e. large capacitor.
Circuit shown in Figure 3 also has the B system that is used to back up except A system as shown in Figure 1, wherein the A system by power supply 11 (for example 5V) and the constant voltage source 12 that is used to export constant voltage (for example 2.5V) constitute.The B system for example is included in the second source 21 of the 5V in the system that is different from power supply 11, the diode 23 that is used to export the constant voltage source 22 of constant voltage (for example 2.5V) and is used to prevent reverse current flows.Preferably, the Schottky-barrier diode with low-voltage drop characteristic is used as reversed flow and prevents diode 23.
Usually, first constant voltage source 12 from the A system provides for example voltage of 2.5V to the circuit unit 13 such as flash memory, CPU and RAM etc.Also provide for example voltage of 2.5V from second constant voltage source 22 in the mode identical with first constant voltage source 12, but be lower than voltage from the voltage of second constant voltage source 22 owing to reversed flow prevents that voltage drop in the diode 23 from becoming, thereby power can not be provided to circuit unit 13 from second constant voltage source 22 from first constant voltage source 12.And because reversed flow prevents diode 23, the voltage in the A system can not be provided to the B system yet.
When first power supply 11 was closed, the output voltage of first constant voltage source 12 was reduced to 0.Because the power source voltage in the B system is normal, therefore prevent that by reversed flow diode 23 is provided in the circuit unit 13 such as flash memory, CPU and RAM etc. from the voltage of the power circuit in the B system (being the second source 21 and second constant voltage source 22).
But, even in the time Schottky-barrier diode that low-voltage falls will be shown prevent diode 23 as reversed flow, forward voltage also for example reduces about 0.4V, even therefore from the voltage of second constant voltage source, 22 output 2.5V, the voltage that is provided to circuit unit 13 (for example flash memory, CPU and RAM etc.) also becomes about 2.1V.This voltage is compared with the driving voltage of circuit unit 13 (for example flash memory, CPU and RAM etc.) on being operated in rated voltage 2.5V, reduced about 20%, thereby can produce adverse influence to the operation of circuit unit 13 (for example flash memory, CPU and RAM etc.).
In order to overcome above-mentioned defective, can consider to improve the output voltage of the second source 21 and second constant voltage source 22.But, when the supply voltage in the B system raises, reversed flow prevents that diode 23 from flow electric current on direction, even and exist under normal condition, the power also power supply from the B system is fed to the possibility of circuit unit 13 (for example flash memory, CPU and RAM etc.), thereby in some cases, power circuit can become the aspects such as current capacity of system to be adversely affected with power supply.
The forward voltage of diode changes with temperature, and characteristic changes with element, therefore in some cases, can cause disadvantageous result in low voltage range.
In view of above-mentioned viewpoint, storer and the CPU that is used can be operated with the performance that low-voltage is operated by depending in preservation usually constantly.
Especially in flash memory, if the operation in the flash memory continues when CPU normally starts power-off operation, it is not readable or destroyed that the data of being stored then can become.
Fig. 4 is the arrangement plan of another power circuit of correlation technique.
Power circuit shown in Figure 4 comprises the AC power AC with commercial frequency, it is used for providing power to circuit unit 13 (for example flash memory, CPU and RAM etc.), comprises that also power switch 32, first rectifier circuit 10, DC-DC converter 11, first constant voltage circuit 12, standby (backup) transformer 20, second rectifier circuit 21, second constant voltage circuit 22 and reversed flow prevent diode 23.
When power circuit shown in Figure 4 was compared with power circuit shown in Figure 3, power switch 32, first rectifier circuit 10, DC-DC converter 11 and first constant voltage circuit 12 were included to as the power circuit in the A system; And the circuit that is illustrated as first power supply 11 in Fig. 3 is disposed by the power switch among Fig. 4 32, first rectifier circuit 10 and DC-DC converter 11.And the power circuit in the B system prevents that by spare transformer 20, second rectifier circuit 21, second constant voltage circuit 22 and reversed flow diode 23 from being disposed; And the circuit that is illustrated as second source 21 in Fig. 3 is disposed by spare transformer 20, second rectifier circuit 21.
