CN106100379B - Synchronous rectifying controller - Google Patents
Synchronous rectifying controller Download PDFInfo
- Publication number
- CN106100379B CN106100379B CN201610577242.6A CN201610577242A CN106100379B CN 106100379 B CN106100379 B CN 106100379B CN 201610577242 A CN201610577242 A CN 201610577242A CN 106100379 B CN106100379 B CN 106100379B
- Authority
- CN
- China
- Prior art keywords
- temperature
- ref
- threshold value
- com
- shutdown
- 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.)
- Active
Links
- 230000001360 synchronised effect Effects 0.000 title claims abstract description 41
- 239000004065 semiconductor Substances 0.000 claims abstract description 59
- 238000001514 detection method Methods 0.000 claims abstract description 18
- 238000004364 calculation method Methods 0.000 claims description 9
- 239000003990 capacitor Substances 0.000 claims description 6
- 230000000875 corresponding effect Effects 0.000 description 16
- 238000010586 diagram Methods 0.000 description 7
- 238000000034 method Methods 0.000 description 6
- 230000007423 decrease Effects 0.000 description 4
- 230000002596 correlated effect Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of AC power input into DC power output; Conversion of DC power input into AC power output
- H02M7/02—Conversion of AC power input into DC power output without possibility of reversal
- H02M7/04—Conversion of AC power input into DC power output without possibility of reversal by static converters
- H02M7/12—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/21—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/217—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Rectifiers (AREA)
Abstract
The invention discloses synchronous rectifying controller, temperature-compensation circuit is connected with the end B for opening comparator and the end A for turning off comparator, and temperature-compensation circuit receives threshold value Vref, output, which is opened, compensates threshold value Vref_on_comThreshold value V is compensated with shutdownref_off_comTo shutdown comparator, opens the end comparator A and receive detection voltage value VDET, opening comparator will test voltage value VDETThreshold value V is compensated with openingref_on_comIt compares, opens comparator and generate open signal SR_on and export to driving circuit, turn off the end comparator B and receive detection voltage value VDET, turning off comparator will test voltage value VDETThreshold value V is compensated with shutdownref_off_comIt compares, shutdown comparator generates cut-off signals SR_off and exports to driving circuit, generates drive voltage signal Vsr_g, the switch of control switch metal-oxide-semiconductor N2, the accurate switch of realization.
Description
Technical field
The present invention relates to a kind of synchronous rectifying controllers, belong to switch power technology field.
Background technique
Currently, inverse-excitation type switch power-supply system is due to, input and output voltage isolation, at low cost, volume simple with circuit
The advantages that small and be widely used, but when export electric current it is larger, output voltage is lower when, traditional inverse-excitation type switch power-supply
Secondary commutation diode on-state loss and reverse recovery loss in system is big, and efficiency is lower, therefore uses synchronous rectification,
Rectifier diode is replaced using the extremely low switch metal-oxide-semiconductor of on-state resistance value, the conversion effect of entire converter can be improved well
Rate.The circuit of existing synchronous rectifying controller on-off mode is as shown in Figure 1, unlatching comparator 602 will be from synchronous rectifying controller
The detection voltage value V that 600 end VDET obtainsDETWith unlatching threshold value Vref_onIt compares, as detection voltage value VDETReach unlatching threshold value
Vref_onWhen, it opens comparator 602 and issues open signal SR_on and export to driving circuit 604.Shutdown comparator 603 will test
Voltage value VDETWith shutdown threshold value Vref_offIt compares, as detection voltage value VDETReach shutdown threshold value Vref_offWhen, turn off comparator
603 issue cut-off signals SR_off and export to driving circuit 604.Finally by driving circuit 604 receive open signal SR_on and
Cut-off signals SR_off generates drive voltage signal Vsr_gAnd it is transferred to the end GATE of synchronous rectifying controller 600, control switch
The switch of metal-oxide-semiconductor N2.Find out from the relational graph of switch metal-oxide-semiconductor body diode conduction voltage drop shown in Fig. 2 and junction temperature, switch MOS
The body diode conduction voltage drop V of pipeSDRelationship is negatively correlated with junction temperature.From two pole of prior art opening ways lower body shown in Fig. 3
The relational graph of pipe conduction voltage drop and the relative value and junction temperature of opening threshold value is found out, when the temperature increases, if directlying adopt unlatching
Threshold value Vref_onAs the condition that judgement is opened, the conducting of the body diode D2 after changing can be greater than because opening the setting of threshold value
Pressure drop VSDAnd fail to open switch metal-oxide-semiconductor N2, i.e. body diode conduction voltage drop and the relative value for opening threshold value has temperature characterisitic,
Know that the variation of temperature will affect the accurate unlatching of switch metal-oxide-semiconductor.From the conducting resistance and junction temperature of switch metal-oxide-semiconductor shown in Fig. 4
Relational graph it is found that switch metal-oxide-semiconductor conducting resistance Rds(on)With junction temperature positive correlation.It is closed from the prior art shown in fig. 5
Threshold current is turned off under disconnected mode and the relational graph of junction temperature is found out, when the temperature increases, if directlying adopt shutdown threshold value
Vref_offAs the condition of judgement shutdown, corresponding shutdown threshold current Isec(off)It can become smaller, i.e. shutdown threshold current
Isec(off)With temperature characterisitic, it is known that the variation of temperature will affect the accurate shutdown of switch metal-oxide-semiconductor.
