CN105954681A - Fully differential analog/digital sampling and conversion circuit applied to battery monitoring chip - Google Patents

Fully differential analog/digital sampling and conversion circuit applied to battery monitoring chip Download PDF

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Publication number
CN105954681A
CN105954681A CN201610318022.1A CN201610318022A CN105954681A CN 105954681 A CN105954681 A CN 105954681A CN 201610318022 A CN201610318022 A CN 201610318022A CN 105954681 A CN105954681 A CN 105954681A
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Prior art keywords
module
switch
sampling
low pressure
high pressure
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张启东
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Xian Orisilicon Semiconductor Co Ltd
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Xian Orisilicon Semiconductor Co Ltd
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Priority to CN201610318022.1A priority Critical patent/CN105954681A/en
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G01R31/3644—Constructional arrangements
    • G01R31/3648—Constructional arrangements comprising digital calculation means, e.g. for performing an algorithm
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G01R31/396—Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M1/00—Analogue/digital conversion; Digital/analogue conversion
    • H03M1/12—Analogue/digital converters
    • H03M1/124—Sampling or signal conditioning arrangements specially adapted for A/D converters

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Secondary Cells (AREA)

Abstract

The invention provides a fully differential analog/digital sampling and conversion circuit applied to a battery monitoring chip, which is characterized by comprising a high voltage sampling module, a low voltage processing module, a comparator, a digital processing and control module and a digital/analog conversion module, wherein a battery is connected to the high voltage sampling module, and high voltage signals of the battery are sampled by the high voltage sampling module and then outputted to the low voltage processing module; the output of the low voltage processing module is sent to the comparator; a comparison result of the comparator is sent to the digital processing and control module; the digital processing and control module controls the digital/analog conversion module; and the digital/analog conversion module is respectively connected with the high voltage sampling module and the low voltage processing module. The fully differential analog/digital sampling and conversion circuit has the advantages that a high voltage switch and a low voltage switch are adopted to acquire voltage of a cascaded battery pack directly by being combined with a high voltage capacitor at the same time, and a voltage conversion unit is not required to convert the voltage of the battery pack into low voltage and then carries out voltage conversion, so that the sampling rate and the sampling precision are improved.

