CN206595894U - Conversion switch with multi-mode current constant control - Google Patents
Conversion switch with multi-mode current constant control Download PDFInfo
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- CN206595894U CN206595894U CN201720301040.9U CN201720301040U CN206595894U CN 206595894 U CN206595894 U CN 206595894U CN 201720301040 U CN201720301040 U CN 201720301040U CN 206595894 U CN206595894 U CN 206595894U
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Abstract
The utility model provides a kind of conversion switch with multi-mode current constant control, including：Internal stepdown circuit, reference circuit, holding circuit, current sampling circuit, equivalent sampling resistance R105, switch control metal-oxide-semiconductor Q106, it is synchronous to arrange metal-oxide-semiconductor Q107, drive circuit, rest-set flip-flop, pierce circuit, PWM comparators, adjust metal-oxide-semiconductor Q114, error amplifier, current input amplifier, signal summation module, high voltage selection circuit, external Constant flow sample signal amplification circuit, constant current mode selection circuit, constant-current source I121, feedback pin FB, ILIMIT pins, power pin VIN, output pin SW, ground pin GND；The utility model can be by judging that the external connection mode of single pin realizes setting and the current constant control pattern switching of constant current value；So that client can be set by outside according to demand selects suitable current constant control mode.
Description
Technical field
The utility model is related to a kind of constant-current control circuit, more particularly to the switch conversion being had higher requirements to constant-current characteristics
Circuit.
Background technology
In switching power circuit, control circuit often only provides Isobarically Control.But powered for battery charger
When often may require that out-put supply has constant current function.Conventional constant current control is main to be entered by power resistor sampling to output current
Row sampling, feeds back to control circuit and carries out current constant control, output current needs to flow through power samples resistance, can be in power samples electricity
Power loss is produced in resistance.And current constant control is realized by sampling internal inductive current, due to inductive current and reality output electricity
There is certain deviation between stream, while there is also certain deviation during inductive current sampling so that inductive current is realized by sampling
The mode of current constant control, constant current accuracy is frequently not fine.
The content of the invention
The purpose of this utility model is to overcome the deficiencies in the prior art to have multi-mode constant current control there is provided one kind
The conversion switch of system, it can be by judging that the external connection mode of single pin realizes setting and the current constant control of constant current value
Pattern switching；So that client can be set by outside according to demand selects suitable current constant control mode.The utility model is used
Technical scheme be：
A kind of conversion switch with multi-mode current constant control, including：Internal stepdown circuit, reference circuit, holding
Circuit, current sampling circuit, equivalent sampling resistance R105, switch control metal-oxide-semiconductor Q106, synchronous arrangement metal-oxide-semiconductor Q107, driving electricity
Road, rest-set flip-flop, pierce circuit, PWM comparators, adjustment metal-oxide-semiconductor Q114, error amplifier, current input amplifier, signal
Summation module, high voltage selection circuit, external Constant flow sample signal amplification circuit, constant current mode selection circuit, constant-current source I121,
Feedback pin FB, ILIMIT pin, power pin VIN, output pin SW, ground pin GND；
The input termination power pin VIN of internal stepdown circuit, the input of output termination reference circuit；Reference circuit is
The reference current of reference voltage and each constant-current source is provided inside conversion switch, the reference voltage V ref that reference circuit is produced connects
The in-phase input end of error amplifier；
An equivalent sampling resistance R105 termination power pin VIN, the input of another termination current sampling circuit and is opened
Control metal-oxide-semiconductor Q106 source electrode is closed, Q106 drain electrode connects output pin SW and Q107 drain electrode；Output pin SW is used to connect defeated
The source electrode for going out the inductance L123, Q107 that are connected between pin SW and output loading anode meets ground pin GND, drive circuit difference
Connect and controlling switch control metal-oxide-semiconductor Q106 and the synchronous grid for arranging metal-oxide-semiconductor Q107；Equivalent sampling resistance R105 sampling inductance
L123 electric currents；Drive circuit realizes relay protective scheme and provides driving and Power MOSFET to Q106 and Q107；Rest-set flip-flop
Output end connects the input of drive circuit；
The output end of current sampling circuit connects the input of holding circuit, the input connection electric current input of holding circuit
The in-phase input end of amplifier；Current sampling circuit is sampled to inductance L123 electric currents, inductance of the holding circuit to sampling
L123 current signals are kept；
Pierce circuit provides clock signal and oblique wave compensation signal, and clock signal connects the S ends of rest-set flip-flop；Signal is added
Module is added to inductance L123 current sampling signals with oblique wave compensation signal, and the signal after addition is connect PWM comparators
