CN204886731U - Switching power supply controller and contain switching power supply of this switching power supply controller - Google Patents
Switching power supply controller and contain switching power supply of this switching power supply controller Download PDFInfo
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- CN204886731U CN204886731U CN201520426073.7U CN201520426073U CN204886731U CN 204886731 U CN204886731 U CN 204886731U CN 201520426073 U CN201520426073 U CN 201520426073U CN 204886731 U CN204886731 U CN 204886731U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
Abstract
The utility model provides a switching power supply controller and contain the switching power supply of this switching power supply controller. This switching power supply controller includes that zero cross detection circuit, variable turn -on time length control circuit and drive signal produce the circuit. The drive signal of offset voltage and switch tube is received to this variable turn -on time length control circuit, makes square being inversely proportional to of turn -on time, and square being directly proportional of the on off cycle of switch tube of switching power supply's switch tube with turn -off time of switch tube to produce and turn -off the signal. This drive signal produces the circuit and produces drive signal according to zero cross signal and shutoff signal, and drive signal transmits to the bars end of switch tube, and in response to the zero cross signal, the drive signal control switch piping leads to, and in response to turn -offing the signal, drive signal control switch manages the shutoff. The utility model discloses the critical mode control's of switching on of step -down structure switching power supply's power factor can be optimized, total harmonic distortion is reduced.
Description
Technical field
The utility model relates to switch power technology, particularly relates in a kind of buck configuration the switch power controller with power factor adjustment function, critical conduction mode control, and comprises the Switching Power Supply of this switch power controller.
Background technology
Traditional Alternating Current Power Supply, band power factor adjustment (PFC) function, critical conduction mode buck configuration LED constant-current driver as shown in Figure 1, mainly comprise: AC input rectification circuit 101, interchange input source 102, input capacitance Cin, inductance L 1, switching tube M1, sampling resistor Rs, sustained diode 1, output capacitance Cbulk, constant-current switch power source controller 100.Wherein, constant-current switch power source controller 100 is for receiving feedback signals FB, and sampling resistor Rs sampled output current, with this driving switch pipe M1.
Wherein, constant-current switch power source controller 100 comprises: zero cross detection circuit 125, for detect represent drive singal GD terminate after the feedback signal FB of inductance L 1 current over-zero, provide the Continuity signal of switching tube M1 when inductance L 1 current over-zero, actuating switch pipe M1; Constant current counting circuit 120, calculates output current by carrying out sampling to the voltage Vcs on sampling resistor Rs; Error amplifier 121, the output current calculate constant current counting circuit 120 and reference current do error and amplify, and export bucking voltage Vcomp, bucking voltage Vcomp and connect building-out capacitor 103, after making loop stability, bucking voltage Vcomp is substantially fixing; Fixing ON time control circuit 122, the ON time of control switch pipe M1, timing is started when switching tube M1 starts conducting, when reaching the ON time of setting, exporting cut-off signals to trigger 123, removing on-off switching tube M1, after loop stability, when bucking voltage Vcomp fixes, the ON time of switching tube M1 is constant, realizes power factor adjustment thus; Trigger 123, receives the zero cross signal ZCD of zero cross detection circuit 125 output and the cut-off signals of fixing ON time control circuit 122 output; Driver 124, connects the grid end of trigger 123 and switching tube M1, and the turn-on and turn-off realizing switch tube M1 drive.
During switching tube M1 conducting, input current flows through sampling resistor Rs, inductance L 1, output capacitance Cbulk, output end vo ut, and the electric current flowing through inductance L 1 increases, inductance L 1 stored energy.Switching tube M1 closes and has no progeny, and flow through the electric current of inductance L 1 through sustained diode 1 afterflow, the electric current flowing through inductance L 1 reduces gradually, and inductance L 1 releases energy output capacitance Cbulk and output end vo ut.When the electric current flowing through inductance L 1 reduces to zero, zero cross detection circuit 125 detects the feedback signal FB of inductance L 1 current over-zero, produces zero cross signal ZCD and transfers to trigger 123, through driver 124 actuating switch pipe M1.Switching tube M1 repeats switch motion above, circuit continuous firing, is in critical current mode conduction mode all the time.
