CN105207488A - Loop control circuit of fly-back switching power supply and fly-back switching power supply adopting loop control circuit - Google Patents
Loop control circuit of fly-back switching power supply and fly-back switching power supply adopting loop control circuit Download PDFInfo
- Publication number
- CN105207488A CN105207488A CN201510705176.1A CN201510705176A CN105207488A CN 105207488 A CN105207488 A CN 105207488A CN 201510705176 A CN201510705176 A CN 201510705176A CN 105207488 A CN105207488 A CN 105207488A
- Authority
- CN
- China
- Prior art keywords
- resistance
- input
- voltage
- pin
- output
- 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.)
- Granted
Links
Landscapes
- Dc-Dc Converters (AREA)
Abstract
A loop control circuit of a fly-back switching power supply in open-loop operation comprises an input end VI1, an input end VI2, a booster S1, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a voltage stabilizing pipe IC1 and an operational amplifier A1, wherein the output pin of the operational amplifier A1 is connected with an FB pin of a pulse-width modulation controller IC2; when the input voltage is slightly lower than a first preset value, the operational amplifier outputs high level, and the IC2 outputs the minimum duty ratio; when the input voltage is greater than the first preset value, the operational amplifier outputs low level, the IC2 outputs greater duty ratio, and the trend of the output of the IC2 is the same as that of the input voltage. When used for the fly-back switching power supply which is in the open-loop operation in an equalizing charge circuit, the loop control circuit can normally operate, is simple, and is convenient to debug.
Description
Technical field
The present invention relates to inverse-excitation type switch power-supply, particularly the loop control circuit of inverse-excitation type switch power-supply.
Background technology
At present, for the Switching Power Supply of input power at below 75W, to power factor (PF) (PF, PowerFactor, also claims power factor) do not make the occasion that requires, inverse-excitation type (Fly-back) Switching Power Supply has charming advantage, circuit topology is simple, wide input voltage range.Inverse-excitation type switch power-supply due to element few, the reliability of circuit is relatively high, so application is very wide, conveniently, a lot of document is referred to as reverse exciting switching voltage regulator.
Inverse-excitation type switch power-supply in order to realize the stable of output voltage, or during for charging purposes, requires the stable of output current, and all will realize the stable of loop, major part adopts two kinds of feedbacks, loop control methods at present:
The first: classical opto-coupled feedback loop control methods, the accurate integrated circuit of this three end group of general employing TL431, be also called the accurate integrated circuit of three end groups, hereinafter referred to as three end a reference sources, output voltage is sampled, when output voltage uprises, the Absorption Current of TL431 becomes large, the ER effect flowing through optocoupler is large, also direct proportion change is large for the electric current of the output of optocoupler, the duty ratio of the Switching Power Supply on former limit diminishes, and the energy like this through flyback transformer transmission diminishes, and makes the output voltage of inverse-excitation type switch power-supply drop to output voltage preset value.This mode is applied extremely wide.Fig. 1 shows this application, in FIG, input voltage is lower, for 36v to 75V, wherein, U3 is the accurate integrated circuit TL431 of three end groups, U2 is optocoupler, the circuit of Fig. 1 is from official's tables of data (DataSheet) the 4th page of the ISL6840 of intersil company of U.S. version in 2012, and reference number of a document is FN9124.11, PDM keyer ISL6840 is one of substitute of PDM keyer UC3843, the operating frequency of ISL6840 is higher, in the application that most operating frequency is more conventional, and UC3843 can directly exchange, representative.In order to realize the stable of output voltage, loop gain is general all larger, DC current gain (0Hz) is general at more than 60dB, namely 1000 times, conveniently understand, can understand so simply, make output voltage decline 1V for a certain reason, due to the existence of loop, when finally settling out, only decline 1V/1000=1mV; Generally more than 30dB is had, namely more than 30 times under the frequency of 10Hz,
This mode is similar to operational amplifier, and the open-loop gain of operational amplifier is higher, exports more stable after closed loop.Classical opto-coupled feedback method shown in Fig. 1, drop to example with output voltage, its closed loop path is: the output current of output voltage decline → TL431 diminishes → electric current of optocoupler U2 diminishes → Absorption Current of optocoupler U2 diminishes → the OUT pin output duty cycle of the voltage drop → PDM keyer U4 of FB pin that the output of optocoupler U2 is connected become large → master power switch pipe Q1 to the transformer T1 excitatory time elongated → rising of transformer T1 secondary afterflow energy increases → output voltage.
The FB pin of attention: ISL6840 and COMP pin voltage reversal, FB is its anti-phase input pin, COMP pin is corresponding inside amplifier output, and the control IC of common AC-DC converter, as NCP1234, the voltage rise of its FB pin, corresponding GATE drives pin output duty cycle to become large, and GATE drives pin to be also designated as OUT pin in official's tables of data of a lot of company.
Drop to output voltage from output voltage to rise, the gain of this loop, DC current gain (0Hz) is general at more than 60dB, certain reason causes output voltage to rise, and the course of work is similar, so parameter changes in the opposite direction, ER effect is changed into greatly as electric current diminishes, etc.