Summary of the invention
The purpose of the present invention is overcoming the shortcomings of the prior art, one kind is provided and is mended with threshold temperature is switched on and off
Repay the synchronous rectifying controller of circuit.
The purpose of the present invention is achieved through the following technical solutions:
Synchronous rectifying controller, feature are: including temperature-compensation circuit, opening comparator and shutdown comparator, the temperature
Degree compensation circuit is connected with the end B for opening comparator and the end A for turning off comparator, and temperature-compensation circuit receives threshold value Vref, temperature
Compensation threshold value V is opened in compensation circuit outputref_on_comTo comparator is opened, output shutdown compensates threshold value Vref_off_comTo shutdown ratio
Compared with device；
The end A for opening comparator receives detection voltage value V from the end VDET of synchronous rectifying controllerDET, unlatching compares
Device will test voltage value VDETThreshold value V is compensated with openingref_on_comIt compares, as detection voltage value VDETReach unlatching compensation threshold value
Vref_on_comWhen, it opens comparator and generates open signal SR_on and export to driving circuit；
The end B of the shutdown comparator receives detection voltage value V from the end VDET of synchronous rectifying controllerDET, shutdown compares
Device will test voltage value VDETThreshold value V is compensated with shutdownref_off_comIt compares, as detection voltage value VDETReach shutdown compensation threshold value
Vref_off_comWhen, shutdown comparator generates cut-off signals SR_off and exports to driving circuit；
The driving circuit receives open signal SR_on and cut-off signals SR_off and generates drive voltage signal Vsr_gAnd it passes
Transport to the end GATE of synchronous rectifying controller, the switch of control switch metal-oxide-semiconductor.
Further, above-mentioned synchronous rectifying controller, wherein open stage switchs the body of metal-oxide-semiconductor when temperature increases
The conduction voltage drop V of diodeSDIt increases and becomes smaller with temperature；If opened, threshold value is unchanged, and the setting because opening threshold value, which is greater than, to be changed
The conduction voltage drop V of body diode after changeSDAnd it fail to open switch metal-oxide-semiconductor；Temperature-compensation circuit, which is adjusted, opens threshold value, passes through tune
After section, compensation threshold value V is openedref_on_comIt is appropriate when the temperature rises to reduce, by adjusting reduced amplitude, opened when keeping it turning on
It closes the body diode conduction voltage drop of metal-oxide-semiconductor and opens the relative value of threshold value not with temperature significant change, it is ensured that switch the standard of metal-oxide-semiconductor
Really open.
Further, above-mentioned synchronous rectifying controller, wherein off-phases switch metal-oxide-semiconductor when temperature increases
Conducting resistance Rds(on)It increases and becomes larger with temperature, if shutdown threshold value is unchanged, turn off threshold current Isec(off)With the liter of temperature
It is high and reduces, shutdown threshold current Isec(off)The current value of switch metal-oxide-semiconductor is flowed through when being off；Temperature-compensation circuit adjusts shutdown
Threshold value, after adjusting, shutdown compensation threshold value Vref_off_comIt keeps and temperature raises simultaneously, by adjusting raised amplitude, most
Threshold current I is turned off when being held off eventuallysec(off)Not with temperature significant change, it is ensured that switch the accurate shutdown of metal-oxide-semiconductor.
Further, above-mentioned synchronous rectifying controller, wherein the temperature-compensation circuit includes the first operation amplifier
Device, the first PMOS tube, first capacitor, first resistor, second resistance, 3rd resistor, the 4th resistance and the 5th resistance, described first
The output end of operational amplifier connects the first PMOS tube and first capacitor, the end the V+ connection temperature-compensating electricity of the first operational amplifier
The input terminal IN on road, the end V- of the first operational amplifier are connected to second resistance and 3rd resistor；
First PMOS tube is connected with power voltage terminal, first resistor and second resistance；
The 3rd resistor, the 4th resistance, the 5th resistance are successively connected in order；
5th resistance connects with ground terminal.
Still further, above-mentioned synchronous rectifying controller, wherein temperature is arranged between the 3rd resistor and the 4th resistance
Spend the first output end OUT1 of compensation circuit.
Still further, above-mentioned synchronous rectifying controller, wherein temperature is arranged between the 4th resistance and the 5th resistance
Spend the second output terminal OUT2 of compensation circuit.
