CN101599696A - Non-isolation DC/DC control circuit and transducer - Google Patents
Non-isolation DC/DC control circuit and transducer Download PDFInfo
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- CN101599696A CN101599696A CNA2009101610032A CN200910161003A CN101599696A CN 101599696 A CN101599696 A CN 101599696A CN A2009101610032 A CNA2009101610032 A CN A2009101610032A CN 200910161003 A CN200910161003 A CN 200910161003A CN 101599696 A CN101599696 A CN 101599696A
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Abstract
The invention discloses a kind of non-isolation DC/DC control circuit and transducer, adopt unordered at random mode Dead Time to be set, the problem that causes the switching loss in non-isolation DC/DC transducer to increase severely to solve conventional non-isolated DC/DC control circuit along with the increase of switching frequency.This circuit comprises: voltage detection unit is used to detect the pressure difference signal at each switching device two ends; The inner control logic unit, be used to provide the indication logic control signal that each switching device turns on and off, wherein after the indication logic control signal that one of them switching device turn-offs is provided, determine to begin to provide the moment of the indication logic control signal that this another switching device is opened according to the pressure difference signal at another switching device two ends; Driver element is used for providing driving two drive signals that switching device alternately turns on and off according to described logic control signal.
Description
Technical field
The present invention relates to electronic device control field, relate in particular to a kind of non-isolation DC (Direct Current)/DC (Direct Current) control circuit and the sequential control method of logic control signal is provided, and non-isolation DC (Direct Current)/DC (Direct Current) transducer.
Background technology
Metal oxide layer semiconductor field-effect transistor (Metal Oxide Semiconductor Field-EffectTransistor, MOSFET) being called for short metal-oxide half field effect transistor, is a kind of field-effect transistor (field-effect transistor) that can be widely used in analogous circuit and digit circuit.MOSFET can be divided into the MOSFET of N type and P type according to the polarity difference of its " passage ", is called NMOS and PMOS usually again.
Non-isolation DC (Direct Current)/DC (Direct Current) transducer is a kind of circuit that certain direct voltage DC is converted to another direct voltage DC.Using in non-isolation DC/DC transducer is NMOS more widely, as shown in Figure 1, non-isolation DC/DC transducer comprises the inner control logic unit 101 that connects successively, driver element 102, converting unit 103, output unit 104, wherein inner control logic unit 101 is used to provide logic control signal, driver element 102 provides drive signal according to described logic control signal for converting unit 103, described converting unit 103 is converted to output dc voltage with input direct voltage under the driving of drive signal, the output dc voltage that will obtain after the DC/DC conversion is input to output unit 104.
Be illustrated in figure 2 as traditional non-isolation DC/DC transducer schematic diagram, converting unit adopts nmos device Q1 and the Q2 that is connected in series, driver element 102 is included as second driver element 1022 that Q1 provides first driver element 1021 of drive signal and drive signal is provided for Q2, A1, A2 and A3 are respectively source electrode, the drain and gate of Q1, and B1, B2 and B3 are respectively source electrode, the drain and gate of Q2.If apply certain forward voltage between grid and drain electrode, the resistance between source electrode and the drain electrode will approach 0, and at this moment, nmos device is in opening state; Otherwise if do not apply this forward voltage, the resistance between source electrode and the drain electrode will approach infinity, and at this moment, nmos device is in off state.Therefore, NMOS possesses switching characteristic.This paper is called switching tube Q1 and Q2 with nmos device Q1 and Q2 again.Output unit is for being connected in the Q2 two ends in parallel, comprising inductance component L and the capacity cell C that is connected in series, and load is inserted at the two ends of capacity cell C.