Fig. 2 shows the popular inverse-excitation type switch power-supply of another money, from official's tables of data of the TNY290 of U.S. PowerIntegrations, Inc., file name is " TNY284-290TinySwitch-4Family ", the 8th page of version B08/13, wherein, U2 is TL431, U3 is optocoupler, in this kind of scheme, the integrated circuit of TNY2XX series, year shipment amount be greater than 100,000,000, to be widely used in the ATX power supply of computer, as standby power, having representativeness.
The second: adopt former limit feedback loop control, a winding is set up on former limit, utilize that desirable inverse-excitation type switch power-supply multiple-channel output voltage is to the turn ratio exported between winding relevant to be realized, the output of inverse-excitation type switch power-supply obtains energy so gain the name when former limit winding deenergization, output voltage depends on loop control circuit, has nothing to do with the former limit of flyback transformer (the transformer T1 in Fig. 1, Fig. 2) and the turn ratio of secondary; In energy transfer process, transformer T1 is not the effect of voltage of transformation, but across the effect of magnetic core afterflow, is the isolation version of One Buck-Boost converter body; So transformer T1 is also called flyback transformer usually;
Inverse-excitation type switch power-supply does not have output inductor in theory, only has output filter capacitor, be equivalent to voltage source, as long as a road is stablized, do not consider the pressure drop of the diode of other rectification, all the other each roads of multiple-channel output export by the turn ratio is stable substantially, this is a normal shock process, be equivalent to the driving source winding of normal shock by this road of voltage stabilizing, other is vice-side winding this moment, and its output voltage is the induced voltage by the turn ratio.But due to the existence of leakage inductance between each winding, produce intersection adjustment problem, also referred to as cross regulation rate problem.
This winding set up on former limit, also connects rectification circuit, utilizes its output voltage to monitor the output voltage of main road, realizes the output voltage stabilization of main road, this mode, is former limit feedback fly-back Switching Power Supply.This winding that former limit is set up also is in fact one of vice-side winding.
Fig. 3 shows the schematic diagram of former limit feedback fly-back Switching Power Supply, and equally from the scheme of U.S. PowerIntegrations, Inc., official's tables of data of LNK603-606, file name is " LNK603-606/613-616
product line "; the 4th page of version F01/10; wherein, whole circuit can not find optocoupler and TL431, in flyback transformer T1; this winding of terminal 2 to 4; sign in secondary by vice-side winding is in figure 3 exactly former limit feedback winding, by resistance R5 and R6 dividing potential drop; give the FB pin of integrated circuit U1, realizes the stable of output voltage.In this kind of scheme, the integrated circuit of LNK6XX series, year shipment amount be greater than 100,000,000, be widely used in the standby power of intelligent appliance, and in charger for mobile phone, have representativeness.
Shown in Fig. 4 is the charger of the iW1677 scheme of iWatt company of the U.S., also be former limit feedback fly-back Switching Power Supply, official tables of data EBC10004 the 5th page, wherein, whole circuit can not find optocoupler and TL431, and in flyback transformer T1, former limit feedback winding is connected with diode D6 anode, by resistance R7 and R9 dividing potential drop, give the V of integrated circuit (IC) 1
sENSEpin, realizes the stable of output voltage 5V.In this kind of scheme, the integrated circuit of this series of iWatt, year shipment amount be greater than 100,000,000, be widely used in the standby power of intelligent appliance, and in charger for mobile phone, have representativeness equally.
Scheme shown in Fig. 3 and Fig. 4, still similar with the course of work of classical opto-coupled feedback method in essence, former limit feedback transmitter shown in Fig. 3, example is dropped to output voltage, its closed loop path is: diode D7 negative electrode output voltage declines → at D and the S pin blocking interval of integrated circuit U1, during diode D7 afterflow, 2 of transformer T1, 4 feels answer the dividing potential drop of voltage in proportion decline → resistance R5 and R6 tie point also decline → D and the S pin output duty cycle of the voltage drop → integrated circuit U1 of FB pin becomes large → PDM keyer U1 to 3 of transformer T1, excitatory time of 5 former limit windings is elongated → and transformer T1 secondary afterflow energy increase → diode D7 negative electrode output voltage rises.
Drop to output voltage from output voltage to rise, the gain of this loop, in order to realize the stable of output voltage, DC current gain (0Hz) is general at more than 60dB.
These two kinds of modes are main flow circuit modes that current inverse-excitation type switch power-supply loop controls, the output voltage precision of former limit feedback fly-back Switching Power Supply is not high, dynamic load ability is poor, because really by stable be the both end voltage of feedback winding, be generally used for charger and standby power, these two kinds of circuit, all cannot be used for Chinese application number is in " a kind of equalization charging circuit and the battery pack " of 201410459391.3, in the disclosure in this patent, give a kind of equalization charging circuit, the inverse-excitation type DC-DC converter comprising testing circuit and controlled by testing circuit, lay special stress on: when testing circuit detects that the voltage between first input end and the second input is greater than set point, the output output duty cycle signal of testing circuit, control N-MOS pipe is operated on off state, when testing circuit detects that voltage between first input end and the second input is below set point, the output output low level of testing circuit, allows N-MOS pipe end.