For realizing good power factor Adjustment effect, require that the AC input current of each switch periods well can follow the change of input voltage.In the buck configuration of critical conduction mode, ignore pressure drop when input rectifying tube voltage drop, switching tube conducting, the average current input of each switch periods is:
Wherein, V
outfor output voltage, V
infor input voltage, I
infor input current, T
onfor ON time, L is the inductance value of inductance L 1.But, adopt fixing ON time (T
onconstant), critical conduction mode control time, input current I
ininput voltage V can not be followed completely
inchange, power factor is deteriorated, and total harmonic distortion strengthens, so the power factor of circuit traditional is at present not desirable especially, total harmonic distortion is also larger.
Utility model content
The technical problems to be solved in the utility model is to provide and a kind ofly applies to the switch power controller of buck configuration and comprise the Switching Power Supply of this switch power controller, the power factor of the Switching Power Supply that critical conduction mode controls can be optimized, reduce total harmonic distortion.
For solving the problems of the technologies described above, the utility model provides a kind of switch power controller, comprising:
Zero cross detection circuit, carries out zero passage detection to the feedback signal of input and produces zero cross signal;
Variable ON time length control circuit, receive the drive singal of bucking voltage and switching tube, make square being inversely proportional to the turn-off time of switching tube of the ON time of the switching tube of Switching Power Supply, to square being directly proportional of the switch periods of switching tube, and produce cut-off signals; And
Drive signal generation circuit, produce drive singal according to described zero cross signal and cut-off signals, described drive singal transfers to the grid end of described switching tube, to control the turn-on and turn-off of described switching tube.
According to an embodiment of the present utility model, described variable ON time length control circuit comprises:
ON time testing circuit, detects the ON time of the switching tube in described Switching Power Supply, to obtain ON time timing voltage;
Turn-off time testing circuit, detects the ON time of the switching tube in described Switching Power Supply, to obtain turn-off time timing voltage;
Switch periods time detection circuit, detected the switch periods time of described switching tube, to obtain switch periods time timing voltage;
Timing circuit produces circuit, according to described ON time timing voltage, turn-off time timing voltage, switch periods time timing voltage, produce timing circuit, described timing circuit be directly proportional to ON time timing voltage, be directly proportional to turn-off time timing voltage, and square being inversely proportional to of switch periods time timing voltage;
Timing capacitor and comparator, in switching tube conduction period, described timing circuit charges to timing capacitor, and compares with bucking voltage, obtains cut-off signals.
According to an embodiment of the present utility model, described variable ON time length control circuit comprises:
Turn-off time testing circuit, detects the ON time of the switching tube in described Switching Power Supply, to obtain turn-off time timing voltage;
Switch periods time detection circuit, detected the switch periods time of described switching tube, to obtain switch periods time timing voltage;
Timing circuit produces circuit, according to described turn-off time timing voltage, switch periods time timing voltage, produces timing circuit, and described timing circuit and turn-off time timing voltage obtain square root and be directly proportional, be inversely proportional to switch periods time timing voltage;
Timing capacitor and comparator, in described switching tube conduction period, described timing circuit charges to timing capacitor, and compares with bucking voltage, obtains cut-off signals.
According to an embodiment of the present utility model, the ON time timing voltage that described ON time testing circuit obtains represents the ON time of described switching tube in previous switch periods, or represents the mean value of the ON time of described switching tube in front multiple switch periods.
According to an embodiment of the present utility model, the turn-off time timing voltage that described turn-off time testing circuit obtains represents the turn-off time of described switching tube in previous switch periods, or represents the mean value of the turn-off time of described switching tube in front multiple switch periods.
According to an embodiment of the present utility model, the switch periods time timing voltage that described switch periods time detection circuit obtains represents the switch periods time of described switching tube in previous switch periods, or represents the mean value of the switch periods time of described switching tube in front multiple switch periods.
According to an embodiment of the present utility model, the input of described ON time testing circuit is directly connected with the grid end of described switching tube, to detect the ON time of described switching tube.
According to an embodiment of the present utility model, the input of described turn-off time testing circuit is directly connected with the grid end of described switching tube, to detect the ON time of described switching tube.
According to an embodiment of the present utility model, the input of described switch periods time detection circuit is directly connected with the grid end of described switching tube, to detect the switch periods time of described switching tube.