Non-isolation DC/DC control circuit to the control of non-isolation DC/DC transducer comprises inner control logic unit 101 and driver element 102, provide logic control signal to first driver element 1021 and second driver element 1022 by inner control logic unit 101, first driver element 1021 provides first drive signal to switching tube Q1 according to logic control signal, second driver element 1022 provides second drive signal to switching tube Q2 according to logic control signal, and then the turning on and off of control switch pipe Q1 and Q2.The dotted portion that feeds back to first driver element 1021 among the figure is represented the reference voltage that first driver element 1021 adopts.The dotted portion that feeds back to second driver element 1022 among the figure is represented the reference voltage that second driver element 1022 adopts.It is for referencial use when providing logic control signal for it that the source voltage of Q1 and the drain voltage of Q2 feed back to inner control logic unit 101.Simultaneously, sampling also to the direct voltage of output, voltage feedback unit feeds back to inner control logic unit 101, to sample output dc voltage and internal reference relatively, adjust the time length that switching tube turns on and off by the time length of controlling first driver element 1021 and the effective drive signal of second driver element, 1022 outputs then, realize the adjustment of output dc voltage.
Second drive signal of first drive signal of common first driver element 1021 outputs and 1022 outputs of second driver element can be simultaneously not effectively, and when general first drive signal was effective, second drive signal was invalid; When second drive signal was effective, first drive signal was invalid.Drive signal described herein effectively is meant between switching tube grid under the driving of this drive signal and drain electrode and reaches forward voltage and make it be in opening state, and invalid being meant described herein do not reach forward voltage and make it be in off state between switching tube grid under the driving of this drive signal and drain electrode.Effectively finish to second drive signal effectively since first drive signal, perhaps second drive signal effectively finishes to be called Dead Time to the time difference that first drive signal effectively begins, and as the t1 among Fig. 3, can be called the switch mosfet time again.Owing to generally be connected with energy-storage travelling wave tube such as inductance, electric capacity in the output unit, therein under the situation of a MOSFET shutoff, because the electric current in the inductance can not change at once, therefore the variation of electric current can produce pressure drop in the inductance, cause refluxing, the purpose that Dead Time is set is to guarantee therein under the situation that a MOSFET turn-offs, and is just open-minded after the source electrode of another MOSFET and drain electrode pressure reduction are gone to zero gradually, otherwise may cause burning out circuit.Usually, the service time of MOSFET (as the t3 among Fig. 3) is called duty ratio than service time (as the t3 among Fig. 3) and turn-off time (as the t2 among Fig. 3) sum.
It is exactly that it only is responsible for adjusting output dc voltage that above-mentioned traditional non-isolation DC/DC control circuit has an obvious defects, in order to reach this purpose, the inner control logic unit is by controlling first drive signal and second drive signal is adjusted Q1, the time length that Q2 turns on and off, open or turn-off MOSFET but it can not accurately determine " what constantly ", promptly after turn-offing one of them MOSFET, it is unordered control that the Dead Time of opening another MOSFET experience is controlled, be to set Dead Time at random disorderly, therefore, MOSFET turns on and off moment and always exists switching loss.
Switching loss is meant the unnecessary heat that the MOSFET in non-isolation DC/DC transducer is produced in the process of turning on and off, this part heat is useless for whole non-isolation DC/DC transducer.Below in conjunction with traditional non-isolation DC/DC transducer, MOSFET in the analysis chart 2 (Q1) illustrates that in the operating state of a switch periods idle work is the problem how to produce.
Be illustrated in figure 4 as MOSFET (Q1) the current-voltage waveform figure in when work, also represent the current-voltage waveform figure of typical MOSFET in the DC/DC transducer, V
Q1Be the source electrode of Q1 and the voltage waveform between the drain electrode, i
Q1For flowing through the current waveform of Q1, (comprise service time t at Dead Time
OpenWith turn-off time t
Close) in, they are intersected in U
qAnd I
q
Can see that when Q1 opened, the voltage between the source electrode of Q1 and the drain electrode did not drop to zero as yet fully, the electric current that flows through Q1 has begun to rise, when finally reaching maximum, and the voltage vanishing between the source electrode of Q1 and the drain electrode at this moment.During shutoff, source electrode and drain voltage at first rise, and electric current just begins to descend then.Suppose that voltage, electric current rise and descend all is linear.Can obtain switching loss P
LossFor:
Wherein T is the switch periods of Q1, and f is the switching frequency of Q1.For non-isolation DC/DC transducer since the turn-off time can ignore i.e. t
CloseBe generally zero, thus can think that it all is that no-voltage is closed that MOSFET turn-offs, and t
OpenNon-vanishing under normal conditions, draw by formula (1), switching loss always exists, it and switching frequency, switching time, length was directly proportional, and it doesn't matter with duty ratio.Therefore in the DC/DC translation circuit, switching frequency is high more, and switching loss is just big more.