Its claim specify that described equalization charging circuit is a kind of flyback sourse of operate in open loop state, the above-mentioned two kinds feedback systems for loop control are all improper, for those skilled in the art, utilizing feedback method that two kinds of above-mentioned prior aries provide in conjunction with above-mentioned patent application, is cannot carry out effectively implementing to described patent.As: when testing circuit detects that the voltage between first input end and the second input is greater than set point, the output output duty cycle signal of testing circuit, control N-MOS pipe is operated on off state; How to solve the magnetic saturation electric current of transformer? how to control duty ratio in certain suitable value?
For those skilled in the art, it is in " a kind of equalization charging circuit and the battery pack " of 201410459391.3 that the loop control method of existing inverse-excitation type switch power-supply cannot be directly used in application number.
Summary of the invention
In view of this, the present invention will solve the inverse-excitation type switch power-supply that existing loop control circuit cannot be applied to operate in open loop state, particularly when this inverse-excitation type switch power-supply is used for equalization charging circuit, the invention provides a kind of loop control circuit of inverse-excitation type switch power-supply, still keep operate in open loop state state, during for equalization charging circuit, can normally effectively work.
The object of the present invention is achieved like this, a kind of loop control circuit of inverse-excitation type switch power-supply, comprise input VI1, input VI2, output VO1, stepup transformer S1, resistance R1, resistance R2, resistance R3, resistance R4, resistance R5, voltage-stabiliser tube IC1, operational amplifier A 1, described stepup transformer S1 comprises three terminals: input 1, earth terminal 2, output 3.Its annexation is: input VI1 connects the earth terminal 2 of stepup transformer S1, one end of contact resistance R2 while of input VI, and input VI1 connects the anode of voltage-stabiliser tube IC1 simultaneously, the lower margin of input VI1 concatenation operation simultaneously amplifier A1; Input VI2 connects the input 1 of stepup transformer S1, one end of contact resistance R1 while of input VI2; The other end of the other end contact resistance R2 of resistance R1, the homophase input pin of tie point also concatenation operation amplifier A1; The supply pin of the output 3 concatenation operation amplifier A1 of stepup transformer S1, the output 3 of stepup transformer S1 goes back one end of contact resistance R3, and the other end of resistance R3 connects the negative electrode of voltage-stabiliser tube IC1, and tie point is also by resistance R5 concatenation operation amplifier A1 anti-phase input pin; Anti-phase input pin also contact resistance R4 one end of operational amplifier A 1, the output pin of resistance R4 other end concatenation operation amplifier A1; The output pin of operational amplifier A 1 is the output VO2 of the loop control circuit of inverse-excitation type switch power-supply.
Preferably, stepup transformer S1 is controlled stepup transformer, and when the voltage between input VI1 and input VI2 is more than or equal to the first preset value, the voltage of the output 3 of stepup transformer S1 just has output.
Preferably, voltage-stabiliser tube IC1 is three end adjustable shunt reference sources.
More preferably, the loop control circuit of inverse-excitation type switch power-supply also comprises diode D1, and the negative electrode of diode D1 is connected to the resistance R4 other end, and the anode of diode D1 is connected to the output pin of operational amplifier A 1; Or the negative electrode of diode D1 is connected to resistance R4 one end, the anode of diode D1 is connected to the reverse input pin of operational amplifier A 1.
As a kind of concrete execution mode of above-mentioned stepup transformer S1, its inside comprises: resistance R61, resistance R62, resistance R63, resistance R64, voltage checking chip IC61, CMOS boosting DC/DC control chip IC62, inductance L 61, diode D61, electric capacity C61 and switch transistor T R61; Input 1 according to this after resistance R61 and resistance R62 to earth terminal 2; The ON/OFF pin that the grounding leg 1 of voltage checking chip IC61 connects earth terminal 2, level output pin 2 meets CMOS boosting DC/DC control chip IC62, the tie point of voltage input pin 3 connecting resistance R61 and resistance R62, supply pin 4 connect input 1; Input 1 is also connected to the collector electrode of switch transistor T R61 after inductance L 61, and the emitter of switch transistor T R61 is connected to earth terminal 2, and the ground level of switch transistor T R61 is connected to the EXT pin of CMOS boosting DC/DC control chip IC62; The anode of diode D61 be connected to the collector electrode of switch transistor T R61, negative electrode according to this after resistance R63 and resistance R64 to earth terminal 2; The tie point that VDD pin is connected to input 1, VSS pin is connected to earth terminal 2, Vout pin is connected to resistance R63 and resistance R64 of CMOS boosting DC/DC control chip IC62; Output 3 serial capacitance C61 is to earth terminal 2.
The present invention also provides a kind of Switching Power Supply applying above-mentioned loop control circuit, and concrete technical scheme is as follows:
A kind of inverse-excitation type switch power-supply, comprises power stage circuit and PDM keyer, includes a power switch pipe, it is characterized in that in described power stage circuit: comprise arbitrary described loop control circuit above.