In supply voltage shown in Figure 4, in normal running, power switch 32 is in on-state, and power is provided to circuit unit 13 by the power circuit from the A system that comprises first rectifier circuit 10, DC-DC converter 11 and first constant voltage circuit 12.In this state, the power circuit of B system (promptly, spare transformer 20, second rectifier circuit 21 and second constant voltage circuit 22) also be in the work, but because reversed flow prevents the voltage drop in the diode 23, power can not be provided to circuit unit 13 from the power circuit the B system.
For example, when power switch 32 was disconnected (open mode), 13 power supply was ended from the A circuit system to circuit unit.But owing to the power circuit in the B system is in the work, so power is provided to circuit unit 13 by the power circuit from the B system under without any discontinuous situation.
The operation of the power circuit among above-mentioned Fig. 4 is identical with the operation of the power circuit that illustrates with reference to figure 3.
In the mode identical with second constant voltage circuit 22 with first constant voltage circuit 12 shown in Figure 3, when hypothesis during from the constant voltage of first constant voltage circuit 12 shown in Figure 4 and second constant voltage circuit 22 output 2.5V, from the power circuit of B system when circuit unit 13 provides power, can cause adverse effect owing to above-mentioned reversed flow prevents that voltage drop in the diode 23 from causing to the undertension of circuit 13.
On the other hand, when the output voltage of second constant voltage circuit 22 raises when improving the situation that voltage lacks, can cause above-mentioned adverse effect.
Not substantive examination patent of Japan announces that No.11-175203 discloses a kind of technology of preserving data, and this technology is not by using backup battery etc., but by using the power that produces via the inertial force that uses rotating recording medium to preserve data.
Summary of the invention
Disclosed method is limited to be applied to the device that comprises rotating recording medium in above patent is announced, and must provide power to produce circuit.
Therefore, we want by providing a kind of power circuit to overcome above-mentioned defective, and in this power circuit, even when the conventional power supply that uses when normal running is cut off, the power supply in backup (standby) system also can be worked effectively.
And, according to the present invention, provide a kind of electronic equipment that power is provided by power circuit.
According to a first aspect of the invention, provide a kind of power circuit that is used for providing to circuit unit power, having comprised: first power-supply system is used for providing first voltage to circuit unit when normal running; And the second source system, be used for when first power-supply system can't provide first voltage, providing first voltage to circuit unit; Wherein said second source system comprises: first power supply that is used to export second voltage; The regulator of power is provided by first power supply; Be arranged on the output of regulator and the reversed flow between the circuit unit and prevent diode; And feedback circuit, it is used to detect the voltage that will be provided to circuit unit, and detected Voltage Feedback is arrived regulator; And described regulator is adjusted its output voltage, so that the voltage that will be provided to circuit unit approximately becomes first voltage in first power-supply system becomes one period schedule time after first voltage can not be provided.
According to a second aspect of the invention, provide a kind of power circuit that is used to provide the DC voltage that produces based on the alternating voltage that provides via power switch, comprising: first power-supply system is used for providing first voltage to first circuit unit; And the second source system, being used for providing second voltage higher than first voltage to the second circuit unit, described second circuit unit provides with the load of first circuit unit and compares lighter load; Wherein said second source system comprises: the regulator that power is provided by second source; Be arranged on the output of regulator and the reversed flow between first circuit unit and prevent diode, and feedback circuit, it is used to detect the voltage that will be provided to first circuit unit, and detected Voltage Feedback is arrived regulator; Wherein regulator approximately becomes first voltage so that will be provided to the voltage of first circuit unit in one period schedule time after power switch disconnects based on adjusting its output voltage by the detected voltage of feedback circuit.
Preferably, described feedback circuit comprises: first and second resistors that pair of series connects, and this is connected to the two ends that reversed flow prevents diode to first and second resistors; And third and fourth resistor of pair of series connection, this is connected to the coupling part of first and second resistors to third and fourth resistor; And the coupling part of described third and fourth resistor is connected to the return signal input terminal of described regulator.
According to a third aspect of the invention we, provide a kind of electronic equipment that comprises above-mentioned power circuit, it comprises: power switch is used for the supply of controlling AC power by being switched on or switched off; And as the storer of first circuit unit be used for the control circuit of control store; Wherein said control circuit is handled by the preservation that the data that power comes execute store are provided by the second source system when power switch is disconnected.