Along with non-isolation DC/DC transducer is more and more obvious towards the trend of miniaturization, low-voltage, big sense of current development, more and more littler for reaching DC circuit volume, a lot of power supply chip suppliers greatly improve the switching frequency of controller, bring up to the hundreds of KHz from 40 KHz at first, even last megahertz, meanwhile, traditional switching loss has just promoted 10 times quickly, even tens multiples, this quickly becoming sharply of outstanding problem not in conventional non-isolated DC/DC transducer.One 300 KHz left and right sides switching frequency for example, efficient can accomplish that 85% has been not easy very much, and along with output current is big more, switching frequency is high more, traditional non-isolation DC/DC transducer is because himself inherent shortcoming, all the more awkward when promoting efficient, can not adapt to this trend all the more.
Summary of the invention
The invention provides a kind of non-isolation DC/DC control circuit and the sequential control method and the non-isolation DC/DC transducer of logic control signal are provided, the problem that increases severely along with the increase of switching frequency in order to the switching loss that solves in existing conventional non-isolated DC/DC control circuit and the transducer.
According to a kind of non-isolation DC/DC control circuit of embodiment of the present invention, be used to control two switching devices and alternately turn on and off and carry out DC/DC conversion, this circuit comprises:
Voltage detection unit is used to detect the pressure difference signal at each switching device two ends;
The inner control logic unit, be used to provide the indication logic control signal that each switching device turns on and off, wherein after the indication logic control signal that one of them switching device turn-offs is provided, determine to begin to provide the moment of the indication logic control signal that this another switching device is opened according to the pressure difference signal at another switching device two ends;
Driver element is used for providing driving two drive signals that switching device alternately turns on and off according to described logic control signal.
According to a kind of non-isolation DC/DC transducer of embodiment of the present invention, this transducer comprises:
Above-mentioned non-isolation DC/DC control circuit;
Two switching devices that are connected, under the driving of described drive signal, alternately turn on and off with the driver element in described non-isolation DC/DC control circuit.
A kind of non-isolation DC/DC control circuit according to embodiment of the present invention provides the sequential control method of logic control signal, is used to determine to provide the sequential of the indication logic control signal that each switching device turns on and off, wherein,
The moment of the indication logic control signal that each switching device turn-offs is provided to begin to provide by the output dc voltage of collection after the DC/DC conversion;
After the indication logic control signal that one switching device turn-offs is provided, determine to begin to provide the moment of the indication logic control signal that this another switching device is opened by the pressure difference signal of gathering another switching device two ends.
The present invention is by introducing voltage detecting mechanism and corresponding control strategies, can realize the control of voltage winding, Dead Time is adopted ordered control, the switching loss that switching device such as MOSFET produce in opening process in realization reduction non-isolation DC/DC transducer, reach the purpose that promotes efficient, to realizing that non-isolation DC/DC transducer miniaturization is very beneficial.
Description of drawings
Fig. 1 is the structured flowchart of non-isolation DC in the prior art/DC transducer;
Fig. 2 is a conventional non-isolated DC/DC transducer schematic diagram in the prior art;
The logic control signal schematic diagram that Fig. 3 provides for existing conventional non-isolated DC/DC control circuit;
Fig. 4 is the current-voltage waveform figure of the work of the switching tube Q1 in the conventional non-isolated DC/DC transducer in the prior art;
Fig. 5 is the structured flowchart of non-isolation DC of the present invention/DC control circuit;
Fig. 6 is the structured flowchart of the non-isolation DC/DC transducer according to one embodiment of the present invention;
Fig. 7 is the structured flowchart of the non-isolation DC/DC transducer according to another embodiment of the present invention;
Fig. 8 is the schematic diagram of non-isolation DC in the embodiment of the invention/DC transducer;
Fig. 9 is the sequencing control figure of inner control logic unit output in the embodiment of the invention;
Figure 10 is the current-voltage waveform figure the when Q1 among Fig. 8 works in the embodiment of the invention.