Still further, above-mentioned synchronous rectifying controller, wherein the input terminal IN of temperature-compensation circuit, the first output
The voltage value for holding OUT1 and second output terminal OUT2 is respectively VIN、VOUT1、VOUT2, then the calculation formula of the offset obtained are as follows:
The temperature coefficient value of resistance is normal number or negative constant, so that output voltage VOUT1、VOUT2For positive temperature characterisitic or bear
Temperature characterisitic；R3, R5 are positive temperature coefficient, and R4 is negative temperature coefficient；
For temperature-compensation circuit, input terminal IN receives threshold value Vref, the first output end OUT1 output, which is opened, compensates threshold value
Vref_on_com, second output terminal OUT2 output shutdown compensation threshold value Vref_off_com；
For open stage, threshold value V is compensated using the unlatching that temperature-compensation circuit generatesref_on_comIt is opened as judgement
Condition is worked as
VDET=Vref_on_com
When meet unlocking condition, body diode conduction voltage drop and open threshold value relative value calculation formula are as follows:
Wherein, threshold value VrefIt is zero-temperature coefficient, V for a standard voltage valueSDFor the conducting for switching metal-oxide-semiconductor N2 body diode
Pressure drop；
When the temperature increases, the resistance value of R3, R5 become larger, and the resistance value of R4 becomes smaller, by the setting to temperature coefficient, so thatBecome larger, Vref_on_comBecome smaller, i.e., the unlatching compensation threshold value V exported at this timeref_on_comFor negative temperature characteristic；
For off-phases, threshold value V is compensated using the shutdown that temperature-compensation circuit generatesref_off_comAs judgement shutdown
Condition is worked as
VDET=Vref_off_com
When meet turn-off criterion, turn off threshold current Isec(off)Calculation formula are as follows:
Wherein, threshold value VrefIt is zero-temperature coefficient, R for a standard voltage valueds(on)For the conducting resistance for switching metal-oxide-semiconductor N2；
When the temperature increases, the resistance value of R3, R5 become larger, and the resistance value of R4 becomes smaller, by the setting to temperature coefficient, so thatBecome larger, Vref_off_comBecome larger, that is, the shutdown compensation threshold value V exportedref_off_comFor positive temperature characterisitic；
When temperature increases, switch metal-oxide-semiconductor body diode conduction voltage drop becomes smaller, and opens compensation threshold value Vref_on_comBecome smaller, most
The relative value of body diode conduction voltage drop and unlatching threshold value is not with temperature significant change when keeping it turning on eventually, it is ensured that switch metal-oxide-semiconductor
Accurate unlatching.
Still further, above-mentioned synchronous rectifying controller, wherein threshold value VrefFor a standard voltage value.
Still further, above-mentioned synchronous rectifying controller, wherein be applied in inverse-excitation type switch power-supply system.
Technical solution of the present invention substantive distinguishing features outstanding and significant progress are mainly reflected in:
The present invention can adjust with the variation of temperature and open threshold value and shutdown threshold value, weaken synchronous rectification switch metal-oxide-semiconductor
Switch is acted upon by temperature changes, and when the temperature is changed, opens threshold temperature compensation circuit and opens as the variation of temperature is adjusted
Threshold value and shutdown threshold value, can be achieved the accurate switch of switch metal-oxide-semiconductor after adjusting.
Detailed description of the invention
Fig. 1: the electrical block diagram of background technique synchronous rectifying controller on-off mode；
Fig. 2: the relational graph of switch metal-oxide-semiconductor body diode conduction voltage drop and junction temperature；
Fig. 3: the relationship of the relative value and junction temperature of background technique opening ways lower body diode conduction voltage drop and unlatching threshold value
Figure；
Fig. 4: the relational graph of switch metal-oxide-semiconductor conducting resistance and junction temperature；
Fig. 5: the relational graph of threshold current and junction temperature is turned off under background technique shutdown mode；
Fig. 6: electrical block diagram of the invention；
Fig. 7: the schematic diagram of temperature-compensation circuit of the invention；
Fig. 8: the relational graph of body diode conduction voltage drop and the relative value and junction temperature of opening threshold value of the invention；
Fig. 9: the relational graph of shutdown threshold current and junction temperature of the invention.
Figure 10: the work wave schematic diagram under background technique on-off mode；
Figure 11: work wave schematic diagram of the invention.
Specific embodiment
Present invention setting is switched on and off threshold temperature compensation circuit, can be adjusted according to temperature difference and open threshold value and pass
Disconnected threshold value.
As shown in fig. 6, synchronous rectifying controller 600, including temperature-compensation circuit 601, unlatching comparator 602 and shutdown ratio
Compared with device 603, temperature-compensation circuit 601 is connected with the end B for opening comparator 602 and the end A for turning off comparator 603, temperature-compensating
Circuit 601 receives threshold value Vref, threshold value VrefFor a standard voltage value, compensation threshold value V is opened in outputref_on_comTo unlatching comparator
602, output shutdown compensation threshold value Vref_off_comTo shutdown comparator 603.