According to an embodiment of the present utility model, described ON time testing circuit comprises:
Current source;
First switch, its first end connects the output of described current source;
Second switch, its first end connects the second end of described first switch, its second end ground connection;
First electric capacity, its first end connects the second end of described first switch and the first end of second switch, its second end ground connection;
Voltage follower, its input connects the first end of described first electric capacity;
3rd switch, its first end connects the output of described voltage follower; And
Second electric capacity, its first end connects the second end of described 3rd switch, and its second end ground connection, the second end of described second electric capacity is for exporting described ON time timing voltage.
According to an embodiment of the present utility model, described drive signal generation circuit comprises:
Trigger, its set input receives described zero cross signal, and its RESET input receives described cut-off signals, and its output produces described drive singal; And
Driver, described drive singal transfers to the grid end of described switching tube via described driver.
According to an embodiment of the present utility model, calculate output current by carrying out sampling to the voltage on sampling resistor, and output current and reference current are carried out error amplification, to export bucking voltage.
According to an embodiment of the present utility model, obtain sampled voltage by carrying out sampling to the output end voltage of Switching Power Supply, and sampled voltage and reference voltage are carried out error amplification, to export bucking voltage.
The utility model also provides a kind of Switching Power Supply, it is characterized in that, comprising:
The switch power controller of buck configuration as above; And
The peripheral circuit be connected with described switch power controller.
According to an embodiment of the present utility model, described peripheral circuit comprises: alternating message source, rectifier bridge, input capacitance, switching tube, sampling resistor, loop compensation electric capacity, fly-wheel diode, output capacitance and inductance; Wherein, the first end of described input capacitance connects input voltage incoming end, its second end ground connection; The source of described switching tube connects input voltage incoming end, and its drain terminal connects the first end of sampling resistor, and its grid termination receives drive singal; The first end of described inductance connects the second end of sampling resistor, and the second end of inductance connects the first end of output capacitance; The negative electrode of described fly-wheel diode connects the first end of sampling resistor, and its anode connects the second end of output capacitance, and described output capacitance is used in parallel with load.
According to an embodiment of the present utility model, described peripheral circuit comprises: alternating message source, rectifier bridge, input capacitance, switching tube, sampling resistor, loop compensation electric capacity, fly-wheel diode, output capacitance and inductance; Wherein, the first end of described input capacitance connects input voltage incoming end, its second end ground connection; The negative electrode of described fly-wheel diode connects input voltage incoming end; The first end of described output capacitance connects the negative electrode of fly-wheel diode, and described output capacitance is used in parallel with load; The first end of described inductance connects the anode of fly-wheel diode, and its second end connects the second end of output capacitance; The source of described switching tube connects the first end of inductance, and its drain terminal connects the first end of sampling resistor, and via sampling resistor ground connection, its grid termination receives drive singal.
Compared with prior art, the utility model has the following advantages:
The ON time of switch power controller switch tube of the present utility model controls, make the ON time of previous or front multiple switch periods of itself and switching tube, turn-off time, switch periods time correlation connection, thus improve the power factor of circuit, reduce the total harmonic distortion of Switching Power Supply.
Furthermore, the switch power controller of the utility model embodiment make square being inversely proportional to the turn-off time of switching tube of the ON time of switching tube, to square being directly proportional of the switch periods of switching tube, i.e. the ON time T of switching tube
on, turn-off time T
off, switch periods T meet
keep fixing, make input current well follow input voltage change, realize good power factor performance.
Accompanying drawing explanation
Fig. 1 is the structural representation having power factor adjustment function in a kind of buck configuration of the prior art, adopt the LED constant-current driver that fixing ON time controls, critical conduction mode controls;
Fig. 2 is the structural representation having power factor adjustment function in the utility model embodiment one in buck configuration, adopt the LED constant-current driver that variable ON time controls, critical conduction mode controls;
Fig. 3 is the structural representation of a kind of variable ON time control circuit in the utility model embodiment one;
Fig. 4 is the structural representation of another kind of variable ON time control circuit in the utility model embodiment one;
The structural representation of ON time testing circuit in Fig. 5 the utility model embodiment one;
Fig. 6 is the structural representation having power factor adjustment function in the utility model embodiment two in buck configuration, adopt the LED constant-current driver that variable ON time controls, critical conduction mode controls.
Embodiment
Known according to the formula (1) in background technology, can not follow input voltage completely due to input current changes because fixing ON time controls caused, so in order to optimizing power factor, optimize total harmonic distortion, ON time can be revised, it is not fixed amount that fixing ON time length is revised as, but joins with the ON time of previous or front multiple switch periods, turn-off time, switch periods time correlation.
Further, formula (1) is converted into following formula:
Wherein T is the switch periods time, T
offfor the turn-off time.
In order to good power factor can be realized, need input current to follow input voltage change completely, therefore need to ensure
fixing, thus improve power factor, i.e. the ON time T of switching tube
onsquare with the turn-off time T of switching tube
ofbe inversely proportional to, to square being directly proportional of the switch periods T of switching tube.
In the utilization field of this product, the ON time of the adjacent several switch periods in Switching Power Supply is substantially the same with the switch periods time, the ON time of previous switch periods and switch periods time can be used to determine to control the ON time of next switch periods, thus realize opening square being directly proportional to the turn-off time of switching tube of the ON time of switching tube, be directly proportional to the switch periods of switching tube.
Below in conjunction with specific embodiments and the drawings, the utility model is described in further detail, but should not limit protection range of the present utility model with this.
Show the electrical block diagram of the buck topology Switching Power Supply of embodiment one with reference to figure 2, Fig. 2, this buck topology Switching Power Supply can be used as LED driver.As described in Figure 2, this Switching Power Supply comprises: alternating message source 102, rectifier bridge 101, input capacitance Cin, switching tube M1, sampling resistor Rs, loop compensation electric capacity 103, sustained diode 1, output capacitance Cbulk and switch power controller 200.The integrated connection mode of above-mentioned all parts is identical, such as identical with the Integral connection structure of Fig. 1 in background technology with conventional step-down switching power supply.That is, the first end of input capacitance Cin connects input voltage incoming end Vin, its second end ground connection; The source of switching tube M1 connects input voltage incoming end Vin, and its drain terminal connects the first end of sampling resistor Rs, and its grid termination receives drive singal GD; The first end of inductance L 1 connects second end of sampling resistor Rs, and the second end of inductance L 1 connects the first end of output capacitance Cbulk; The negative electrode of sustained diode 1 connects the first end of sampling resistor Rs, and its anode connects second end of output capacitance Cbulk; Output capacitance Cbulk is used in parallel with load, such as in parallel with LED load.
In the present embodiment, switch power controller 200 comprises: constant current counting circuit 120, error amplifier 121, variable ON time control circuit 122, trigger 123, driver 124 and zero cross detection circuit 125.
Wherein, zero cross detection circuit 125, the feedback signal FB of inductance L 1 current over-zero after detection expression drive singal GD terminates, in response to inductive current zero passage, export zero cross signal ZCD, provide the Continuity signal of switching tube M1 when inductance L 1 current over-zero, actuating switch pipe M1.The input of zero cross detection circuit 125 can be connected to the drain terminal of switching tube M1, realizes the zero passage detection to inductive current by the drain terminal signal of sense switch pipe M1, thus produces zero cross signal ZCD.
Constant current counting circuit 120, calculates output current by carrying out sampling to the voltage Vcs on sampling resistor Rs.Error amplifier 121, does error by output current and reference current and amplifies, and export bucking voltage Vcomp, bucking voltage Vcomp and connect building-out capacitor 103, after making loop stability, bucking voltage Vcomp is substantially fixing.
Variable ON time control circuit 122, the ON time of control switch pipe M1, starting timing when switching tube M1 starts conducting, when reaching the ON time of setting, exporting cut-off signals to trigger 123, remove on-off switching tube M1, after loop stability, when bucking voltage Vcomp fixes, the ON time of switching tube M1 meets following relation, square being directly proportional to the turn-off time of switching tube of ON time, to be directly proportional to the switch periods of switching tube, to realize power factor adjustment thus.
Trigger 123, receives the zero cross signal ZCD of zero cross detection circuit 125 output and the cut-off signals of variable ON time control circuit 122 output.Driver 124, connects the grid end of trigger 123 and switching tube M1, and the turn-on and turn-off realizing switch tube M1 drive.Namely, the drive signal generation circuit be made up of trigger 123 and driver 124, drive singal is produced according to described zero cross signal and cut-off signals, in response to described zero cross signal, described drive singal control switch pipe M1 conducting, in response to described cut-off signals, described drive singal control switch pipe M1 turns off.
Fig. 3 is a kind of structural representation of variable ON time control circuit.As shown in Figure 3, variable ON time control circuit 122 comprises: ON time testing circuit 401, turn-off time testing circuit 402, timing circuit produce circuit 403, timing capacitor 203 and comparator 404.
The ON time of ON time testing circuit 401 sense switch pipe, and convert this ON time to voltage signal and keep, be designated as ON time timing voltage V
ton;
The turn-off time of turn-off time testing circuit 402 sense switch pipe, and convert this ON time to voltage signal and keep, be designated as turn-off time timing voltage V
off;
The switch periods time of switch periods testing circuit 403 sense switch pipe, and this switch periods time is converted to voltage signal and keeps, be designated as switch periods time timing voltage V
t;
Timing circuit produces circuit 404, according to ON time timing voltage V
ton, turn-off time timing voltage V
off, switch periods time timing voltage V
tobtain timing circuit I1, timing circuit I1 and ON time timing voltage V
tonbe directly proportional, with turn-off time timing voltage V
offbe directly proportional, with switch periods time timing voltage V
tsquare to be inversely proportional to, that is:
Or be expressed as:
Wherein K1, K2 are constant.
Timing circuit I1 charges to timing capacitor 203, then compares with bucking voltage Vcomp, the cut-off signals of comparator 404 output switch pipe, to determine ON time, now:
Substitute into the current expression of I1, can realize
fixing.
Specifically, the ON time timing voltage that ON time testing circuit 401 obtains can represent the ON time of switching tube M1 in previous switch periods, also can represent the mean value of the ON time of switching tube M1 in front multiple switch periods.The turn-off time timing voltage that turn-off time testing circuit 402 obtains represents the turn-off time of switching tube M1 in previous switch periods, or represents the mean value of the turn-off time of switching tube M1 in front multiple switch periods.The switch periods time timing voltage that switch periods time detection circuit 403 obtains represents the switch periods time of switching tube M1 in previous switch periods, or represents the mean value of the switch periods time of switching tube M1 in front multiple switch periods.
In one embodiment, the input of ON time testing circuit 401 is directly connected with the grid end of switching tube M1, detects with the ON time of switch tube M1; The input of turn-off time testing circuit 402 is also directly connected with the grid end of switching tube M1, detects with the ON time of switch tube M1; Equally, the input of switch periods time detection circuit 403 is directly connected with the grid end of switching tube M1, detects with the switch periods time of switch tube M1.
Fig. 4 is the structural representation of another kind of variable ON time control circuit.As shown in Figure 4, variable ON time control circuit 122 comprises: turn-off time testing circuit 501, switch periods testing circuit 502, timing circuit produce circuit 503, timing capacitor 203 and comparator 404.
The turn-off time of turn-off time testing circuit 501 sense switch pipe, and convert this ON time to voltage signal and keep, be designated as turn-off time timing voltage V
off;
The switch periods time of switch periods testing circuit 502 sense switch pipe, and this switch periods time is converted to voltage signal and keeps, be designated as switch periods time timing voltage V
t;
Timing circuit produces circuit 503, according to turn-off time timing voltage V
off, switch periods time timing voltage V
tobtain timing circuit I2, timing circuit I2 and turn-off time timing voltage V
offsquare root be directly proportional, with switch periods time timing voltage V
tbe inversely proportional to, that is:
Wherein K3, K4 are constant.
Timing circuit I2 charges to timing capacitor 203, then compares with bucking voltage Vcomp, the cut-off signals of comparator 404 output switch pipe, to determine ON time, passes through and derivation similar above, can realize equally
fixing.
Show a kind of realizing circuit of ON time testing circuit 401 with reference to figure 5, Fig. 5, comprising: current source 601, first switch S 1, second switch S2, the 3rd switch S 3, first electric capacity 604, voltage follower 605 and the second electric capacity 607.
Wherein, the first switch S 1, its first end connects the output of current source 601; Second switch S2, its first end connects the second end of the first switch S 1, its second end ground connection; First electric capacity 604, its first end connects the second end of the first switch S 1 and the first end of second switch S2, its second end ground connection; Voltage follower 605, its input connects the first end of the first electric capacity 604; 3rd switch S 3, its first end connects the output of voltage follower 605; Second electric capacity 607, its first end connects the second end of the 3rd switch S 3, and its second end ground connection, the second end of the second electric capacity 607 is for exporting ON time timing voltage V
ton.
Furthermore, during switching tube M1 conducting, first switch S 1 is controlled as conducting, second switch S2 is controlled as shutoff, 3rd switch S 3 is controlled as shutoff, the output current I3 of current source 601 charges to the first electric capacity 604, and the voltage at the first electric capacity 604 two ends is directly proportional to the ON time of switching tube M1, directly can react ON time; When switching tube M1 turns off, first switch S 1 is controlled as shutoff, second switch S2 is controlled as shutoff, 3rd switch S 3 is controlled as conducting, the voltage at the first electric capacity 607 two ends is maintained, the voltage at the first electric capacity 604 two ends is delivered on the second electric capacity 607 through voltage follower 605, the 3rd switch S 3, thus obtains the ON time timing voltage V representing ON time at the two ends of the second electric capacity 607
ton; After Preset Time, the first switch S 1 turns off, second switch S2 conducting, and the 3rd switch S 3 turns off, and the voltage at the first electric capacity 604 two ends resets, and the voltage at the second electric capacity 607 two ends remains unchanged.Next, wait for next switch periods, again detect ON time.
Be understandable that, the realizing circuit of switch periods time detection circuit 403 and the realizing circuit of turn-off time testing circuit 403 can be identical with ON time testing circuit 401.Such as, also the circuit structure shown in Fig. 5 can be adopted.
The set input of trigger 123 receives zero cross signal ZCD, and the RESET input receives the cut-off signals from variable ON time length control circuit 301, and its output produces drive singal with the turn-on and turn-off of control switch pipe M1.As a nonrestrictive example, this drive singal is via the grid end transferring to switching tube M1 after driver 124.
Fig. 6 is the structural representation having power factor adjustment function in the utility model embodiment two in buck configuration, adopt the LED constant-current driver that variable ON time controls, critical conduction mode controls.In the embodiment shown in fig. 6, the switch power controller 300 in Fig. 2 is applied in the Switching Power Supply of buck configuration on the spot.Shown in figure 6, the first end of input capacitance Cin connects input voltage incoming end Vin, its second end ground connection; The negative electrode of sustained diode 1 connects input voltage incoming end Vin; The first end of output capacitance Cbulk connects the negative electrode of sustained diode 1, and output capacitance Cbulk is used in parallel with load, such as in parallel with LED load; The first end of inductance L 1 connects the anode of sustained diode 1, and its second end connects second end of output capacitance Cbulk.The source of switching tube M1 connects the first end of inductance L 1, and its drain terminal connects the first end of sampling resistor Rcs, and via sampling resistor Rcs ground connection, its grid termination receives drive singal GT.So, the first end of inductance L 1 is via switching tube M1 and sampling resistor Rcs formation path over the ground.Sampling resistor Rcs by flowing through inductance L 1, the inductive current of switching tube M1 is converted to sampled voltage CS.
It will be appreciated by those skilled in the art that what adopt in the embodiment shown in Fig. 2 and Fig. 6 is current constant control loop, what it controlled is LED output current, and wherein loop compensation electric capacity 103 is for loop compensation.If adopt Isobarically Control loop, controlled quentity controlled variable is changed to output voltage Vout, then loop compensation electric capacity 103 is for the stability of bucking voltage loop, and bucking voltage Vcomp is that error amplifies voltage.Specifically, the constant current counting circuit 120 in Fig. 6 is replaced by voltage sampling circuit, the output end vo ut voltage of Switching Power Supply is sampled, obtains sampled voltage; And the sampled voltage that error amplifier 121 changes into voltage sampling circuit exports carries out error amplification with default reference voltage, export bucking voltage, this bucking voltage is applied on loop compensation electric capacity 103; Other circuit structures are constant, can realize power factor adjustment, realize output voltage constant simultaneously.The mode being configured with constant current counting circuit or voltage sampling circuit with switch power controller is above described in detail, but will be appreciated that, as long as variable ON time control circuit can receive the drive singal of bucking voltage and switching tube, described current constant control loop or voltage sampling circuit to be also configurable in peripheral circuit but not to be limited to switch power controller inside.