Embodiment
Below in conjunction with accompanying drawing the embodiment of the embodiment of the invention is done further and to be elaborated.
According to as can be known noted earlier, alternately turn on and off two switching devices of string when carrying out the DC/DC conversion adopting in non-isolation DC/DC control circuit by drive signal, in switching device (as MOSFET device Q1 and Q2) opening process, always there is switching loss, because when increasing through the switching device electric current, this moment, switching device voltage did not drop to 0V usually, according to power=voltage * current relationship, be consumed work by the power that electric current and voltage produced this time, it is idle work, therefore this power need be dropped to minimumly, optimal result is zero.
As shown in Figure 5, the invention discloses a kind of non-isolation DC/DC control circuit, be used to control two switching devices and alternately turn on and off and carry out DC/DC conversion, voltage detection unit 505 is used to detect the pressure difference signal at each switching device two ends; Inner control logic unit 501, be used to provide the indication logic control signal that each switching device turns on and off, wherein after the indication logic control signal that one of them switching device turn-offs is provided, the moment of the indication logic control signal that this another switching device is opened is provided to provide according to the pressure difference signal at another switching device two ends, as beginning to provide the indication logic control signal that this another switching device is opened at pressure reduction for moment of zero, making the switching loss of this another switching device in opening process is zero; Driver element 502 is used for providing driving two drive signals that switching device alternately turns on and off according to described logic control signal.Voltage detection unit 505 is as the pressure difference signal of feedback circuit feedback switch device in this circuit, and then the inner control logic unit can make switching loss be reduced to minimum according to this pressure difference signal.
The voltage detection unit 505 that obtains the pressure difference signal at two switching devices (first switching device and second switch device) two ends in this control circuit comprises and is connected in first voltage comparator that the first switching device two ends are used to detect the first switching device two ends pressure reduction in parallel, and is connected in second voltage comparator that second switch device two ends are used to detect second switch device two ends pressure reduction in parallel.Certainly, also can adopt circuit with the voltage comparator equivalence, as zero-crossing detector, as shown in Figure 7, voltage detection unit 505 comprises and is connected in first zero-crossing detector that the first switching device two ends are used to detect the first switching device two ends pressure reduction in parallel, and is attempted by second zero-crossing detector that second switch device two ends are used to detect second switch device two ends pressure reduction.
The present invention also provides a kind of non-isolation DC/DC transducer, and this transducer comprises:
Above-mentioned non-isolation DC/DC control circuit;
Converting unit 503, comprise with described non-isolation DC/DC control circuit in driver element two switching devices being connected, under the driving of described drive signal, alternately turning on and off.
As shown in Figure 6, this transducer also comprises and is used for and will offers the output unit 504 of load after carrying out voltage stabilizing through the output dc voltage after the DC/DC conversion, the output dc voltage that converting unit 503 will obtain after will changing is input to output unit 504, and output unit 504 inserts load and provides required voltage for it.
Switching device in above-mentioned non-isolation DC/DC transducer can adopt the first metal oxide layer semiconductor field-effect transistor and the second metal oxide layer semiconductor field-effect transistor that is connected in series, and preferentially adopts the metal oxide layer semiconductor field-effect transistor of N type.Above-mentioned voltage detection unit is incorporated in the non-isolation DC/DC transducer of this kind form, can promotes the efficient of non-isolation DC/DC transducer or the switching loss of reduction MOSFET pipe.