Operation principle:
It is in " a kind of equalization charging circuit and the battery pack " of 201410459391.3 that technique scheme is used for application number, testing circuit U1 described in this patent application of Some substitute, so, the output pin of operational amplifier A 1, be the output VO1 of the loop control circuit of inverse-excitation type switch power-supply, connect the COMP pin of PDM keyer, COMP is the output of the error amplifier of PDM keyer inside and the input of PWM comparator.The output of PDM keyer, is generally designated as OUT or GATE pin, is connected with the grid of N-MOS pipe, realizes the control to inverse-excitation type DC-DC converter.Namely technique scheme also will connect PDM keyer, the testing circuit U1 described in could realizing.PDM keyer is exactly common Switching Power Supply main control integrated circuit, ISL6840 as described in the background art.
So, the present invention is the technical characteristic goal of the invention how realizing above-mentioned patent: when testing circuit detects that the voltage between input VI1 and input VI2 is greater than set point, the output output duty cycle signal of testing circuit, control N-MOS pipe is operated on off state; When testing circuit detects that voltage between input VI1 and input VI2 is below set point, the output output low level of testing circuit, allows N-MOS pipe end.
When input voltage between input VI1 and input VI2 is less than set point, as cell voltage be less than set point time, namely the first preset value is less than, at this moment, resistance R1 and resistance R2 is series relationship, resistance R2 gets voltage in two ends pro rata, this voltage is the homophase input pin being added to operational amplifier A 1, now, the bias voltage of the anti-phase input pin of operational amplifier A 1 equals the puncture voltage of voltage-stabiliser tube IC1, the puncture voltage source of voltage-stabiliser tube IC1: input VI2 is to the input voltage of input VI1, after stepup transformer S1 boosts, voltage-stabiliser tube IC1 two ends are added to through resistance R3, voltage-stabiliser tube IC1 two ends obtain the puncture voltage of a voltage stabilizing.
Anti-phase input pin also contact resistance R4 one end of operational amplifier A 1, the output pin of resistance R4 other end concatenation operation amplifier A1; Namely resistance R4 is the feedback resistance of operational amplifier A 1, and this operational amplifier A 1 is connected into homophase amplification mode, and its gain is [(resistance R4/ resistance R5)+1];
At this moment the voltage at resistance R2 two ends is less than the both end voltage of voltage-stabiliser tube IC1, namely operational amplifier A 1 homophase input pin voltage is lower than anti-phase input pin, operational amplifier A 1 output low level is to the COMP pin of PDM keyer, PDM keyer will possess following feature: COMP pin voltage raises, its pulse duty cycle exported raises, otherwise be COMP pin voltage drop, its pulse duty cycle exported declines.
So, when the input voltage between input VI1 and input VI2 is less than set point, operational amplifier A 1 output low level, PDM keyer exports minimum duty cycle.
When input voltage between input A1 and input A2 is greater than set point, as cell voltage be greater than set point time, namely the first preset value is greater than, at this moment, the voltage at resistance R2 two ends is greater than the both end voltage of voltage-stabiliser tube IC1, namely operational amplifier A 1 homophase input pin is higher than anti-phase input pin, and operational amplifier A 1 exports high level to the COMP pin of PDM keyer, and PDM keyer exports comparatively big space rate.
Utilize known technology, be not difficult to obtain: operational amplifier A 1 is connected into homophase amplification mode, its gain is [(resistance R4/ resistance R5)+1]; Desirable operational amplifier A 1 is when homophase amplifies configuration, and the input impedance of homophase input pin itself is infinitely great.
By the voltage ratio of regulating resistance R1 and resistance R2, or adjust the puncture voltage of voltage-stabiliser tube IC1, i.e. voltage stabilizing value, can change the size of described set point.
By the resistance of regulating resistance R4 or resistance R5, the gain of operational amplifier A 1 just can be changed; Meanwhile, do not affect resistance R1 and resistance R2 voltage ratio, change gain very convenient, so just can realize following function:
When input voltage between input VI1 and input VI2 reaches limit value, or more time, the output pin of PDM keyer exports maximum duty cycle, and maximum duty cycle will meet: inverse-excitation type DC-DC converter magnetic core is unsaturated, and other circuit normally works.
Beneficial effect of the present invention is:
(1) being applied to Chinese application number is in " a kind of equalization charging circuit and the battery pack " of 201410459391.3, can normally work;
(2) principle is easily grasped and is implemented;
(3) control strategy is comparatively simple, and various control strategy can be used to implement.
Accompanying drawing explanation
Fig. 1 is the classical opto-coupled feedback method inverse-excitation type switch power-supply of existing employing ISL6840 as control chip;
Fig. 2 is the classical opto-coupled feedback method inverse-excitation type switch power-supply of existing employing TNY290 as control chip;
Fig. 3 is the classics former limit feedback fly-back Switching Power Supply of existing employing LNK6XX as control chip;
Fig. 4 is the classics former limit feedback fly-back Switching Power Supply of existing employing iW1677 as control chip;
Fig. 5 is the schematic diagram of first, second embodiment;
Fig. 6 is the schematic diagram of controlled stepup transformer;
Fig. 7 is the schematic diagram of the 3rd embodiment.