The utility model discloses and there is power factor adjustment function, the switch power controller that critical conduction mode controls, and describe embodiment of the present utility model and effect with reference to the accompanying drawings.It is to be understood that above-described embodiment is just to explanation of the present utility model; instead of to restriction of the present utility model; any utility model do not exceeded in the utility model spirit is created; comprise zero cross detection circuit, ON time length control circuit, flip-flop circuit; the replacement of the change to the local structure of circuit, the type to components and parts or model; and the replacement of other unsubstantialities or amendment, all fall within the utility model protection range.
Claims (14)
1. a switch power controller, is characterized in that, comprising:
Zero cross detection circuit, carries out zero passage detection to the feedback signal of input and produces zero cross signal;
Variable ON time length control circuit, receive the drive singal of bucking voltage and switching tube, make square being inversely proportional to the turn-off time of switching tube of the ON time of the switching tube of Switching Power Supply, to square being directly proportional of the switch periods of switching tube, and produce cut-off signals; And
Drive signal generation circuit, produce drive singal according to described zero cross signal and cut-off signals, described drive singal transfers to the grid end of described switching tube, to control the turn-on and turn-off of described switching tube.
2. switch power controller as claimed in claim 1, it is characterized in that, described variable ON time length control circuit comprises:
ON time testing circuit, detects the ON time of the switching tube in described Switching Power Supply, to obtain ON time timing voltage;
Turn-off time testing circuit, detects the ON time of the switching tube in described Switching Power Supply, to obtain turn-off time timing voltage;
Switch periods time detection circuit, detected the switch periods time of described switching tube, to obtain switch periods time timing voltage;
Timing circuit produces circuit, according to described ON time timing voltage, turn-off time timing voltage, switch periods time timing voltage, produce timing circuit, described timing circuit be directly proportional to ON time timing voltage, be directly proportional to turn-off time timing voltage, and square being inversely proportional to of switch periods time timing voltage;
Timing capacitor and comparator, in switching tube conduction period, described timing circuit charges to timing capacitor, and compares with bucking voltage, obtains cut-off signals.
3. switch power controller as claimed in claim 1, it is characterized in that, described variable ON time length control circuit comprises:
Turn-off time testing circuit, detects the ON time of the switching tube in described Switching Power Supply, to obtain turn-off time timing voltage;
Switch periods time detection circuit, detected the switch periods time of described switching tube, to obtain switch periods time timing voltage;
Timing circuit produces circuit, according to described turn-off time timing voltage, switch periods time timing voltage, produces timing circuit, described timing circuit is directly proportional to the square root of turn-off time timing voltage, is inversely proportional to switch periods time timing voltage;
Timing capacitor and comparator, in described switching tube conduction period, described timing circuit charges to timing capacitor, and compares with bucking voltage, obtains cut-off signals.
4. switch power controller as claimed in claim 2, it is characterized in that, the ON time timing voltage that described ON time testing circuit obtains represents the ON time of described switching tube in previous switch periods, or represents the mean value of the ON time of described switching tube in front multiple switch periods.
5. switch power controller as claimed in claim 2 or claim 3, it is characterized in that, the turn-off time timing voltage that described turn-off time testing circuit obtains represents the turn-off time of described switching tube in previous switch periods, or represents the mean value of the turn-off time of described switching tube in front multiple switch periods.
6. switch power controller as claimed in claim 2 or claim 3, it is characterized in that, the switch periods time timing voltage that described switch periods time detection circuit obtains represents the switch periods time of described switching tube in previous switch periods, or represents the mean value of the switch periods time of described switching tube in front multiple switch periods.
7. switch power controller as claimed in claim 2, it is characterized in that, the input of described ON time testing circuit is directly connected with the grid end of described switching tube, to detect the ON time of described switching tube.
8. switch power controller as claimed in claim 2 or claim 3, it is characterized in that, the input of described turn-off time testing circuit is directly connected with the grid end of described switching tube, to detect the ON time of described switching tube.
9. switch power controller as claimed in claim 2 or claim 3, it is characterized in that, the input of described switch periods time detection circuit is directly connected with the grid end of described switching tube, to detect the switch periods time of described switching tube.
