CN107317478B - A kind of turn-on time control circuit in DC-DC converter for ACOT control model - Google Patents
A kind of turn-on time control circuit in DC-DC converter for ACOT control model Download PDFInfo
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- CN107317478B CN107317478B CN201710440088.2A CN201710440088A CN107317478B CN 107317478 B CN107317478 B CN 107317478B CN 201710440088 A CN201710440088 A CN 201710440088A CN 107317478 B CN107317478 B CN 107317478B
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
- H02M3/158—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load
Abstract
The invention discloses the turn-on time control circuits in a kind of DC converter for ACOT control model, including one first phase-locked loop module, one second phase-locked loop module, a translinear loop module, a switching mode control module.Control circuit of the invention is under different working conditions, and intrinsic working frequency has adaptivity, and working frequency is stable, adjustable, has extensive lockable external pulse frequency range when especially working asynchronously outside, has a wide range of application, is practical.
Description
Technical field
The invention belongs to switch power technology fields, are related to a kind of control circuit, especially a kind of to control mould for ACOT
Turn-on time control circuit in the DC-DC converter of formula.
Background technique
ACOT (Adaptive Constant On Time) control model in DC/DC converter is typically led to input electricity
Pressure feedforward and output voltage feedback technique, eliminate the influence of input, output voltage to switching frequency, simultaneously because it is without oblique
Slope compensation and supper-fast transient response and high conversion efficiency, make it be widely used.DC/ with outer synchronizing function
DC converter can work according to the additional pulse signal of user (within the scope of certain frequency), this brings greatly just to user
Benefit further increases its application range.
ACOT control model DC/DC converter circuit block diagram in the prior art is as shown in Figure 1, control electricity by turn-on time
Road 100, circuit for power conversion 101, load circuit 102, feed circuit 103, error amplifying circuit 104, reference circuit 105, paddy
It is worth current sampling circuit 106, current comparator 107 forms.The turn-on time control circuit 100 generates and input, output electricity
Press relevant turn-on time Ton；The 103 sampling and outputting voltage Vout of feed circuit, with 105 reference voltage of reference circuit
Vref determines valley point current limit after amplifying by the error amplifying circuit 104, when the valley point current sample circuit 106 triggers
The electric current limit, toff signal are got higher by low, pass through the logic and driver circuitry in the turn-on time control circuit 100
Logic and driver turns off the lower power tube M2 in the circuit for power conversion 101, and power tube M1 in unlatching is triggered simultaneously
Timer on_timer in the turn-on time control circuit 100 starts timing.When its timing terminates, ton signal is become by height
It is low, then the upper power in the circuit for power conversion 101 is turned off by the logic and driver circuitry Logic and driver
Pipe M1 opens lower power tube M2, while the timing signal of the turn-on time control circuit 100 resets, until the valley electricity
Stream sample circuit 106 triggers the electric current limit again, opens next period.It gradually adjusts output voltage Vout and reaches predetermined value,
Circuit enters stable state.The turn-on time control circuit 100 turns electric current electricity by phase frequency detector PFD, the first linear voltage
Road V-I, switch K, electric current plus/minus musical instruments used in a Buddhist or Taoist mass D, the second linear voltage turn current circuit V-I, timer on_timer, logic and drive
Dynamic circuit Logic and driver composition.The timer on_timer circuit diagram is as shown in Fig. 2, by charging current
Ion, timing capacitor C0, switch S, voltage comparator Comp and two phase inverters composition.Voltage comparator Comp normal phase input end
Output voltage Vout is connected, as voltage comparator Comp threshold value.The switch S and function upper in the circuit for power conversion 101
Rate pipe M1 is related, and when upper power tube is opened, switch S is disconnected, timing capacitor C0It starting to charge, timer starts timing, conversely,
Switch S closure, timing capacitor C0Electric discharge；Second linear voltage turns current circuit V-I input terminal and input voltage vin connects
It connects, generates the electric current Iin=ki*Vin directly proportional to input voltage vin；Two input terminal of phase frequency detector PFD respectively with
External input pulse signal input terminal PLLin is connected with signal SW in the circuit for power conversion 101.