The end A for opening comparator 602 receives detection voltage value V from the end VDET of synchronous rectifying controller 600DET, open ratio
It will test voltage value V compared with device 602DETThreshold value V is compensated with openingref_on_comIt compares, as detection voltage value VDETReach unlatching to mend
Repay threshold value Vref_on_comWhen, it opens comparator 602 and generates open signal SR_on and export to driving circuit 604.
The end B for turning off comparator 603 receives detection voltage value V from the end VDET of synchronous rectifying controller 600DET, shutdown ratio
It will test voltage value V compared with device 603DETThreshold value V is compensated with shutdownref_off_comIt compares, as detection voltage value VDETReach shutdown to mend
Repay threshold value Vref_off_comWhen, shutdown comparator 603 generates cut-off signals SR_off and exports to driving circuit 604.
Driving circuit 604 receives open signal SR_on and cut-off signals SR_off and generates drive voltage signal Vsr_gAnd it passes
The defeated end GATE to synchronous rectifying controller 600, the switch of control switch metal-oxide-semiconductor N2.
When unlatching, when the temperature rises, the conduction voltage drop V of the body diode D2 of metal-oxide-semiconductor N2 is switchedSDIt increases and becomes with temperature
It is small.If opened, threshold value is unchanged, and the conduction voltage drop V of the body diode D2 after changing can be greater than because opening the setting of threshold valueSDAnd
It is fail to open switch metal-oxide-semiconductor N2, temperature-compensation circuit 601 is to adjust unlatching threshold value, after adjusting, opens compensation threshold value
Vref_on_comIt is appropriate when the temperature rises to reduce, by adjusting reduced amplitude, body diode conducting pressure when finally keeping it turning on
The relative value of drop and unlatching threshold value is not with temperature significant change, it is ensured that switchs the accurate unlatching of metal-oxide-semiconductor；
Threshold current I is turned off when shutdownsec(off)It is shown below:
Wherein, Rds(on)For the conducting resistance for switching metal-oxide-semiconductor N2.
When the temperature rises, Rds(on)It increases and becomes larger with temperature, if shutdown compensation threshold value Vref_off_comIt is unchanged, it closes
Disconnected threshold current Isec(off)It is reduced with the raising of temperature, temperature-compensation circuit 601 passes through adjusting to adjust shutdown threshold value
Afterwards, shutdown compensation threshold value Vref_off_comIt keeps and temperature raises simultaneously, by adjusting raised amplitude, pass when being finally held off
Disconnected threshold current Isec(off)Not with temperature significant change, it is ensured that switch the accurate shutdown of metal-oxide-semiconductor.
As shown in fig. 7, temperature-compensation circuit 601 includes the first operational amplifier A1, the first PMOS tube P1, first capacitor
C1, first resistor R1, second resistance R2,3rd resistor R3, the 4th resistance R4 and the 5th resistance R5, the first operational amplifier A1's
The end V+ of output the first PMOS tube P1 of connection and first capacitor C1, the first operational amplifier A1 connect the end IN, the first operation amplifier
The end V- of device A1 connects second resistance R2 and 3rd resistor R3.
First PMOS tube P1 is connected with power voltage terminal VCC, first resistor R1 and second resistance R2.
3rd resistor R3 is connected in order with the 4th resistance R4 and the 5th resistance R5.
5th resistance R5 connects with ground terminal；
First output end OUT1 of temperature-compensation circuit 601 is set between 3rd resistor R3 and the 4th resistance R4.
The second output terminal OUT2 of temperature-compensation circuit 601 is set between the 4th resistance R4 and the 5th resistance R5.
The principle Analysis of temperature-compensation circuit 601: metal-oxide-semiconductor body diode conduction voltage drop is switched as known to Fig. 2, Fig. 3
It is negatively correlated relationship with junction temperature, if to accomplish that temperature increases, corresponding body diode conduction voltage drop and the phase for opening threshold value
It will not significant change to value, it is desirable that open compensation threshold value Vref_on_comFor negative temperature characteristic；And the switch MOS as known to Fig. 4, Fig. 5
Pipe conducting resistance and junction temperature positive correlation will make corresponding shutdown threshold current if to accomplish that temperature increases
Isec(off)It will not significant change, it is desirable that shutdown compensation threshold value Vref_off_comFor positive temperature characterisitic.
The voltage value of the input terminal IN of temperature-compensation circuit 601, the first output end OUT1 and second output terminal OUT2 are distinguished
For VIN、VOUT1、VOUT2, then the calculation formula of the offset obtained are as follows:
The temperature coefficient value of resistance is set as normal number or negative constant, so that output voltage VOUT1、VOUT2For positive temperature characterisitic
Or negative temperature characteristic.R3, R5 are positive temperature coefficient herein, and R4 is negative temperature coefficient.