Embodiment
First embodiment
Refer to Fig. 5, a kind of loop control circuit of inverse-excitation type switch power-supply, comprise input VI1, input VI2, the output VO1 (output of operational amplifier A 1 in figure, be connected with the COMP pin of IC2), stepup transformer S1, resistance R1, resistance R2, resistance R3, resistance R4, resistance R5, voltage-stabiliser tube IC1, operational amplifier A 1, described stepup transformer S1 comprises three terminals: input 1, earth terminal 2, output 3.Its annexation is: input VI1 connects the earth terminal 2 of stepup transformer S1, one end of contact resistance R2 while of input VI1, and input VI1 connects the anode of voltage-stabiliser tube IC1 simultaneously, the lower margin of input VI1 concatenation operation simultaneously amplifier A1; Input VI2 connects the input 1 of stepup transformer S1, one end of contact resistance R1 while of input VI2; The other end of the other end contact resistance R2 of resistance R1, the homophase input pin of tie point also concatenation operation amplifier A1; The supply pin of the output 3 concatenation operation amplifier A1 of stepup transformer S1, the output 3 of stepup transformer S1 goes back one end of contact resistance R3, the other end of resistance R3 connects the negative electrode of voltage-stabiliser tube IC1, and tie point is also by the anti-phase input pin of resistance R5 concatenation operation amplifier A1; Anti-phase input pin also contact resistance R4 one end of operational amplifier A 1, the output pin of resistance R4 other end concatenation operation amplifier A1; The output pin of operational amplifier A 1 is the output VO1 of the loop control circuit of inverse-excitation type switch power-supply, is connected with the COMP pin of integrated circuit (IC) 2.
IC2 is PDM keyer, is ISL6841; Other circuit parameter is as follows:
Resistance R1 is 2.7M, and resistance R2 is 1.2M, and resistance R3 is 82K, and resistance R4 is 2.4M, and resistance R5 is 10K, and voltage-stabiliser tube IC1 is the voltage-stabiliser tube of 1.4V, and operational amplifier A 1 is uA741, and stepup transformer is the typical application circuit of S-8356Q50.
Stepup transformer is S-8356Q50, and the input voltage of 3.0V to 4.4V is risen to 9.0V, and voltage-stabiliser tube IC1 is the voltage-stabiliser tube of 1.4V, be used in traditional broadcast receiver as biasing circuit, because its current-limiting resistance R3 obtains comparatively large, be 82K, the terminal voltage of actual measurement voltage-stabiliser tube IC1 is 1.29V.
Circuit connects well, and connect external adjustable stabilized voltage power supply between input VI1 and input VI2, voltage is between 4.1V to 4.3V, and actual measurement can complete goal of the invention:
When input voltage is at below 4.195V, PDM keyer IC2 output low level;
When input voltage is at 4.195V to 4.196V, PDM keyer IC2 exports minimum duty cycle.Visible, 4.195V is the first preset value.
When input voltage is at more than 4.197V, but be less than 4.249V, PDM keyer IC2 exports and strains large duty ratio mutually;
When input voltage 4.250V and above time, PDM keyer IC2 exports maximum duty ratio: 50%;
Above-mentioned voltage is the voltage design by present more popular lithium battery, if deboost is changed into 4.30V, so, resistance R4 will suitably reduce, or increase R5.
The weak point of this circuit is: when input voltage is at below 4.195V, and circuit is still in running order, and power consumption is 10.9mA, and embodiment two improves this deficiency.
Second embodiment
Second embodiment circuit composition and annexation identical with the first embodiment, difference is that PDM keyer IC2 is UC3843; And TL432, said above, voltage-stabiliser tube IC1 is the voltage-stabiliser tube of 1.4V, because its current-limiting resistance R3 obtains comparatively large, is 75K, and the terminal voltage of actual measurement voltage-stabiliser tube IC1 is 1.29V, and the temperature drift of voltage-stabiliser tube is comparatively large, in a second embodiment, is replaced by TL432; And to limit IC2 maximum duty cycle by IC2 the 4th pin outer meeting resistance be 0.65, other circuit parameter is as follows:
Resistance R1 is 4.3M, resistance R2 is 1.8M, resistance R3 is 20K Ω, and resistance R4 is 1.1M, and resistance R5 is 4.3K, voltage-stabiliser tube IC1 is TL432, the reference voltage of an acquisition 1.24V that reference edge is connected with negative electrode, and operational amplifier A 1 is OP-09, stepup transformer is the circuit shown in Fig. 6, is controlled stepup transformer.