There are two types of working conditions for the turn-on time control circuit 100: described when input terminal PLLin is hanging or ground connection
Switch S is disconnected, charging current Ion=ki*Vin in the timer on_timer circuit, then turn-on time Ton=C0*
Vout/Ion=C0* Vout/ (ki*Vin), and by the input of BUCK type DC/DC converter and output voltage relationship, Ton can be obtained
=Tsw* (Vout/Vin), then Tsw=C0/ ki, then the intrinsic switching frequency fswo=ki/C of converter0；As input terminal PLLin
When external pulse signal, the switch S closure, the phase frequency detector PFD compares external switch frequency f0With own switch frequency
The frequency/phase difference of rate fsw, and output voltage VPFD, electric current I is generated through the described first linear Voltage-current conversion circuit V-IPLL1
=kp* (VPFD- Vref0), wherein Vref0 is the described first linear Voltage-current conversion circuit V-I central task point, with the Iin
It is added by electric current plus/minus musical instruments used in a Buddhist or Taoist mass D and generates the timer on_timer charging current Ion=Iin+IPLL1, then can must be connected
Time Ton=C0* Vout/Ion=C0*Vout/(Iin+IPLL1), then can further obtain converter switch frequency:
From analyzing above: input terminal PLLin is hanging or ground connection, i.e., converter is without using the outer synchronizing function of converter
When, eliminate the influence of input, output voltage to its switching frequency.But in fact, due to the presence of circuit transmission delay everywhere,
Its switching frequency still can change with input, output voltage and load etc., especially input voltage is low, change in duty cycle
In the big and higher situation of switching frequency；In the external pulse signal of input terminal PLLin, i.e., when converter uses outer synchronizing function,
Require converter that there is broader, more stable switching frequency range, generally to adapt to different working environments.But by formula (1)
Know that its lockable external pulse frequency range is within the scope of its intrinsic switching frequency fswo changes delta f, in which:
Obviously, Δ f is related to input voltage vin, and different input voltages has different lockable external pulse frequency models
It encloses.On the other hand, even if wider lockable switching frequency range requires V in the case where input voltage vin is fixedPFDHave compared with
Big variation range, this requires the phase frequency detector PFD broader comparable phase difference and faster lock speed, together
First linear Voltage-current conversion circuit V-I described in Shi Yaoqiu has broader linear work area, to increase circuit design difficulty.
Summary of the invention
It is an object of the invention to overcome the above-mentioned prior art, a kind of DC- for ACOT control model is provided
Turn-on time control circuit in DC converter.Under different working conditions, intrinsic working frequency has adaptivity, work for it
Working frequency is stable, adjustable, has extensive lockable external pulse frequency range when especially working asynchronously outside.
The purpose of the present invention is achieved through the following technical solutions:
Turn-on time control circuit in this DC-DC converter for ACOT control model, including the first phaselocked loop
Module, the second phase-locked loop module, translinear loop module and switching mode control module；Wherein first phase-locked loop module
First input end connects external pulse signal input part PLLin；Second input terminal of the first phase-locked loop module connects the second locking phase
First output end of ring moulds block；The end SW of the third input terminal connection DC/DC converter main circuit of first phase-locked loop module；The
The output end of the 4th input terminal connection translinear loop module of one phase-locked loop module；5th input terminal of the first phase-locked loop module
Connect the output voltage Vout of DC/DC converter；The main electricity of the 6th input terminal connection DC/DC converter of first phase-locked loop module
The output end of current comparator circuit in road；The output end of first phase-locked loop module connects DC/DC converter main circuit gate leve
Drive end；The first input end connection external pulse signal input part PLLin of second phase-locked loop module and the first phaselocked loop
The first input end of module；Second input terminal of the second phase-locked loop module connect the second input terminal of the first phase-locked loop module and with
First output end of the second phase-locked loop module connects；The third input terminal of second phase-locked loop module connects external frequency modulation resistance Rt；
First output end of the second phase-locked loop module connects the second of second the second input terminal of phase-locked loop module and the first phase-locked loop module
Input terminal；Second input terminal of the second output terminal connection translinear loop module of the second phase-locked loop module；The transconductance linearity
The first input end of ring moulds block connects input voltage vin；Second input terminal of translinear loop module connects the second locking phase ring moulds
The second output terminal of block；The output end of translinear loop module connects the 4th input terminal of the first phase-locked loop module；The switch
Each output end of mode control module connects the first phase-locked loop module, each switch control terminal in the second phase-locked loop module, control
Its on-off under different working modes.