In-phase input end；The reverse input end of PWM comparators connects the output end of error amplifier；The output termination RS of PWM comparators
The R ends of trigger；Signal amplifies with error after PWM comparators are added to inductance L123 current sampling signals and oblique wave compensation signal
Device output signal is compared, output pwm signal control power tube Q106, Q107 switch；The reverse input end of error amplifier
The output of high voltage selection circuit is connect, the error signal to feedback signal and internal reference voltage Vref is amplified；Error is put
The output end output COMP signals of big device；
The anti-phase input of current input amplifier terminates the current output terminal of constant current mode selection circuit；Electric current input amplification
The output termination adjustment metal-oxide-semiconductor Q114 of device grid, adjustment metal-oxide-semiconductor Q114 drain electrode connects the output end of error amplifier, source electrode
Ground connection；Metal-oxide-semiconductor Q114 is adjusted as the adjustment metal-oxide-semiconductor under internal current constant control pattern, passes through the output of clamper error amplifier
Realize current constant control；
One input of high voltage selection circuit meets feedback pin FB, another external Constant flow sample signal of input termination
The output end of amplifying circuit；The function of high voltage selection circuit is to select the higher input signal of voltage in two input voltages to pass
It is defeated to arrive output end；
The input termination constant-current source of the input of constant current mode selection circuit and external Constant flow sample signal amplification circuit
I121 output and ILIMIT pins；Constant current mode selection circuit selects corresponding current constant control according to ILIMIT pin status
Pattern；ILIMIT pins are hanging or outer meeting resistance, and the resistance that constant-current source I121 is flowed through on ILIMIT pins produces voltage to set
Constant current value and judge current constant control pattern；
The low level that the control end of constant current mode selection circuit connects external Constant flow sample signal amplification circuit respectively effectively makes
Energy end and the effective Enable Pin of high level of current input amplifier.
Further, constant current mode selection circuit include operational amplifier U601, adjustment NMOS tube Q602, resistance R613,
PMOS Q603, Q604, Q6041, Q605, Q606, Q607, Q608, Q609；Constant-current source I610, I611, I612, phase inverter
U614, NAND gate U615；
Operational amplifier U601 in-phase input end connects PMOS as the input of constant current mode selection circuit
Q604, Q606, Q607, Q608 grid；Positive electricity crimping PMOS of powering Q604, Q606, Q607, Q608 source electrode and constant current
Source I610 input；Constant-current source I610 output termination PMOS Q609 source electrode；PMOS Q604 drain electrode connects Q603's
Source electrode, PMOS Q603 grid is connected to body drain electrode and Q6041 grid, Q605 grid；PMOS Q603 drain electrode connects
NMOS tube Q602 drain electrode, NMOS tube Q602 grid connects operational amplifier U601 output end, and NMOS tube Q602 source electrode connects
Operational amplifier U601 inverting input, and be grounded by resistance R613；PMOS Q606 drain electrode connects Q6041 source electrode,
PMOS Q6041 drain electrode connects constant-current source I611 input and phase inverter U614 input；Constant-current source I611 output end
Ground connection；PMOS Q607 drain electrode connects constant-current source I612 input, NAND gate U615 an input and Q609 grid
Pole；Constant-current source I612 output head grounding；Phase inverter U614 output termination NAND gate U615 another input；NAND gate
U615 output end as constant current mode selection circuit control end；PMOS Q608 drain electrode connects Q605 source electrode, PMOS
Q605 drain electrode connects PMOS Q609 drain electrode；PMOS Q609 drain electrode is exported as the electric current of constant current mode selection circuit
End.
Further, high voltage selection circuit includes comparator U401, phase inverter U402, transmission gate U403 and U404；Than
In-phase input end and inverting input compared with device U401 as high voltage selection circuit two inputs；Comparator U401's is defeated
Go out to terminate the positive control end of phase inverter U402 input, transmission gate U403 negative control end and transmission gate U404；Phase inverter
U402 output termination transmission gate U403 positive control end and transmission gate U404 negative control end；Transmission gate U403 input termination
Comparator U401 inverting input；Transmission gate U404 input termination comparator U401 in-phase input end；Transmission gate U403
It is connected with U404 output end and as the output end of high voltage selection circuit.
Further, the utility model also includes the loop compensation circuit that resistance R112 and electric capacity C113 are connected into；The ring
Road compensation circuit one terminates the output end of error amplifier, other end ground connection.
Further, switch control metal-oxide-semiconductor Q106 uses PMOS, and the synchronous metal-oxide-semiconductor Q107 that arranges uses NMOS tube.
Further, adjustment metal-oxide-semiconductor Q114 uses NMOS tube.
Further, the utility model also includes overvoltage crowbar and thermal-shutdown circuit；Thermal-shutdown circuit is connected
Drive circuit, overheat protector is provided for conversion switch；Overvoltage crowbar connects drive circuit, is that conversion switch is carried
Supply into overvoltage and output over-voltage protection.