The stepup transformer of Fig. 6 circuit comprises three terminals: input 1, earth terminal 2, output 3.Stepup transformer inside comprises resistance R61, resistance R62, resistance R63, resistance R64, voltage checking chip IC61, CMOS boost DC/DC control chip IC62, inductance L 61, diode D61, electric capacity C61, switch transistor T R61, and annexation is: input 1 according to this after resistance R61 and resistance R62 to earth terminal 2; The ON/OFF pin that the grounding leg 1 of voltage checking chip IC61 connects earth terminal 2, level output pin 2 meets CMOS boosting DC/DC control chip IC62, the tie point of voltage input pin 3 connecting resistance R61 and resistance R62, supply pin 4 connect input 1; Input 1 is also connected to the collector electrode of switch transistor T R61 after inductance L 61, and the emitter of switch transistor T R61 is connected to earth terminal 2, and the ground level of switch transistor T R61 is connected to the EXT pin of CMOS boosting DC/DC control chip IC62; The anode of diode D61 be connected to the collector electrode of switch transistor T R61, negative electrode according to this after resistance R63 and resistance R64 to earth terminal 2; The tie point that VDD pin is connected to input 1, VSS pin is connected to earth terminal 2, Vout pin is connected to resistance R63 and resistance R64 of CMOS boosting DC/DC control chip IC62; Output 3 serial capacitance C61 is to earth terminal 2.
Principle is sketched: voltage checking chip IC61 is PT7M6102, when the dividing potential drop of its 3rd pin is greater than 200mV, its 2nd pin just exports high level, and IC62 is in running order for DC/DC control chip to allow CMOS boost, the voltage ratio of regulating resistance R61 and R62, can regulate the value of the first preset value; The CMOS DC/DC control chip IC62 that boosts is S-8356M50, the same with S-8356Q50, for ultra low quiescent power consumption, booster type microminiature 600kHz controller, for BOOST circuit, the voltage ratio of regulating resistance R63 and R64, the voltage of output can be changed, total resistance of resistance R63 and R64 can be greater than 1M, to reduce quiescent dissipation, total resistance of resistance R61 and R62 can be greater than 1M, guarantees that the electric current flow through is less, even at below 10uA, minimum on the self-discharge impact of supplying cell like this.
Other parameter is as follows:
R61 is 2M Ω, R62 be 100K Ω, IC61 be PT7M6102, R63 is 510K Ω, R64 is 620K Ω, IC62 be S-8356M50, TR61 be FMMT491, L61 is 22uH inductance, D61 is RB160 diode, and because operating current is little, output filter capacitor is 1uF/16V electric capacity.
Circuit connects well, and connect external adjustable stabilized voltage power supply between input VI1 and input VI2, voltage is between 3.9V to 5.0V, and actual measurement can complete goal of the invention:
When input voltage is at below 4.199V, because there is no operating voltage, IC2 PDM keyer output low level; Operating current is only 4.6uA,
When input voltage is at 4.199V to 4.202V, in Fig. 6, output has PDM keyer IC2 to export minimum duty cycle;
When input voltage is at more than 4.203V, but be less than 4.249V, PDM keyer IC2 exports and strains large duty ratio mutually;
When input voltage 4.250V and above time, PDM keyer IC2 exports maximum duty ratio: 65%;
Above-mentioned voltage is the voltage design by present more popular lithium battery, if the first preset value is suitably declined, deboost changes 4.15V into, and so, resistance R4 will suitably reduce.
In addition, for some concerning PDM keyer with not yet done people, circuit existing problems of the present invention:
For first embodiment of Fig. 5, when input voltage is near the first preset value, the offset voltage of associative operation amplifier A1, at this moment, there is the chance that output voltage equals voltage-stabiliser tube IC1 reference voltage in operational amplifier A 1, namely at this moment operational amplifier A 1 exports 1.29V, and now integrated circuit ISL6841 can not export minimum duty cycle.3rd embodiment overcomes this deficiency.
3rd embodiment
Refer to Fig. 7, compared with Fig. 5, only in resistance R4, seal in a diode D1, the i.e. connection of the output pin of the off resistance R4 other end and operational amplifier A 1, seal in diode D1, the diode D1 negative electrode contact resistance R4 other end, the output pin of diode D1 anode concatenation operation amplifier A1.
Diode D1 seals in, and the working method of circuit will change:
When input voltage is a little less than the first preset value, because circuit configurations are that homophase amplifies, at this moment amplifier A1 output voltage is lower than the voltage of inverting input, output voltage cannot carry out negative feedback through diode D1, thus make operational amplifier A 1 be in open loop magnifying state, at this moment operational amplifier A 1 output voltage one is decided to be the voltage in the place of working of operational amplifier A 1, for low level, thus make the COMP pin of integrated circuit (IC) 2 be low level, now integrated circuit ISL6841 exports minimum duty cycle, or complete output low level.
When input voltage is a little more than the first preset value, because circuit configurations are that homophase amplifies, at this moment operational amplifier A 1 output voltage is higher than the voltage of inverting input, output voltage is through diode D1, and resistance R4 carries out negative feedback, thus make operational amplifier A 1 be in closed loop magnifying state, at this moment operational amplifier A 1 output voltage meets following formula:
Au＝(R4/R5)+1
I.e. output voltage, be [reference voltage+Au (input voltage-reference voltage)], circuit is in normal operating state.
Equally, embodiment two is suitable for this method: the connection of the output pin of the off resistance R4 other end and operational amplifier A 1, seals in diode D1, and diode D1 negative electrode connects the 4th resistance R4 other end, the output pin of diode D1 anode concatenation operation amplifier A1.
