CN101599696B - Non-isolation DC/DC control circuit and converter - Google Patents
Non-isolation DC/DC control circuit and converter Download PDFInfo
- Publication number
- CN101599696B CN101599696B CN200910161003A CN200910161003A CN101599696B CN 101599696 B CN101599696 B CN 101599696B CN 200910161003 A CN200910161003 A CN 200910161003A CN 200910161003 A CN200910161003 A CN 200910161003A CN 101599696 B CN101599696 B CN 101599696B
- Authority
- CN
- China
- Prior art keywords
- switching device
- voltage
- isolation
- signal
- control signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Abstract
The invention discloses a non-isolation DC/DC control circuit and a converter to solve a problem that the conventional non-isolation DC/DC control circuit adopts a random disordered mode to set dead zone time, so the switch loss in the non-isolation DC/DC converter is sharply increased with the switching frequency increase. The circuit comprises a voltage detecting unit, an internal control logic unit and a drive unit, wherein the voltage detecting unit is used for detecting voltage differential signals at both ends of each switch device; the internal control logic unit is used for providing a logic control signal which indicates each switch device to switch on and switch off, and after the internal control logic unit provides the logic control signal which indicates one switch device to switch off, the time of starting to provide the logic control signal which indicates the other switch device to switch on is determined according to the voltage differential signals at both ends of the other switch device; and the drive unit is used for providing a drive signal which drives both switch devices to alternatively switch on and switch off according to the 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-EfiectTransistor; 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 is different according to the polarity of its " passage ", can be divided into the MOSFET of N type and P type, 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 other a kind of direct voltage DC.In non-isolation DC/DC transducer, using is NMOS more widely; As shown in Figure 1; Non-isolation DC/DC transducer comprises inner control logic unit 101, driver element 102, converting unit 103, the output unit 104 that connects successively; Wherein inner control logic unit 101 is used to provide logic control signal; Driver element 102 is that converting unit 103 provides drive signal according to said logic control signal, and said converting unit 103 converts input direct voltage into output dc voltage under the driving of drive signal, and the output dc voltage that will after the DC/DC conversion, obtain is input to output unit 104.
Be illustrated in figure 2 as traditional non-isolation DC/DC transducer sketch map; Converting unit adopts nmos device Q1 and the Q2 that is connected in series; Driver element 102 is included as that Q1 provides first driver element 1021 of drive signal and second driver element 1022 of 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 between grid and drain electrode, apply certain forward voltage, 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 respectively 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 supplying it that logic control signal is provided 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 through 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 like 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; Under the situation of a MOSFET shutoff, owing to the electric current in the inductance can not change at once, so change in current can produce pressure drop in the inductance therein; 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 is gone to zero with drain electrode pressure reduction gradually, otherwise possibly cause burning out circuit.Usually, the service time of MOSFET (like the t3 among Fig. 3) is called duty ratio than service time (like the t3 among Fig. 3) and turn-off time (like the t2 among Fig. 3) sum.
It is exactly that it only is responsible for the adjustment output dc voltage that above-mentioned traditional non-isolation DC/DC control circuit has an obvious defects; In order to reach this purpose; The time length that Q1, Q2 turn on and off is adjusted through controlling first drive signal and second drive signal in the inner control logic unit, but it can not confirm accurately that " what constantly " open or turn-off MOSFET, promptly after turn-offing one of them MOSFET; Dead Time control to opening another MOSFET experience is unordered control; 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) explains 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 miniaturization, low-voltage, big sense of current Development Trend; 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 KHzs at first, even go up 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, and 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 the 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; According to the pressure difference signal at another switching device two ends, confirm at pressure difference signal to be the moment that is less than or equal to 0.3V to begin to provide the indication logic control signal that this another switching device is opened;
Driver element is used for providing driving two drive signals that switching device alternately turns on and off according to said 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 said drive signal, alternately turn on and off with the driver element in said 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 confirm to provide the sequential of the indication logic control signal that each switching device turns on and off, wherein,
Confirm to begin to provide the moment of the indication logic control signal that each switching device turn-offs through 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,, confirm at pressure difference signal to be the moment that is less than or equal to 0.3V to begin to provide the indication logic control signal that this another switching device is opened through gathering the pressure difference signal at another switching device two ends.
The present invention is through 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 reaches 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 sketch map in the prior art;
The logic control signal sketch map 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 according to the non-isolation DC/DC transducer of one embodiment of the present invention;
Fig. 7 is the structured flowchart according to the non-isolation DC/DC transducer of another embodiment of the present invention;
Fig. 8 is the sketch map of non-isolation DC in the embodiment of the invention/DC transducer;
Fig. 9 is the SECO 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 elaboration in detail.