In power circuit of the present invention, reversed flow for the power circuit of the power circuit from first system in second system, prevent the voltage at diode two ends about being applied to reversed flow, because the voltage of the power circuit in second system can be set to be lower than the voltage of the power circuit in first system from the beginning, therefore the voltage of the power circuit in second system can not become and be higher than the voltage of the power circuit in first system, and can avoid the unusual supply of electric current.Power circuit in first system is in fact during abnormal operation, even electric current is owing to reversed flow prevents that the forward drop of diode from flowing through reversed flow and preventing diode and change to a certain degree, this voltage drop also can be fed, and the output voltage of regulator is suitably adjusted (raising) automatically, thereby, before circuit operation is finished, can stably produce the voltage that hope is provided.
In addition, according to power circuit of the present invention, from state (for example resetting) that complete operation occurs to the operation of each parts is actual finish during, can stably keep essential voltage for the power supply of flash memory, RAM and CPU etc. (decline that it needs management circuit voltage is regularly).
Electronic equipment utilization of the present invention is operated from the power that above-mentioned power circuit provides, thereby even when the power circuit in first system becomes cisco unity malfunction, this electronic equipment also can operate as normal.
Description of drawings
From below in conjunction with the accompanying drawing description of preferred embodiments, these and other purposes of the present invention and feature will become more obvious, in the accompanying drawings:
Fig. 1 is the arrangement plan of first power circuit of correlation technique;
Fig. 2 is the arrangement plan of the second source circuit of correlation technique;
Fig. 3 is the arrangement plan of the 3rd power circuit of correlation technique;
Fig. 4 is the arrangement plan of another power circuit of correlation technique;
Fig. 5 is the arrangement plan of the power circuit of the embodiment of the invention;
Fig. 6 shows the operating characteristic of power circuit shown in Figure 4;
Fig. 7 shows the operating characteristic of power circuit shown in Figure 5;
Fig. 8 is the arrangement plan of the power circuit of second embodiment of the invention; And
Fig. 9 is the arrangement plan of modification embodiment of the power circuit of second embodiment of the invention.
Embodiment
Figure 5 illustrates the circuit arrangement of the first embodiment of the present invention.
Fig. 5 shows the power circuit in electronics and the circuit unit of power is provided by this power circuit.
In circuit shown in Figure 5, at first power supply 11 that is used to export 5V voltage for example that is used for the A of normal running (first) system and first constant voltage source 12 that is used for providing the constant voltage of 2.5V for example to circuit unit 13 (for example flash memory, CPU and RAM etc.) with described those are identical with reference to figure 3 and Fig. 4.Note, control whole equipment by following the program that is stored among the ROM that connects via bus as the CPU of the control module of electronics.At this moment RAM is used as the perform region.Flash memory is for example stored user's setting.
In the power circuit of B shown in Figure 5 (second) system (standby system), error voltage (return signal) input terminal " c " that is used to receive as the error voltage of return signal is provided, to replace Fig. 3 and second constant voltage source 22 shown in Figure 4, and use variable output controller 22A, it is used for according to exporting predetermined voltage from the error voltage (return signal) of input terminal " c " input from lead-out terminal " b ".
And, in order to monitor the voltage (providing a voltage at N1 place) that is provided to circuit unit 13 (for example flash memory, CPU and RAM etc.) in order to monitor at voltage, power circuit in the B shown in Figure 5 system has the feedback circuit 26 that is configured to the resistor network circuit, this resistor network circuit comprises resistor R 1 to R4, be used to monitor the terminal voltage that reversed flow prevents diode 23, detect the terminal voltage that reversed flow prevents diode 23, and with the error voltage input terminal " c " of detected Voltage Feedback to regulator 22A.
In addition, power circuit in B system shown in Figure 5 can preferably have the second source 24 in different system, be used to export for example voltage of 8V, to improve the reliability of the backup except first power supply 21 that in different system, is used to export 5V voltage for example.Certainly, second source 24 is always unessential, but when second source 24 is provided, and is closed or is under the situation of off position at first power supply 11, perhaps first power supply 21 in the different system be closed or idle situation under, also can improve reliability.
In addition, when first power supply 21 in different system, also provide when being used for exporting than the more high-tension second source 24 of first power supply 21 of different system, regulator 22A comes output voltage according to output than the voltage of first power supply, 21 more high-tension second sources 24.