Further, above-mentioned first phase-locked loop module includes first switch, second switch, the first phase frequency detector, First Line
Property Voltage-current conversion circuit, the first electric current plus/minus musical instruments used in a Buddhist or Taoist mass, timer, logical AND driving circuit；Wherein, the first switch
First end is connected to external pulse signal input part PLLin as the first input end of first phase-locked loop module；Described
The second end of one switch connects the first input end of the phase frequency detector；The first end of the second switch is as described first
Second input terminal of phase-locked loop module is connected to the first output end of second phase-locked loop module；The second end of second switch
Connect the second input terminal of the first phase frequency detector；The third input terminal of first phase frequency detector is as the first locking phase ring moulds
The third input terminal of block is connected to the end SW of the DC/DC converter main circuit；The output end of first phase frequency detector
Connect the input terminal of the first linear Voltage-current conversion circuit；The output end of the first linear Voltage-current conversion circuit is connected to institute
State the first electric current plus/minus musical instruments used in a Buddhist or Taoist mass first input end；First the second input terminal of electric current plus/minus musical instruments used in a Buddhist or Taoist mass is as the first locking phase ring moulds
4th input terminal of block is connected to the output end of the translinear loop module；The first electric current plus/minus musical instruments used in a Buddhist or Taoist mass output end connects
Connect the first input end of the timer；Fiveth input of second input terminal of the timer as the first phase-locked loop module
End, is connected to converter output voltage Vout；The input terminal of the output end connection logical AND drive module of timer；The logic
DC/DC converter main circuit gate leve driving end is connect with drive module output end；The timer and logical AND drive mould
The turn-on time of upper power tube in block regulation power conversion circuit.
Further, above-mentioned second phase-locked loop module includes third switch, the 4th switch, the second phase frequency detector, the second line
Property Voltage-current conversion circuit, the 5th switch, the second electric current plus/minus musical instruments used in a Buddhist or Taoist mass, oscillator, frequency adjustment circuit；Wherein
The first end of the third switch is the first input end of the second phase-locked loop module, and it is defeated to be connected to external pulse signal
Enter to hold PLLin；The second end of the third switch connects the first input end of the second phase frequency detector；The first end of 4th switch
For the second input terminal of the second phase-locked loop module, it is connected to the second output terminal and the second phase-locked loop module of the first phase-locked loop module
The first output end；The second end of 4th switch connects the second input terminal of the second phase frequency detector；Second phase frequency detector
Output end connects the input terminal that the second linear voltage turns current circuit；The output end that second linear voltage turns current circuit connects
It is connected to the second electric current plus/minus musical instruments used in a Buddhist or Taoist mass first input end；Second input terminal rate of connections of the second electric current plus/minus musical instruments used in a Buddhist or Taoist mass adjusts circuit
Output end；The external frequency modulation resistance Rt of the input terminal of frequency adjustment circuit；The output end of second electric current plus/minus musical instruments used in a Buddhist or Taoist mass is as described
The second output terminal of second phase-locked loop module, is connected to the second input terminal of translinear loop module, while being connected to oscillator
Input terminal；The output end of oscillator be connected to the first phase-locked loop module the second input terminal and the second phase-locked loop module second
Input terminal.
Further, above-mentioned translinear loop module include third linear Voltage-current conversion circuit, reference current generating circuit,
Transconductance linearity loop circuit；Wherein: the third linear Voltage-current conversion circuit input terminal is the first defeated of translinear loop module
Enter end, connects converter input voltage Vin；The third linear Voltage-current conversion circuit output end connects transconductance linearity loop circuit
First input end；The reference current generating circuit output end is connected to the third input terminal of transconductance linearity loop circuit；Mutual conductance
Second input terminal of second input terminal of linear loop circuit as translinear loop module；The output of the transconductance linearity loop circuit
End is connected to the 4th input terminal of the first phase-locked loop module as translinear loop module (30) output end.
Further, the input terminal of above-mentioned switching mode control module connects external pulse signal input part PLLin.
Further, above-mentioned switching mode control module includes mode control circuit；The wherein input terminal of mode control circuit
Connect external pulse signal input part PLLin；The output end of mode control circuit connects the first phase-locked loop module and the second locking phase
Each switch control terminal in ring moulds block.
Compared with the prior art, the invention has the following advantages:
(1) present invention be obviously improved the DC-DC converter switching frequency of existing ACOT control model with input voltage and
The problem of load changes a lot.Switching frequency is stablized, and EMI is concentrated, convenient for processing.
(2) when using outer synchronizing function, the present invention makes the intrinsic switching frequency of converter have adaptivity, automatically tracks
External pulse frequency can accelerate phaselocked loop capture velocity；The present invention has stable, wide lockable external pulse frequency model
It encloses, has a wide range of application, strong applicability.
(3) present invention is novel in design, can reduce the design difficulty of partial circuit；The exportable frequency of the present invention is equal to converter
The pulse signal CLK_OUT of switching frequency is convenient for multiple converter parallel operations, improves load capacity.
Detailed description of the invention
Fig. 1 is ACOT control model DC/DC converter circuit block diagram in the prior art；
Fig. 2 is the electrical block diagram of prior art timer on_timer；
Fig. 3 be according to the present invention for ACOT control model DC/DC converter in turn-on time control circuit 300 and
Main circuit diagram 308.
Specific embodiment
The invention will be described in further detail with reference to the accompanying drawing:
Fig. 3 is that the turn-on time in a kind of DC-DC converter for ACOT control model according to the present invention controls electricity
Road 300 and main circuit diagram 308.As shown, main circuit 308 includes circuit for power conversion 301, load circuit 302, feed circuit
303, error amplifying circuit 304, reference circuit 305, valley point current sample circuit 306, the composition of current comparator 307.Wherein function
Rate conversion circuit 301 includes upper power tube M1, lower power tube M2, inductance L；Load circuit 302 includes resistance R and electricity in parallel
Hold C；Feed circuit 303 includes concatenated resistance Rf1 and resistance Rf2.The input voltage of parallel operation is switched through in the drain electrode of upper power tube M1
Vin, source electrode are connected to the drain electrode of lower power tube M2 and one end of inductance L；The other end of inductance L connects resistance R and capacitor C
One end；The source electrode of the other end of resistance R and capacitor C and lower power tube M2 are connected to the ground；Upper power tube M1 and lower power tube M2
Grid connection turn-on time control circuit 300 two output ends；One end of resistance Rf1 connects conversion in feed circuit 303
The output voltage Vout of device, other end series resistance Rf2, and it is connected to the negative-phase input of error amplifying circuit 304, resistance
The other end of Rf2 is connected to the ground；The output Vref of the normal phase input end connection reference circuit 305 of error amplifying circuit 304；Accidentally
The output end of poor amplifying circuit 304 is connected to the normal phase input end of current comparator 307, limits as valley point current；Electric current compares
The output end of the negative-phase input connection valley point current sample circuit 306 of device 307；The input terminal of valley point current sample circuit 306
The end SW for connecting circuit for power conversion 301 samples valley point current in the shutdown of upper power tube；The output end of current comparator 307
It is connected to an input terminal of turn-on time control circuit 300.
The present invention includes the first phaselocked loop for the turn-on time control circuit in the DC-DC converter of ACOT control model
Module 10, the second phase-locked loop module 20, translinear loop module 30, switching mode control module 40.First phase-locked loop module 10
Including first switch K1, second switch K2, the first phase frequency detector PFD, the first linear Voltage-current conversion circuit V-I, electric current
Plus/minus musical instruments used in a Buddhist or Taoist mass D1, timer on_timer, logical AND driving circuit Logic and driver；Wherein the of first switch K1
One end is connected to external pulse signal input part PLLin as the first input end of the first phase-locked loop module 10；First switch
Second end connects the first input end of the first phase frequency detector PFD；The first end of second switch K2 is as the first phase-locked loop module
10 the second input terminal is connected to the first output end of the second phase-locked loop module 20；The second end connection first of second switch K2
The second input terminal of phase frequency detector PFD；First phase frequency detector PFD third input terminal as the first phase-locked loop module 10
Three input terminals are connected to the end SW of the circuit for power conversion 301 in DC/DC converter main circuit 308, the first phase frequency detector
PFD compares the frequency/phase difference of converter own switch frequency and external pulse frequency or self-oscillation device output pulse frequency,
Generate voltage VPFD1；The output end of first phase frequency detector PFD connects the input terminal of the first linear Voltage-current conversion circuit V-I,
Generate electric current IPLL1=kp* (VPFD1- Vref0), wherein Vref0 is the first linear Voltage-current conversion circuit V-I central task point；
The output end of first linear Voltage-current conversion circuit V-I is connected to the electric current plus/minus musical instruments used in a Buddhist or Taoist mass D1 first input end；Electric current adds/
The second input terminal of subtracter D1 is connected to translinear loop module 30 as the 4th input terminal of the first phase-locked loop module 10
Output end；Electric current plus/minus musical instruments used in a Buddhist or Taoist mass D1 output end connects the first input end of timer on_timer, electric current Ion=IPLL1+
Charging current of the Io as timer on_timer；The second input terminal of timer on_timer is as the first phase-locked loop module
10 the 5th input terminal, is connected to converter output voltage Vout, as the comparison threshold value of timer on_timer, timer
On_timer generates turn-on time Ton relevant to Ion and Vout；The output end connection logical AND of timer on_timer drives
The input terminal of dynamic model block Logic and driver；Logical AND drive module Logic and driver output end connects DC/DC
308 gate leve of converter main circuit drives end；Timer on_timer and logical AND drive module Logic and driver is adjusted
The turn-on time of upper power tube in circuit for power conversion.
Second phase-locked loop module 20 include third switch K3, the 4th switch K4, the second phase frequency detector PFD, second linearly
Voltage-current conversion circuit V-I, the 5th switch K5, the second electric current plus/minus musical instruments used in a Buddhist or Taoist mass D2, oscillator OSC, frequency adjustment circuit RT；Its
Described in third switch K3 first end as the first input end of the second phase-locked loop module 20, it is defeated to be connected to external pulse signal
Enter to hold PLLin；The second end of third switch K3 connects the first input end of the second phase frequency detector PFD；The of 4th switch K4
One end is connected to the second output terminal and second of the first phase-locked loop module 10 as the second input terminal of the second phase-locked loop module 20
First output end of phase-locked loop module 20；The second end of 4th switch K4 connects the second input terminal of the second phase frequency detector PFD,
The frequency/phase difference of second phase frequency detector PFD the device OSC oscillation frequency and external pulse frequency generates voltage
VPFD2；The output end of second phase frequency detector PFD connects the input terminal that the second linear voltage turns current circuit V-I, generates electric current
IPLL2=kp* (VPFD2- Vref0), wherein Vref0 is that the second linear voltage turns current circuit V-I central task point；Second is linear
The output end of Voltage-current conversion circuit V-I is connected to the second electric current plus/minus musical instruments used in a Buddhist or Taoist mass D2 first input end；Second electric current plus/minus method
The second input terminal of device D2 connects the output end of the frequency adjustment circuit RT；The external tune of the input terminal of frequency adjustment circuit RT
Frequency resistance Rt；The output end of second electric current plus/minus musical instruments used in a Buddhist or Taoist mass D2 exports electric current I2, as the second output of the second phase-locked loop module 20
End, is connected to the second input terminal of translinear loop module 30, while being connected to the input terminal of the oscillator OSC；Oscillator
OSC generates the pulse signal that frequency is fosc=k0*I2, and wherein k0 is constant, is connected to the second of the first phase-locked loop module 10
Second input terminal of input terminal and the second phase-locked loop module 20.
Translinear loop module 30 include third linear Voltage-current conversion circuit V-I, reference current generating circuit Iref, across
Wire-conducting performance loop circuit Translinear Loop；Wherein third linear Voltage-current conversion circuit V-I input terminal is as the mutual conductance
The first input end of linear loop module 30 connects converter input voltage Vin, generates electric current Ii=ki*Vin, wherein ki is normal
Number；Third linear Voltage-current conversion circuit V-I output end connects the of the transconductance linearity loop circuit Translinear Loop
One input terminal；Reference current generating circuit Iref generates reference current I0, is connected to transconductance linearity loop circuit Translinear
The third input terminal of Loop；The second input terminal of transconductance linearity loop circuit Translinear Loop is as translinear loop module
30 the second input terminal is connected to the second output terminal of the second phase-locked loop module 20, transconductance linearity loop circuit Translinear
Loop utilizes translinear loop principle, generates the effect of I0*Ion1=Ii*I2, and wherein Ion1 exports electric current for it；Transconductance linearity
The output end of loop circuit Translinear Loop is connected to the first locking phase as the output end of the translinear loop module 30
4th input terminal of ring moulds block 10.
Switching mode control module 40 includes mode control circuit mode；The wherein input terminal of mode control circuit mode
Connect external pulse signal input part PLLin；In the first phase-locked loop module 10 of its output end connection, the second phase-locked loop module 20
Each switch control terminal controls its on-off under different working modes.
The course of work of the present invention for the DC-DC converter of ACOT control model are as follows: the sampling output electricity of feed circuit 303
Vout is pressed, valley point current limit is determined after amplifying with 305 reference voltage Vref of reference circuit by error amplifying circuit 304, works as paddy
Value current sampling circuit 306 triggers the electric current limit, and toff signal is got higher by low, in turn-on time control circuit 300
Logic and driver circuitry Logic and driver in first phase-locked loop module 10 is turned off in the circuit for power conversion 301
Lower power tube M2, power tube M1 in unlatching, while 300 in triggering and conducting time control circuit in the first phase-locked loop module 10
Timer on_timer start timing, timer on_timer timing duration is Ton.When its timing terminates, ton signal by
Height is lower, then passes through the logic and driver circuitry Logic in 300 in turn-on time control circuit in the first phase-locked loop module 10
Upper power tube M1 in and driver switch-off power conversion circuit 301 opens lower power tube M2, while timing circuit on_
The timing signal of timer resets, and limits until valley point current sample circuit 306 triggers the electric current again, opens next period.By
Step section output voltage Vout reaches predetermined value, and circuit enters stable state.
300 have different timing control modes under different working conditions in turn-on time control circuit:
Input terminal PLLin is hanging or ground connection, i.e., when not enabling outer synchronizing function, switching mode control module 40 is controlled
Switch K1, K3, K4, K5 shutdown, switch K2 conducting；Second phase-locked loop module 20 only has the work of oscillator interlock circuit, no longer has
There is the phase-locked function, the external frequency modulation resistance Rt of frequency adjustment circuit RT generates output electric current I1=k1*Rt, and wherein k1 is constant, this
When oscillator OSC input current I2=I1, generate output pulse CLK_OUT frequency be fosc=k0*I2=k0*k1*Rt；
The function that translinear loop module 30 is realized is I0*Ion1=Ii*I2, wherein Ii=ki*Vin, then Ion1=Ii*I2/I0
=ki*Vin*k1*Rt/I0；Phase frequency detector PFD in first phase-locked loop module 10 compares the frequency fosc of CLK_OUT and turns
The phase difference of parallel operation own switch frequency fsw generates corresponding voltage VPFD1=kp* (fosc-fsw)+V0, and it is converted to electric current
IPLL1=kp* (VPFD1- Vref0), wherein Vref0 is the first linear Voltage-current conversion circuit V-I central task point, IPLL11With
Ion1 is added through electric current plus/minus musical instruments used in a Buddhist or Taoist mass D1, generates the charging current Ion=I of timer on_timerPLL1+ Ion1 is then connected
Time Ton=C0*Vout/(Ion1+IPLL1), and by the input of BUCK type DC/DC converter and output voltage relationship, Ton can be obtained
=Tsw* (Vout/Vin)=(1/fsw) * (Vout/Vin), then DC/DC converter switch frequency can be obtained are as follows:
When designing, k0=ki/ (I0*C0) is enabled, then can be obtained by formula (2):
In parallel operation the operation is stable, the first translinear loop 10 adjusts the frequency that converter switch frequency is equal to CLK_OUT
Rate, i.e. fsw=fosc=k0*k1*Rt eliminate the influence of input, output voltage to switching frequency, and eliminate converter
Internal circuit postpones the variation for input and output voltage, load variation and changing and causing its switching frequency, switch frequency everywhere
The offset of rate is only caused by oscillator OSC.Compared to the DC/DC converter of traditional ACOT control model, switching frequency is with defeated
Enter the problem of output voltage and load etc. change be improved significantly.On the other hand, in converter the operation is stable, by formula
(3) V can be obtainedPFD1=Vref0, i.e. phase frequency detector PFD and voltage turn current module V-I work in its center near operating point,
Circuit performance is stable and optimal, and phaselocked loop captures and lock speed is most fast.
In the external pulse signal CLK_IN of input terminal PLLin, that is, when enabling outer synchronizing function, switching mode control module
40 control switch K1, K3, K4, K5 conducting, switch K2 shutdown；Second phase-locked loop module, 20 the phase-locked function is opened, and final locking is outer
Portion pulse signal CLK_IN makes oscillator OSC output pulse signal CLK_OUT frequency be equal to the frequency of CLK_IN frequency, i.e.,
Fosc=f0, at this time I2=fosc/k0=fo/k0；For translinear loop module 30, Ion1=Ii*I2/I0=is exported
ki*Vin*(fo/k0)/I0；For the first phase-locked loop module 10, phase frequency detector PFD compares the frequency fo and DC/ of CLK_IN
The frequency/phase difference of DC converter own switch frequency fsw generates corresponding voltage VPFD1=kp* (fo-fsw)+V0, and convert
At electric current IPLL1=kp* (VPFD1- Vref0), IPLL11It is added with Ion1 through electric current plus/minus musical instruments used in a Buddhist or Taoist mass D1, generates timer on_
The charging current Ion=I of timerPLL1+ Ion1 can obtain turn-on time Ton=C0*Vout/(IPLL1+ Ion1), equally by BUCK
The input of type DC/DC converter and output voltage relationship can obtain DC/DC converter switch frequency are as follows:
Front has enabled k0=ki/ (I0*C0), then can be obtained by formula (4):
That is the intrinsic switching frequency of the converter frequency that automatically tracks external pulse signal CLK_OUT, with adaptivity,
Compared to the DC/DC converter of traditional ACOT control model, lockable external pulse frequency range is more extensive, and no longer with defeated
Enter voltage to change.Phase frequency detector PFD and voltage turn current module V-I and also work near operating point in its center simultaneously,
Circuit performance stablize it is optimal, phaselocked loop capture and lock speed it is most fast.