It should be noted that resistance R4 and diode D1 is series relationship, the direction of transposition all risk insurance card diode D1 is constant, and circuit is equivalent, and function is identical.
The parameter of regulating element, circuit of the present invention is adapted in the equipment using super capacitor to power equally.The terminal voltage of super capacitor is often operated between 2.0V to 2.9V.Voltage-stabiliser tube IC1 will change the AZ431L that reference voltage is low to moderate 1.24V into.
Below be only the preferred embodiment of the present invention, it should be pointed out that above-mentioned preferred implementation should not be considered as limitation of the present invention.
For those skilled in the art; without departing from the spirit and scope of the present invention; some improvements and modifications can also be made; as in current supply circuit, seal in inductance and on electric capacity with ripple of smoothly powering; anti-dry sorrow electric capacity in parallel on divider resistance, feedback resistance; improve the antijamming capability of circuit; these improvements and modifications also should be considered as protection scope of the present invention; here no longer repeat by embodiment, protection scope of the present invention should be as the criterion with claim limited range.
Claims (6)
1. the loop control circuit of an inverse-excitation type switch power-supply, comprise input VI1, input VI2, output VO1, stepup transformer S1, resistance R1, resistance R2, resistance R3, resistance R4, resistance R5, voltage-stabiliser tube IC1, operational amplifier A 1, described stepup transformer S1 comprises three terminals: input 1, earth terminal 2, output 3; The earth terminal 2 of the stepup transformer S1 described in described input VI1 connects, described input VI connects one end of described resistance R2 simultaneously, described input VI1 connects the anode of described voltage-stabiliser tube IC1 simultaneously, and described input VI1 connects the lower margin of described operational amplifier A 1 simultaneously; The input 1 of the stepup transformer S1 described in described input VI2 connects, described input VI2 connects one end of described resistance R1 simultaneously; The other end of the resistance R2 described in other end connection of described resistance R1, tie point also connects the homophase input pin of described operational amplifier A 1; The output 3 of described stepup transformer S1 connects the supply pin of described operational amplifier A 1, the output 3 of described stepup transformer S1 also connects one end of described resistance R3, the negative electrode of the voltage-stabiliser tube IC1 described in other end connection of described resistance R3, tie point is also by described resistance R5 concatenation operation amplifier A1 anti-phase input pin; The anti-phase input pin of described operational amplifier A 1 also connects described resistance R4 one end, the output pin of the operational amplifier A 1 described in the described resistance R4 other end connects; The output pin of described operational amplifier A 1 is the output VO2 of the loop control circuit of described inverse-excitation type switch power-supply.
2. the loop control circuit of inverse-excitation type switch power-supply according to claim 1, it is characterized in that: described stepup transformer S1 is controlled stepup transformer, when voltage between described input VI1 and described input VI2 is more than or equal to the first preset value, the voltage of the output 3 of described stepup transformer S1 just has output.
3. the loop control circuit of inverse-excitation type switch power-supply according to claim 1, is characterized in that: described voltage-stabiliser tube IC1 is three end adjustable shunt reference sources.
4. the loop control circuit of inverse-excitation type switch power-supply according to claim 1, it is characterized in that: the loop control circuit of inverse-excitation type switch power-supply also comprises diode D1, the negative electrode of described diode D1 is connected to the described resistance R4 other end, and the anode of described diode D1 is connected to the output pin of described operational amplifier A 1; Or the negative electrode of described diode D1 is connected to described resistance R4 one end, the anode of described diode D1 is connected to the reverse input pin of described operational amplifier A 1.
5. the loop control circuit of inverse-excitation type switch power-supply according to claim 1, is characterized in that: described stepup transformer S1 inside comprises: resistance R61, resistance R62, resistance R63, resistance R64, voltage checking chip IC61, CMOS boosting DC/DC control chip IC62, inductance L 61, diode D61, electric capacity C61 and switch transistor T R61; Input 1 according to this after resistance R61 and resistance R62 to earth terminal 2; The ON/OFF pin that the grounding leg 1 of voltage checking chip IC61 connects earth terminal 2, level output pin 2 meets CMOS boosting DC/DC control chip IC62, the tie point of voltage input pin 3 connecting resistance R61 and resistance R62, supply pin 4 connect input 1; Input 1 is also connected to the collector electrode of switch transistor T R61 after inductance L 61, and the emitter of switch transistor T R61 is connected to earth terminal 2, and the ground level of switch transistor T R61 is connected to the EXT pin of CMOS boosting DC/DC control chip IC62; The anode of diode D61 be connected to the collector electrode of switch transistor T R61, negative electrode according to this after resistance R63 and resistance R64 to earth terminal 2; The tie point that VDD pin is connected to input 1, VSS pin is connected to earth terminal 2, Vout pin is connected to resistance R63 and resistance R64 of CMOS boosting DC/DC control chip IC62; Output 3 serial capacitance C61 is to earth terminal 2.