When first power supply 21 in different system, when also providing second source 24, reversed flow prevents that diode circuit 27 is provided.When first power supply 21 that only uses in different system, reversed flow prevents that diode circuit 27 is optional.
Be used for preventing electric current identical in role that the reversed flow that the power supply of normal running from the A system leaks into the power circuit in the B system prevents diode 23 and Fig. 3 and circuit shown in Figure 4, and preferably for example be Schottky-barrier diode, wherein voltage breakdown is very low, and voltage drop is very little.
Even the time from first power supply, the 21 input 5V voltages of the different system that is used for exporting 5V voltage for example, perhaps the time from the second source 24 input 8V voltages that are used for exporting the different system of 8V voltage for example, regulator 22A exports for example voltage of 2.5V, and this voltage is conditioned as the voltage that is used for circuit unit 13 (for example flash memory, CPU and RAM etc.).Notice that regulator 22A is configured to feed back to according to the feedback circuit 26 from the resistor network circuit that comprises resistor R 1 to R4 the error voltage of error voltage input terminal " c ", adjusts its output voltage.
The regulator 22A that operates in the above-described manner for example is a series controller.
Electric current during circuit unit 13 (for example flash memory, CPU and RAM etc.) is finished processing is 1A or littler normally, for example is about 100mA under the situation of flash memory.Regulator 22A is provided to electric current circuit unit 13 (for example flash memory, CPU and RAM etc.) when backup operation.
In the power circuit of Fig. 5, carry out voltage that the reversed flow of dividing potential drop prevents diode 23 two ends further by the resistor circuit of resistors in series R3 and R4 institute dividing potential drop by resistors in series R1 and R2, and institute's component voltage is transfused to (feedback) error voltage input terminal " c " to regulator 22A as error voltage (return signal).
When normal running, the value of four resistor R 1 to R4 is determined, and is lower than voltage in the A system slightly so that the voltage in the B system becomes.
The resistance value of resistor R 1 and R2 is set to following value: this value is used for determining that reversed flow prevents the voltage of diode 23 (preferably, schottky diode) is fed back to regulator 22A with which kind of degree.The general resistance value of resistor R 1 and R2 is about tens ohm, and the preferred ratio of the resistance value of resistor R 1 and R2 is about 5: 1.When this ratio was very little, the voltage drop among the regulator 22A became very big when feedback is provided to regulator 22A.On the other hand, when this ratio is very big, the circuit from the B system provide the frequency of electric current can be during normal running the voltage in the A system become very high when changing.
Notice that resistor R 3 and R4 have the resistance of several kilohms of orders of magnitude, this low-resistance value with resistor R 1 and R2 has been determined the voltage of B system.When the power circuit work in the A system and the circuit in the B system when not working (normal running), load lightens, and in backup operation, it is heavy that the load in the B system on the circuit becomes; Therefore the power circuit in the B system preferably has and is used to prevent the capacitor (not shown) that vibrates.
When power normally is provided to circuit unit 13 (for example flash memory, CPU and RAM etc.) by the power circuit from the A system, the voltage of the power circuit in the B system is set to be lower than slightly the voltage in the A system, in other words, the voltage of the power circuit in the A system becomes and is higher than the voltage of the power circuit in the B system.In other words, electric current can not flow to the power circuit of B system from the power circuit of A system because reversed flow prevents diode 23, thereby can overcome with reference to figure 3 and the illustrated defective of Fig. 4.
When the voltage of the power circuit in the A system for example owing to first power supply 11 is closed etc. when descending, the voltage of the power circuit in the B system becomes higher, thereby electric current prevents that via reversed flow diode 23 is provided to circuit unit 13 (for example flash memory, CPU and RAM etc.) by the power circuit from the B system.At this moment, the voltage that will be provided to circuit unit 13 (for example flash memory, CPU and RAM etc.) reduces the amount of pressure drop that reversed flow prevents the forward voltage of diode 23 just, but it is fed circuit 26 and detects, and be imported into the error voltage input terminal " c " of regulator 22A, to be used to feed back to regulator 22A.So, in the circuit of Fig. 5, can provide a N1 place to detect voltage at the voltage of going to circuit unit 13 (for example flash memory, CPU and RAM etc.) and change.Regulator 22A improves output voltage according to detected voltage, and the amount with the voltage drop in the compensation diode 23 is conditioned voltage thereby provide a voltage at N1 place to become at voltage.So, provide a voltage at N1 place to become identical when the power circuit from the A system provides power in normal running at voltage.
