The content of the invention
The present inventor is regarding to the issue above and technical need, it is proposed that a kind of multi thresholds low-voltage detection circuit, the application
Multigroup low voltage test threshold value can be set, so as to meet requirement of the different integrated circuits to low voltage test function.
Technical scheme is as follows:
A kind of multi thresholds low-voltage detection circuit, the circuit includes:Signal input part, m control signal end, signal output
End, division module, band-gap reference module, resistive control module, comparison module and trigger, it is individual defeated that resistive control module includes m
Enter end and 2mIndividual output end, m is positive integer;
The input connection signal input part of division module, the output end of division module connects the first voltage of comparison module
Input, the output end of band-gap reference module connects the second voltage input of comparison module, the output end connection of comparison module
The input of trigger, the output end connection signal output part of trigger;It is first variable that division module includes being sequentially connected in series
Resistance, first resistor and second resistance, the input of one end connection division module of the series circuit, other end ground connection, first
Resistance and the common port of second resistance connect the output end of division module, the control end connection resistance control mould of the first variable resistor
The output end of block, each input of resistive control module connects a control signal end respectively;Signal input part is used to connect
Supply voltage to be detected, signal output part is used to export low voltage detection, and m control signal end is used to receive at least two
Individual different control signal group, multi thresholds low-voltage detection circuit is defeated by signal when receiving different control signal groups
Go out end output low voltage detection corresponding with control signal group.
Its further technical scheme is that the first variable resistor includes N number of divider resistance being sequentially connected in series, each partial pressure electricity
Resistance is in parallel with a transmission gate respectively, and the control end of each transmission gate connects an output end of resistive control module respectively, 1≤
N≤2mAnd N is integer.
Its further technical scheme is, comparison module includes the first PMOS, the second PMOS, the first NMOS tube and the
Two NMOS tubes, the grid of the first NMOS tube is connected with the grid of the second NMOS tube and is connected the drain electrode of the first NMOS tube, first
The source electrode of NMOS tube and the source electrode of the second NMOS tube are grounded respectively, and the drain electrode of the first NMOS tube is also connected with the source of the first PMOS
Pole, the grid of the first PMOS connects the first voltage input of comparison module, and the drain electrode of the second NMOS tube connects the 2nd PMOS
The source electrode of pipe, the grid of the second PMOS connects the second voltage input of comparison module, the second NMOS tube and the second PMOS
Common port connect comparison module output end;
The drain electrode of first PMOS connects signal input part, the drain electrode of the second PMOS by 3rd resistor and the 4th resistance
Signal input part is connected by the 5th resistance and the 6th resistance, 3rd resistor is identical with the resistance of the 5th resistance, the 4th resistance with
The resistance of 6th resistance is identical, and the 4th resistance is in parallel with a transmission gate, transmission gate also with the 6th resistor coupled in parallel, the control of transmission gate
End processed connects the output end of resistive control module.
Its further technical scheme is that circuit includes 2 control signal ends, and the first variable resistor is gone here and there successively including 3
The divider resistance of connection;Then resistance control circuit includes first input end, the second input, the first output end, the second output end, the
Three output ends and the 4th output end, the first output end, the second output end and the 3rd output end are respectively used to connection and each partial pressure
The control end of the transmission gate of resistor coupled in parallel, the 4th output end is used to connect and the transmission gate of the 4th resistance and the 6th resistor coupled in parallel
Control end;
First input end connects the input of the first OR gate, the second OR gate and the 4th and door respectively, and first input end also leads to
Cross end of oppisite phase connect the first OR gate, the second OR gate and the 3rd with the input of door, the second input connects first and door, the respectively
Two with door, the 3rd with door and the 4th with the input of door, the output end connection first of the first OR gate and the input of door, second or
Output end connection second and the input of door of door, first is connected the first output end with the output end of door, and second and door and the 3rd
The input of the 3rd OR gate is connected respectively with the output end of door, and the output end of the 3rd OR gate connects the second output end, the 4th and door
Output end connect the 3rd output end, first is connected the 4th OR gate respectively with door, the 3rd OR gate and the 4th with the output end of door
Input, the output end of the 4th OR gate connects the 4th output end.