For temperature-compensation circuit 601, the end IN receives threshold value Vref, the output of the end OUT1, which is opened, compensates threshold value Vref_on_com,
The end OUT2 output shutdown compensation threshold value Vref_off_com。
For open stage, threshold value V is compensated using the unlatching that temperature-compensation circuit 601 generatesref_on_comIt is opened as judgement
The condition opened, that is, work as
VDET=Vref_on_com
When meet unlocking condition, body diode D2 conduction voltage drop and open threshold value relative value calculation formula it is as follows:
Wherein, threshold value VrefIt is zero-temperature coefficient, V for a standard voltage valueSDFor the conducting for switching metal-oxide-semiconductor N2 body diode
Pressure drop.
When the temperature increases, the resistance value of R3, R5 become larger, and the resistance value of R4 becomes smaller, and by the setting to temperature coefficient, can make
?Become larger, Vref_on_comBecome smaller, i.e., the unlatching compensation threshold value V exported at this timeref_on_comFor negative temperature spy
Property, it switchs metal-oxide-semiconductor body diode conduction voltage drop as known to Fig. 2 and junction temperature is negatively correlated relationship, then it is when the temperature increases, corresponding
Body diode D2 conduction voltage drop and the relative value for opening threshold value will not significant changes.
For off-phases, threshold value V is compensated using the shutdown that temperature-compensation circuit 601 generatesref_off_comIt is closed as judgement
Disconnected condition, that is, work as
VDET=Vref_off_com
When meet turn-off criterion, turn off threshold current Isec(off)Calculation formula it is as follows:
Wherein, threshold value VrefIt is zero-temperature coefficient, R for a standard voltage valueds(on)For the conducting resistance for switching metal-oxide-semiconductor N2.
When the temperature increases, the resistance value of R3, R5 become larger, and the resistance value of R4 becomes smaller, and by the setting to temperature coefficient, can make
?Become larger, Vref_off_comBecome larger, i.e., the shutdown compensation threshold value V exported at this timeref_off_comThe temperature that is positive is special
Property, metal-oxide-semiconductor conducting resistance and junction temperature positive correlation, then when the temperature increases, corresponding shutdown threshold value are switched as known to Fig. 4
Electric current Isec(off)It will not significant change.
Fig. 8 is the relational graph of body diode conduction voltage drop and the relative value and junction temperature of opening threshold value of the invention, temperature liter
Gao Shi, switch metal-oxide-semiconductor body diode D2 conduction voltage drop become smaller, and open compensation threshold value Vref_on_comBecome smaller, when finally keeping it turning on
The relative value of body diode D2 conduction voltage drop and unlatching threshold value is not with temperature significant change, it is ensured that switchs the accurate unlatching of metal-oxide-semiconductor.
Fig. 9 is the relational graph of shutdown threshold current and junction temperature of the invention, when temperature increases, Rds(on)Become larger, shutdown compensation
Threshold value Vref_off_comBecome larger, threshold current I is turned off when being finally held offsec(off)Not with temperature significant change, it is ensured that switch
The accurate shutdown of metal-oxide-semiconductor.
It can be seen that temperature-compensation circuit of the invention can weaken synchronous rectification switch metal-oxide-semiconductor switch by the shadow of temperature change
It rings.Temperature-compensation circuit of the invention can be switched on and off threshold value as the variation of temperature is adjusted, and can be achieved after adjusting split
Close the accurate switch of metal-oxide-semiconductor.
Open compensation threshold value Vref_on_comThreshold value V is compensated with shutdownref_off_comActual temp characteristic can offset detection voltage
Value VDETTemperature characterisitic.It can be applied in inverse-excitation type switch power-supply system, but be not limited to inverse-excitation type switch power-supply system.
Figure 10 is the work wave schematic diagram under background technique on-off mode, VDETWaveform is set forth temperature and increases, is warm
Corresponding waveform when degree is normal and temperature reduces, for open stage, when the temperature increases, if directlying adopt unlatching threshold value
Vref_onAs the condition that judgement is opened, corresponding body diode conduction voltage drop and unlatching threshold value Vref_onRelative value compared with temperature
It can become smaller when normal.When the temperature decreases, corresponding body diode conduction voltage drop and unlatching threshold value Vref_onRelative value compared with temperature
It can become larger when normal, it is seen that the variation of temperature will affect the accurate unlatching of switch metal-oxide-semiconductor；For off-phases, when temperature increases
When, if directlying adopt shutdown threshold value Vref_offAs the condition of judgement shutdown, IsecThe corresponding shutdown threshold current of waveform
Isec(off)It can become smaller when normal compared with temperature, can be delayed when the drop point position of GATE waveform is normal compared with temperature.When the temperature decreases,
IsecThe corresponding shutdown threshold current I of waveformsec(off)It can become larger when normal compared with temperature, the drop point position of GATE waveform is compared with temperature
It can shift to an earlier date when normal, it is seen that the variation of temperature will affect the accurate shutdown of switch metal-oxide-semiconductor.