As mentioned above, the circuit among Fig. 5 has overcome the defective of Fig. 3 and circuit shown in Figure 4.
Fig. 6 is the Fig. 3 of property example as a comparison and the process characterization diagram of circuit shown in Figure 4.Fig. 7 is the process characterization diagram of circuit shown in Figure 5.
When the characteristic among Fig. 6 is compared with the characteristic among Fig. 7, in Fig. 7, the electromotive force that provides a N1 when voltage is owing to closing first power supply, 11 grades when reducing, and the voltage of the power circuit of B system becomes higher, and the amount that exceeds equals the amount that reversed flow prevents the voltage drop of diode 23 just.On the other hand, in Fig. 6, the electromotive force that provides a N1 when voltage is owing to closing first power supply, 11 grades when reducing, and the voltage of the power circuit in the B system does not change.
As mentioned above, in the circuit of Fig. 5, when using reversed flow to prevent diode 23, if forward voltage for example reduces about 0.4V, this voltage drop is comprised, and the feedback circuit 26 of the resistor network circuit of resistor R 1 to R4 detects, and is imported into regulator 22A as feedback voltage.So, the voltage of 2.8V compensates the amount that reversed flow prevents the voltage drop in the diode 23 to regulator 22A by for example exporting approximately, and correct reversed flow immediately and prevent voltage drop in the diode 23, thereby can be to provide mode identical under the situation of power that the voltage of about 2.4V is provided to circuit unit 13 (for example flash memory, CPU and RAM etc.) with the power circuit from the A system in normal running.
According to embodiments of the invention, can obtain following effect.
(1) voltage of the power circuit in the B system can be set to be lower than the voltage of the power circuit in the A system from the beginning, thereby the voltage of the power circuit in the B system can not become and is higher than the voltage of the power circuit in the A system.Therefore, can not cause power circuit from the A system to the abnormal current supply of the power circuit of B system.In addition, for example, prevent that by reversed flow diode 23 from can also avoid the reversed flow from the A system to the B system.
(2) when the power circuit in the A system is closed, power is provided to circuit unit 13 by diode 23 from regulator 22A.At this moment,, utilize the feedback of feedback circuit 26, voltage can be provided the voltage on the N1 to remain on the voltage of adjusting though have voltage drop in the diode 23.
(3) so, before circuit operation is finished, can stably produce and wish held voltage.
According to present embodiment, the required voltage of power supply that can stably keep flash memory, RAM and CPU etc., the power supply of described flash memory, RAM and CPU etc. need management voltage reduces during actual the finishing of operation from state (for example resetting) that complete operation occurs to each parts timing.
Second embodiment
Fig. 8 shows the circuit arrangement of second embodiment of power circuit of the present invention.
In power circuit shown in Figure 8, except first power supply 11 that is used to export 5V voltage for example, add and to be used to export for example first power supply 21 of 5V voltage in the different system, and except the second source 24 that is used to export 8V voltage for example, interpolation is used to export for example the 3rd power supply 25 of 11V voltage, guarantees backup with this.Together with adding the 3rd power supply 25, also in diode circuit 27, add a reversed flow and prevent diode.
Because first power supply 11 is carried out heavy duty, therefore when power switch 32 is disconnected, this voltage decline is the fastest.In contrast to this, those power supplys that have underload and a slowly voltage drop are chosen as first power supply 21, second source 24 and the 3rd power supply 25 in different system.
As mentioned above, when first power supply 21, second source 24 and the 3rd power supply 25 were provided in different system, regulator 22A operated according to the voltage that provides from the power supply with ceiling voltage when power switch 32 disconnects.
For example, under the situation of televisor, when existence has the power supply of electrolytic condenser of high voltage and high power capacity, for example have the power supply of LNB (antenna), it can be used as the 3rd power supply 25.
For example, when the 3rd power supply 25 from for example 11V provided power, regulator 22A will spend several seconds time before voltage drops to 5V.Therefore, preferred way provides the circuit that is used for preventing (ending) fallback circuit when normal running and recovery.