Its further technical scheme is, band-gap reference module include the second adjustable resistance, the 7th resistance, the 8th resistance,
9th resistance, the first triode, the second triode, the tenth resistance, electric capacity and comparator;
7th resistance, the 8th resistance and the 9th resistance are sequentially connected in series, and one end of the series circuit connects the first triode
Emitter stage, the other end connect the emitter stage of the second triode, and the base stage connection colelctor electrode of the first triode is simultaneously grounded, the two or three pole
The base stage connection colelctor electrode of pipe is simultaneously grounded, and the 7th resistance is connected the positive input of comparator with the common port of the first triode,
8th resistance is connected the negative input of comparator, the output end connection band-gap reference mould of comparator with the common port of the 9th resistance
The output end of block;The common port connection the second adjustable resistance of 7th resistance and the 8th resistance, the other end of the second adjustable resistance connects
Connect the output end of comparator, the output end of comparator is also respectively connected with the tenth resistance and electric capacity, the tenth resistance and electric capacity it is another
End is grounded respectively.
Its further technical scheme is that the second adjustable resistance uses fuse-wires structure, the second adjustable resistance of fuse-wires structure
Including M fuse resistor being sequentially connected in series, each fuse resistor is in parallel with a fuse respectively, the two ends point of each fuse resistor
Not Lian Jie a fuse pressure point, M is positive integer.
Its further technical scheme is that each resistance in band-gap reference module uses temperature compensation structure, and temperature is mended
The resistance of compensation structure includes the thermo-compensator group that several are sequentially connected in series, and each thermo-compensator group includes being serially connected
Two compensation resistance and two compensation resistance temperature-coefficient of electrical resistances it is complementary.
Its further technical scheme is that two compensation resistance in each thermo-compensator group are respectively to have negative electricity
Hinder the high resistant polycrystalline resistor of temperature coefficient and the trap resistance with positive temperature coefficient.
The method have the benefit that:
1st, multi thresholds low-voltage detection circuit disclosed in the present application can set multiple low voltage test threshold values, namely have many
Group low voltage test release value LVDR, low voltage test virtual value LVDA can use selection, i.e., only need to change the control of control signal end
The value of signal group processed, it is possible to easily select different LVDR/LVDA values, is examined so as to meet different integrated circuits to low-voltage
The requirement of brake.
2nd, reference voltage is provided using band-gap reference module, the reference voltage for comparing is highly stable, little with electricity
Source voltage and temperature and change;Resistance in other band-gap reference module all employs temperature compensation structure, therefore further subtracts
Small influence of the temperature to reference voltage.
3rd, when integrated circuit processing technique has deviation, it can be adjusted using fuse-wires structure so that reference voltage energy
The deviation of integrated circuit processing technique is enough adapted to, the precision of low voltage test value is improved.
4th, the first variable resistor carries out selection control using passgate structures, and control method more succinctly facilitates;Second can
Become resistance and use fuse-wires structure, method of adjustment is more accurate, can accurately adjust some Parameters variations caused by process deviation.
Embodiment
The embodiment to the present invention is described further below in conjunction with the accompanying drawings.
Fig. 2 is refer to, it illustrates the circuit structure diagram of multi thresholds low-voltage detection circuit disclosed by the invention, the circuit
Including:Vin, m control signal ends of signal input part, signal output part Vout, division module, band-gap reference module, resistance control
Molding block, comparison module and trigger, trigger can be Schmidt trigger (Schmitt), and resistive control module includes m
Input and 2mIndividual output end, m is positive integer, and the present invention is by taking m=2 as an example, and Fig. 2 includes two control signal end S with the circuit0
And S1Exemplified by, and each output end of resistive control module is not shown respectively by Fig. 2.