It can be seen that turn-on time control circuit 300 provided by the invention is under two kinds of working conditions, equal switching frequency is steady
It is fixed, it is easy to lock, it is functional, have a wide range of application.
The above is only presently preferred embodiments of the present invention, not does any restrictions to the present invention, it is all according to the present invention
Technical spirit any simple modification to the above embodiments, change and equivalent structural changes still fall within skill of the present invention
In the protection scope of art scheme.
Claims (6)
1. the turn-on time control circuit in a kind of DC-DC converter for ACOT control model, which is characterized in that including
One phase-locked loop module (10), the second phase-locked loop module (20), translinear loop module (30) and switching mode control module (40)；
Wherein:
The first input end of first phase-locked loop module (10) connects external pulse signal input part PLLin；First phaselocked loop
First output end of the second input terminal connection the second phase-locked loop module (20) of module (10)；The of first phase-locked loop module (10)
The end SW of three input terminals connection DC/DC converter main circuit；4th input terminal of the first phase-locked loop module (10) connects trsanscondutor
The output end of property ring moulds block (30)；The output voltage of the 5th input terminal connection DC/DC converter of first phase-locked loop module (10)
Vout；Current comparator circuit in the main circuit of the 6th input terminal connection DC/DC converter of first phase-locked loop module (10)
Output end；The output end connection DC/DC converter main circuit gate leve of first phase-locked loop module (10) drives end；
The first input end connection external pulse signal input part PLLin of second phase-locked loop module (20) and the first phaselocked loop
The first input end of module (10)；The of the second input terminal connection the first phase-locked loop module (10) of second phase-locked loop module (20)
Two input terminals are simultaneously connect with the first output end of the second phase-locked loop module (20)；The third input terminal of second phase-locked loop module (20)
Connect external frequency modulation resistance Rt；It is defeated that first output end of the second phase-locked loop module (20) connects the second phase-locked loop module (20) second
Enter the second input terminal of end and the first phase-locked loop module (10)；The second output terminal of second phase-locked loop module (20) connects trsanscondutor
Second input terminal of property ring moulds block (30)；
The first input end of the translinear loop module (30) connects input voltage vin；The of translinear loop module (30)
Two input terminals connect the second output terminal of the second phase-locked loop module (20)；The output end connection first of translinear loop module (30)
4th input terminal of phase-locked loop module (10)；
Each output end of the switching mode control module (40) connects the first phase-locked loop module (10), the second phase-locked loop module
(20) each switch control terminal in controls its on-off under different working modes.
2. special according to claim 1 for the turn-on time control circuit in the DC-DC converter of ACOT control model
Sign is that first phase-locked loop module (10) includes first switch (K1), second switch (K2), the first phase frequency detector,
One linear voltage turns current circuit (V-I), the first electric current plus/minus musical instruments used in a Buddhist or Taoist mass (D1), timer, logical AND driving circuit；Wherein:
The first end of the first switch (K1) is connected to outside as the first input end of first phase-locked loop module (10)
Pulse signal input terminal PLLin；The second end of the first switch (K1) connects the first input of first phase frequency detector
End；The first end of the second switch (K2) is connected to described as the second input terminal of first phase-locked loop module (10)
First output end of the second phase-locked loop module (20)；The second of second end the first phase frequency detector of connection of second switch (K2) is defeated
Enter end；The third input terminal of first phase frequency detector is connected to as the third input terminal of first phase-locked loop module (10)
The end SW of the DC/DC converter main circuit；The output end of first phase frequency detector connects the first linear voltage and turns electric current
The input terminal of circuit；The output end of the first linear Voltage-current conversion circuit is connected to the first electric current plus/minus musical instruments used in a Buddhist or Taoist mass
One input terminal；First the second input terminal of electric current plus/minus musical instruments used in a Buddhist or Taoist mass connects as the 4th input terminal of first phase-locked loop module (10)
It is connected to the output end of the translinear loop module (30)；The first electric current plus/minus musical instruments used in a Buddhist or Taoist mass output end connects the timer
First input end；Second input terminal of the timer is connected to as the 5th input terminal of the first phase-locked loop module (10)
Converter output voltage Vout；The input terminal of the output end connection logical AND drive module of timer；The logical AND drives mould
Block output end connects the DC/DC converter main circuit gate leve and drives end；The timer and logical AND drive module adjust function
The turn-on time of upper power tube in rate conversion circuit.