Further, holding circuit is also filtered to the inductance L123 current signals of sampling.
The utility model has the advantage of：The utility model is innovated to constant-current control circuit, it is proposed that one kind can lead to
Cross and judge that the external connection mode of single pin realizes the setting of constant current value and the constant-current control circuit of current constant control pattern switching,
So that having wider application using integrated circuit of the present utility model, user can want in precision, efficiency, cost etc.
The suitable control model of the lower selection of element constraint.
Brief description of the drawings
Fig. 1 is the application circuit schematic diagram that constant current value of the present utility model is inner setting default value.
Fig. 2 is the application circuit schematic diagram of settable constant current value of the present utility model.
Fig. 3 is the application circuit schematic diagram under outside current constant control pattern of the present utility model.
Fig. 4 is a kind of embodiment schematic diagram of high pressure selection circuit of the present utility model.
Fig. 5 is a kind of embodiment schematic diagram of constant current mode selection circuit of the present utility model.
Embodiment
With reference to specific drawings and examples, the utility model is described in further detail.
The utility model provides a kind of conversion switch with multi-mode current constant control, as shown in figure 1, including：
Internal stepdown circuit 101, reference circuit 102, holding circuit 103, current sampling circuit 104, equivalent sampling resistance
R105, switch control metal-oxide-semiconductor Q106, synchronous arrangement metal-oxide-semiconductor Q107, drive circuit 108, rest-set flip-flop 109, pierce circuit
110th, PWM comparators 111, resistance R112, electric capacity C113, adjustment metal-oxide-semiconductor Q114, error amplifier 115, current input amplifier
116th, signal summation module 117, high voltage selection circuit 118, external Constant flow sample signal amplification circuit 119, constant current mode choosing
Select circuit 120, constant-current source I121, feedback pin FB, ILIMIT pin, power pin VIN, output pin SW, ground pin
GND, and overvoltage crowbar 127 and thermal-shutdown circuit 128；
Internal stepdown circuit 101 is provides power supply inside conversion switch, and it inputs termination power pin VIN, output
Terminate the input of reference circuit 102；Reference circuit 102 for provide inside conversion switch reference voltage (such as Vref) and
The reference current of each constant-current source, the reference voltage V ref that reference circuit is produced connects the in-phase input end of error amplifier 115；
Equivalent sampling resistance R105 one termination power pin VIN, the input of another termination current sampling circuit 104 and
Switch control metal-oxide-semiconductor Q106 source electrode, switch control metal-oxide-semiconductor Q106 uses PMOS, and the synchronous metal-oxide-semiconductor Q107 that arranges uses NMOS
Pipe, Q106 drain electrode connects output pin SW and Q107 drain electrode；Output pin SW is used to connect output pin SW and output loading
The inductance L123, Q107 that are connected between anode source electrode meet ground pin GND, and drive circuit 108 is connected and controlling switch respectively
Control metal-oxide-semiconductor Q106 and the synchronous grid for arranging metal-oxide-semiconductor Q107；Equivalent sampling resistance R105 sampling inductance L123 electric currents are used for electricity
Road Isobarically Control and internal current constant control, Q106 are inductance L123 chargings in conducting while being that (load is connected on Fig. 1, figure for load
2nd, the OUT+ ends and OUT- ends in Fig. 3) electric current is provided；Q107 is turned on after Q106 closings, and afterflow is provided for inductance L123 electric currents
Path；Drive circuit 108 realizes relay protective scheme and provides driving and Power MOSFET to power tube Q106 and Q107；RS is triggered
The output end of device 109 connects the input of drive circuit 108, and it provides logic control for conversion switch；
The output end of current sampling circuit 104 connects the input of holding circuit 103, and the input of holding circuit 103 connects
Connect the in-phase input end of current input amplifier 116；Current sampling circuit 104 is sampled to inductance L123 electric currents, keeps electricity
The inductance L123 current signals of the 103 pairs of samplings in road are kept and filtered；
Pierce circuit 110 provides clock signal and oblique wave compensation signal, and clock signal connects the S ends of rest-set flip-flop；Signal
Summation module 117 is added to inductance L123 current sampling signals with oblique wave compensation signal, and the signal after addition is met PWM
The in-phase input end of comparator 111；The reverse input end of PWM comparators 111 connects the output end of error amplifier 115；PWM compares
The R ends of the output termination rest-set flip-flop of device 111；PWM comparators 111 are to inductance L123 current sampling signals and oblique wave compensation signal
Signal is compared with the output signal of error amplifier 115 after addition, output pwm signal control power tube Q106, Q107 switch；
The reverse input end of error amplifier 115 connects the output of high voltage selection circuit 118, to feedback signal and internal reference voltage
Vref error signal is amplified；The output end output COMP signals of error amplifier 115；
Resistance R112 and electric capacity C113 are connected into loop compensation circuit；The loop compensation circuit one terminates error amplifier
115 output end, one end ground connection；