Figure 11 is work wave schematic diagram of the invention, VDETWaveform is set forth that temperature increases, temperature is normal and temperature
Corresponding waveform when reduction, for open stage, when the temperature increases, corresponding unlatching compensates threshold value Vref_on_comJust compared with temperature
Suitably reduce when often.When the temperature decreases, corresponding unlatching compensates threshold value Vref_on_comSuitably increase when normal compared with temperature.Finally
The relative value of body diode conduction voltage drop and unlatching threshold value is not with temperature significant change when keeping it turning on, it is ensured that switchs metal-oxide-semiconductor
It is accurate to open；For off-phases, when the temperature increases, corresponding shutdown compensates threshold value Vref_off_comIt is appropriate when normal compared with temperature
Increase.When the temperature decreases, corresponding shutdown compensates threshold value Vref_off_comSuitably reduce when normal compared with temperature.Finally it is held off
When IsecThe corresponding shutdown threshold current I of waveformsec(off)Not with temperature significant change, the drop point position of GATE waveform keeps solid
It is fixed not to be affected by temperature, it is ensured that switch the accurate shutdown of metal-oxide-semiconductor.
In conclusion the present invention can be switched on and off threshold value as the variation of temperature is adjusted, weaken synchronous rectification switch
Metal-oxide-semiconductor switch is acted upon by temperature changes, and the accurate switch to switch metal-oxide-semiconductor can be achieved after adjusting.
It should be understood that the foregoing is merely the preferred embodiment of the present invention, the power that is not intended to limit the invention
Sharp range；The description above simultaneously, should can be illustrated and implement for the special personage of correlative technology field, thus it is other without departing from
The equivalent change or modification completed under disclosed spirit, should be included in claim.
Claims (8)
1. synchronous rectifying controller, it is characterised in that: including temperature-compensation circuit (601), open comparator (602) and shutdown ratio
Compared with device (603), the end B of comparator (602) and the A of shutdown comparator (603) are opened in temperature-compensation circuit (601) connection
End, temperature-compensation circuit (601) receive threshold value (Vref), compensation threshold value (V is opened in temperature-compensation circuit (601) outputref_on_com)
To comparator (602) are opened, output shutdown compensates threshold value (Vref_off_com) extremely shutdown comparator (603)；
The end A for opening comparator (602) receives detection voltage value (V from the end VDET of synchronous rectifying controller (600)DET),
Opening comparator (602) will test voltage value (VDET) and unlatching compensation threshold value (Vref_on_com) compare, when detection voltage value
(VDET) reach unlatching compensation threshold value (Vref_on_com) when, it opens comparator (602) and generates open signal (SR_on) and export extremely
Driving circuit (604)；
The end B of shutdown comparator (603) receives detection voltage value (V from the end VDET of synchronous rectifying controller (600)DET),
Shutdown comparator (603) will test voltage value (VDET) and shutdown compensation threshold value (Vref_off_com) compare, when detection voltage value
(VDET) reach shutdown compensation threshold value (Vref_off_com) when, shutdown comparator (603) generates cut-off signals (SR_off) and exports extremely
Driving circuit (604)；
The driving circuit (604) receives open signal (SR_on) and cut-off signals (SR_off) generate drive voltage signal Vsr_g
And it is transmitted to the end GATE of synchronous rectifying controller (600), the switch of control switch metal-oxide-semiconductor (N2)；
Switch the conduction voltage drop V of the body diode (D2) of metal-oxide-semiconductor (N2)SDIt increases and becomes smaller with temperature；If opening compensation threshold value
Unchanged, the setting because opening compensation threshold value is greater than the conduction voltage drop V of the body diode (D2) after changingSDAnd it fail to open switch
Metal-oxide-semiconductor (N2)；Temperature-compensation circuit (601), which is adjusted, opens compensation threshold value, after adjusting, opens compensation threshold value (Vref_on_com)
It is appropriate when the temperature rises to reduce, by adjusting reduced amplitude, the body diode (D2) of metal-oxide-semiconductor (N2) is switched when keeping it turning on
The relative value of conduction voltage drop and unlatching compensation threshold value is not with temperature significant change, it is ensured that switchs the accurate unlatching of metal-oxide-semiconductor.
2. synchronous rectifying controller according to claim 1, it is characterised in that: off-phases, when temperature increases, switch
The conducting resistance R of metal-oxide-semiconductor (N2)ds(on)It increases and becomes larger with temperature, if shutdown compensation threshold value is unchanged, shutdown compensation threshold value
Electric current Isec(off)It is reduced with the raising of temperature, shutdown compensation threshold current Isec(off)Switch metal-oxide-semiconductor (N2) is flowed through when being off
Current value；Temperature-compensation circuit (601) adjusts shutdown compensation threshold value, after adjusting, while temperature increases, and shutdown compensation
Threshold value (Vref_off_com) raising is also followed, by adjusting raised amplitude, shutdown compensation threshold current when being finally held off
Isec(off)Not with temperature significant change, it is ensured that switch the accurate shutdown of metal-oxide-semiconductor.