10. switch power controller as claimed in claim 2, it is characterized in that, it is characterized in that, described ON time testing circuit comprises:
Current source;
First switch, its first end connects the output of described current source;
Second switch, its first end connects the second end of described first switch, its second end ground connection;
First electric capacity, its first end connects the second end of described first switch and the first end of second switch, its second end ground connection;
Voltage follower, its input connects the first end of described first electric capacity;
3rd switch, its first end connects the output of described voltage follower; And
Second electric capacity, its first end connects the second end of described 3rd switch, and its second end ground connection, the second end of described second electric capacity is for exporting described ON time timing voltage.
11. switch power controllers as claimed in claim 1, it is characterized in that, described drive signal generation circuit comprises:
Trigger, its set input receives described zero cross signal, and its RESET input receives described cut-off signals, and its output produces described drive singal; And
Driver, described drive singal transfers to the grid end of described switching tube via described driver.
12. 1 kinds of Switching Power Supplies, is characterized in that, comprising:
Switch power controller according to any one of claim 1 to 11; And
The peripheral circuit be connected with described switch power controller.
13. Switching Power Supplies as claimed in claim 12, it is characterized in that, described peripheral circuit comprises: alternating message source, rectifier bridge, input capacitance, switching tube, sampling resistor, loop compensation electric capacity, fly-wheel diode, output capacitance and inductance; Wherein, the first end of described input capacitance connects input voltage incoming end, its second end ground connection; The source of described switching tube connects input voltage incoming end, and its drain terminal connects the first end of sampling resistor, and its grid termination receives drive singal; The first end of described inductance connects the second end of sampling resistor, and the second end of inductance connects the first end of output capacitance; The negative electrode of described fly-wheel diode connects the first end of sampling resistor, and its anode connects the second end of output capacitance, and described output capacitance is used in parallel with load.
14. Switching Power Supplies as claimed in claim 12, it is characterized in that, described peripheral circuit comprises: alternating message source, rectifier bridge, input capacitance, switching tube, sampling resistor, loop compensation electric capacity, fly-wheel diode, output capacitance and inductance; Wherein, the first end of described input capacitance connects input voltage incoming end, its second end ground connection; The negative electrode of described fly-wheel diode connects input voltage incoming end; The first end of described output capacitance connects the negative electrode of fly-wheel diode, and described output capacitance is used in parallel with load; The first end of described inductance connects the anode of fly-wheel diode, and its second end connects the second end of output capacitance; The source of described switching tube connects the first end of inductance, and its drain terminal connects the first end of sampling resistor, and via sampling resistor ground connection, its grid termination receives drive singal.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201520426073.7U CN204886731U (en) | 2015-06-18 | 2015-06-18 | Switching power supply controller and contain switching power supply of this switching power supply controller |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201520426073.7U CN204886731U (en) | 2015-06-18 | 2015-06-18 | Switching power supply controller and contain switching power supply of this switching power supply controller |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105048832A (en) * | 2015-06-18 | 2015-11-11 | 杭州士兰微电子股份有限公司 | Switch power supply controller and switch power supply including the switch power supply controller |
| CN111025035A (en) * | 2018-10-10 | 2020-04-17 | 深圳市必易微电子有限公司 | Demagnetization detection circuit and control circuit and method thereof |
| CN112954844A (en) * | 2020-09-15 | 2021-06-11 | 青岛胶州海尔智控电子有限公司 | Lamp brightness adjusting method, lamp brightness adjusting circuit and range hood |
| TWI796869B (en) * | 2020-12-10 | 2023-03-21 | 美商茂力科技股份有限公司 | Adaptive constant on-time control circuit and switching converter and method thereof |
-
2015
- 2015-06-18 CN CN201520426073.7U patent/CN204886731U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105048832A (en) * | 2015-06-18 | 2015-11-11 | 杭州士兰微电子股份有限公司 | Switch power supply controller and switch power supply including the switch power supply controller |
| CN111025035A (en) * | 2018-10-10 | 2020-04-17 | 深圳市必易微电子有限公司 | Demagnetization detection circuit and control circuit and method thereof |
| CN112954844A (en) * | 2020-09-15 | 2021-06-11 | 青岛胶州海尔智控电子有限公司 | Lamp brightness adjusting method, lamp brightness adjusting circuit and range hood |
| TWI796869B (en) * | 2020-12-10 | 2023-03-21 | 美商茂力科技股份有限公司 | Adaptive constant on-time control circuit and switching converter and method thereof |
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