As shown in Figure 8, adopt the first metal oxide layer semiconductor field-effect transistor Q1 and the second metal oxide layer semiconductor field-effect transistor Q2 at switching device in the present embodiment, driver element is included as the first metal oxide layer semiconductor field-effect transistor Q1 first drive signal, the first driven element unit of (be called for short and drive 1) is provided, and the second driven element unit of second drive signal (abbreviation drives 2) is provided for the second metal oxide layer semiconductor field-effect transistor Q2; The source electrode A1 of Q1 is connected with input direct voltage, and grid A3 is connected with the first driven element unit, and drain electrode A2 is connected with the source electrode B1 of Q2; The grid B3 of Q2 is connected with the second driven element unit, the drain electrode B2 be connected with reference to ground voltage; Output unit is connected in the source electrode B1 of Q2 and the B2 that drains in parallel, comprises the inductance component L and the capacity cell C that are connected in series, and capacity cell C two ends are connected in parallel to load.First voltage comparator 16 is connected in the source electrode A1 of Q1 and the A2 that drains in parallel, and second voltage comparator 17 is connected in the source electrode B1 of Q2 and the B2 that drains in parallel; The source electrode A1 of Q1 and drain electrode A2 two ends also are connected to the diode D1 that is used for overvoltage protection; The source electrode B1 of Q2 and drain electrode B2 two ends also are connected to the diode D2 that is used for overvoltage protection; Voltage feedback unit, be used to sample after the DC/DC conversion output dc voltage and feed back to the inner control logic unit.
Compare with traditional non-isolation DC/DC transducer, pass through to increase by first voltage comparator 16 and second voltage comparator 17 in the present embodiment, the reference voltage of first voltage comparator 16 is the voltage of 13 of inputs, it is the source voltage (input direct voltage) of Q1, the reference voltage of second voltage comparator 17 is 15 a voltage, be the drain voltage (with reference to ground voltage) of Q2, the sampling input of two comparators is the intermediate point of Q1 and Q2.Feed back by the voltage of MOSFET being managed two ends, electric current and voltage window is constantly opened according to the pressure difference signal control MOSFET of feedback in the inner control logic unit, makes the t among Fig. 4
OpenAlso reach zero, thereby reduce switching loss to greatest extent.
The invention provides also provides a kind of non-isolation DC/DC control circuit that the sequential control method of logic control signal is provided, be used to determine to provide the sequential of the indication logic control signal that each switching device turns on and off, wherein, determine to begin to provide the moment of the indication logic control signal that each switching device turn-offs by the output dc voltage of collection after the DC/DC conversion; After the indication logic control signal that one switching device turn-offs is provided, determine to begin to provide the moment of the indication logic control signal that this another switching device is opened by the pressure difference signal of gathering another switching device two ends.
In the present embodiment, to adopting non-isolation DC shown in Figure 8/DC control circuit to provide in the sequential control method of logic control signal, the inner control logic unit is used to provide indication two switching device Q1, the logic control signal that Q2 alternately turns on and off, as Fig. 9 for the inner control logic unit provide logic control signal sequencing control figure, among Fig. 9, first drive signal is the reinforcement signal of signal 11, second drive signal is that (strengthening signal is level signal in the same way for the reinforcement signal of signal 12, when being 3.3v as signal 11, driving 1 is 5v), signal 8 is the signal of first voltage comparator output, signal 9 is the signal of second voltage comparator output, and signal 10 is in the signal that the switching device of opening state turn-offs for indication.
In the present embodiment, adopt following testing mechanism and control strategy:
When the voltage of 14 of the inputs of first voltage comparator was equal to or higher than 13 voltage, promptly when the voltage of the drain electrode A2 of Q1 was equal to or higher than the voltage of source electrode A1, the signal 8 of first voltage comparator output was effective, otherwise signal 8 is invalid.
When the voltage of 14 of the inputs of second voltage comparator was equal to or less than 15 voltage, promptly when the voltage as the source electrode B1 of Q2 was equal to or less than the voltage of drain electrode B2, the signal 9 of second voltage comparator output was effective, otherwise the signal 9 of output is invalid;
It is that signal 8 is effective that internal control control logic unit begins the prerequisite of the indication logic control signal that Q1 opens is provided, and beginning the prerequisite of the indication logic control signal that Q2 opens is provided is that signal 9 is effective.That is: after the indication logic control signal that Q1 turn-offs is provided, detect the pressure reduction of Q2 source electrode and drain electrode;
When being equal to or less than drain voltage, Q2 begins to provide the indication logic control signal that Q2 opens;
After the indication logic control signal that Q2 turn-offs is provided, detect the pressure reduction of Q1 source electrode and drain electrode;
When the Q1 drain voltage is equal to or higher than drain voltage, begin to provide the indication logic control signal that the first metal oxide layer semiconductor field-effect transistor is opened.