3. synchronous rectifying controller according to claim 1 or 2, it is characterised in that: temperature-compensation circuit (601) packet
Include the first operational amplifier (A1), the first PMOS tube (P1), first capacitor (C1), first resistor (R1), second resistance (R2),
Three resistance (R3), the 4th resistance (R4) and the 5th resistance (R5), the output end connection first of first operational amplifier (A1)
The end V+ of the grid end and first capacitor (C1) of PMOS tube (P1), the first operational amplifier (A1) connects temperature-compensation circuit (601)
Input terminal IN, the end V- of the first operational amplifier (A1) is connected to second resistance (R2) and 3rd resistor (R3)；
The source of first PMOS tube (P1) is connected with power voltage terminal (VCC), the drain terminal of the first PMOS tube (P1) connection the
One resistance (R1) and second resistance (R2)；
The 3rd resistor (R3), the 4th resistance (R4), the 5th resistance (R5) are successively connected in order；
5th resistance (R5) connects with ground terminal.
4. synchronous rectifying controller according to claim 3, it is characterised in that: the 3rd resistor (R3) and the 4th resistance
(R4) the first output end OUT1 of temperature-compensation circuit (601) is set between.
5. synchronous rectifying controller according to claim 3, it is characterised in that: the 4th resistance (R4) and the 5th resistance
(R5) the second output terminal OUT2 of temperature-compensation circuit (601) is set between.
6. synchronous rectifying controller according to claim 3, it is characterised in that: the input terminal of temperature-compensation circuit (601)
The voltage value of IN, the first output end OUT1 and second output terminal OUT2 are respectively VIN、VOUT1、VOUT2, then the offset that obtains
Calculation formula are as follows:
The temperature coefficient value of resistance is normal number or negative constant, so that output voltage VOUT1、VOUT2For positive temperature characterisitic or negative temperature
Characteristic；R3 is 3rd resistor (R3), and temperature coefficient value is normal number, and R5 is the 5th resistance (R5), and temperature coefficient value is normal number,
R4 is 3rd resistor (R4), and temperature coefficient value is negative constant；
For temperature-compensation circuit (601), input terminal IN receives threshold value (Vref), compensation threshold is opened in the first output end OUT1 output
It is worth (Vref_on_com), second output terminal OUT2 output shutdown compensation threshold value (Vref_off_com)；
For open stage, threshold value (V is compensated using the unlatching that temperature-compensation circuit (601) generateref_on_com) opened as judgement
Condition, that is, work as
VDET=Vref_on_com
When meet unlocking condition, wherein VDETTo detect voltage value (VDET), Vref_on_comThreshold value (V is compensated to openref_on_com)；
The calculation formula of the relative value of body diode (D2) conduction voltage drop and unlatching compensation threshold value are as follows:
Wherein, threshold value (Vref) it is a standard voltage value, it is zero-temperature coefficient, VSDFor leading for switch metal-oxide-semiconductor N2 body diode (D2)
Logical pressure drop；
When the temperature increases, 3rd resistor (R3), the resistance value of 3rd resistor (R5) become larger, and the resistance value of the 4th resistance (R4) becomes smaller,
By the setting to temperature coefficient, so thatBecome larger, Vref_on_comBecome smaller, i.e., the unlatching compensation exported at this time
Threshold value (Vref_on_com) it is negative temperature characteristic；
For off-phases, threshold value (V is compensated using the shutdown that temperature-compensation circuit (601) generateref_off_com) closed as judgement
Disconnected condition, that is, work as
VDET=Vref_off_com
When meet turn-off criterion, wherein Vref_off_comThreshold value (V is compensated for shutdownref_off_com)；
Turn off threshold current Isec(off)Calculation formula are as follows:
Wherein, VrefFor threshold value (Vref), for the reference voltage value that benchmark circuit generates, VrefWith zero-temperature coefficient characteristic, Rds(on)For
Switch the conducting resistance of metal-oxide-semiconductor (N2)；
When the temperature increases, the resistance value of R3, R5 become larger, and the resistance value of R4 becomes smaller, by the setting to temperature coefficient, so thatBecome larger, Vref_off_comBecome larger, that is, the shutdown compensation threshold value (V exportedref_off_com) it is positive temperature characterisitic；
When temperature increases, switch metal-oxide-semiconductor body diode (D2) conduction voltage drop becomes smaller, and opens compensation threshold value (Vref_on_com) become smaller, most
The relative value of body diode (D2) conduction voltage drop and unlatching compensation threshold value is not with temperature significant change when keeping it turning on eventually, it is ensured that opens
Close the accurate unlatching of metal-oxide-semiconductor.