The current output terminal of the anti-phase input termination constant current mode selection circuit 120 of current input amplifier 116；Electric current is defeated
Enter the output termination adjustment metal-oxide-semiconductor Q114 of amplifier 116 grid, adjustment metal-oxide-semiconductor Q114 uses NMOS tube, and drain electrode connects error and put
The output end of big device 115, source ground；Metal-oxide-semiconductor Q114 is adjusted as the adjustment MOS under internal current constant control pattern, passes through pincers
Current constant control is realized in the output of position error amplifier 115；Current input amplifier 116 is operated in internal current constant control pattern；
One input of high voltage selection circuit 118 meets feedback pin FB, another external Constant flow sample of input termination
The output end of signal amplification circuit 119；The function of high voltage selection circuit 118 is to select voltage in two input voltages higher
Input signal is transferred to output end；
The input termination of the input of constant current mode selection circuit 120 and external Constant flow sample signal amplification circuit 119 is permanent
Stream source I121 output and ILIMIT pins；Constant current mode selection circuit 120 selects corresponding according to ILIMIT pin status
Current constant control pattern；ILIMIT pins are hanging or outer meeting resistance, and the resistance that constant-current source I121 is flowed through on ILIMIT pins produces electricity
Press to set constant current value and judge current constant control pattern；The control end of constant current mode selection circuit 120 connects external constant current and adopted respectively
The effective Enable Pin of low level of sample signal amplification circuit 119 and the effective Enable Pin of high level of current input amplifier 116；
Thermal-shutdown circuit 128 connects drive circuit 108, and overheat protector is provided for conversion switch；Overvoltage protection electricity
Road 127 connects drive circuit 108, and input overvoltage and output over-voltage protection are provided for conversion switch；
In application circuit of the present utility model, inductance L123 termination output pin a SW, another terminating resistor R124
One end and electric capacity C126 one end, another terminating resistor R125 one end of resistance R124 and feedback pin FB；The resistance R125 other ends and
The electric capacity C126 other ends are grounded；Inductance L123 and electric capacity C126 composition LC output filter circuits；Resistance R125 and R126 composition are anti-
Network is presented, can feedback voltage signal；
The utility model realizes the current constant control of various modes by setting pin in integrated circuit；ILIMIT pins hang
Space-time, as shown in figure 1, internal current constant control pattern is now operated in, and the constant current value now exported is inner setting default value；
When ILIMIT pins connect a resistance (being more than 10k Ω) to ground, as shown in Fig. 2 internal current constant control pattern is now operated in, but
Constant current value can by resistance R201 resistance R201Determine, resistance is bigger, and constant current value is bigger；When the access of ILIMIT pins and output loading
During the sampling resistor R301 pressure drop signals of negative terminal series connection, as shown in figure 3, now circuit is operated in outside current constant control pattern, electricity
The constant current value of road output determines that the smaller constant current value of resistance is bigger by sampling resistor R301；
Fig. 1 is first Application Example of the present utility model；ILIMIT pins are hanging；The anode and negative terminal of output loading
Electric capacity C126 two ends are connected on respectively；
Error amplifier 115 amplifies feedback signal and internal reference voltage Vref difference, exports COMP signals, R112 and
C113 constitutes internal loop compensation circuit；Equivalent sampling resistance R105, current sampling circuit 104 constitute inductive current sampling electricity
Road；Sampled when power tube Q106 is opened inductance L123 current signals, its output signal is by producing with pierce circuit 110
Signal and COMP signals after the addition of oblique wave compensation signal are compared by PWM comparators 111；When each cycle starts by
The clock signal control power tube Q106 conductings that pierce circuit 110 is produced, afterflow power tube Q107 is closed；When PWM comparators
When 111 output signals are high, the output signal of rest-set flip-flop 109 control power tube Q106 is closed, and afterflow power tube Q107 is opened；Drive
Dynamic circuit 108 provides drive signal for power tube, while the controlling dead error time, prevents two power tubes of Q106 and Q107 while leading
It is logical to form break-through；Power tube Q106, Q107, inductance L123, output capacitance C126 constitute power stage together, when power tube Q106 is led
When logical, afterflow power tube Q107 is closed, and inductance L123 electric currents are linearly increasing, and an electric current part is supplied to output loading, a part
Give output capacitance C126 chargings；When power tube Q106 is closed, afterflow power tube Q107 is opened, due to inductance induced electromotive force
In the presence of, inductance L123 electric currents will not instantaneous variation, the sense of current that it keeps original is constant, and inductive current linearly reduces；Resistance
R124 and R125 composition potential-divider networks, sampling and outputting voltage feeds back to voltage control loop, keeps the stabilization of output voltage；
In Fig. 1, equivalent sampling resistance R105, current sampling circuit 104, holding circuit 103, current input amplifier 116,