Know according to 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, in switching device (like MOSFET device Q1 and Q2) opening process through drive signal; 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; Therefore be idle work, need this power be dropped to minimumly that 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; Confirm 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; As being to begin to provide the indication logic control signal that this another switching device is opened the zero moment at pressure reduction, 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 said 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; Like 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 said non-isolation DC/DC control circuit in driver element two switching devices being connected, under the driving of said drive signal, alternately turning on and off.
As shown in Figure 6; This transducer also comprises the output unit 504 that is used for offering 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 for it required voltage is provided.
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 reduce the switching loss that MOSFET manages.
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 is that the second metal oxide layer semiconductor field-effect transistor Q2 provides second drive signal, the second driven element unit of (be called for short and drive 2); 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 is with drain electrode A2 two ends and be connected to the diode D1 that is used for overvoltage protection; The source electrode B1 of Q2 is with drain electrode B2 two ends and be 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, i.e. the source voltage of Q1 (input direct voltage), and 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.Voltage through MOSFET being managed two ends feeds back, and 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 present 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 confirm to provide the sequential of the indication logic control signal that each switching device turns on and off; Wherein, confirm to begin to provide the moment of the indication logic control signal that each switching device turn-offs through 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, confirm to begin to provide the moment of the indication logic control signal that this another switching device is opened through 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 logic control signals that switching device Q1, Q2 alternately turn on and off, as Fig. 9 for the inner control logic unit provide logic control signal SECO figure; Among Fig. 9; First drive signal is the reinforcement signal of signal 11, and second drive signal is that (strengthening signal is level signal in the same way, when being 3.3v like signal 11 for the reinforcement signal of signal 12; Driving 1 is 5v); Signal 8 is the signal of first voltage comparator output, and 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;
, the source voltage of Q2 begins to provide the indication logic control signal that Q2 opens when being equal to or less than drain voltage; 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 drain voltage of Q1 is equal to or higher than source 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; Have in traditional non-isolation DC/DC control logic drive 1 with 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 through increasing the efficient strategy of adjustment signal 11 and signal 12, and real what change is the action behavior in the switch mosfet time, and no matter Q1 or Q2 can both guarantee that no-voltage is open-minded, and figure below combines Fig. 9 and Figure 10, and details are as follows:
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 between the source electrode of Q1 and the drain electrode is maximum;
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 of treating 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, has provided the source electrode of t1 ' Q1 between the t2 ' time and the pressure reduction decline process between the drain electrode like 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, and 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 through 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 and the reliability that increases MOSFET work of DC/DC translation circuit.
This method is newly introduced comparison circuit based on circuit model shown in Figure 8 at existing DC/DC transducer, or other equivalent electric circuit; Zero cross detection circuit for example, the source electrode and the drain voltage that can detect switching tube MOSFET (Q1, Q2) up and down are poor, and testing result is imported inner control logic; Control logic is according to testing result, and respectively the switching time of control switch pipe MOSFET, reaching in the switching process is the purpose of zero loss; Like 2 comparators commonly used of preferred employing sampling, be reference voltage with the input power supply with reference to ground respectively, sampled voltage be about the intermediate voltage of switching tube; Like 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, and comparator output is overturn; Comparator output inner control logic must detect upset earlier before opening MOSFET after can guarantee like this in the whole switching process that MOSFET keeps minimum switching loss.
The present invention takes above-mentioned testing mechanism and control strategy to non-isolation DC/DC transducer, reaches minimizing switching tube switching loss and protects; It is 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 receive the protection of this patent.For example the power consumption according to the pressure difference signal corresponding switch device two ends of being detected being reached the minimum moment and begin to provide the indication logic control signal that this another switching device is opened, is being 0 to begin to provide the indication logic control signal that this another switching device is opened constantly at another switching device two ends pressure difference signal effectively.
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, belong within the scope of claim of the present invention and equivalent technologies thereof if of the present invention these are revised with modification, then the present invention also is intended to comprise these changes and modification interior.
Claims (11)
1. non-isolation DC/DC control circuit is used to control two switching devices and alternately turns on and off and carry out the 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; According to the pressure difference signal at another switching device two ends, confirm at pressure difference signal to be the moment that is less than or equal to 0.3V to begin to provide the indication logic control signal that this another switching device is opened;
Driver element is used for providing driving two drive signals that switching device alternately turns on and off according to said logic control signal.
2. circuit as claimed in claim 1 is characterized in that,
Said 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,
Said 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. 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 said drive signal, alternately turn on and off with the driver element in said 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 said 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,
Said 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,
Said 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;
Said driver element is included as the first driven element unit that the first metal oxide layer semiconductor field-effect transistor provides drive signal, and is the second driven element unit that the second metal oxide layer semiconductor field-effect transistor provides drive signal;
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;
Said 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 said capacity cell two ends.