In the present embodiment inner control logic unit begin to provide logic control signal that indication opens Q1 the time be engraved in the signal 8 effective time intervals, begin to provide indicate the logic control signal of opening Q2 the time be engraved in the signal 9 effective time intervals.This strategy does not have in traditional non-isolation DC/DC control logic, driving 1 is arranged in traditional non-isolation DC/DC control logic and drive 2 invalid strategies, that is exactly recently to adjust the invalid of signal 11 and signal 12 according to signal 10 duties, and the present invention does not adjust this and changes.
The present invention is by increase adjusting the efficient strategy of signal 11 and signal 12, and real what change is action behavior in the switch mosfet time, and no matter Q1 or Q2 can both guarantee that no-voltage is open-minded, and details are as follows in conjunction with Fig. 9 and Figure 10 for figure below:
T1 ' is before the moment, and among Fig. 9, Q1 is in off state, and Q2 is in opening state; Among Figure 10, the pressure reduction maximum between the source electrode of Q1 and the drain electrode;
T1 ' constantly, among Fig. 9, it is 2 invalid to drive, Q2 turn-offs because the electric current in the inductance component L can not suddenly change, therefore 14 voltage begins to rise, experience one section time-delay after, 14 voltage rises to 13 voltage and equates that at this moment signal 8 begins effective;
T2 ' constantly, the voltage for the treatment of at 14 rises to greater than behind 13 the voltage diode D1 conducting being discharged, voltage drop to be lower than 13 point voltages after signal 8 invalid, at arbitrary moment of 8 valid periods of signal such as t2 ' constantly, the inner control logic unit begins to provide indication to open the logic control signal of Q1, the source electrode of t1 ' Q1 between the t2 ' time and the pressure reduction decline process between the drain electrode have been provided as Figure 10, open Q1 when waiting not have pressure reduction, make the source electrode of Q1 in the opening process and the pressure reduction V between the drain electrode
Q1Be zero, its electric current rises to maximum gradually;
T3 ' is before the moment, and among Fig. 9, Q1 is in opening state, and Q2 is in off state; Among Figure 10, the pressure reduction between the source electrode of Q1 and the drain electrode is 0, and it is maximum that electric current reaches;
T3 ' constantly, signal 11 becomes invalidly under the triggering of signal 10, Q1 turn-offs, and thinks V in the turn off process
Q1Be zero, because the electric current in the inductance component L can not suddenly change, therefore 14 voltage begins to descend, experience one section time-delay after, 14 voltage drops to when 15 voltage equates, signal 9 begins effective;
T4 ' constantly, treat after 14 voltage drops to the voltage that is lower than at 15 diode D2 conducting to be discharged, signal 9 was invalid after voltage rose to and is higher than 15 point voltages, at arbitrary moment of 9 valid periods of signal such as t4 ' constantly, the inner control logic unit begins to provide indication to open the logic control signal of Q2, open Q2 when waiting not have pressure reduction, make the source electrode of opening process Q2 and the pressure reduction V between the drain electrode
Q2Be zero, its electric current rises to maximum gradually.
T5 ' repeats t1 ' action constantly constantly.
To sum up chat the switching loss P of switching device Q1, Q2
LossFor:
Wherein, V
Q1Be the source electrode of switching tube Q1 and the voltage waveform between the drain electrode, i
Q1For flowing through the current waveform of Q1, in Dead Time, they are intersected in U
qAnd I
q, owing to adopt the present embodiment scheme (to comprise service time t at Dead Time
OpenWith turn-off time t
Close) interior no joint, this shows that in the work period, for the MOSFET in non-isolation DC/DC transducer, switching loss is zero.
To sum up chat, realize reducing switching device (MOSFET) in the switch loss of moment by introducing MOSFET voltage control closed loop, control circuit is simple in structure, need not increase other periphery circuit, simplicity of design is reliable, satisfies the miniaturization demand, can easily rise to about 95% from 85% having efficient now, the MOSFET total losses descend more than 70%, greatly promote the efficient of DC/DC translation circuit and increase the reliability that MOSFET works.