Adjust metal-oxide-semiconductor Q114, high voltage selection circuit 118, external Constant flow sample signal amplification circuit 119, constant-current source I121 and perseverance
Stream mode selection circuit 120 constitutes constant-current control circuit；It can be worked different work by the connected mode of ILIMIT pins
Pattern, when as shown in figure 1, ILIMIT pins are hanging, now internal constant-current source I121 draws high ILIMIT pins, constant current mould
The output CC_mode signals of formula selection circuit 120 are height, are operated in internal current constant control pattern；Equivalent sampling resistance R105, electric current
Sample circuit 104, holding circuit 103, current input amplifier 116 and adjustment metal-oxide-semiconductor Q114 composition internal sample constant current rings
Road, is kept by sampling, calculates inductance average current；Inductance average current and constant current mode selection circuit 120 are produced
Give tacit consent to reference current (I hereinafterREF1That is, the constant current value of inner setting acquiescence) and pass through the He of current input amplifier 116
The output end (COMP ends) that metal-oxide-semiconductor Q114 controls error amplifier 115 is adjusted, it is now corresponding when output load current is smaller
Inductance average current is also smaller, now adjusts metal-oxide-semiconductor Q114 shut-offs, system is operated in Isobarically Control pattern, with output loading
Electric current increase, inductance average current also accordingly increases, and its sample rate current also increases, when sample rate current is equal to internal default benchmark electricity
Output signal turns on adjustment metal-oxide-semiconductor Q114 by current input amplifier 116 during stream, and the dutycycle for changing pwm signal realizes perseverance
Flow control.
Fig. 2 is second Application Example of the present utility model；ILIMIT pins are grounded by resistance R201；Output loading
Anode and negative terminal be connected on electric capacity C126 two ends respectively；
When ILIMIT pins connect the resistance R201 for being more than 10K Ω to ground, system is operated in internal current constant control pattern；
But constant current value can be determined by resistance R201 resistance；
Fig. 3 is the 3rd Application Example of the present utility model；Output loading negative terminal connection sampling resistor R301 to, together
When output loading negative terminal be connected to ILIMIT pins, inductance L123 another termination output loading anode；Output load current meeting
Sampling resistor R301 is flowed through, loss is produced, so resistance R301 is the smaller the better；Now ILIMIT pin voltages are less than internal judgment
Threshold value, constant current mode selection circuit output signal CC_mode is low, and current input amplifier 116 is closed；External Constant flow sample letter
Number amplifying circuit 119 works；The multiplication factor of external Constant flow sample signal amplification circuit 119 is 10 in this example, and circuit is operated in
Outside current constant control pattern；Its operation principle is：Sampling resistor R301 upstream overload electric currents, produce pressure drop, because internal electricity
Stream source 121 is microampere order electric current, and the pressure drop on sampling resistor R301 is far smaller than the pressure drop of load current generation；Sampling resistor
The pressure drop signal that R301 upstream overload electric currents are produced amplifies after 10 times and anti-by external Constant flow sample signal amplification circuit 119
By the selection of high voltage selecting module 118, both middle the maximum are output to error amplifier to constant pressure feedback signal on feedback pin FB
115；It is more than voltage on feedback pin FB after sampling resistor R301 voltages are amplified 10 times, system enters outside current constant control mould
Formula, now output constant current IOUTIt can calculate：
IOUT·R30110=Vref so as to
R301For resistance R301 resistance；
Now output constant current precision is mainly adopted by internal reference voltage Vref, foreign current it can be seen from above-mentioned formula
The precision of sample resistance R301 and amplification coefficient determines that internal reference voltage and amplification coefficient can pass through in actual applications
Programming fuse is trimmed or other technologies means ensure precision, so planting current constant control mode has a good constant current accuracy；
Fig. 4 is a kind of embodiment of high voltage selection circuit 118；Including comparator U401, phase inverter U402, transmission gate
U403 and U404；Comparator U401 in-phase input end and inverting input is inputted as two of high voltage selection circuit 118
End；Comparator U401 output end connects phase inverter U402 input, transmission gate U403 negative control end and transmission gate U404's
Positive control end；Phase inverter U402 output termination transmission gate U403 positive control end and transmission gate U404 negative control end；Transmission
Door U403 input termination comparator U401 inverting input；Transmission gate U404 input termination comparator U401's is same mutually defeated
Enter end；Transmission gate U403 is connected with U404 output end and as the output end of high voltage selection circuit 118；Its operation principle
It is that now comparator U401 is output as low, and phase inverter U402 is output as height, now transmission gate U403 when inputting 1 and being more than input 2
Gating, input 1 goes to be transferred to output；When inputting 1 less than input 2, now comparator U401 is output as height, and phase inverter U402 is defeated
Go out to be low, now transmission gate U404 is gated, input 2 is transferred to output.
Fig. 5 is a kind of embodiment of constant current mode selection circuit 120；Including operational amplifier U601, adjustment NMOS tube
Q602, resistance R613, PMOS Q603, Q604, Q6041, Q605, Q606, Q607, Q608, Q609；Constant-current source I610, I611,
I612, phase inverter U614, NAND gate U615；Wherein constant-current source I610 reference current is IREF1, constant-current source I611 benchmark electricity
Flow for IREF2；
Operational amplifier U601 in-phase input end connects PMOS as the input of constant current mode selection circuit 120
Q604, Q606, Q607, Q608 grid；Positive electricity crimping PMOS of powering Q604, Q606, Q607, Q608 source electrode and constant current
Source I610 input；Constant-current source I610 output termination PMOS Q609 source electrode；PMOS Q604 drain electrode connects Q603's
Source electrode, PMOS Q603 grid is connected to body drain electrode and Q6041 grid, Q605 grid；PMOS Q603 drain electrode connects
NMOS tube Q602 drain electrode, NMOS tube Q602 grid connects operational amplifier U601 output end, and NMOS tube Q602 source electrode connects
Operational amplifier U601 inverting input, and be grounded by resistance R613；PMOS Q606 drain electrode connects Q6041 source electrode,
PMOS Q6041 drain electrode connects constant-current source I611 input and phase inverter U614 input；Constant-current source I611 output end
Ground connection；PMOS Q607 drain electrode connects constant-current source I612 input, NAND gate U615 an input and Q609 grid
Pole；Constant-current source I612 output head grounding；Phase inverter U614 output termination NAND gate U615 another input；NAND gate
U615 output end as constant current mode selection circuit 120 control end；PMOS Q608 drain electrode connects Q605 source electrode, PMOS
Pipe Q605 drain electrode connects PMOS Q609 drain electrode；PMOS Q609 drain electrode as constant current mode selection circuit 120 electric current
Output end；
Its operation principle is：When ILIMIT pins are hanging, now constant-current source I121 draws high ILIMIT pin voltages；
PMOS Q604, Q606, Q607, Q608 are closed, and the control end of constant current mode selection circuit 120 output CC_mode signals are height, choosing
Current input amplifier 116 in middle internal sample constant current loop；And now Q609 is turned on, constant current mode selection circuit 120 is defeated
The constant current reference current I gone outREFEqual to the acquiescence reference current I of inner settingREF1；
When ILIMIT pins connect resistance R201 to ground as shown in Fig. 2 now PMOS Q604, Q606, Q607, Q608 is led
It is logical, operational amplifier U601, NMOS tube Q602 and resistance R613 composition voltage-current converter circuits, Q603, Q6041, Q605
Constitute current mirror；Now PMOS Q609 is closed；The constant current reference current I that constant current mode selection circuit 120 is exportedREFIt can calculate
Go out：Wherein I121For constant-current source I121 reference current, R201For resistance R201 resistances, R613For resistance
R613 resistances；Need to meet simultaneouslyTo ensure CC_mode signals as height, conversion switch is operated in
Internal current constant control pattern；
When as shown in figure 3, output loading negative terminal connects sampling resistor R301 to ground, while output loading negative terminal is connected to
ILIMIT pins, now ILIMIT pins equivalent resistance meetCC_mode signals are low, are now gated
External Constant flow sample signal amplification circuit 119, and bucking current input amplifier 116, conversion switch are operated in outside perseverance
Flow control pattern.
Claims (8)
1. a kind of conversion switch with multi-mode current constant control, it is characterised in that including：Internal stepdown circuit (101),
Reference circuit (102), holding circuit (103), current sampling circuit (104), equivalent sampling resistance R105, switch control metal-oxide-semiconductor
Q106, synchronous arrangement metal-oxide-semiconductor Q107, drive circuit (108), rest-set flip-flop (109), pierce circuit (110), PWM comparators
(111), adjustment metal-oxide-semiconductor Q114, error amplifier (115), current input amplifier (116), signal summation module (117), height
Voltage selecting circuit (118), external Constant flow sample signal amplification circuit (119), constant current mode selection circuit (120), constant-current source
I121, feedback pin FB, ILIMIT pin, power pin VIN, output pin SW, ground pin GND；
The input termination power pin VIN of internal stepdown circuit (101), the input of output termination reference circuit (102)；Benchmark
Circuit (102) provides the reference current of reference voltage and each constant-current source, the base that reference circuit is produced for conversion switch inside
Quasi- voltage Vref connects the in-phase input end of error amplifier (115)；
An equivalent sampling resistance R105 termination power pin VIN, the input of another termination current sampling circuit (104) and is opened
Control metal-oxide-semiconductor Q106 source electrode is closed, Q106 drain electrode connects output pin SW and Q107 drain electrode；Output pin SW is used to connect defeated
The source electrode for going out the inductance L123, Q107 that are connected between pin SW and output loading anode meets ground pin GND, drive circuit
(108) connect respectively and controlling switch controls metal-oxide-semiconductor Q106 and synchronously arrangement metal-oxide-semiconductor Q107 grid；Equivalent sampling resistance
R105 sampling inductance L123 electric currents；When drive circuit (108) realizes relay protective scheme and provides driving and dead band to Q106 and Q107
Between control；The input of the output end connection drive circuit (108) of rest-set flip-flop (109)；
The input of the output end connection holding circuit (103) of current sampling circuit (104), the input of holding circuit (103)
Connect the in-phase input end of current input amplifier (116)；Current sampling circuit (104) is sampled to inductance L123 electric currents,
Holding circuit (103) is kept to the inductance L123 current signals of sampling；
Pierce circuit (110) provides clock signal and oblique wave compensation signal, and clock signal connects the S ends of rest-set flip-flop；Signal phase
Plus module (117) is added to inductance L123 current sampling signals with oblique wave compensation signal, and the signal after addition is met PWM
The in-phase input end of comparator (111)；The reverse input end of PWM comparators (111) connects the output end of error amplifier (115)；
The R ends of the output termination rest-set flip-flop of PWM comparators (111)；PWM comparators (111) to inductance L123 current sampling signals and
Signal is compared with error amplifier (115) output signal after oblique wave compensation signal is added, output pwm signal control power tube
Q106, Q107 are switched；The reverse input end of error amplifier (115) connects the output of high voltage selection circuit (118), to feedback letter
Number and internal reference voltage Vref error signal be amplified；The output end output COMP signals of error amplifier (115)；
The current output terminal of the anti-phase input termination constant current mode selection circuit (120) of current input amplifier (116)；Electric current is defeated
Enter the output termination adjustment metal-oxide-semiconductor Q114 of amplifier (116) grid, adjustment metal-oxide-semiconductor Q114 drain electrode connects error amplifier
(115) output end, source ground；Metal-oxide-semiconductor Q114 is adjusted as the adjustment metal-oxide-semiconductor under internal current constant control pattern, passes through pincers
Current constant control is realized in the output of position error amplifier (115)；
One input of high voltage selection circuit (118) meets feedback pin FB, the external Constant flow sample letter of another input termination
The output end of number amplifying circuit (119)；The function of high voltage selection circuit (118) is to select voltage in two input voltages higher
Input signal be transferred to output end；
The input termination of the input of constant current mode selection circuit (120) and external Constant flow sample signal amplification circuit (119) is permanent
Stream source I121 output and ILIMIT pins；Constant current mode selection circuit (120) selects correspondence according to ILIMIT pin status
Current constant control pattern；ILIMIT pins are hanging or outer meeting resistance, and the resistance that constant-current source I121 is flowed through on ILIMIT pins is produced
Voltage constant current value and judges current constant control pattern to set；
The control end of constant current mode selection circuit (120) connects the low level of external Constant flow sample signal amplification circuit (119) respectively
The effective Enable Pin of high level of effective Enable Pin and current input amplifier (116).
2. there is the conversion switch of multi-mode current constant control as claimed in claim 1, it is characterised in that
Constant current mode selection circuit (120) includes operational amplifier U601, adjustment NMOS tube Q602, resistance R613, PMOS
Q603、Q604、Q6041、Q605、Q606、Q607、Q608、Q609；Constant-current source I610, I611, I612, phase inverter U614, with it is non-
Door U615；
Operational amplifier U601 in-phase input end connects PMOS as the input of constant current mode selection circuit (120)
Q604, Q606, Q607, Q608 grid；Positive electricity crimping PMOS of powering Q604, Q606, Q607, Q608 source electrode and constant current
Source I610 input；Constant-current source I610 output termination PMOS Q609 source electrode；PMOS Q604 drain electrode connects Q603's
Source electrode, PMOS Q603 grid is connected to body drain electrode and Q6041 grid, Q605 grid；PMOS Q603 drain electrode connects
NMOS tube Q602 drain electrode, NMOS tube Q602 grid connects operational amplifier U601 output end, and NMOS tube Q602 source electrode connects
Operational amplifier U601 inverting input, and be grounded by resistance R613；PMOS Q606 drain electrode connects Q6041 source electrode,
PMOS Q6041 drain electrode connects constant-current source I611 input and phase inverter U614 input；Constant-current source I611 output end
Ground connection；PMOS Q607 drain electrode connects constant-current source I612 input, NAND gate U615 an input and Q609 grid
Pole；Constant-current source I612 output head grounding；Phase inverter U614 output termination NAND gate U615 another input；NAND gate
U615 output end as constant current mode selection circuit (120) control end；PMOS Q608 drain electrode connects Q605 source electrode,
PMOS Q605 drain electrode connects PMOS Q609 drain electrode；PMOS Q609 drain electrode is used as constant current mode selection circuit (120)
Current output terminal.