3. special according to claim 1 for the turn-on time control circuit in the DC-DC converter of ACOT control model
Sign is, second phase-locked loop module (20) includes third switch (K3), the 4th switch (K4), the second phase frequency detector, the
Bilinear Voltage-current conversion circuit, the 5th switch (K5), the second electric current plus/minus musical instruments used in a Buddhist or Taoist mass, oscillator, frequency adjustment circuit；Wherein:
The first end of the third switch (K3) is the first input end of the second phase-locked loop module (20), is connected to external pulse letter
Number input terminal PLLin；The second end of the third switch (K3) connects the first input end of the second phase frequency detector；4th switch
First end be the second phase-locked loop module (20) the second input terminal, be connected to the second input terminal of the first phase-locked loop module (10)
With the first output end of the second phase-locked loop module (20)；The second end of 4th switch (K4) connects the second of the second phase frequency detector
Input terminal；The output end of second phase frequency detector connects the input terminal that the second linear voltage turns current circuit；Described second is linear
The output end of Voltage-current conversion circuit is connected to the second electric current plus/minus musical instruments used in a Buddhist or Taoist mass first input end；The of second electric current plus/minus musical instruments used in a Buddhist or Taoist mass
The output end of two input terminal rate of connections adjusting circuit；The external frequency modulation resistance Rt of the input terminal of frequency adjustment circuit；Second electric current
The output end of plus/minus musical instruments used in a Buddhist or Taoist mass is connected to translinear loop module as the second output terminal of second phase-locked loop module (20)
(30) the second input terminal, while being connected to the input terminal of oscillator；The output end of oscillator is connected to the first phase-locked loop module
(10) the second input terminal of the second input terminal and the second phase-locked loop module (20).
4. special according to claim 1 for the turn-on time control circuit in the DC-DC converter of ACOT control model
Sign is that the translinear loop module (30) includes third linear Voltage-current conversion circuit, reference current generating circuit, mutual conductance
Linear loop circuit；Wherein
The third linear Voltage-current conversion circuit input terminal is the first input end of translinear loop module (30), connection conversion
Device input voltage vin；The first input end of the third linear Voltage-current conversion circuit output end connection transconductance linearity loop circuit；
The reference current generating circuit output end is connected to the third input terminal of transconductance linearity loop circuit；The of transconductance linearity loop circuit
Second input terminal of two input terminals as translinear loop module (30)；The output end of the transconductance linearity loop circuit is as mutual conductance
The output end of linear loop module (30) is connected to the 4th input terminal of the first phase-locked loop module (10).
5. special according to claim 1 for the turn-on time control circuit in the DC-DC converter of ACOT control model
Sign is that the input terminal of the switching mode control module (40) connects external pulse signal input part PLLin.
6. it is used for the turn-on time control circuit in the DC-DC converters of ACOT control model according to claim 1 or described in 5,
It is characterized in that, the switching mode control module (40) includes mode control circuit；The wherein input terminal of mode control circuit
Connect external pulse signal input part PLLin；The output end of mode control circuit connects the first phase-locked loop module (10) and second
Each switch control terminal in phase-locked loop module (20).
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| CN201710440088.2A CN107317478B (en) | 2017-06-12 | 2017-06-12 | A kind of turn-on time control circuit in DC-DC converter for ACOT control model |
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| CN201710440088.2A CN107317478B (en) | 2017-06-12 | 2017-06-12 | A kind of turn-on time control circuit in DC-DC converter for ACOT control model |
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| CN107317478B true CN107317478B (en) | 2019-03-26 |
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| CN108282084B (en) * | 2018-01-25 | 2019-05-31 | 福州瑞芯微电子股份有限公司 | BUCK converter and its frequency locking control circuit |
| CN108809062A (en) * | 2018-06-22 | 2018-11-13 | 西安电子科技大学 | Timer for COT pattern buck converters |
| CN111224546B (en) * | 2020-03-03 | 2021-03-30 | 电子科技大学 | Buck converter of high frequency stability |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105932875A (en) * | 2016-05-09 | 2016-09-07 | 昌芯(西安)集成电路科技有限责任公司 | Adaptive external synchronization DC/DC converter with PLL latch function |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105932875A (en) * | 2016-05-09 | 2016-09-07 | 昌芯(西安)集成电路科技有限责任公司 | Adaptive external synchronization DC/DC converter with PLL latch function |
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