The power supply that input connection the signal input part Vin, signal input part Vin of division module are to be detected for connecting is electric
Pressure, the output end of division module connects the first voltage input of comparison module, and supply voltage to be detected passes through division module
Partial pressure after from first voltage input input comparison module, band-gap reference module output end connection comparison module second electricity
Press input, band-gap reference module output reference voltage from second voltage input input comparison module, comparison module it is defeated
Go out the input of end connection trigger, the output end connection signal output part Vout of trigger, comparison module is used for the first electricity
Pressure input and the voltage of second voltage input are compared, then after trigger shaping it is defeated by signal output part Vout
Go out low voltage detection.
Division module includes variable resistor, and the control end of variable resistor connects the output end of resistive control module, resistance
Each input of control module connects a control signal end respectively.M control signal end is used to receive at least two differences
Control signal group, resistive control module be used for according to the control signal group that receives change in control division module can power transformation
The resistance of resistance, when the resistance of the variable resistor in division module changes, supply voltage to be detected passes through division module
Partial pressure after input comparison module magnitude of voltage it is different, therefore the low voltage detection of the circuit output is also different, Ye Jiduo
Threshold value low-voltage detection circuit passes through signal output part output and control signal group pair when receiving different control signal groups
The low voltage detection answered, realizes the selection to different low voltage detections.
It is related to specific circuit structure, the present invention there can be numerous embodiments, below with a typical embodiment
To illustrate the particular circuit configurations and operation principle of the present invention.
As shown in figure 3, division module includes the first variable resistor R being sequentially connected in seriesV, first resistor R1And second resistance
R2, one end of the series circuit connects the input of division module, namely connection signal input part Vin, the series circuit it is another
One end is grounded, first resistor R1With second resistance R2Common port connect division module output end, in this application, first electricity
Hinder R1Resistance be 560K Ω, second resistance R2Resistance be 520K Ω.First variable resistor RVHindered using passgate structures
Value regulation, its structure is as shown in figure 4, the first variable resistor RVIncluding N number of divider resistance being sequentially connected in series, each divider resistance
In parallel with a transmission gate respectively, the control end of each transmission gate connects an output end of resistive control module, 1≤N respectively
≤2mAnd N is integer.The present invention is by taking N=3 as an example, the first variable resistor RVIncluding the divider resistance r being sequentially connected in series1、r2And r3, often
Individual divider resistance is in parallel with a transmission gate, the control end CP of three transmission gates1、CP2And CP3Resistive control module is connected respectively
Output end, in this application, r1、r2And r3Resistance be respectively 200K Ω, 240K Ω and 60K Ω.Each transmission gate includes
The drain electrode of PMOS, NMOS tube and phase inverter, PMOS and NMOS tube is connected and connected one end of resistance, PMOS and NMOS tube
Source electrode be connected and connect the other end of resistance, the input of the grid connection phase inverter of PMOS and the control for connecting the transmission gate
End processed, the output end of phase inverter connects the grid of NMOS tube.First variable resistor RVIn each divider resistance whether work
Determined by transmission gate connected in parallel, it can be seen that when the signal of the control end of transmission gate is 0, transmission gate conducting,
Divider resistance connected in parallel is short-circuited and not worked, otherwise when the signal of the control end of transmission gate is 1, transmission gate is not led
Logical, divider resistance connected in parallel works.With divider resistance r1Exemplified by, as CP1=0,200K Ω divider resistance r1Do not rise
Effect, as CP1=1,200K Ω divider resistance r1Worked in access circuit.
Comparison module includes the first PMOS P1, the second PMOS P2, the first NMOS tube N1 and the second NMOS tube N2, first
NMOS tube N1 grid is connected with the second NMOS tube N2 grid and is connected the first NMOS tube N1 drain electrode, the first NMOS tube N1's
Source electrode and the second NMOS tube N2 source electrode are grounded respectively, and the first NMOS tube N1 drain electrode is also connected with the first PMOS P1 source electrode,
First PMOS P1 grid connects the first voltage input of comparison module, namely the P1 of the first PMOS grid connection the
One resistance R1With second resistance R2Common port;First PMOS P2 the second PMOS P2 of drain electrode connection source electrode, the 2nd PMOS
Pipe P2 grid connects the second voltage input of comparison module, namely the second PMOS P2 grid connects band gap base modules
Output end;Second NMOS tube N2 and the second PMOS P2 common port connect the output end of comparison module, namely connection triggering
The input of device.