Via power switch 32, provide power to first power supply 11 and first to the 3rd power supply 21,24 and 25 different system from public commercial power 31.
Fig. 9 is the arrangement plan of power circuit of the modification embodiment of power circuit shown in Figure 8.In order to provide power to circuit unit 13 and a plurality of load 1 to 3, power circuit shown in Figure 9 comprises that AC power AC, power switch 32, rectifier circuit 10, DC-DC converter 35, first constant voltage circuit 12, reversed flow with commercial frequency prevent diode circuit 27, the regulator 22A as second constant voltage circuit, diode 23 and feedback circuit 26.
A plurality of load L1 are to the required 5V of L3,8V and 11V voltage for 35 outputs of DC-DC converter.Because the 5V voltage requirements is big, therefore export two 5V voltages.Load L1 for example is LNB, and load L2 is a note amplifier, and load L3 is the fore-end that comprises tuner, and load L4 comprises CPU, flash memory, RAM and digital signal processing circuit and be the heaviest load.
In order to provide power, be provided to first constant voltage circuit 12 from the 5V of DC-DC converter 35, and the voltage of 2.5V is provided to circuit unit 13 from first constant voltage circuit 12 to circuit unit 13.
Note, when power switch 32 is disconnected, the output of the output of first constant voltage circuit 12 and regulator 22A is all lost, but, even only can be closed by first constant voltage circuit 12 of the heavy duty of 5V operation, can also can work on a period of time by the regulator 22A of the operations such as underload of 11V, thereby can during during this period of time, the preservation of execute store handle or the like.
When comprising power circuit of the present invention, can carry out the various modifications except that above-mentioned modification.
According to embodiments of the invention, a kind of power circuit is provided, this circuit is used for providing when the power supply of electronic equipment (for example digital device) is closed wishes held voltage, the operation of certain circuit in this electronic equipment is finished.
Particularly, by using other available voltage, can be by come automatic switched voltage with very little voltage change amount so that stable voltage to be provided immediately, with the power supply (it needs the decline timing of managing electrical power voltage) that is used for flash memory, RAM and CPU etc.
Especially effective during the power supply of flash memory, RAM and the CPU etc. of the present invention in the circuit of a plurality of power supplys of conduct use (it need manage the decline timing of the circuit voltage that will be used).
In addition, the power circuit in the embodiment of the invention can easily be added in the existing power circuit, and therefore, it can be the effective measures that tackle degradation problem under the supply voltage.
Notice that the present invention is not limited to the configuration in the foregoing description.For example, the example that the preservation of data in the flash memory of digital equipment or RAM is handled has been described in an embodiment, but the present invention can also be widely used in externally preserving data conditions in the recording medium (for example being inserted into the storage card in the groove).
It should be appreciated by those skilled in the art that to depend on design requirement and other factors, various modifications, combination, sub-portfolio and replacement can take place, as long as they are in the scope of appended claims or its equivalent.
Claims (5)
1. power circuit that is used for providing to circuit unit power comprises:
First power-supply system is used for providing first voltage to described circuit unit when normal running; And
The second source system is used for providing voltage to described circuit unit when described first power-supply system can't provide described first voltage,
Described second source system comprises:
Be used to export first power supply of second voltage,
Provide the regulator of power by described first power supply,
Be arranged on the output of described regulator and the reversed flow between the described circuit unit and prevent diode, and
Feedback circuit, it is used to detect the described voltage that will be provided to described circuit unit, and detected Voltage Feedback is arrived described regulator, and
Described regulator is adjusted its output voltage, approximately becomes described first voltage so that will be provided to the voltage of described circuit unit in described first power-supply system becomes one period schedule time after described first voltage can not be provided.
2. power circuit as claimed in claim 1, wherein:
Described feedback circuit comprises
First and second resistors that pair of series connects, this is connected to the two ends that described reversed flow prevents diode to first and second resistors, and
Third and fourth resistor that pair of series connects, this is connected to the coupling part of described first and second resistors to third and fourth resistor; And
The coupling part of described third and fourth resistor is connected to the return signal input terminal of described regulator, and the return signal input terminal of described regulator receives the described detected voltage that feeds back to described regulator.
