CN1185780C - DC-DC transfer circuit, power selection circuit and equipment - Google Patents

Abstract

The present invention relates into a transformation circuit for transforming a DC voltage to lower a DC voltage, which improves transformation efficiency. The transformation circuit is equipped with a power selecting unit 110, which has a plurality of input terminals IN1and IN2, a plurality of DC powers Vin1 and Vin2 are inputted from the input terminals, among the DC powers, the DC power with lowest voltage in case of being higher than stipulation voltage is selected, also the transformation circuit is equipped with a step-down adjuster unit 10 having a output terminal OUT, the DC power voltage selected from the power selecting unit is transformed into a lower stipulation voltage Vout outputted from the output terminal.

Description

DC-DC transfer circuit, power selection circuit and apparatus

Technical field

The present invention relates to be equipped with the DC-DC translation circuit that dc voltage is transformed to another dc voltage, select the power selection circuit of a power supply in a plurality of power supplys, and the apparatus that is equipped with the DC-DC translation circuit.

Background technology

The most formation of portable electric appts device of notebook computer etc. is, except by the work about electric power that obtains from civil power, battery can also be installed, and is battery operated with this.

In the apparatus that constitutes like this, usually, packed into from the electric power of mains supply with switch the circuit (for example, open flat 9-182288 communique with reference to the spy, the spy opens flat 9-308102 communique) of the work that is used for apparatus from one of electric power of battery.The type of known circuit wherein is, when having electric power from mains supply to offer this apparatus, preferentially uses this electric power, detect from the electric power of mains supply supply with switch to when stopping battery-powered.In addition, known also have such power supply switch circuit, and its formation is to be used to electric power from mains supply generally than the high this point of cell voltage, receives the power supply from the highest electric power of voltage in a plurality of electric power.

, because the voltage of battery is along with the general slow reduction of discharge, therefore in apparatus, for the voltage of the electric power of portion's use is within it kept necessarily being equipped with the DC-DC translation circuit.

Fig. 7 is a circuit diagram of showing first example of linear regulator.Linear regulator is a kind of of DC-DC translation circuit, generally is widely used.

This linear regulator unit 10 is installed on 1 LSI, its formation is the electric power from its input terminal IN input voltage vin, (electric power of Vin＞Vout) is from the electric power of lead-out terminal OUT output output voltage V out to be transformed to the output voltage V out also lower than this input voltage vin in this linear regulator unit 10.

Between input terminal IN and lead-out terminal OUT, the NPN transistor 11 of configuration output voltage adjustment usefulness, between the base stage of input terminal IN and this NPN transistor 11, dispose constant-current source 12, except the base current as NPN transistor 11 flowed, also the collector current as another NPN transistor 13 flowed from the electric current of this constant-current source 12 outputs.The emitter of this NPN transistor 13 is connected on the earth terminal GND, and this earth terminal GND is grounded.The voltage Vout of lead-out terminal OUT is input to the form with 2 resistance 14,15 dividing potential drops on the positive input terminal of differential amplifier 16, at negative input end of differential amplifier 16, and the reference voltage that input is generated by reference voltage source 17.The lead-out terminal of this differential amplifier 16 is connected the base stage of NPN transistor 13.

At this, if the voltage Vout of lead-out terminal OUT is offset to also higher than predefined certain benchmark output voltage, then the output voltage of differential amplifier 16 improves, the collector current that flows through NPN transistor 13 increases, the part of using as the collector current of NPN transistor 13 the electric current that flows out from constant-current source 12 increases, its result, the base current of the NPN transistor 11 of output voltage adjustment usefulness reduces, and the voltage Vout of lead-out terminal OUT descends.

On the other hand, in contrast, when if the voltage Vout of lead-out terminal OUT is offset to than the also low voltage of predefined certain benchmark output, the output voltage of differential amplifier 16 reduces, the collector current that flows through NPN transistor 13 reduces, this part electric current increases the electric current of transistor 11, and the voltage Vout of lead-out terminal OUT improves.

By such control, just can export the electric power of certain output voltage V out from lead-out terminal.

Fig. 8 is a circuit diagram of showing second example of linear regulator.Difference with first example shown in Figure 7 is described.

Linear regulator unit 10 shown in Figure 8 ' in, the NPN transistor 11 that replaces the output voltage adjustment usefulness in the linear regulator unit 10 shown in Figure 7, be equipped with PNP transistor 18 and be used for the output voltage adjustment, thereupon, be imported into negative input end of differential amplifier 16 with the voltage Vout of the lead-out terminal OUT of 2 resistance, 14,15 dividing potential drop forms, reference voltage source 17 is connected the positive input terminal of this differential amplifier 16.

At this, when if the voltage Vout of lead-out terminal OUT is offset to than the also high voltage of predefined benchmark output voltage, the output voltage of differential amplifier 16 descends, the collector current that flows through NPN transistor reduces, because the electric current that flows out from constant-current source is certain, so the base current of the part PNP transistor 18 that collector current reduces reduces, and follows the minimizing of the base current of this PNP transistor 18, the voltage Vout of lead-out terminal OUT descends.

On the other hand, in contrast, when if the voltage Vout of lead-out terminal OUT is offset to than the also low voltage of predefined benchmark output voltage, the output voltage of differential amplifier 16 rises, the collector current that flows through NPN transistor increases, because the electric current that flows out from constant-current source is certain, so the base current of the part PNP transistor 18 that collector current increases increases, follow the increase of the base current of this PNP transistor 18, the voltage Vout of lead-out terminal OUT rises.

Linear regulator unit 10 shown in Figure 8 ' in, by such control, just can from lead-out terminal OUT, export the electric power of certain voltage Vout.

Fig. 9 is a circuit diagram of showing the 3rd example of linear regulator.

With the second routine difference shown in Figure 8 be, replace output voltage adjustment usefulness shown in Figure 8 PNP transistor 18, disposed P channel MOS transistor 19.Because the situation of the circuit operation and second example shown in Figure 8 is the same, solid and omission repeat specification.

Figure 10 is a circuit diagram of showing an example of switching regulaor.Switching regulaor also is a kind of of DC-DC translation circuit, generally is widely used.

From the electric power of the input terminal IN input voltage vin of this switching regulaor, (at this is object with the voltage-dropping type to the second lead-out terminal OUT2 output output voltage V out from the first and second lead-out terminal OUT1, OUT2, the electric power of thereby Vin＞Vout).Between 2 lead-out terminal OUT1, OUT2, connect external coil 31, between this second lead-out terminal OUT2 and ground connection, connecting external capacitor 32.

Removing the coil 31 that is set at the outside of this switching regulaor 20 and the part of capacitor 32 is produced on 1 LSI.

Between the input terminal IN and the first lead-out terminal OUT1, configuration P channel MOS transistor 21 on its grid, connects the output of PWM comparator 26.On this PWM comparator 26, the output of input differential amplifier 24 and the output of triangular wave oscillator 27.The effect aftermentioned of PWM comparator 26.

On the positive input terminal of differential amplifier 24, to import the voltage Vout of the second lead-out terminal OUT2 with the form of 2 resistance 22,23 dividing potential drops, on negative input end of differential amplifier 24, the reference voltage that input generates in reference voltage source 25.In addition, connecting diode between the first lead-out terminal OUT1 and earth terminal GND, the negative electrode of this diode is connected the first lead-out terminal OUT, one side, and anode is connected earth terminal GND one side.Earth terminal GND is grounded.

At this, PWM comparator 26, compare the output voltage of differential amplifier 24 and the triangular signal of exporting from triangular wave oscillator 27, when also hanging down than triangle wave voltage, the output voltage of differential amplifier 24 generates the pulse signal of ' H ' level, when the output voltage of differential amplifier 24 is also higher than triangle wave voltage, generate the pulse signal of ' L ' level, this pulse signal of input on the grid of MOS transistor 21, this MOS transistor 21 is according to ' H ' level of this pulse signal, the variation of ' L ' level, become respectively and end conducting.That is, MOS transistor 21 is with the repetition rate switch input voltage vin identical with the repetition rate of triangular wave.

Diode 28, coil 31, and capacitor 32 plays the effect that input voltage vin behind the slicked switch generates Vout.

If output voltage V out compares with the voltage of having set a little and raises, then the output voltage of differential amplifier 24 reduces, the pulse duration (' L ' low level pulse duration) of the pulse signal that generates in PWM comparator 26 narrows down a little, and output voltage V out reduces.In contrast, if output voltage V out reduces, then the output voltage of differential amplifier 24 increases, and the pulse duration (pulse duration of ' L ' level) of the pulse signal that generates in PWM comparator 26 broadens, and output voltage V out rises.In this switching regulaor 20, so control the electric power of feasible output certain voltage Vout.

At this, for example in the electronic apparatus of personal computer etc., there is the circuit unit that moves respectively with a plurality of different dc voltages mostly, in such apparatus, be equipped with a plurality of DC-DC translation circuits of the electric power of exporting various voltages respectively.The DC-DC translation circuit consumes considerable var when the conversion of dc voltage, cause consuming the increase of electric power, and the drawback of the temperature rising that battery is consumed too early or cause apparatus is arranged.For example under the situation of the DC-DC translation circuit of the linear regulator mode of Fig. 7～shown in Figure 9, for the input voltage from 16V is transformed to the output voltage of 3.3V, conversion efficiency is 20%, and remaining 80% all is power loss.Particularly using a plurality of different dc voltages in inside, needing to have the problem that how to improve the conversion efficiency in the DC-DC translation circuit in the apparatus of a plurality of DC-DC translation circuits in order to make these different dc voltages.

Summary of the invention

The present invention is exactly in view of the above problems, to provide conversion efficiency high DC-DC translation circuit, use existing DC-DC translation circuit to carry out the power selection circuit of the high voltage transformation of conversion efficiency, and the apparatus that is built-in with the high DC-DC translation circuit of this conversion efficiency is a purpose.

DC-DC translation circuit in the DC-DC translation circuit of the present invention to achieve these goals, it is characterized in that comprising: the power supply selected cell, it has a plurality of input terminals, import a plurality of DC power supplys separately respectively from these input terminals, in these DC power supplys, more than assigned voltage the DC power supply that condition is selected minimum voltage with voltage; The adjuster of voltage-dropping type, it has lead-out terminal, and the DC supply voltage of selecting in the power supply selected cell, the voltage that is transformed to the regulation also lower than this voltage is exported from lead-out terminal.

As mentioned above, under the situation of the DC-DC of linear regulator mode translation circuit, for the conversion efficiency that 16V is transformed to 3.3V is 20%, and under the situation that the 5V power supply exists, the conversion efficiency when using this 5V power conversion as 3.3V becomes 66%.Like this, obtain output voltage, just can improve conversion efficiency greatly from the input voltage near output voltage as far as possible.The situation of using the conversion efficiency of alap input voltage to rise, not only in the linear regulator mode but also in the switching regulaor mode too.

A DC-DC translation circuit of the present invention has utilized this principle exactly.

That is, in the power supply selected cell, in a plurality of DC power supplys that are transfused to, select the DC power supply of minimum voltage to deliver to adjuster.But, even if minimum voltage, in order to prevent that perhaps connected power supply is to be in the 0V that does not have function to go out as minimum voltage detecting not connecting power supply, being condition more than assigned voltage.In conditioner unit, the DC power source voltage of selecting like this is changed to than exporting behind the also low dc voltage of this voltage.Thus, the high efficiency voltage transformation of the optimal power supply that can select according to the situation of at this moment power supply.

In addition, the 2nd DC-DC translation circuit in the DC-DC translation circuit of the present invention, it is characterized in that comprising: the power supply selected cell, first input end with DC power supply of input regulation, import second input terminal of the 2nd DC power supply of the voltage also lower than a DC supply voltage, from the 2nd DC power source voltage of this second input terminal input during more than or equal to assigned voltage, selection is from the 2nd DC power supply of above-mentioned second input terminal input, and, selecting from a DC power supply of first input end input during less than assigned voltage from the 2nd DC power source voltage of this second input terminal input; The voltage-dropping type conditioner unit, the voltage that the DC power source voltage of selecting is transformed to the regulation also lower than this voltage in above-mentioned power supply selected cell is exported from lead-out terminal.

When determining and comparing from a DC power supply of first input end input when the 2nd DC supply voltage one side of second input terminal input is the low voltage DC power supply, or connected when constituting like that, follow the consideration method of an above-mentioned DC-DC translation circuit of the present invention, can simplify the power supply selected cell as described above.

At this, no matter in which circuit of the of the present invention first and the 2nd DC-DC translation circuit, above-mentioned conditioner unit can be made up of linear regulator.In this case, preferably using the power supply selected cell, and, be formed in the monolithic integrated circuit with the conditioner unit that linear regulator constitutes.Perhaps, externally install under the transistorized situation of output voltage adjustment usefulness, preferably use the power supply selected cell removing, and the transistorized part of output voltage adjustment that is installed in the outside in the adjusting device of linear regulator formation, be formed in the monolithic integrated circuit.

In addition, no matter at the of the present invention first and the 2nd DC-DC translation circuit in which, above-mentioned conditioner unit can be made up of switching regulaor.In this case, preferably use the power supply selected cell removing, and the part that is installed in outside voltage smoothing circuit part in the conditioner unit of switching regulaor formation, be formed in the monolithic integrated circuit.

By being formed in the monolithic integrated circuit, just can realize that more stable action, cost reduce, save space.

In addition, state first power selection circuit in the power selection circuit of the present invention of purpose in realization, it is characterized in that comprising: a plurality of input terminals, import a plurality of DC power supplys separately; The power supply selected cell a plurality of DC power supplys on being connected these input terminals, is the DC power supply that condition is selected minimum voltage more than assigned voltage with voltage; Lead-out terminal, the DC power supply that output is selected in the power supply selected cell.

In addition, second source selection circuit in power selection circuit of the present invention is characterised in that and comprises: first and second input terminal, the 2nd DC power supply of a DC power supply of input regulation respectively and second voltage also lower than a DC power source voltage; The power supply selected cell, from the 2nd DC power source voltage of this second input terminal input during more than or equal to assigned voltage, selection is from the 2nd DC power supply of above-mentioned second input terminal input, and, selecting from a DC power supply of first input end input during less than assigned voltage from the 2nd DC power source voltage of this second input terminal input; Lead-out terminal, the DC power supply that output is selected in above-mentioned power supply selected cell.

Of the present invention first and second source select circuit, each the power supply selected cell that is equivalent to the of the present invention first and the 2nd DC-DC translation circuit respectively, these first and second source select the back segment of circuit, connect and to be equivalent to of the present invention first and the DC-DC varying circuit of the conditioner unit of the 2nd DC-DC translation circuit, can in this DC-DC translation circuit, carry out high efficiency DC-DC conversion.