6. an inverse-excitation type switch power-supply, comprises power stage circuit and PDM keyer, includes a power switch pipe, it is characterized in that in described power stage circuit: comprise the arbitrary described loop control circuit of claim 1-5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510705176.1A CN105207488B (en) | 2015-10-26 | 2015-10-26 | The loop control circuit of inverse-excitation type switch power-supply a kind of and apply its inverse-excitation type switch power-supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510705176.1A CN105207488B (en) | 2015-10-26 | 2015-10-26 | The loop control circuit of inverse-excitation type switch power-supply a kind of and apply its inverse-excitation type switch power-supply |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105207488A true CN105207488A (en) | 2015-12-30 |
| CN105207488B CN105207488B (en) | 2017-08-29 |
Family
ID=54954984
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510705176.1A Active CN105207488B (en) | 2015-10-26 | 2015-10-26 | The loop control circuit of inverse-excitation type switch power-supply a kind of and apply its inverse-excitation type switch power-supply |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105207488B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109039092A (en) * | 2018-09-20 | 2018-12-18 | 广州金升阳科技有限公司 | A kind of voltage detecting circuit and the reversible transducer using the circuit |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090206804A1 (en) * | 2008-02-20 | 2009-08-20 | Ming Xu | Quasi-Parallel Voltage Regulator |
| CN102545572A (en) * | 2010-12-29 | 2012-07-04 | 华润矽威科技（上海）有限公司 | Capacitor multiplexing soft-start circuit and method |
| CN104201744A (en) * | 2014-09-10 | 2014-12-10 | 广州金升阳科技有限公司 | Equalizing charge circuit and battery pack |
| CN204046424U (en) * | 2014-08-21 | 2014-12-24 | 北京新雷能科技股份有限公司 | A kind of output voltage stabilization circuit |
| CN104779803A (en) * | 2015-04-03 | 2015-07-15 | 深圳市泰金田科技有限公司 | Sound switching power supply |
-
2015
- 2015-10-26 CN CN201510705176.1A patent/CN105207488B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090206804A1 (en) * | 2008-02-20 | 2009-08-20 | Ming Xu | Quasi-Parallel Voltage Regulator |
| CN102545572A (en) * | 2010-12-29 | 2012-07-04 | 华润矽威科技（上海）有限公司 | Capacitor multiplexing soft-start circuit and method |
| CN204046424U (en) * | 2014-08-21 | 2014-12-24 | 北京新雷能科技股份有限公司 | A kind of output voltage stabilization circuit |
| CN104201744A (en) * | 2014-09-10 | 2014-12-10 | 广州金升阳科技有限公司 | Equalizing charge circuit and battery pack |
| CN104779803A (en) * | 2015-04-03 | 2015-07-15 | 深圳市泰金田科技有限公司 | Sound switching power supply |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109039092A (en) * | 2018-09-20 | 2018-12-18 | 广州金升阳科技有限公司 | A kind of voltage detecting circuit and the reversible transducer using the circuit |
| CN109039092B (en) * | 2018-09-20 | 2024-01-16 | 广州金升阳科技有限公司 | Voltage detection circuit and bidirectional converter using same |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105207488B (en) | 2017-08-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103312200B (en) | Power converter, current limiting unit, control circuit and related control method | |
| CN102832809B (en) | Adjustment of inductance switched capacitor passive clamping soft switch high gain boost code converter | |
| CN102820765B (en) | Bias voltage generation circuit and switch power supply with bias voltage generation circuit | |
| Howimanporn et al. | Performance comparison of continuous conduction mode (CCM) and discontinuous conduction mode (DCM) flyback converters | |
| CN103023337B (en) | Power circuit of switching power converter | |
| CN105634287A (en) | Charge-mode control device for a resonant converter | |
| CN101350554A (en) | Multipath insulation output power supply | |
| WO2019029106A1 (en) | Direct current step-down regulation circuit structure | |
| CN105322798A (en) | Multipath output flyback converter | |
| CN105207489A (en) | Loop control method and circuit for fly-back switching power supply | |
| CN103401428A (en) | Switch power supply control chip and switch power supply control system | |
| CN105375761A (en) | Fly-back switching power supply and loop control circuit thereof | |
| CN103929060B (en) | Step-down conversion circuit | |
| CN109842301A (en) | A kind of current control circuit and its control method | |
| CN103501114B (en) | There is the anti exciting converter of critical conduction mode | |
| CN117543961A (en) | Direct current conversion circuit | |
| CN104821634A (en) | Lithium battery multiple-path low-voltage DC power supply system with electric quantity detection and method for realizing electric quantity detection by utilizing same | |
| CN105207488A (en) | Loop control circuit of fly-back switching power supply and fly-back switching power supply adopting loop control circuit | |
| CN202178706U (en) | AC-DC power conversion chip and power conversion circuit | |
| CN104793683B (en) | Mixed stable voltage power supply | |
| US8116107B2 (en) | Synchronous rectification control circuit assembly | |
| CN203660879U (en) | Constant current/constant voltage converter based on PWM modulation | |
| CN103580508A (en) | Ac/dc converter circuit | |
| CN204014223U (en) | Low cost compact led drive circuit chip | |
| CN203233312U (en) | Switch power supply controller and switch power supply device |
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 |