3. there is the conversion switch of multi-mode current constant control as claimed in claim 1, it is characterised in that
High voltage selection circuit (118) includes comparator U401, phase inverter U402, transmission gate U403 and U404；Comparator U401
In-phase input end and inverting input as high voltage selection circuit (118) two inputs；Comparator U401 output
Terminate phase inverter U402 input, transmission gate U403 negative control end and transmission gate U404 positive control end；Phase inverter U402
Output termination transmission gate U403 positive control end and transmission gate U404 negative control end；Transmission gate U403 input termination compares
Device U401 inverting input；Transmission gate U404 input termination comparator U401 in-phase input end；Transmission gate U403 and
U404 output end is connected and as the output end of high voltage selection circuit (118).
4. there is the conversion switch of multi-mode current constant control as claimed in claim 1, it is characterised in that
Also include the loop compensation circuit that resistance R112 and electric capacity C113 are connected into；The loop compensation circuit one termination error amplification
The output end of device (115), other end ground connection.
5. there is the conversion switch of multi-mode current constant control as claimed in claim 1, it is characterised in that
Switch control metal-oxide-semiconductor Q106 uses PMOS, and the synchronous metal-oxide-semiconductor Q107 that arranges uses NMOS tube.
6. there is the conversion switch of multi-mode current constant control as claimed in claim 1, it is characterised in that
Adjustment metal-oxide-semiconductor Q114 uses NMOS tube.
7. there is the conversion switch of multi-mode current constant control as claimed in claim 1, it is characterised in that
Also include overvoltage crowbar (127) and thermal-shutdown circuit (128)；Thermal-shutdown circuit (128) connects drive circuit
(108), overheat protector is provided for conversion switch；Overvoltage crowbar (127) connection drive circuit (108), turns for switch
Change circuit and input overvoltage and output over-voltage protection are provided.
8. there is the conversion switch of multi-mode current constant control as claimed in claim 1, it is characterised in that
Holding circuit (103) is also filtered to the inductance L123 current signals of sampling.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720301040.9U CN206595894U (en) | 2017-03-24 | 2017-03-24 | Conversion switch with multi-mode current constant control |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720301040.9U CN206595894U (en) | 2017-03-24 | 2017-03-24 | Conversion switch with multi-mode current constant control |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN206595894U true CN206595894U (en) | 2017-10-27 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201720301040.9U Withdrawn - After Issue CN206595894U (en) | 2017-03-24 | 2017-03-24 | Conversion switch with multi-mode current constant control |
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| Country | Link |
|---|---|
| CN (1) | CN206595894U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106992681A (en) * | 2017-03-24 | 2017-07-28 | 无锡硅动力微电子股份有限公司 | Conversion switch with multi-mode current constant control |
| CN109597326A (en) * | 2018-11-16 | 2019-04-09 | 深圳和而泰智能控制股份有限公司 | Control circuit and dust catcher |
| CN111063313A (en) * | 2019-12-04 | 2020-04-24 | Tcl华星光电技术有限公司 | Control circuit and display panel applying same |
| CN117200831A (en) * | 2023-11-03 | 2023-12-08 | 上海安其威微电子科技有限公司 | Contactless connector and contactless connector system |
-
2017
- 2017-03-24 CN CN201720301040.9U patent/CN206595894U/en not_active Withdrawn - After Issue
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106992681A (en) * | 2017-03-24 | 2017-07-28 | 无锡硅动力微电子股份有限公司 | Conversion switch with multi-mode current constant control |
| CN109597326A (en) * | 2018-11-16 | 2019-04-09 | 深圳和而泰智能控制股份有限公司 | Control circuit and dust catcher |
| CN109597326B (en) * | 2018-11-16 | 2024-02-13 | 深圳和而泰智能控制股份有限公司 | Control circuit and dust collector |
| CN111063313A (en) * | 2019-12-04 | 2020-04-24 | Tcl华星光电技术有限公司 | Control circuit and display panel applying same |
| CN117200831A (en) * | 2023-11-03 | 2023-12-08 | 上海安其威微电子科技有限公司 | Contactless connector and contactless connector system |
| CN117200831B (en) * | 2023-11-03 | 2024-01-23 | 上海安其威微电子科技有限公司 | Contactless connector and contactless connector system |
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