In order to aid in adjusting the magnitude of voltage for inputting comparison module, as shown in figure 3, first in the comparison module in the present invention
PMOS P1 drain electrode passes through 3rd resistor R3With the 4th resistance R4Signal input part is connected, the second PMOS P2 drain electrode passes through
5th resistance R5With the 6th resistance R6Connect signal input part, 3rd resistor R3With the 5th resistance R5Resistance it is identical, the 4th resistance
R4With the 6th resistance R6Resistance it is identical, in this application, 3rd resistor R3, the 5th resistance R5, the 4th resistance R4With the 6th resistance
R6Resistance be 50K Ω, the 4th resistance R4It is in parallel with a transmission gate, the transmission gate also simultaneously with the 6th resistance R6Parallel connection, should
The output end of the control end CP4 connection resistive control modules of transmission gate.Similarly, the 4th resistance R4With the 6th resistance R6Whether act as
Determined with by transmission gate connected in parallel, as CP4=0, transmission gate conducting, the 4th resistance R4With the 6th resistance R6It is short-circuited
And do not work, so from two branch roads the first PMOS P1, the second PMOS P2 to signal input part Vin only
One 50K resistance;Otherwise as CP4=1, transmission gate is not turned on, the 4th resistance R4With the 6th resistance R6Access circuit and act as
With, so have from two branch roads the first PMOS P1, the second PMOS P2 to signal input part Vin 100K electricity
Resistance.
In this embodiment, m=2, N=3, then resistance control circuit include first input end S0With the second input S1, the
One input S0With the second input S1Respectively with 2 control signal end S of the circuit0And S1It is connected, resistance control circuit is also wrapped
The first output end CP1, the second output end CP2, the 3rd output end CP3 and the 4th output end CP4 are included, the first output end CP1 is used for
Connection and divider resistance r1The control end CP1, the second output end CP2 of transmission gate in parallel are used for connection and divider resistance r2It is in parallel
Transmission gate control end CP2, the 3rd output end CP3 is used to connect and divider resistance r3The control end CP3 of transmission gate in parallel,
4th output end CP is used to connect and the 4th resistance R4With the 6th resistance R6The control end CP4 of transmission gate in parallel.
The structure of resistance control circuit is as shown in figure 5, first input end S0The first OR gate G is connected respectivelyO1, the second OR gate GO2
With the 4th and door GA4Input, first input end S0The first OR gate G is also connected by end of oppisite phaseO1, the second OR gate GO2With the 3rd
With door GA3Input, the second input S1First and door G are connected respectivelyA1, second with door GA2, the 3rd with door GA3With the 4th with
Door GA4Input, the first OR gate GO1Output end connection first with door GA1Input, the second OR gate GO2Output end connection
Second and door GA2Input, first with door GA1Output end connection the first output end CP1, second with door GA2With the 3rd and door
GA3Output end connect the 3rd OR gate G respectivelyO3Input, the 3rd OR gate GO3Output end connect the second output end CP2, the
Four and door GA4Output end connect the 3rd output end CP3, first with door GA1, the 3rd OR gate GO3With the 4th and door GA4Output end
The 4th OR gate G is connected respectivelyO4Input, the 4th OR gate GO4Output end connect the 4th output end CP4.
Fig. 6 is refer to, it illustrates the circuit diagram of the band-gap reference module in the application, band-gap reference module is integrated electricity
The common One function module in road, it can provide the voltage of the change little with temperature and supply voltage, and the usual voltage is about
For 1.25V, due to close with the band gap voltage value of silicon, so being referred to as bandgap voltage reference (Bandgap Voltage
Reference), due to the parameter of each technique, difference also has difference, actual band gap base plus device size parameter
Quasi- magnitude of voltage and 1.25V have some difference.In this application, the bandgap voltage reference of band-gap reference module output is to input extremely
The reference voltage of comparison module, band-gap reference module includes the second adjustable resistance RS, the 7th resistance R7, the 8th resistance R8, the 9th electricity
Hinder R9, the first triode Q0, the second triode Q1, the tenth resistance R10, electric capacity C and comparator IO, in this application, the one or three pole
Pipe Q0For single triode, the second triode Q1It is formed in parallel by 8 triodes;7th resistance R7With the 8th resistance R8Resistance
It is 247.5K Ω, the 9th resistance R9Resistance be 26.5K Ω, the tenth resistance R10Resistance be 240K Ω, electric capacity C capacitance is
3pF。
Wherein, the 7th resistance R7, the 8th resistance R8With the 9th resistance R9It is sequentially connected in series, one end of series circuit connection the
One triode Q0Emitter stage, the other end connect the second triode Q1Emitter stage, the first triode Q0Base stage connection colelctor electrode
And be grounded, the second triode Q1Base stage connection colelctor electrode and be grounded, the 7th resistance R7With the first triode Q0Common port connection
Comparator IO positive input, the 8th resistance R8With the 9th resistance R9Common port connection comparator IO negative input, than
Output end compared with device IO connects the output end of band gap base modules;7th resistance R7With the 8th resistance R8Common port connection second
Variable resistor RS, the second adjustable resistance RSOther end connection comparator IO output end, comparator IO output end also connects respectively
Meet the tenth resistance R10With electric capacity C, the tenth resistance R10It is grounded respectively with the electric capacity C other end.
The second adjustable resistance RSUsing fuse-wires structure, the second adjustable resistance R of fuse-wires structureSM including being sequentially connected in series molten
Silk resistance, each fuse resistor is in parallel with a fuse respectively, and the two ends of each fuse resistor connect a fuse pressure point respectively,
M is positive integer.The second adjustable resistance RSStructure refer to Fig. 7, by taking M=4 as an example, the second adjustable resistance RSIncluding being sequentially connected in series
4 resistance r4、r5、r6And r7, the resistance of this 4 resistance is respectively 4.5K Ω, 9K Ω, 18K Ω and 36K Ω, resistance r4With melting
Silk Fuse1 is in parallel, resistance r5It is in parallel with fuse Fuse2, resistance r6It is in parallel with fuse Fuse3, resistance r7It is in parallel with fuse Fuse4.
Resistance r4One end connection fuse pressure point FPAD1, resistance r4With resistance r5Common port connection fuse pressure point FPAD2, resistance r5With
Resistance r6Common port connection fuse pressure point FPAD3, resistance r6With resistance r7Common port connection fuse pressure point FPAD4, resistance r7
Other end connection fuse pressure point FPAD5.The second adjustable resistance RSBand-gap reference module is exported for correcting technological parameter
The influence of voltage, the mode of amendment is to utilize five fuse pressure points of FPAD1~FPAD5, according to the electrical parameter pair during chip testing
Fuse to tetra- fuse selections of Fuse1~Fuse4, so that the reference voltage of output is adjusted near 1.25V..Molten
In silk design process, the adjustment stepping accuracy for the reference voltage that band-gap reference module is exported is designed as 4mV, is measured by experiment
It is 0.32% to obtain bandgap voltage reference output accuracy.
Further, since the resistance in integrated circuit is all can be with temperature with the resistance of temperature characterisitic, i.e. resistance
Change and change, the size that resistance changes can be characterized with the temperature coefficient of the resistance, be generally integrated the electricity in circuit
Resistance all has a positive temperature coefficient, such as polycrystalline resistor, trap resistance (nwell), active area resistance, with the rise of temperature, this
The resistance of the resistance of type can be raised;Also the resistance for having particular type has negative temperature coefficient, such as high resistant polycrystalline resistor
(hpoly), the resistance of such resistance can with temperature rise and reduce.In order to reduce temperature to resistance
Influence, further the stability of the voltage of raising band-gap reference module output, therefore each resistance in band-gap reference module is adopted
With temperature compensation structure, the resistance of temperature compensation structure includes several thermo-compensator groups being sequentially connected in series, each temperature
Compensation resistance group includes two compensation resistance being serially connected and the temperature-coefficient of electrical resistance of two compensation resistance is complementary, in order that warm
The effect for spending compensation more preferably, would generally use at least two thermo-compensator groups in the resistance of each temperature compensation structure, please
With reference to Fig. 8, it is so that the resistance of temperature compensation structure includes 2 thermo-compensator groups as an example, optionally, each temperature-compensating electricity
Two compensation resistance in resistance group are respectively the high resistant polycrystalline resistor R with negative temperature coefficient of resistancehpolyWith with positive resistance temperature
Spend the trap resistance R of coefficientnwell, namely the resistance of a temperature compensation structure includes the trap resistance R that is sequentially connected in seriesnwell, high resistant it is many
Brilliant resistance Rhpoly, trap resistance RnwellWith high resistant polycrystalline resistor Rhpoly.In the figure 7, the size (i.e. square number) of each compensation resistance
R/ (4*R can be designed toWnwell), or R/ (4*RWhpoly), in layout design, above resistance is also using shown in Fig. 7
Compensate the form of resistant series.
As a result of band-gap reference module, it is highly stable to thus be accordingly used in the reference voltage compared, little with power supply electricity
Pressure and temperature and change;Temperature compensation structure is all employed additionally, due to resistance, therefore further reduces temperature to voltage
Influence.In this programme band-gap reference module output reference voltage with temperature simulation waveform as shown in Figure 9, with power supply electricity
The simulation waveform of buckling is as shown in Figure 10;It can be seen that 1.25V reference voltages are highly stable, and temperature drift exists
It is 50ppm/ DEG C or so, highly stable.
The operation principle of multi thresholds low-voltage detection circuit disclosed in the present application is:
Control signal group is received by 2 control signal ends, as control signal group S0And S1Value it is different when, in the application
4 transmission gates control end CP1~CP4 value it is different, then the conducting state of 4 transmission gates is different, therefore power supply electricity
The magnitude of voltage inputted after pressure partial pressure to comparison module is also different, after comparison module is compared with reference voltage the magnitude of voltage after partial pressure
The low voltage detection of generation is also different, i.e., supply voltage LVDR, low voltage test when corresponding low voltage test discharges
Supply voltage LVDA values when effectively are different, and the different corresponding control logics of control signal group and low voltage detection are such as
Shown in following table:
Control signal group |
CP4 |
CP3 |
CP2 |
CP1 |
LVDR values |
LVDA values |
S0=0, S1=0 |
0 |
0 |
0 |
0 |
2.474 |
2.218 |
S0=0, S1=1 |
1 |
1 |
0 |
0 |
2.859 |
2.505 |
S0=1, S1=0 |
1 |
1 |
1 |
0 |
3.289 |
2.935 |
S0=1, S1=1 |
1 |
1 |
1 |
1 |
3.91 |
3.509 |
S0=0, S1The simulation result of low voltage detection is as shown in figure 11 in the case of=0, S0=1, S1=1 feelings
As shown in figure 12, comparison diagram 11 and Figure 12 are it can also be seen that disclosed in the present application for the simulation result of low voltage detection under condition
Multi thresholds low-voltage detection circuit can set multigroup low voltage test threshold value, and low-voltage is examined so as to meet different integrated circuits
The requirement of brake.
Above-described is only the preferred embodiment of the present invention, and the invention is not restricted to above example.It is appreciated that this
Other improvement and become that art personnel directly export or associated without departing from the spirit and concept in the present invention
Change, be considered as being included within protection scope of the present invention.