9. non-isolation DC/DC control circuit provides the sequential control method of logic control signal, is used to confirm to provide the sequential of the indication logic control signal that each switching device turns on and off, it is characterized in that,
Confirm to begin to provide the moment of the indication logic control signal that each switching device turn-offs through 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,, confirm at pressure difference signal to be the moment that is less than or equal to 0.3V to begin to provide the indication logic control signal that this another switching device is opened through gathering the pressure difference signal at 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 said pressure difference signal at said 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 said another switching device two ends is to begin to provide the indication logic control signal that this another switching device is opened the zero moment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910161003A CN101599696B (en) | 2009-07-27 | 2009-07-27 | Non-isolation DC/DC control circuit and converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910161003A CN101599696B (en) | 2009-07-27 | 2009-07-27 | Non-isolation DC/DC control circuit and converter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101599696A CN101599696A (en) | 2009-12-09 |
| CN101599696B true CN101599696B (en) | 2012-09-12 |
Family
ID=41420991
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200910161003A Expired - Fee Related CN101599696B (en) | 2009-07-27 | 2009-07-27 | Non-isolation DC/DC control circuit and converter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101599696B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2704325A1 (en) * | 2012-08-29 | 2014-03-05 | Siemens Aktiengesellschaft | Output module and method for operation |
| CN103488226B (en) * | 2013-09-09 | 2015-06-10 | 天脉聚源(北京)传媒科技有限公司 | Output voltage control circuit |
| CN115632541B (en) * | 2022-12-22 | 2023-04-18 | 苏州贝克微电子股份有限公司 | Self-adaptive no-signal time control circuit |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1992494A (en) * | 2005-12-26 | 2007-07-04 | 富士通株式会社 | Dc-dc converter and control circuit for dc-dc converter |
| CN101093957A (en) * | 2006-06-13 | 2007-12-26 | 美国凹凸微系有限公司 | Direct current/direct current transducer with modified type transient response |
-
2009
- 2009-07-27 CN CN200910161003A patent/CN101599696B/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1992494A (en) * | 2005-12-26 | 2007-07-04 | 富士通株式会社 | Dc-dc converter and control circuit for dc-dc converter |
| CN101093957A (en) * | 2006-06-13 | 2007-12-26 | 美国凹凸微系有限公司 | Direct current/direct current transducer with modified type transient response |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101599696A (en) | 2009-12-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8917068B2 (en) | Quasi-resonant controlling and driving circuit and method for a flyback converter | |
| CN102128973B (en) | Voltage zero-crossing detecting circuit and DC-DC converter with same | |
| CN103702486B (en) | LED driving circuit system, control circuit and control method | |
| CN101707837B (en) | LED drive circuit of source driver with change of output voltage and induction quantity keeping constant current | |
| CN101572974B (en) | High efficiency constant current LED drive circuit and drive method | |
| CN101489342B (en) | LED driver circuit and driving method thereof | |
| CN101895201B (en) | LLC (Logical Link Control) series resonance converter and drive method thereof | |
| CN201388313Y (en) | High-efficiency constant-current LED driving circuit | |
| CN207053838U (en) | Constant-current controller | |
| CN104319983B (en) | A kind of source driving method, drive circuit and Switching Power Supply being used in Switching Power Supply | |
| CN201571234U (en) | Source electrode drive LED drive circuit with output voltage and inductance variation keeping constant current | |
| CN106130378A (en) | Synchronous commutating control circuit and method | |
| CN102055341B (en) | Control circuit of switching power supply and switching power supply | |
| CN110165872A (en) | Switch control circuit and control method thereof | |
| CN104796015B (en) | System and method for powering to synchronous rectifier drive circuit | |
| CN104333936A (en) | Closed-loop control circuit for LED constant current drive circuit | |
| CN110391736A (en) | The control circuit of BUCK converter | |
| CN101599696B (en) | Non-isolation DC/DC control circuit and converter | |
| CN103025021B (en) | Step-down light emitting diode (LED) drive circuit based on electrical inductance discharge time modulation | |
| CN107742971A (en) | A kind of drive circuit and switching power circuit | |
| CN102082521B (en) | Circuit for accurately detecting resonance trough | |
| CN201557044U (en) | Frequency limited circuit capable of controlling power factor correcting circuit via critical current | |
| CN104393755A (en) | High-efficiency booster circuit | |
| CN104185345A (en) | Control device used for LED constant-current driving circuit | |
| CN205017636U (en) | A peak current detection circuitry for LED constant -current drive circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120912 Termination date: 20150727 |
|
| EXPY | Termination of patent right or utility model |