7. synchronous rectifying controller according to claim 1, it is characterised in that: threshold value (Vref) it is what benchmark circuit generated
Reference voltage value.
8. synchronous rectifying controller according to claim 1, it is characterised in that: the synchronous rectifier is applied to inverse-excitation type
In switch power supply system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610577242.6A CN106100379B (en) | 2016-07-20 | 2016-07-20 | Synchronous rectifying controller |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610577242.6A CN106100379B (en) | 2016-07-20 | 2016-07-20 | Synchronous rectifying controller |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106100379A CN106100379A (en) | 2016-11-09 |
| CN106100379B true CN106100379B (en) | 2019-04-30 |
Family
ID=57449845
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610577242.6A Active CN106100379B (en) | 2016-07-20 | 2016-07-20 | Synchronous rectifying controller |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106100379B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107508473B (en) * | 2017-07-13 | 2019-08-23 | 苏州博创集成电路设计有限公司 | Synchronous rectifier converter |
| CN108206640B (en) * | 2017-12-28 | 2020-02-18 | 重庆平伟实业股份有限公司 | A synchronous rectification module, rectification method and manufacturing method thereof |
| CN108923660B (en) * | 2018-08-14 | 2020-01-24 | 无锡芯朋微电子股份有限公司 | Synchronous rectification converter |
| CN108983007B (en) * | 2018-08-24 | 2023-09-05 | 深圳南云微电子有限公司 | Detection circuit and detection method of short circuit protection |
| CN111865088B (en) * | 2020-07-09 | 2021-07-20 | 无锡芯朋微电子股份有限公司 | Control circuit for synchronous rectification |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1722466A1 (en) * | 2005-05-13 | 2006-11-15 | STMicroelectronics S.r.l. | Method and relative circuit for generating a control voltage of a synchronous rectifier |
| CN102684459A (en) * | 2012-05-22 | 2012-09-19 | 大连连顺电子有限公司 | Reference voltage and current circuit with ultra-low temperature sensitivity and switching power supply using it |
| CN105529800A (en) * | 2014-09-28 | 2016-04-27 | 比亚迪股份有限公司 | Charging system based on secondary control and its secondary control device |
-
2016
- 2016-07-20 CN CN201610577242.6A patent/CN106100379B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1722466A1 (en) * | 2005-05-13 | 2006-11-15 | STMicroelectronics S.r.l. | Method and relative circuit for generating a control voltage of a synchronous rectifier |
| CN102684459A (en) * | 2012-05-22 | 2012-09-19 | 大连连顺电子有限公司 | Reference voltage and current circuit with ultra-low temperature sensitivity and switching power supply using it |
| CN105529800A (en) * | 2014-09-28 | 2016-04-27 | 比亚迪股份有限公司 | Charging system based on secondary control and its secondary control device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106100379A (en) | 2016-11-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106100379B (en) | Synchronous rectifying controller | |
| CN107508473B (en) | Synchronous rectifier converter | |
| CN109980946B (en) | Synchronous rectification control circuit and control method thereof | |
| CN105356727B (en) | Switching tube drive control method and control circuit for Switching Power Supply | |
| CN102185466B (en) | Driving circuit and driving method applied to flyback-type converter and quasi-resonant soft-switching flyback-type converter applying same | |
| CN103490605B (en) | Isolated switch converter and controller and control method thereof | |
| CN104022650B (en) | Flyback switching power supply with output short circuit protection function | |
| CN101662275B (en) | Control method for alternating current solid-state power switch | |
| CN107147302B (en) | A kind of numerical control system and its control method of synchronous rectification LLC converter | |
| CN104578341B (en) | An on-board charger with adjustable dead time based on phase-shifted full-bridge circuit | |
| CN102790543B (en) | A kind of synchronous rectificating device | |
| CN103269161A (en) | Constant current output BUCK power supply circuit | |
| CN110308315A (en) | A kind of current transformer sample circuit | |
| CN104348360B (en) | Voltage conversion controller and voltage conversion circuit | |
| CN105529800A (en) | Charging system based on secondary control and its secondary control device | |
| CN203883693U (en) | Switching inductive current-type synchronous rectifying circuit with phase compensation function | |
| CN203984738U (en) | For the phase-cut dimming control circuit of LED lamp | |
| CN103889114B (en) | A kind of LED dimming driving circuit | |
| CN207664888U (en) | High efficiency full bridge rectifier | |
| CN104411035B (en) | A kind of LED drive circuit powered without assists winding | |
| CN107147297B (en) | An inductively coupled power transfer control method with pull-down auxiliary switch | |
| CN107134927B (en) | An inductively coupled power transmission device with pull-down auxiliary switch | |
| CN213990523U (en) | A synchronous rectifier device | |
| CN102135556B (en) | Detection circuit and synchronous rectification circuit | |
| CN114567182A (en) | Synchronous rectification control device, chip and switching power supply |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |