CN209472437U - A kind of power supply automatic switchover circuit - Google Patents
A kind of power supply automatic switchover circuit Download PDFInfo
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- CN209472437U CN209472437U CN201920517548.1U CN201920517548U CN209472437U CN 209472437 U CN209472437 U CN 209472437U CN 201920517548 U CN201920517548 U CN 201920517548U CN 209472437 U CN209472437 U CN 209472437U
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Abstract
The utility model discloses a kind of power supply automatic switchover circuit, including first voltage end, second voltage end, voltage output end, power cathode, the connection of the current input terminal of first voltage end and reference current source, the current output terminal of reference current source is connect with the reference current input terminal of the first current mirror, the image current input terminal of first current mirror is connect with the reference current output end of the second current mirror, the inverting input terminal of first image current output end and amplifier of the second current mirror, the reference current input terminal of third current mirror connects, the image current input terminal of third current mirror is connect with the reference current output end of the 4th current mirror, the image current output end of 4th current mirror is connect with the input terminal of the mirror image circuit input terminal of the 5th current mirror and hysteresis comparator circuit, comparison to supply voltage, low function is realized by built-in current comparator Power consumption source is automatically switched, to improve power utilization rate, and saves electronic system cost of hardware design.
Description
Technical field
The utility model relates to power supply switch circuit field more particularly to a kind of power supply automatic switchover circuits.
Background technique
Field of consumer electronics, in order to realize the automatic switchover design in off-chip capacitive source, traditional circuit uses discrete component
It realizes, needs two diodes to connect the automatic switchover realized outside piece, will increase PCB design area in this way and two discrete
The cost of diode, and the diode that will cause 0.3V~0.7V opens junction voltage loss, and power utilization rate is deteriorated.
Utility model content
For this reason, it may be necessary to provide a kind of power supply automatic switchover circuit, solution existing power supply switching circuit is at high cost, utilization rate is poor
The problem of.
To achieve the above object, a kind of power supply automatic switchover circuit, including first voltage end, the second electricity are inventor provided
The current input terminal of pressure side, voltage output end, power cathode, first voltage end and reference current source connects, reference current source
Current output terminal is connect with the reference current input terminal of the first current mirror, the image current input terminal of the first current mirror and the second electricity
Flow the reference current output end connection of mirror, the inverting input terminal of the first image current output end of the second current mirror and amplifier, the
The reference current input terminal of three current mirrors connects, the image current input terminal of third current mirror and the reference current of the 4th current mirror
The image current output end of output end connection, the 4th current mirror is electric compared with the mirror image circuit input terminal of the 5th current mirror and sluggishness
The input terminal on road connects, and the output end of hysteresis comparator circuit is connect with the input terminal of LS circuit, and the output end and DT of LS circuit are dead
The input terminal of area's circuit connects, and the output end of DT dead-zone circuit is connect with the grid end of transistor PM7, dead-zone circuit it is another defeated
Outlet is connect with the grid end of transistor PM8, and the drain terminal of transistor PM7 is connect with second voltage end, the drain terminal of transistor PM8 with
The connection of first voltage end, the source of transistor PM7 are connect with the source of transistor PM8 and voltage output end；
The reference current input terminal of 5th current mirror is connect with the source of transistor NM6, the grid end and amplifier of transistor NM6
Output end connection, the normal phase input end of amplifier connect with the second image current output end of the second current mirror；
The output end of amplifier is connect with one end of resistance R1, and the other end of resistance R1 is connect with one end of capacitor C1, electricity
The other end for holding C1 is connect with the first image current output end of the second current mirror；
The ginseng of the reference voltage output terminal of first current mirror, the image current output end of the first current mirror, third current mirror
Examine voltage output end, the image current output end of third current mirror, the reference voltage output terminal of the 5th current mirror, the 5th current mirror
Image current output end connect with power cathode, the first mirror of the reference voltage input terminal of the second current mirror, the second current mirror
Image current input terminal, the reference voltage input terminal of the 4th current mirror, the 4th current mirror image current input terminal and first voltage
End connection, the second image current input terminal of the second current mirror are connect with second voltage end.
Further, hysteresis comparator circuit includes low-pass filter, Schmidt trigger Smt0, Schmidt trigger
Smt1, signal selector Mux2-0, signal selector Mux2-1, transistor PM5 and transistor PM6, the input of low-pass filter
End is connect with the drain terminal of the image current output end of the 4th current mirror, the drain terminal of transistor PM5 and transistor PM6, low-pass filtering
The output end of device is connect with the input terminal of Schmidt trigger Smt0, the output end and schmidt trigger of Schmidt trigger Smt0
The input terminal of device Smt1, the control terminal of signal selector Mux2-0 are connected with the input terminal of LS, and Schmidt trigger Smt1's is defeated
Outlet is connect with the control terminal of signal selector Mux2-1, the output end of signal selector Mux2-0 and the grid of transistor PM5
Connection, the output end of signal selector Mux2-1 are connect with the grid of transistor PM6, an input terminal of signal selector Mux2-0
It is connect with an input terminal of signal selector Mux2-1 and first voltage end, another input terminal and letter of signal selector Mux2-0
The reference current output end connection of another input terminal and the 4th current mirror of number selector Mux2-1, the source of transistor PM5 and
The source of transistor PM6 is connect with first voltage end.
Further, first voltage end is connect with the pole P of diode Diode1, and second voltage end is with diode Diode0's
The connection of the pole P, the pole N of diode Diode0 is connect with the pole N of diode Diode1 and voltage output end.
Further, mos capacitance is connected between voltage output end and power cathode.
Further, the bias current end of the third image current output end of the second current mirror and amplifier connects.
Further, the first current mirror includes transistor NM0 and transistor NM1, the drain terminal and reference current of transistor NM0
The current output terminal in source, the grid end of transistor NM0 are connected with the grid end of transistor NM1, the source and transistor of transistor NM0
The source of NM1 is connect with power cathode, and the drain terminal of transistor NM1 is connect with the reference current output end of the second current mirror.
Further, the second current mirror includes transistor PM0, transistor PM1 and transistor PM2, the drain terminal of transistor PM0
With the grid of the image current input terminal of the first current mirror, the grid end of transistor PM0, the grid end of transistor PM1 and transistor PM2
End connection, the source of the source of transistor PM0, the source of transistor PM1 and transistor PM2 are connect with first voltage end, crystal
The drain terminal of pipe PM1 and the inverting input terminal of amplifier connect, and the drain terminal of transistor PM2 and the normal phase input end of amplifier connect.
Further, third current mirror includes transistor NM2 and transistor NM3, the drain terminal of transistor NM2 and amplifier it is anti-
Phase input terminal, transistor NM2 grid end connected with the grid end of transistor NM3, the source of transistor NM2 and the source of transistor NM3
End is connect with power cathode, and the drain terminal of transistor NM3 is connect with the reference current output end of the 4th current mirror.
Further, the 4th current mirror includes transistor PM7 and transistor PM4, the drain terminal and third electric current of transistor PM7
The image current input terminal of mirror, the grid end of transistor PM7 are connected with the grid end of transistor PM4, the source and crystal of transistor PM7
The source of pipe PM4 is connect with first voltage end, and the drain terminal of transistor PM4 and the input terminal of hysteresis comparator circuit connect.
Further, the 5th current mirror includes transistor NM4 and transistor NM5, the drain terminal and transistor of transistor NM4
The source of NM6, the grid end of transistor NM4 are connected with the grid end of transistor NM5, the source of transistor NM4 and transistor NM5's
Source is connect with power cathode, and the drain terminal of transistor NM5 and the input terminal of hysteresis comparator circuit connect.
It is different from the prior art, above-mentioned technical proposal passes through built-in current comparator by the comparison to supply voltage
It realizes that low-power dissipation power supply automatically switches, greatly reduces and knot electricity is opened by 0.3V~0.7V that discrete diode element circuitry has
Crushing loses, to improve power utilization rate, and saves electronic system cost of hardware design.
Detailed description of the invention
Fig. 1 is the circuit diagram of an embodiment；
Fig. 2 is the comparison schematic diagram of first voltage end AVDDL and second voltage end AVDDH；
Fig. 3 is the circuit structure diagram of one embodiment of Schmidt trigger；
Fig. 4 is the circuit structure diagram of an embodiment of dead-zone circuit (DT)；
Fig. 5 is the circuit structure diagram of an embodiment of level shift (LS).
Specific embodiment
Technology contents, construction feature, the objects and the effects for detailed description technical solution, below in conjunction with specific reality
It applies example and attached drawing is cooperated to be explained in detail.
Fig. 1 to Fig. 5 is please referred to, the present embodiment provides a kind of power supply automatic switchover circuit, including first voltage end AVDDL,
The electric current of second voltage end AVDDH, voltage output end AVDDX, power cathode AVSS, first voltage end and reference current source inputs
End connection, the current output terminal of reference current source are connect with the reference current input terminal of the first current mirror, the mirror of the first current mirror
Image current input terminal is connect with the reference current output end of the second current mirror, the first image current output end of the second current mirror with
The reference current input terminal connection of the inverting input terminal of amplifier, third current mirror, the image current input terminal of third current mirror with
The reference current output end of 4th current mirror connects, the image current output end of the 4th current mirror and the mirror image electricity of the 5th current mirror
Road input terminal is connected with the input terminal of hysteresis comparator circuit, and the output end of hysteresis comparator circuit is connect with the input terminal of LS circuit,
The output end of LS circuit is connect with the input terminal of DT dead-zone circuit, and the output end of DT dead-zone circuit and the grid end of transistor PM7 connect
It connects, another output end of dead-zone circuit is connect with the grid end of transistor PM8, and the drain terminal of transistor PM7 and second voltage end connect
It connects, the drain terminal of transistor PM8 is connect with first voltage end, the source of transistor PM7 and the source and voltage output of transistor PM8
End connection.
Wherein, hysteresis comparator circuit is a comparator with sluggish winding transmission characteristic, and integrated circuit fields often use 6
Pipe structure composition, convenient for integrated, which can effectively improve the noise inhibiting ability to input signal.Such as single limit compares
Device, if input signal Uin has small interference near threshold value, output voltage will generate corresponding shake and (rise
Volt), this disadvantage can be overcome by introducing hysteresis comparator circuit in circuit.DT dead-zone circuit is generally termed Power MOSFET electricity
Road is usually used in when power switch control signal overturning avoiding that false triggering occurs.Simplest implementation method is Delayed conducting, circuit
On the delay of Schmidt trigger and logic can be taken to realize, as shown in Figure 4.LS circuit, that is, level displacement circuit, passes through
Digital signal may be implemented by the switching between different electrical power domain, as shown in Figure 5 in the circuit.
The reference current input terminal of 5th current mirror is connect with the source of transistor NM6, the grid end and amplifier of transistor NM6
Output end connection, the normal phase input end of amplifier connect with the second image current output end of the second current mirror；The output of amplifier
End is connect with one end of resistance R1, and the other end of resistance R1 is connect with one end of capacitor C1, the other end of capacitor C1 and the
First image current output end of two current mirrors connects；Resistance R1 and capacitor C1 constitute Muller compensation circuit, improve system
Closed loop stability.
The ginseng of the reference voltage output terminal of first current mirror, the image current output end of the first current mirror, third current mirror
Examine voltage output end, the image current output end of third current mirror, the reference voltage output terminal of the 5th current mirror, the 5th current mirror
Image current output end connect with power cathode, the first mirror of the reference voltage input terminal of the second current mirror, the second current mirror
Image current input terminal, the reference voltage input terminal of the 4th current mirror, the 4th current mirror image current input terminal and first voltage
End connection, the second image current input terminal of the second current mirror are connect with second voltage end.Comparison to supply voltage, by interior
The current comparator set realizes that low-power dissipation power supply automatically switches, and greatly reduces the 0.3V being had by discrete diode element circuitry
~0.7V opens junction voltage loss, to improve power utilization rate, and saves electronic system cost of hardware design.
At work, reference current source IREF generates voltage VN1 by the first current mirror, the second current mirror.Second electric current
The voltage domain of mirror is AVDDL, and amplifier AMP is a single-stage amplifier, and amplifier output end connects the grid end of NM6, according to amplifier AMP
The short and empty disconnected characteristic of void, the equivalent resistance of transistor NM6 is adjusted by amplifier, thus after two power domains of guarantee power on
Node voltage VN2 and node voltage VN3 approximately equal (open-loop gain depending on amplifier).The second mirror image electricity of second current mirror
Flow the electric current I of input terminalD2Voltage node VN4 is flowed through by the 5th current mirror.First image current input terminal of the second current mirror
Electric current ID1By third current mirror, flows through the 4th current mirror and flow through on voltage node VN4.When power domain AVDDH and power domain
When AVDDL voltage is identical, VGS1(the first image current input side transistor grid end and source voltage terminal of the second current mirror) and
VGS2(the second image current input side transistor grid end of the second current mirror with source voltage terminal) identical, Δ IDIt is 0, voltage node
VN4 is substantially in the level of medium voltage.When AVDDH is greater than AVDDL, | VGS2|>|VGS1|, Δ ID<0.Then there is ID2>
ID1, then low level can be embodied on node voltage VN4.When AVDDH is less than AVDDL, | VGS2|<|VGS1|, Δ ID
>0.Then there is ID2<ID1, high level can be embodied on node voltage VN4, to realize the function of tentatively comparing.In order to improve
Stability when system voltage switches introduces hysteresis comparator circuit.The output signal of hysteresis comparator circuit has passed through LS first
Circuit, the effect of the circuit are that the control signal that will compare is switched on AVDDX from power domain AVDDL, then pass through the dead zone DT
Circuit realizes the switching to MOS power tube, and DT dead-zone circuit can guarantee that power tube PM7 and power tube PM8 will not be led simultaneously
It is logical, extend the service life of power transistor, that is, when working as AVDDH > AVDDL and be more than hysteresis voltage, by dead time,
VHON exports low level, opens power tube PM7, the voltage of AVDDX output is approximately the supply voltage of AVDDH；When AVDDH <
AVDDL and be more than hysteresis voltage when, pass through dead time, VLON export low level, open power tube PM8, AVDDX output
Voltage be approximately AVDDL supply voltage, realize voltage switching.
As a kind of alternative embodiment, hysteresis comparator circuit includes low-pass filter, Schmidt trigger Smt0, Shi Mi
Special trigger Smt1, signal selector Mux2-0, signal selector Mux2-1, transistor PM5 and transistor PM6, low-pass filtering
The input terminal of device is connect with the drain terminal of the image current output end of the 4th current mirror, the drain terminal of transistor PM5 and transistor PM6,
The output end of low-pass filter is connect with the input terminal of Schmidt trigger Smt0, the output end of Schmidt trigger Smt0 with apply
The input terminal of schmitt trigger Smt1, the control terminal of signal selector Mux2-0 are connected with the input terminal of LS, Schmidt trigger
The output end of Smt1 is connect with the control terminal of signal selector Mux2-1, the output end and transistor of signal selector Mux2-0
The grid of PM5 connects, and the output end of signal selector Mux2-1 is connect with the grid of transistor PM6, signal selector Mux2-0
An input terminal connect with an input terminal of signal selector Mux2-1 and first voltage end, signal selector Mux2-0's is another
Input terminal is connect with the reference current output end of another input terminal of signal selector Mux2-1 and the 4th current mirror, transistor
The source of PM5 and the source of transistor PM6 are connect with first voltage end.Lower water is arranged in low-pass filter Filter cutoff frequency
It is flat, it is determined according to circuit.Wherein the breadth length ratio of transistor PM5 is 2 times of transistor PM6, and the breadth length ratio of PM4 transistor with
PM6 is identical；When AVDDH < AVDDL, Mux2-0, Mux2-1 control the grid end voltage that PM5 grid end voltage is equal to PM4, this
When node VN4 P pipe pull-up current source have 3, respectively PM4, PM5 control is constituted, and such NM5 needs bigger electric current ability
The voltage of VN4 is pulled down, i.e. ID2Bigger electric current is needed, AVDDH and AVDDL is embodied in and needs bigger voltage difference ability
Realization is compared, and upper sluggishness Hys1 may be implemented by this mechanism.When working as AVDDH > AVDDL, Mux2-0, Mux2-1 control
The grid end voltage of PM6 processed is equal to the grid end voltage of PM4, and the P pipe pull-up current source of node VN4 has 2 at this time, respectively PM4,
PM6 control is constituted, and such NM5 needs lesser electric current that could pull down the voltage of VN4, i.e. ID2Lesser electric current is needed, specifically
Be embodied in compared with AVDDH and AVDDL need lesser voltage difference can be achieved with, by this mechanism can following sluggishness Hys2, such as
Shown in Fig. 2.
The output signal of Smt0 has passed through LS circuit first, and the effect of the circuit is the control signal that will compare from power domain
AVDDL is switched on AVDDX, then realizes the switching to MOS power tube by DT dead-zone circuit, and DT dead-zone circuit can guarantee
Power tube PM7 and power tube PM8 will not be simultaneously turned on, and extend the service life of power transistor, that is, worked as AVDDH > AVDDL and surpassed
When crossing hysteresis voltage Hys1, by dead time, VHON exports low level, opens power tube PM7, the electricity of AVDDX output
Pressure is approximately the supply voltage of AVDDH；As AVDDH < AVDDL and when be more than hysteresis voltage Hys2, by dead time,
VLON exports low level, opens power tube PM8, and the voltage of AVDDX output is approximately the supply voltage of AVDDL, realizes voltage
Switching, as shown in Figure 2.
In order to guarantee the normal work of circuit, first voltage end is connect with the pole P of diode Diode1, second voltage end with
The pole P of diode Diode0 connects, and the pole N of diode Diode0 is connect with the pole N of diode Diode1 and voltage output end.
Diode Diode0 and Diode1 effect are to ensure DT dead-zone circuit and LS circuit in switching transition or power on when
The power supply of AVDDX power domain is normal, to guarantee the normal work of these circuits.
Mos capacitance Moscap is connected between voltage stabilization voltage output end and power cathode in order to realize, Moscap makees
With being in power switch in handoff procedure, the voltage of AVDDX output is relatively stable, plays the role of an energy storage, can replace
Change other energy storage components into.
It is that the third image current output end of the second current mirror and the bias current end of amplifier connect in embodiment certain
It connects.
As the optional simple embodiment of one kind of the first current mirror, the first current mirror includes transistor NM0 and transistor
The drain terminal of NM1, transistor NM0 and current output terminal, the grid end of transistor NM0 and the grid end of transistor NM1 of reference current source
Connection, the source of transistor NM0 and the source of transistor NM1 are connect with power cathode, the drain terminal of transistor NM1 and the second electric current
The reference current output end of mirror connects.
As the optional simple embodiment of one kind of the second current mirror, the second current mirror includes transistor PM0, transistor PM1
With transistor PM2, the drain terminal of transistor PM0 and the image current input terminal of the first current mirror, the grid end of transistor PM0, crystal
The grid end of pipe PM1 is connected with the grid end of transistor PM2, the source of transistor PM0, the source of transistor PM1 and transistor PM2
Source connect with first voltage end, the inverting input terminal of the drain terminal of transistor PM1 and amplifier connects, the drain terminal of transistor PM2
It is connect with the normal phase input end of amplifier.
As the optional simple embodiment of one kind of third current mirror, third current mirror includes transistor NM2 and transistor
The grid end connection of the inverting input terminal, the grid end of transistor NM2 and transistor NM3 of the drain terminal and amplifier of NM3, transistor NM2, it is brilliant
The source of body pipe NM2 and the source of transistor NM3 are connect with power cathode, the reference of the drain terminal of transistor NM3 and the 4th current mirror
Current output terminal connection.
As the optional simple embodiment of one kind of the 4th current mirror, the 4th current mirror includes transistor PM7 and transistor
The drain terminal of PM4, transistor PM7 and the image current input terminal of third current mirror, the grid end of transistor PM7 and transistor PM4
Grid end connection, the source of transistor PM7 and the source of transistor PM4 connect with first voltage end, the drain terminal of transistor PM4 with it is slow
The input terminal of stagnant comparison circuit connects.
As the optional simple embodiment of one kind of the 5th current mirror, the 5th current mirror includes transistor NM4 and transistor
The drain terminal of NM5, transistor NM4 are connect with the grid end of the source of transistor NM6, the grid end of transistor NM4 and transistor NM5, brilliant
The source of body pipe NM4 and the source of transistor NM5 are connect with power cathode, the drain terminal of transistor NM5 and hysteresis comparator circuit
Input terminal connection.
In specific embodiment as shown in figure 1, its working principles are as follows: reference current source IREF, passes through the first current mirror
(metal-oxide-semiconductor NM0 and NM1 are constituted), the second current mirror (PM0 and PM1 are constituted) and the diode generation voltage being made up of NM2
VN1.The voltage domain of second current mirror (PM0 and PM1 are constituted) is AVDDL, and amplifier AMP is a single-stage amplifier, anode connection
The drain terminal of PM1, negative terminal connect the drain terminal of PM2, and the source of PM2 connects power domain AVDDH, and amplifier output end connects the grid of NM6
End, according to the short and empty disconnected characteristic of void of amplifier AMP, it is ensured that node voltage VN2 and node after two power domains power on
Voltage VN3 is equal, according to metal-oxide-semiconductor saturated characteristic it is found that the current characteristics equation of transistor can be by 1 approximate expression of formula:
Wherein VDSFor the drain-source voltage of transistor, VGSFor the gate source voltage of transistor, VTHFor the threshold voltage of transistor.
If the threshold voltage of transistor be considered as in the case where length and width are fixed it is constant, the transistor of long channel length in saturation region,
VDSVariation to IDContribution can't be too big, and VGSContribution can become much larger.When metal-oxide-semiconductor is when saturation region, work as VDS
=VGS–VTHWhen, there are maximum electric currents, and in VDS>VGS–VTHWhen VDSTo IDInfluence it is little, electric current can be with
With 2 approximate expression of formula:
Metal-oxide-semiconductor PM1 and PM2 are in saturation region, V in this circuitGS1For the gate source voltage of metal-oxide-semiconductor PM1, VGS2For metal-oxide-semiconductor PM2
Gate source voltage, the threshold voltage of transistor PM1 and PM2 it is approximately uniform be VTH。
The electric current I of metal-oxide-semiconductor PM2D2By the 5th current mirror (metal-oxide-semiconductor NM4 and NM5 are constituted), voltage node VN4 is flowed through；MOS
The electric current I of pipe PM1D1By third current mirror (metal-oxide-semiconductor NM2 and NM3 constitute), flow through the 4th current mirror (metal-oxide-semiconductor PM4, PM5,
PM6, PM7 are constituted), it is flowed through on voltage node VN4 by electric current mirror tube PM4.Electricity on the power domain AVDDH and PM1 on PM2
When source domain AVDDL voltage is identical, VGS1And VGS2It is identical, Δ IDIt is 0, voltage node VN4 is substantially in the level of medium voltage
On.When AVDDH is greater than AVDDL, | VGS2|>|VGS1|, Δ ID<0.Then there is ID2>ID1, then the electric current for flowing through NM5 is greater than
The electric current for flowing through PM4 can embody low level on node voltage VN4；When AVDDH is less than AVDDL, | VGS2|<|
VGS1|, Δ ID>0.Then there is ID2<ID1, then there is the electric current for flowing through NM5 to be less than and flows through the electric current of PM4, it can be on node voltage VN4
High level is embodied, to realize the function of tentatively comparing.In order to improve stability when system voltage switching, introduce sluggish
Comparison circuit, Filter (reduced levels are arranged in low pass filter cutoff frequency, determine according to circuit), Smt0, Smt1, Mux2-
0, Mux2-1, PM5, PM6 constitute a hysteresis circuitry, and wherein the breadth length ratio of transistor PM5 is 2 times of transistor PM6, and PM4
The breadth length ratio of transistor is identical as PM6；When AVDDH < AVDDL, Mux2-0, Mux2-1 control PM5 grid end voltage are equal to
The grid end voltage of PM4, the P pipe pull-up current source of node VN4 has 3 at this time, and respectively PM4, PM5 control is constituted, such NM5
Need bigger electric current that could pull down the voltage of VN4, i.e. ID2Bigger electric current is needed, AVDDH and AVDDL are embodied in
It needs bigger voltage difference to be just able to achieve to compare, upper sluggishness Hys1 may be implemented by this mechanism.Work as AVDDH > AVDDL's
When, the grid end voltage that Mux2-0, Mux2-1 control PM6 is equal to the grid end voltage of PM4, and the P pipe of node VN4 pulls up electricity at this time
Stream source has 2, and respectively PM4, PM6 control is constituted, and such NM5 needs lesser electric current that could pull down the voltage of VN4, i.e.,
ID2Lesser electric current is needed, is embodied in compared with AVDDH and AVDDL need lesser voltage difference can be achieved with, passes through this
Mechanism can following sluggishness Hys2, as shown in Figure 2.
The output signal of Smt0 has passed through LS circuit first, and the effect of the circuit is the control signal that will compare from power domain
AVDDL is switched on AVDDX, then realizes the switching to MOS power tube by DT dead-zone circuit, and DT dead-zone circuit can guarantee
Power tube PM7 and power tube PM8 will not be simultaneously turned on, and extend the service life of power transistor, that is, worked as AVDDH > AVDDL and surpassed
When crossing hysteresis voltage Hys1, by dead time, VHON exports low level, opens power tube PM7, the electricity of AVDDX output
Pressure is approximately the supply voltage of AVDDH；As AVDDH < AVDDL and when be more than hysteresis voltage Hys2, by dead time,
VLON exports low level, opens power tube PM8, the voltage of AVDDX output is approximately the supply voltage of AVDDL, as shown in Figure 2.
The breadth length ratio relationship of the transistor of the present embodiment can be such that
NM0:NM1:NM2:NM3:NM4:NM5=1:1:1:1:1:1；
PM0:PM1:PM2:PM3:PM4:PM5:PM6:PM7=1:1:1:1:1:2:1:1.
It should be noted that being not intended to limit although the various embodiments described above have been described herein
The scope of patent protection of the utility model.Therefore, based on the innovative idea of the utility model, embodiment described herein is carried out
Change and modification or equivalent structure or equivalent flow shift made based on the specification and figures of the utility model, directly
Or above technical scheme is used in other related technical areas indirectly, it is included in the patent protection model of the utility model
Within enclosing.
Claims (10)
1. a kind of power supply automatic switchover circuit, which is characterized in that including first voltage end, second voltage end, voltage output end, electricity
The current input terminal of source cathode, first voltage end and reference current source connects, the current output terminal of reference current source and the first electricity
The reference current input terminal connection of mirror is flowed, the image current input terminal of the first current mirror and the reference current of the second current mirror export
The reference current of the inverting input terminal of end connection, the first image current output end of the second current mirror and amplifier, third current mirror
Input terminal connection, the image current input terminal of third current mirror are connect with the reference current output end of the 4th current mirror, the 4th electricity
The image current output end of stream mirror is connect with the input terminal of the mirror image circuit input terminal of the 5th current mirror and hysteresis comparator circuit, late
The output end of stagnant comparison circuit is connect with the input terminal of LS circuit, and the output end of LS circuit and the input terminal of DT dead-zone circuit connect
It connects, the output end of DT dead-zone circuit is connect with the grid end of transistor PM7, and another output end of dead-zone circuit is with transistor PM8's
Grid end connection, the drain terminal of transistor PM7 are connect with second voltage end, and the drain terminal of transistor PM8 is connect with first voltage end, crystal
The source of pipe PM7 is connect with the source of transistor PM8 and voltage output end；
The reference current input terminal of 5th current mirror is connect with the source of transistor NM6, the grid end of transistor NM6 and amplifier it is defeated
Outlet connection, the normal phase input end of amplifier are connect with the second image current output end of the second current mirror；
The output end of amplifier is connect with one end of resistance R1, and the other end of resistance R1 is connect with one end of capacitor C1, capacitor C1
Other end connect with the first image current output end of the second current mirror；
The reference voltage output terminal of first current mirror, the image current output end of the first current mirror, the reference of third current mirror are electric
Press the mirror of output end, the image current output end of third current mirror, the reference voltage output terminal of the 5th current mirror, the 5th current mirror
Image current output end is connect with power cathode, the first mirror image electricity of the reference voltage input terminal of the second current mirror, the second current mirror
Input terminal, the reference voltage input terminal of the 4th current mirror, the image current input terminal of the 4th current mirror and first voltage end is flowed to connect
It connects, the second image current input terminal of the second current mirror is connect with second voltage end.
2. a kind of power supply automatic switchover circuit according to claim 1, it is characterised in that: hysteresis comparator circuit includes low pass
Filter, Schmidt trigger Smt0, Schmidt trigger Smt1, signal selector Mux2-0, signal selector Mux2-1, crystalline substance
The image current output end of body pipe PM5 and transistor PM6, the input terminal of low-pass filter and the 4th current mirror, transistor PM5
Drain terminal is connected with the drain terminal of transistor PM6, and the output end of low-pass filter is connect with the input terminal of Schmidt trigger Smt0, is applied
The output end of schmitt trigger Smt0 and the input terminal of Schmidt trigger Smt1, the control terminal and LS of signal selector Mux2-0
Input terminal connection, the output end of Schmidt trigger Smt1 connect with the control terminal of signal selector Mux2-1, signal behavior
The output end of device Mux2-0 is connect with the grid of transistor PM5, the output end of signal selector Mux2-1 and the grid of transistor PM6
Pole connection, an input terminal of signal selector Mux2-0 and an input terminal of signal selector Mux2-1 and first voltage end connect
It connects, the ginseng of another input terminal of signal selector Mux2-0 and another input terminal of signal selector Mux2-1 and the 4th current mirror
Current output terminal connection is examined, the source of transistor PM5 and the source of transistor PM6 are connect with first voltage end.
3. a kind of power supply automatic switchover circuit according to claim 1, it is characterised in that: first voltage end and diode
The pole P of Diode1 connects, and second voltage end is connect with the pole P of diode Diode0, the pole N of diode Diode0 and diode
The pole N of Diode1 is connected with voltage output end.
4. a kind of power supply automatic switchover circuit according to claim 1, it is characterised in that: voltage output end and power cathode
Between be connected with mos capacitance.
5. a kind of power supply automatic switchover circuit according to claim 1, it is characterised in that: the third mirror image of the second current mirror
The connection of the bias current end of current output terminal and amplifier.
6. a kind of power supply automatic switchover circuit according to claim 1, it is characterised in that: the first current mirror includes transistor
The grid end and crystal of the current output terminal of the drain terminal of NM0 and transistor NM1, transistor NM0 and reference current source, transistor NM0
The grid end of pipe NM1 connects, and the source of transistor NM0 and the source of transistor NM1 are connect with power cathode, the leakage of transistor NM1
End is connect with the reference current output end of the second current mirror.
7. a kind of power supply automatic switchover circuit according to claim 1, it is characterised in that: the second current mirror includes transistor
Image current input terminal, the transistor of PM0, transistor PM1 and transistor PM2, the drain terminal of transistor PM0 and the first current mirror
The grid end of PM0, the grid end of transistor PM1 are connected with the grid end of transistor PM2, the source of the source of transistor PM0, transistor PM1
The source of end and transistor PM2 are connect with first voltage end, and the drain terminal of transistor PM1 and the inverting input terminal of amplifier connect, brilliant
The drain terminal of body pipe PM2 and the normal phase input end of amplifier connect.
8. a kind of power supply automatic switchover circuit according to claim 1, it is characterised in that: third current mirror includes transistor
The inverting input terminal of the drain terminal of NM2 and transistor NM3, transistor NM2 and amplifier, the grid end of transistor NM2 and transistor NM3
Grid end connection, the source of transistor NM2 and the source of transistor NM3 are connect with power cathode, the drain terminal of transistor NM3 and the 4th
The reference current output end of current mirror connects.
9. a kind of power supply automatic switchover circuit according to claim 1, it is characterised in that: the 4th current mirror includes transistor
The image current input terminal of the drain terminal of PM7 and transistor PM4, transistor PM7 and third current mirror, transistor PM7 grid end and
The grid end of transistor PM4 connects, and the source of transistor PM7 and the source of transistor PM4 are connect with first voltage end, transistor
The drain terminal of PM4 and the input terminal of hysteresis comparator circuit connect.
10. a kind of power supply automatic switchover circuit according to claim 1, it is characterised in that: the 5th current mirror includes crystal
The drain terminal of pipe NM4 and transistor NM5, transistor NM4 and source, the grid end of transistor NM4 and the transistor NM5 of transistor NM6
Grid end connection, the source of transistor NM4 and the source of transistor NM5 connect with power cathode, the drain terminal of transistor NM5 with it is slow
The input terminal of stagnant comparison circuit connects.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920517548.1U CN209472437U (en) | 2019-04-17 | 2019-04-17 | A kind of power supply automatic switchover circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920517548.1U CN209472437U (en) | 2019-04-17 | 2019-04-17 | A kind of power supply automatic switchover circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209472437U true CN209472437U (en) | 2019-10-08 |
Family
ID=68093880
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201920517548.1U Withdrawn - After Issue CN209472437U (en) | 2019-04-17 | 2019-04-17 | A kind of power supply automatic switchover circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN209472437U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109842205A (en) * | 2019-04-17 | 2019-06-04 | 福建超瑞创原信息技术有限公司 | A kind of power supply automatic switchover circuit |
| CN117792361A (en) * | 2024-02-28 | 2024-03-29 | 芯聚威科技(成都)有限公司 | Power-on reset circuit and electronic equipment |
-
2019
- 2019-04-17 CN CN201920517548.1U patent/CN209472437U/en not_active Withdrawn - After Issue
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109842205A (en) * | 2019-04-17 | 2019-06-04 | 福建超瑞创原信息技术有限公司 | A kind of power supply automatic switchover circuit |
| CN109842205B (en) * | 2019-04-17 | 2024-02-23 | 福州码灵微电子科技有限公司 | Automatic switching circuit of power supply |
| CN117792361A (en) * | 2024-02-28 | 2024-03-29 | 芯聚威科技(成都)有限公司 | Power-on reset circuit and electronic equipment |
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Address after: Room 07, 19th Floor, Building 2, Wanfu Center, No. 10 Chuangye Road, Shangjie Town, Minhou County, Fuzhou City, Fujian Province, 350000 Patentee after: Fuzhou Maling Microelectronics Technology Co.,Ltd. Address before: 1907, 19th Floor, Building 2, Wanfu Center, No. 8 Haixiyuan Chuangye Road, High tech Zone, Fuzhou City, Fujian Province, 350000 Patentee before: FUJIAN SUPERRISC INFORMATION TECHNOLOGY CO.,LTD. |
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Granted publication date: 20191008 Effective date of abandoning: 20240223 |
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| AV01 | Patent right actively abandoned |
Granted publication date: 20191008 Effective date of abandoning: 20240223 |