This method is based on circuit model shown in Figure 8, newly introduce comparison circuit at existing DC/DC transducer, or other equivalent electric circuit, zero cross detection circuit for example, can detect switching tube MOSFET (Q1 up and down, Q2) source electrode and drain voltage are poor, testing result is imported inner control logic, control logic is according to testing result, the switching time of difference control switch pipe MOSFET, reaching in the switching process is the purpose of zero loss, as 2 comparators commonly used of preferred employing sampling, is reference voltage with the input power supply with reference to ground respectively, sampled voltage is the intermediate voltage of switching tube up and down, as the signal among Fig. 86, in Dead Time, the voltage of signal 6 always is higher than supply voltage or is lower than with reference to ground voltage, voltage difference is generally 0.3V between them, can myopia be zero, comparator output is overturn, inner control logic must detect the comparator output after the upset earlier before opening MOSFET, can guarantee like this in the whole switching process that MOSFET keeps minimum switching loss.
The present invention is to non-isolation DC/DC transducer; take above-mentioned testing mechanism and control strategy; reaching minimizing switching tube switching loss protects; be understandable that; under enlightenment of the present invention, this cover testing mechanism and controlling mechanism are incorporated in the non-isolation DC/DC transducer of other form, promote the efficient of non-isolation DC/DC transducer or reduce MOSFET pipe power consumption; should regard of the present invention deriving as, also should be subjected to the protection of this patent.For example the power consumption according to the switching device two ends of the pressure difference signal correspondence that is detected is reached the minimum moment and begin to provide the indication logic control signal that this another switching device is opened, effectively constantly beginning to provide the indication logic control signal that this another switching device is opened for 0 at another switching device two ends pressure difference signal.
Obviously, those skilled in the art can carry out various changes and modification to the present invention and not break away from the spirit and scope of the present invention.Like this, if of the present invention these are revised and modification belongs within the scope of claim of the present invention and equivalent technologies thereof, then the present invention also is intended to comprise these changes and modification interior.
Claims (11)
1, a kind of non-isolation DC/DC control circuit is used to control two switching devices and alternately turns on and off and carry out DC/DC conversion, it is characterized in that this circuit comprises:
Voltage detection unit is used to detect the pressure difference signal at each switching device two ends;
The inner control logic unit, be used to provide the indication logic control signal that each switching device turns on and off, wherein after the indication logic control signal that one of them switching device turn-offs is provided, determine to begin to provide the moment of the indication logic control signal that this another switching device is opened according to the pressure difference signal at another switching device two ends;
Driver element is used for providing driving two drive signals that switching device alternately turns on and off according to described logic control signal.
2, circuit as claimed in claim 1 is characterized in that,
Described voltage detection unit comprises first voltage comparator at switching device two ends therein that is connected in parallel, and is connected in second voltage comparator at another switching device two ends in parallel.
3, circuit as claimed in claim 1 is characterized in that,
Described voltage detection unit comprises first zero-crossing detector at switching device two ends therein that is connected in parallel, and is connected in second zero-crossing detector at another switching device two ends in parallel.
4, a kind of non-isolation DC/DC transducer is characterized in that, this transducer comprises:
The described non-isolation DC of claim 1/DC control circuit;
Two switching devices that are connected, under the driving of described drive signal, alternately turn on and off with the driver element in described non-isolation DC/DC control circuit.
5, non-isolation DC as claimed in claim 4/DC transducer is characterized in that,
Voltage detection unit in described non-isolation DC/DC control circuit comprises first voltage comparator at switching device two ends therein that is connected in parallel, and is connected in second voltage comparator at another switching device two ends in parallel.
6, non-isolation DC as claimed in claim 4/DC transducer is characterized in that,
Described voltage detection unit comprises first zero-crossing detector at switching device two ends therein that is connected in parallel, and is connected in second zero-crossing detector at another switching device two ends in parallel.
7, non-isolation DC as claimed in claim 4/DC transducer is characterized in that, this transducer also comprises:
Output unit is used for the output dc voltage after the DC/DC conversion is carried out offering load after the voltage stabilizing;
Voltage feedback unit, be used to sample after the DC/DC conversion output dc voltage and feed back to the inner control logic unit.