In addition, realize the apparatus of the present invention of above-mentioned purpose, it is characterized in that: in the apparatus that after the supply of accepting electric power, moves, comprise,

The one DC-DC converter of voltage-dropping type, it is transformed to second dc voltage and the output of the regulation also lower than this first dc voltage to first dc voltage of a DC power supply of regulation;

First actuating circuit, the electric power that it is received in above-mentioned second dc voltage that obtains in the above-mentioned DC-DC converter is supplied with and is moved;

The 2nd DC-DC converter has the voltage-dropping type conditioner unit, and its is exported after receiving the dc voltage of input and it being transformed to the 3rd dc voltage of the regulation also lower than this dc voltage; The power supply selected cell, it imports the both sides of the output of an above-mentioned DC power supply and an above-mentioned DC-DC converter, in the output of a DC-DC converter during more than or equal to assigned voltage, the output of an above-mentioned DC-DC converter is delivered to above-mentioned conditioner unit, and during less than assigned voltage, an above-mentioned DC power supply is delivered to above-mentioned conditioner unit in the output of a DC-DC converter;

Second actuating circuit, the electric power that it is received in above-mentioned the 3rd dc voltage that obtains in above-mentioned the 2nd DC-DC converter is supplied with and is moved.

Apparatus of the present invention, be equipped with these 2 DC-DC converters of a DC-DC converter and the 2nd DC-DC converter in inside, by the 2nd DC-DC converter of the lower dc voltage of output as of the present invention first or the formation of the 2nd DC-DC translation circuit, just can be used as integral body and carry out the high DC-DC conversion of efficient, realize consuming the reductionization of electric power, the temperature rising of suppression equipment device.

At this, generally be distribution in advance such as power-supply system in apparatus inside, thereby, generally can use the 2nd DC-DC translation circuit of the present invention as above-mentioned the 2nd DC-DC converter, but also can adopt a DC-DC translation circuit of the present invention.At this moment, the power supply of above-mentioned the 2nd DC-DC converter is selected part, output at a DC-DC converter is not reach under the situation of assigned voltage, when a DC power supply does not reach assigned voltage yet, cut off the output of a DC-DC converter is delivered to pathway on the conditioner unit and the both sides that a DC power supply are delivered to the pathway of conditioner unit.

Fig. 1 is the circuit diagram of embodiment 1 of DC-DC translation circuit of the present invention that comprises the embodiment 1 of power selection circuit of the present invention.

Fig. 2 is the circuit diagram of embodiment 2 of DC-DC translation circuit of the present invention that comprises the embodiment 2 of power selection circuit of the present invention.

Fig. 3 is the circuit diagram of the embodiment 3 of DC-DC translation circuit of the present invention.

Fig. 4 is the circuit diagram of the embodiment 4 of DC-DC translation circuit of the present invention.

Fig. 5 is the circuit diagram of the embodiment 5 of DC-DC translation circuit of the present invention.

Fig. 6 is a block diagram of showing an embodiment of apparatus of the present invention.

Fig. 7 is the circuit diagram of first example of linear regulator.

Fig. 8 is the circuit diagram of second example of linear regulator.

Fig. 9 is the circuit diagram of the 3rd example of linear regulator.

Figure 10 is the circuit diagram of an example of switching regulaor.

Below, embodiment of the present invention are described.

Fig. 1 is the circuit diagram of embodiment 1 of DC-DC translation circuit of the present invention that comprises the embodiment 1 of power selection circuit of the present invention.

DC-DC translation circuit 100 shown in Figure 1 is made of input selection circuit 110 and linear regulator unit 10.At this, this DC-DC translation circuit 100, it all is fabricated in 1 LSI chip 190.Input selection circuit 110 also is an embodiment of power selection circuit of the present invention.

In this input selection circuit 110,2 input terminal IN1, IN2 connecting the DC power supply respectively are equipped with, at this, suppose from each input terminal IN1, IN2 input input voltage vin 1, Vin2.

At each input terminal IN1, IN2, (input selection circuit 110 is being constituted as the circuit that has separated with linear regulator unit 10 under the situation of (for example only input selection circuit 110 being installed in 1 LSI) to the give and accept node TML of signal of linear regulator unit 10 from input selection circuit 110 with being used for, this node TML becomes the lead-out terminal of input selection circuit 110) between, each diode 111,112 that the configuration anode is connected with input terminal IN1, IN2, and each P channel MOS transistor 113,114.Input one side of P channel MOS transistor 113,114 is connected by resistance 115,116 respectively with separately grid in addition.In addition, between the grid of P channel MOS transistor 113,114 and earth terminal GND, dispose N-channel MOS transistor 117,118 respectively.Earth terminal GND is grounded.

In addition, in this input selection circuit, be equipped with first, the second and the 3rd comparator 121,122,123 and 1 reference voltage sources 124, on first comparator 121, the negative electrode that on its positive input terminal, connects diode 111, on its negative input end, connect reference voltage source 124, on second comparator 122, the negative electrode that on positive input terminal 5, connects diode 112, the negative electrode that on negative input end, connects diode 111, on the 3rd comparator 123, on its positive input terminal, connect reference voltage source 124, on negative input end, connect the negative electrode of diode 112.

The output of these 3 comparators 121,122,123, be delivered to N-channel MOS transistor 117 through first logical circuit of forming by AND door 131 and OR door 132 133, in addition, be delivered to the grid of another N-channel MOS transistor 118 through second logical circuit of forming by OR door 134 and NAND door 135 136.

At this, first comparator 121, relatively the voltage Vin1 of the sub-IN1 of first input end and the voltage of reference voltage source 124 judge whether the voltage Vin1 of the sub-IN1 of first input end is also higher than the voltage of reference voltage source 124.In other words, judge on the sub-IN1 of first input end, whether just to connect power supply exactly.

Identical therewith, the 3rd comparator 123, relatively the voltage Vin2 of the second input terminal IN2 and the voltage of reference voltage source 124 judge whether the voltage Vin2 of the second input terminal IN2 is also higher than the voltage of reference voltage source 124.Also be to judge on the second input terminal IN2, whether just connecting power supply.

Second comparator 122, different with first comparator 121 and the 3rd comparator 123, be that 2 input terminal IN1, IN2 voltage Vin1, Vin2 separately compares mutually.

At the voltage Vin1 of input terminal IN1 is voltage more than the reference voltage, and during Vin1＜Vin2, signal from first logical circuit, 133 output ' H ' level, nmos pass transistor 117 becomes conducting state, the grid of PMOS transistor 113 is lowered to the current potential of ground connection one side, this PMOS transistor 113 becomes conducting state, and the voltage Vin1 of the sub-IN1 of first input end is delivered to linear regulator unit 10 through node TML.At this moment, the output of second logical circuit 136 (grid of nmos pass transistor 118) becomes ' L ' level, nmos pass transistor 118 becomes cut-off state, and PMOS transistor 114 also becomes cut-off state, and the voltage Vin2 of the second input terminal IN2 can not transmit to linear regulator unit 10.

At this, as an example, if hypothesis Vin1=5.0V, Vin2=16.0V is then when the voltage of linear conditioner unit 10 output 3.3V, in input selection circuit 110, because select Vin1=5.0V, so the efficient of linear regulator unit 10 becomes 66%.

In addition, in contrast, when Vin2＜Vin1, the voltage of Vin2 more than reference voltage as condition, the output of first logical circuit 133 becomes ' L ' level, the output of second logical circuit 136 becomes ' H ' level.Thus, nmos pass transistor 117 and PMOS transistor 113 become cut-off state, are stoping when linear regulator unit 10 transmits Vin1, and nmos pass transistor 118 and PMOS transistor 114 become conducting state, and Vin2 is delivered to linear regulator unit 10.In this case, as an example, if hypothesis Vin1=16.0V, Vin2=5.0V, the voltage of linear regulator unit 10 output 3.3V, then in input selection circuit 110 because select Vin2=5.0V, so the efficient of linear regulator unit becomes 66%.

In addition, at Vin1 more than reference voltage, but during the not enough reference voltage of Vin2 (being typically input terminal IN2 deenergization), first comparator, 121 output ' H ' level signals, second comparator, 122 output ' L ' level signals, the 3rd comparator 123 output ' H ' level signals, its result, from first logical circuit, 133 output ' H ' level signals, from second logical circuit, 136 output ' L ' level signals, nmos pass transistor 117 becomes conducting state, PMOS transistor 113 also becomes conducting state, on the other hand, nmos pass transistor 118 becomes cut-off state, and PMOS transistor 114 also becomes cut-off state.Thereby, in this case, transmit from the voltage Vin1 of the sub-IN1 input of first input end to linear regulator unit 10.When linear regulator unit 10 output 3.3V voltages, the efficient of this linear regulator unit 10 is 66% when Vin1=5.0V, is 20% when Vin1=16.0V.

On the other hand, in contrast, at the not enough reference voltage (being typically input terminal IN1 deenergization) of Vin1, Vin2 is when reference voltage is above, from first comparator, 121 output ' L ' level signals, output ' H ' level signal from second comparator 122, output ' L ' level signal from the 3rd comparator 123, its result is from first logical circuit, 133 output ' L ' level signals, from second logical circuit, 136 output ' H ' level signals.Thereby nmos pass transistor 117 becomes cut-off state, and PMOS transistor 113 also becomes cut-off state, and on the other hand, nmos pass transistor 118 becomes conducting state, and PMOS transistor 114 also becomes conducting state.Thereby, transmit from the voltage Vin2 of second input terminal IN2 input to linear regulator unit 10.Under linear conditioner unit 10 output 3.3V voltage condition, when Vin2=5.0V, the efficient of linear regulator unit 10 is 66%, and when Vin2=16.0V, the efficient of linear regulator unit 10 becomes 20%.

Linear regulator unit 10, identical with the formation of linear regulator shown in Figure 7, principle according to reference Fig. 7 explanation, generate all low stable output voltage V out (Vout＜Vin1, Vin2) of each voltage Vin1, Vin2, for example generate Vout=3.3V and export from lead-out terminal OUT than 2 input terminal IN1, IN2.

Like this, under the situation of this DC-DC varying circuit 100 shown in Figure 1, because, in 2 input voltage vin 1, Vin2, being condition more than reference voltage, the little side of voltage is delivered to linear regulator unit 10 is used to generate output voltage V out, so can carry out the high DC-DC conversion of conversion efficiency.

Fig. 2 is the circuit diagram of embodiment 2 of DC-DC translation circuit of the present invention that comprises the embodiment 2 of power selection circuit of the present invention.

DC-DC translation circuit 200 shown in Figure 2, outfit is than the also simple input selection circuit 210 of input selection circuit 110 of embodiment shown in Figure 11, and constitutes identical linear regulator unit 10 with the linear regulator unit 10 of embodiment 1 shown in Figure 1.At this, the same with embodiment 1 shown in Figure 1, this DC-DC translation circuit 200, it all is fabricated in 1 LSI chip 290.

DC-DC translation circuit 200 shown in Figure 2 is to have preestablished each input voltage vin 1 from each input terminal IN1, IN2 input, the circuit that the Vin2 assurance is in the state of Vin1＞Vin2.As the assurance of Vin1＞Vin2, for example can be by making the form difference of splicing ear, perhaps in realizations such as the inner predetermined fixed of apparatus ground distributions.

As the sub-IN1 of first input end in 2 input terminal IN1, IN2, and the node TML between connection input selection circuit 210 and the linear regulator unit 10 is (under the situation of the circuit of input selection circuit (example of said power selection circuit in the present invention) being arranged to separate with linear regulator unit 10 (for example only input selection circuit 210 being produced on 1 LSI chip), this node TML becomes the lead-out terminal of input selection circuit 210) between, be equipped with diode 211, PMOS transistor 213 that anode is connected with input terminal IN1 one side.Diode 211 1 sides of this PMOS transistor 213 are connected by resistance 215 with its grid.In addition, configuration nmos pass transistor 217 between the grid of this PMOS transistor 213 and earth terminal GND.Earth terminal GND is grounded.

In addition, between another input terminal IN2 and node TML, the diode 212 that the configuration anode is connected with input terminal 2 one sides, the negative electrode of this diode 212 also are connected with negative input end of comparator 221.Also be equipped with reference voltage source 224 therein, this reference voltage source 224 is connected with the positive input terminal of comparator 221.The output of this comparator 221 is connected with the grid of nmos pass transistor 217.

At this, in comparator 221, compare the voltage Vin2 of the second input terminal IN2 and the reference voltage that in reference voltage source 224, obtains.Judge thus and on the second input terminal IN2, whether just connecting power supply.

When Vin2 is also higher than reference voltage, the output of comparator 221 becomes ' L ' level, nmos pass transistor 217 becomes cut-off state, PMOS transistor 212 also becomes cut-off state thus, stop the voltage Vin1 of the sub-IN1 of first input end to be delivered to linear regulator unit 10, and transmit the voltage Vin2 of the second input terminal IN2 to linear regulator unit 10.On the other hand, the voltage of the second input terminal IN2, for example on second input terminal, do not connect power supply, the power supply that perhaps is connected on second input terminal is in off status etc., and during than the also low voltage of reference voltage (being typically 0V), the output of comparator 221 becomes ' H ' level, nmos pass transistor 217 becomes conducting state, thereby PMOS transistor 213 also becomes conducting state, and the voltage Vin1 of the sub-IN1 of first input end is delivered to linear regulator unit 10.

Like this, the input selection circuit 210 of this Fig. 2 is effective circuit under the condition that guarantees Vin1＞Vin2, when Vin2 is effective Vin2 is delivered to linear regulator unit 10, and (0V etc.) are delivered to linear regulator unit 10 to Vin1 when Vin2 is invalid.

Linear regulator unit 10, its formation is identical with linear regulator shown in Figure 1, generates the stable output voltage V out all lower than each voltage Vin1, Vin2 and exports from lead-out terminal OUT.

Like this, under the situation of DC-DC translation circuit 200 shown in Figure 2, also be (among the Vin1＞Vin2), when Vin2 is effective, Vin2 to be delivered to the generation that linear regulator unit 10 is used for output voltage V out, can to carry out the high DC-DC conversion of conversion efficiency in 2 input voltage vin 1, Vin2.

Fig. 3 is the circuit diagram of the embodiment 3 of DC-DC translation circuit of the present invention.Difference with embodiment 2 shown in Figure 2 is described.

The difference of DC-DC translation circuit 300 shown in Figure 3 and embodiment 2 shown in Figure 2 is, the part of the NPN transistor 11 of removing the output voltage adjustment unit that constitutes linear regulator unit 10 is produced on 1 LSI chip 390, NPN transistor 11 is installed in the outside.Therefore, LSI chip 390, needs are provided with 2 lead-out terminal OUT1, OUT2 except the lead-out terminal OUT3 of the lead-out terminal OUT of the embodiment 2 that is equivalent to Fig. 2.

On the circuit operation, so because with the embodiment 2 the same omission repeat specifications of Fig. 2, and transistor 11 be installed in outside reason be because, because this DC-DC translation circuit 300 can consume sizable electric power at secondary (lead-out terminal place), be in the state of big electric current, the device that needs to use the level that can tolerate this state as transistor 11, thereby this transistor 11 is big transistor npn npn, for example also need to install heat radiations such as fin in addition, thereby be the transistorized cause that is not suitable for being built in the LSI chip.

Like this, in the DC-DC of linear regulator mode translation circuit, also the adjustment of handlebar output voltage is installed in outside with transistor.

Fig. 4 is the circuit diagram of the embodiment 4 of DC-DC translation circuit of the present invention.

DC-DC translation circuit 400 shown in Figure 4 is made up of the input selection circuit 110 switching regulaor unit 20 the same with switching regulaor shown in Figure 10 as the embodiment 1 of power selection circuit of the present invention shown in Figure 1.The circuit operation of these input selection circuits 110 and switching regulaor unit 20 is because all illustrate, Gu and omit its explanation at this.DC-DC translation circuit shown in Figure 4 is removed the coil 31 and capacitor 32 outer being produced on 1 LSI chip 490 that constitute switching regulaor unit 20.This is because coil 31 and capacitor 32 are very big, is not suitable for being produced on the cause in the LSI chip.

In input selection circuit 110, from 2 input voltage vin 1 of 2 input terminal IN1, IN2 inputs, Vin2 (Vin1 and Vin2 can be low-voltages), in these 2 input voltage vin 1, Vin2, being that condition is input to switching regulaor unit 20 to low-voltage one side's voltage more than reference voltage.Because switching regulaor unit 20 is the voltage-dropping types that generate the output voltage V out output all lower than Vin1, Vin2, so serve as the side's of basis generation output voltage V out conversion efficiency height with lower input voltage (certainly more than output voltage V out).Like this, in this embodiment shown in Figure 4, also adopt the mode of the voltage generation output voltage V out of low-voltage one side among input Vin1, the Vin2, the DC-DC conversion that implementation efficiency is high.

Fig. 5 is the circuit diagram of the embodiment 5 of DC-DC translation circuit of the present invention.

DC-DC translation circuit 500 shown in Figure 5 is made up of with 20 the same switching regulaor unit 20, switching regulaor unit shown in Figure 4 the input selection circuit 210 of the embodiment 2 of power selection circuit of the present invention shown in Figure 2.Because the circuit operation of these input selection circuits 210 and switching regulaor unit 20 all illustrates, Gu and in this description will be omitted.DC-DC translation circuit shown in Figure 5, the same with embodiment 4 shown in Figure 4, remove outside the coil 31 and capacitor 32 that constitutes switching regulaor unit 20, be produced on 1 LSI chip 590.

In input selection circuit 110, under the situation that connects power supply 2 input terminal IN1, IN2 both sides, must guarantee to satisfy Vin1＞Vin2, only in satisfying the state of this condition, when Vin2 be the regulation reference voltage more than voltage the time, Vin2 is delivered to switching regulaor unit 20, during voltage below Vin2 is reference voltage Vin1 is delivered to switching regulaor unit 20.Thereby, in switching regulaor unit 20, all carry out high efficiency DC-DC conversion.

Fig. 6 is a block diagram of showing an embodiment of apparatus of the present invention.

This apparatus 600 for example is a notebook computer etc., the DC electric power of the 16.0V that generates from mains supply in the AC socket (not shown) externally, and from the DC electric power of 12～9V of internal battery 611, respectively via each diode 612,613 input.Side from the DC electric power of AC socket is 16.0V because than the voltage of battery (12～9V) is also high, thus during from AC socket input DC electric power because the effect of diode 613 output power not from battery.From the electric power of AC socket input interrupt, and during this apparatus action, provide electric power from battery 611.From the electric power of AC socket or from the electric power of battery 611, be imported into DC-DC converter 614 (being an example of the said DC-DC converter of the present invention) and adjuster 615 (being an example of the 2nd DC-DC converter of the present invention).

DC-DC converter 614 serves as that the electric power that the basis generates 5.0V offers first actuating circuit 616 with the electric power that is transfused to.This first actuating circuit 616 is by the driven by power action of the 5.0V that generates in DC-DC converter 614.In this DC-DC converter 614, input is used for the control signal (ON/OFF signal) of action of this DC-DC converter of ON/OFF, and the action for power saving DC-DC converter 614 self when not needing 616 actions of first actuating circuit also stops.

In adjuster 615, except electric power from AC socket or battery 611, the electric power of the 5.0V that input generates in DC-DC converter 614 based on the low side's of the voltage in 2 electric power that are transfused to electric power, generates 3.3V electric power in this adjuster 615.The 3.3V electric power that generates in adjuster 615 is provided for second actuating circuit, 617, the second actuating circuits 617, with the 3.3V electric power action that provides from this adjuster 615.This second actuating circuit 617 is made of constantly the be electrically connected circuit etc. of continuous action of needs.

In adjuster 615, though can adopt one of various embodiments of above-mentioned DC-DC translation circuit of the present invention, because, so for example typically, can adopt DC-DC translation circuit figure shown in Figure 2 in order to be installed in the apparatus distribution in advance.

In 614 actions of DC-DC converter, to adjuster 615 input during from the electric power of the 5.0V of DC-DC converter 614, in adjuster 615, with this 5.0V electric power is the electric power that the basis generates 3.3V, if the action of DC-DC converter 614 stops, then adjuster 615 when perhaps not being connected the AC socket, serves as a electric power that basis generate 3.3V with the 12V～9V electric power from battery 611 at the electric power that does not connect from AC socket 16.0V.

Like this, adjuster 615, because, its formation is the electric power that is generated 3.3V when DC-DC converter 614 action by the electric power at the 5.0V of this generation, so, in adjuster 615, and realize economize on electricity no matter whether the DC-DC converter moves all to use to compare from the situation of the electric power of AC socket or battery.

And then, as adjuster 615, for example also can adopt DC-DC translation circuit shown in Figure 1.In this case, can be connected the input and output of DC-DC converter 614 on any one of 2 input terminals when distribution, the distribution operation becomes easily, and can thoroughly prevent the wiring error of mistaken these 2 distributions.

As mentioned above, if adopt the present invention just can carry out high efficiency DC-DC conversion.

Claims (10)

1. a DC-DC translation circuit is characterized in that, is equipped with: the power supply selected cell, and it imports a plurality of DC power supplys from a plurality of input terminals, is the DC power supply that condition is selected minimum voltage more than assigned voltage with voltage; The voltage-dropping type conditioner unit, it is the DC power source voltage of selecting in above-mentioned power supply selected cell, and the voltage that is transformed to the regulation also lower than this voltage is exported from lead-out terminal.

2. DC-DC translation circuit, it is characterized in that, be equipped with: the power supply selected cell, first input end with DC power supply of input regulation, import second input terminal of the 2nd DC power supply of the voltage also lower than a DC supply voltage, from the 2nd DC power source voltage of this second input terminal input during more than or equal to assigned voltage, selection is from the 2nd DC power supply of above-mentioned second input terminal input, and, selecting from a DC power supply of first input end input during less than assigned voltage from the 2nd DC power source voltage of this second input terminal input; The voltage-dropping type conditioner unit, the voltage that the DC power source voltage of selecting is transformed to the regulation also lower than this voltage in above-mentioned power supply selected cell is exported from lead-out terminal.

3. as claim 1 or 2 described DC-DC translation circuits, it is characterized in that: above-mentioned conditioner unit is made up of linear regulator.

4. DC-DC translation circuit as claimed in claim 3 is characterized in that: the above-mentioned conditioner unit that is made of above-mentioned power supply selected cell and linear regulator is formed in the monolithic integrated circuit.

5. DC-DC translation circuit as claimed in claim 3, it is characterized in that: remove with above-mentioned power supply selected cell, and the output voltage adjustment that is installed in the outside in the above-mentioned conditioner unit of linear regulator formation is formed in the monolithic integrated circuit with the other parts outside the transistor.

6. as claim 1 or 2 described DC-DC translation circuits, it is characterized in that: above-mentioned conditioner unit is made of switching regulaor.

7. DC-DC translation circuit as claimed in claim 6, it is characterized in that: remove with above-mentioned power supply selected cell, and the other parts outside the voltage smoothing circuit part that is installed in the outside in the above-mentioned conditioner unit of switching regulaor formation, be formed in the monolithic integrated circuit.

8. a power selection circuit is characterized in that being equipped with: a plurality of input terminals that are used for importing a plurality of DC power supplys; The power supply selected cell in a plurality of DC power supplys on being connected above-mentioned a plurality of input terminal, is the DC power supply that condition is selected minimum voltage more than assigned voltage with voltage; Lead-out terminal, the DC power supply that output is selected in above-mentioned power supply selected cell.

9. a power selection circuit is characterized in that being equipped with: first and second input terminal, the 2nd DC power supply of a DC power supply of input regulation respectively and second voltage also lower than a DC power source voltage; The power supply selected cell, from the 2nd DC power source voltage of this second input terminal input during more than or equal to assigned voltage, selection is from the 2nd DC power supply of above-mentioned second input terminal input, and, selecting from a DC power supply of first input end input during less than assigned voltage from the 2nd DC power source voltage of this second input terminal input; Lead-out terminal, the DC power supply that output is selected in above-mentioned power supply selected cell.

10. receive electric power and supply with the apparatus that moves, comprising:

The one DC-DC converter of voltage-dropping type, it is transformed to second dc voltage and the output of the regulation also lower than this first dc voltage to first dc voltage of a DC power supply of regulation;

First actuating circuit, the electric power that it is received in above-mentioned second dc voltage that obtains in the above-mentioned DC-DC converter is supplied with and is moved;

The 2nd DC-DC converter has the voltage-dropping type conditioner unit, and its is exported after receiving the dc voltage of input and it being transformed to the 3rd dc voltage of the regulation also lower than this dc voltage; The power supply selected cell, it imports the both sides of the output of an above-mentioned DC power supply and an above-mentioned DC-DC converter, in the output of a DC-DC converter during more than or equal to assigned voltage, the output of an above-mentioned DC-DC converter is delivered to above-mentioned conditioner unit, and during less than assigned voltage, an above-mentioned DC power supply is delivered to above-mentioned conditioner unit in the output of a DC-DC converter;

Second actuating circuit, the electric power that it is received in above-mentioned the 3rd dc voltage that obtains in above-mentioned the 2nd DC-DC converter is supplied with and is moved.

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