3. electronic equipment that comprises power circuit as claimed in claim 1, from the power that exchanges power supply, this electronic equipment comprised since wherein said first and second power-supply systems all were supplied:
Power switch is used for the supply of controlling described AC power by being switched on or switched off; And
Storer and the control circuit that is used to control described storer as described circuit unit;
When described control circuit is disconnected at described power switch, handle by the preservation that the data that power carries out described storer are provided by described second source system.
4. power circuit that is used to provide the DC voltage that produces based on the alternating voltage that provides via power switch comprises:
First power-supply system is used for providing first voltage to first circuit unit; And
The second source system comprises:
Power supply is used for providing second voltage higher than described first voltage to the second circuit unit, and described second circuit unit provides with the load of described first circuit unit and compares lighter load,
Provide the regulator of power by described power supply,
Be arranged on the output of described regulator and the reversed flow between described first circuit unit and prevent diode, and
Feedback circuit, it is used to detect the voltage that will be provided to described first circuit unit, and detected Voltage Feedback is arrived described regulator, and
Described regulator approximately becomes described first voltage based on adjusting its output voltage by the detected voltage of described feedback circuit so that will be provided to the voltage of described first circuit unit in one period schedule time after described power switch disconnects.
5. electronic equipment that comprises power circuit as claimed in claim 4, from the power that exchanges power supply, this electronic equipment comprised since wherein said first and second power-supply systems all were supplied:
Power switch is used for the supply of controlling described AC power by being switched on or switched off; And
Storer and the control circuit that is used to control described storer as described first circuit unit;
When described control circuit is disconnected at described power switch, handle by the preservation that the data that power carries out described storer are provided by described second source system.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004257246 | 2004-09-03 | ||
| JP2004257246 | 2004-09-03 | ||
| JP2005199049 | 2005-07-07 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1744000A CN1744000A (en) | 2006-03-08 |
| CN100353286C true CN100353286C (en) | 2007-12-05 |
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| Application Number | Title | Priority Date | Filing Date |
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| CNB2005100986100A Expired - Fee Related CN100353286C (en) | 2004-09-03 | 2005-09-05 | Power supply circuit and electronic device |
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Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101656108B (en) * | 2008-08-19 | 2012-06-27 | 杭州士兰微电子股份有限公司 | Power supply circuit and application method |
| CN103116254B (en) * | 2012-12-28 | 2016-08-03 | 珠海天威飞马打印耗材有限公司 | The power supply circuits of charging roller and use its method powered |
| CN104883054A (en) * | 2014-02-27 | 2015-09-02 | 株式会社东芝 | DC/DC Converter, Method Of Controlling The DC/DC Converter And Data Storage Apparatus |
| CN109130908A (en) * | 2018-09-17 | 2019-01-04 | 奇瑞商用车（安徽）有限公司 | A kind of electric vehicle auxiliary power supply circuit |
| CN112600295A (en) * | 2020-12-04 | 2021-04-02 | 清华大学 | Power supply method for redundant vehicle-mounted sensor |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5237258A (en) * | 1985-08-26 | 1993-08-17 | Applied Research And Technology, Inc. | Unique computer power system with backup power |
| CN1038962C (en) * | 1994-09-28 | 1998-07-01 | 国际商业机器公司 | A data processing system, and a power supply apparatus and a method for its use with a data processing system |
| CN1121642C (en) * | 1997-04-17 | 2003-09-17 | 宏碁股份有限公司 | Electric-saving computer system |
| CN1157835C (en) * | 2001-09-10 | 2004-07-14 | 倚天资讯股份有限公司 | Voltage stabilization and electric power and voltage regulating and monitoring protection circuit unit |
-
2005
- 2005-09-05 CN CNB2005100986100A patent/CN100353286C/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5237258A (en) * | 1985-08-26 | 1993-08-17 | Applied Research And Technology, Inc. | Unique computer power system with backup power |
| CN1038962C (en) * | 1994-09-28 | 1998-07-01 | 国际商业机器公司 | A data processing system, and a power supply apparatus and a method for its use with a data processing system |
| CN1121642C (en) * | 1997-04-17 | 2003-09-17 | 宏碁股份有限公司 | Electric-saving computer system |
| CN1157835C (en) * | 2001-09-10 | 2004-07-14 | 倚天资讯股份有限公司 | Voltage stabilization and electric power and voltage regulating and monitoring protection circuit unit |
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| CN1744000A (en) | 2006-03-08 |
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