8, non-isolation DC as claimed in claim 7/DC transducer is characterized in that,
Described two switching devices are respectively the first metal oxide layer semiconductor field-effect transistor and the second metal oxide layer semiconductor field-effect transistor that is connected in series;
Described driver element is included as the first driven element unit that the first metal oxide layer semiconductor field-effect transistor provides drive signal, and the second driven element unit of drive signal is provided for the second metal oxide layer semiconductor field-effect transistor;
The source electrode of the first metal oxide layer semiconductor field-effect transistor is connected with input direct voltage, and grid is connected with the first driven element unit, and drain electrode is connected with the source electrode of the second metal oxide layer semiconductor field-effect transistor;
The grid of the second metal oxide layer semiconductor field-effect transistor is connected with the second driven element unit, the drain electrode and be connected with reference to ground voltage;
Described output unit is connected in the source electrode and the drain electrode of the second metal oxide layer semiconductor field-effect transistor in parallel, comprises the voltage component and the capacity cell that are connected in series, the load that is connected in parallel of described capacity cell two ends.
9, a kind of non-isolation DC/DC control circuit provides the sequential control method of logic control signal, is used to determine to provide the sequential of the indication logic control signal that each switching device turns on and off, it is characterized in that,
The moment of the indication logic control signal that each switching device turn-offs is provided to begin to provide by the output dc voltage of collection after the DC/DC conversion;
After the indication logic control signal that one switching device turn-offs is provided, determine to begin to provide the moment of the indication logic control signal that this another switching device is opened by the pressure difference signal of gathering another switching device two ends.
10, method as claimed in claim 9 is characterized in that,
The moment that reaches minimum according to the power consumption of described pressure difference signal at described another switching device two ends begins to provide the indication logic control signal that this another switching device is opened.
11, method as claimed in claim 10 is characterized in that,
Pressure difference signal at described another switching device two ends begins to provide the indication logic control signal that this another switching device is opened for the zero moment.
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| Application Number | Priority Date | Filing Date | Title |
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| CN200910161003A CN101599696B (en) | 2009-07-27 | 2009-07-27 | Non-isolation DC/DC control circuit and converter |
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| CN200910161003A CN101599696B (en) | 2009-07-27 | 2009-07-27 | Non-isolation DC/DC control circuit and converter |
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| CN101599696A true CN101599696A (en) | 2009-12-09 |
| CN101599696B CN101599696B (en) | 2012-09-12 |
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| CN200910161003A Expired - Fee Related CN101599696B (en) | 2009-07-27 | 2009-07-27 | Non-isolation DC/DC control circuit and converter |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103488226A (en) * | 2013-09-09 | 2014-01-01 | 天脉聚源(北京)传媒科技有限公司 | Output voltage control circuit |
| CN103684371A (en) * | 2012-08-29 | 2014-03-26 | 西门子公司 | Output module and method for operating the output module |
| CN115632541A (en) * | 2022-12-22 | 2023-01-20 | 苏州贝克微电子股份有限公司 | Self-adaptive no-signal time control circuit |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4850540B2 (en) * | 2005-12-26 | 2012-01-11 | 富士通セミコンダクター株式会社 | DC-DC converter and control circuit for DC-DC converter |
| TWI331841B (en) * | 2006-06-13 | 2010-10-11 | O2Micro Int Ltd | Dc-to-dc converter with improved transient response |
-
2009
- 2009-07-27 CN CN200910161003A patent/CN101599696B/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103684371A (en) * | 2012-08-29 | 2014-03-26 | 西门子公司 | Output module and method for operating the output module |
| CN103488226A (en) * | 2013-09-09 | 2014-01-01 | 天脉聚源(北京)传媒科技有限公司 | Output voltage control circuit |
| CN115632541A (en) * | 2022-12-22 | 2023-01-20 | 苏州贝克微电子股份有限公司 | Self-adaptive no-signal time control circuit |
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| Publication number | Publication date |
|---|---|
| CN101599696B (en) | 2012-09-12 |
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