Description

A kind of fully differential modulus sampling being applied to battery cell monitoring chip and change-over circuit
Technical field
The present invention relates to the field of power management in electronic circuit, be specifically related to one and be applied to battery cell monitoring chip Fully differential modulus sampling and change-over circuit.
Background technology
Lithium battery monitoring chip for detecting the voltage of chargeable lithium cell, the information such as electric current and temperature, and by this A little information feed back to central control unit, thus ensure safety and the life-span of lithium battery.400V electric automobile needs Electrokinetic cell (the single battery voltage 3.8V) group wanting 96 joint series connection is together in parallel simultaneously and forms electrokinetic cell bag Produce for driving the running voltage of motor and enough driving electric currents.The single channel battery cell monitoring side of early stage Case, needs substantial amounts of discrete device, so that the area of total system and reliability are said and had a greatly reduced quality.
There is following defect in prior art:
Prior art all concentrates on the speed improving high voltage sampling switches, ignores the restriction of overall architecture speed, and And the number of prior art high voltage sampling switches is a lot, because the area that high voltage sampling switches needs is very big, lead Causing whole chip area very big, cost is high.The low pressure sample detecting symmetry of prior art is poor, and measurement result can Low by property.
Summary of the invention
For solving the problems referred to above, the present invention proposes a kind of fully differential modulus sampling being applied to battery cell monitoring chip And change-over circuit.
The technical scheme is that
A kind of fully differential modulus sampling being applied to battery cell monitoring chip and change-over circuit, including: high pressure sampling mould Block, low pressure processing module, comparator, digital processing and control module and D/A switch；Battery connects high pressure sampling Module, the high-voltage signal of battery exports to low pressure processing module after high pressure sampling module is sampled；Low pressure processes mould The output of block is to comparator；Result of the comparison is given digital processing and control module by comparator；Digital processing with Control module controls D/A switch module；D/A switch module processes mould with high pressure sampling module and low pressure respectively Block is connected.
Preferably, high pressure sampling module includes the submodule that two structures are the same: high pressure sampling module P and high pressure Sampling module N；Low pressure processing module includes the submodule that two structures are the same: low pressure processing module P and low pressure Processing module N；D/A switch module includes the submodule that two structures are the same: D/A switch P and D/A turn Change N；The positive and negative electrode of battery meets IN end and the IN of high pressure sampling module N of high pressure sampling module P respectively End；Connected by switch S2 between SW end and the SW end of high pressure sampling module N of high pressure sampling module P； The OUT terminal of high pressure sampling module P, the LSB end of low pressure processing module P and the LSB of D/A switch P End links together；The OUT terminal of high pressure sampling module N, the LSB end of low pressure processing module N and number/ The LSB end of mould conversion N links together；The MSB end of low pressure processing module P and the MSB of D/A switch P End connects；The MSB end of low pressure processing module N and the MSB end of D/A switch N connect；Low pressure processes mould The COMP end of block P is connected with the positive terminal of comparator；The COMP end of low pressure processing module N and comparator End of oppisite phase be connected.
In order to make circuit overall work more stable, the noise etc. filtered in set of cells disturbs, and makes the present invention's Circuit work is more stable reliably:
It is further preferred that also include filter module, wave filter is arranged between battery and high pressure sampling module.
Further preferred, the positive and negative electrode of battery connects input INP and INN of wave filter respectively；Filtering Output INP and INN of device connects IN end and the IN end of high pressure sampling module N of high pressure sampling module P respectively.
It addition, in order to measure the low-voltage signals such as the electric current of battery, temperature:
It is further preferred that also include low pressure sampling module；Low pressure sampling module is connected with D/A switch module.
Further preferred, low pressure sampling module is respectively the first low pressure sampling module and the second low pressure sampling mould Block.
In order to measure the temperature of battery:
Further preferred, the first low pressure sampling module and the second low pressure sampling module are provided with critesistor.
In order to measure the electric current of battery:
Further preferred, the first low pressure sampling module and the second low pressure sampling module are provided with hall device.
It is further preferred that wave filter can be electric capacity C, inductance L, resistance R composition.
Further preferred, wave filter is RC wave filter；One end of port INP connecting resistance Rfi1, resistance One end of another termination capacitor Cfi1 of Rfi1 and port OUTP；One end of port INN connecting resistance Rfi2, The other end of another termination capacitor Cfi1 of resistance Rfi2 and port OUTN.
It is further preferred that the structure of high pressure sampling submodule is: port IN connects one end of switch SW；Switch One end of the other end of SW, one end of switch Sgnd and electric capacity Cs is connected together as high pressure sampling The port S of module；Another termination port OUT of electric capacity Cs.
It is further preferred that low pressure process submodule structure be: MSB end by switch S3 connect power vd DL, Port COMP and one end of switch S5 is met by switch S6；Another termination voltage VCML of switch S5； Low pressure processes the LSB end of submodule by switching S4 ground connection VSSL, meeting port COMP by switch S7 One end with switch S5.
It is further preferred that D/A switch submodule includes the capacitor array module that two structures are identical, two Capacitor array module uses respectively as high-order capacitor array module and bit capacitor array module.High-order electric capacity The port SB of array module meets MSB, bit capacitor array module port SB and meets LSB.
Further preferred, capacitor array module is formed according to the electric capacity of binary weighting arrangement by m, institute The pole plate having electric capacity links together and meets port SB, and the other end of electric capacity is the most permissible by switch switching Being alternatively coupled to REF, TEMP or REFGND end, m is the positive integer more than or equal to 1.
The invention have the advantages that
The present invention uses high pressure and low tension switch directly to gather the voltage of cascade battery in combination with high-voltage capacitance, Without voltage conversion unit, battery voltage is converted to low pressure and carries out voltage conversion again, thus improve sampling Speed and sampling precision.
High pressure pressure measures the structure using fully differential, can effectively eliminate common mode disturbances, have good common mode Rejection ratio (CMRR, Common Mode Rejection Ratio).
For the measurement (temperature or electric current) of low pressure, this structure equally realizes perfect symmetry, altogether In mould rejection ratio (CMRR), there is advantage equally.
Accompanying drawing explanation
Fig. 1 present invention is applied to the sampling of fully differential modulus and the general frame of change-over circuit of battery cell monitoring chip.
Fig. 2 present invention is applied to the sampling of fully differential modulus and the concrete structure frame of change-over circuit of battery cell monitoring chip Figure.
Fig. 3 present invention is applied to the sampling of fully differential modulus and the Filter Principle of change-over circuit of battery cell monitoring chip Figure.
Fig. 4 present invention is applied to the fully differential modulus sampling of battery cell monitoring chip and high pressure sampling of change-over circuit Module principle figure.
The low pressure of the sampling of fully differential modulus and change-over circuit that Fig. 5 present invention is applied to battery cell monitoring chip processes son Module principle figure.
Fig. 6 present invention is applied to the fully differential modulus sampling of battery cell monitoring chip and the D/A switch electricity of change-over circuit Road module diagram.
Fig. 7 present invention is applied to the fully differential modulus sampling of battery cell monitoring chip and the D/A switch electricity of change-over circuit Capacitor array module schematic diagram in the module of road.
Fig. 8 present invention is applied to the sampling of fully differential modulus and the overall schematic diagram of change-over circuit of battery cell monitoring chip One.
The battery voltage sampling process of Fig. 9 specific embodiment of the invention one.
The cell voltage transformation process of Figure 10 specific embodiment of the invention one.
Figure 11 present invention is applied to the sampling of fully differential modulus and the arrangement schematic diagram of change-over circuit of battery cell monitoring chip Two.
The battery voltage sampling process of Figure 12 specific embodiment of the invention two.
The cell voltage transformation process of Figure 13 specific embodiment of the invention two.
Detailed description of the invention
The present invention is made the most in detail below in conjunction with embodiment and accompanying drawing, intactly illustrates.
Main idea is that the voltage to battery (battery here refers to: set of cells or single battery), The parameter such as temperature and electric current detects.Wherein can be divided into detection high-pressure section according to the concrete object of detection With detection low-pressure section.Detection high-pressure section refers mainly to detect cell voltage；It is right that detection low-pressure section is primarily referred to as The temperature of battery, electric current etc. detect.
In concrete detection, processed by high-pressure modular for relating to the part of high pressure；Portion for low pressure Divide and processed by low-voltage module.As Fig. 1 present invention is applied to the fully differential modulus sampling of battery cell monitoring chip Shown in the general frame of change-over circuit, specifically include that high pressure sampling module, low pressure processing module, comparator, Digital processing and control module and D/A switch.
Simultaneously can also include that low pressure is adopted to detect the low-voltage signal such as temperature, electric current (i.e. detecting low-pressure section) Original mold block；In addition to circuit overall work can be made more stable, it is also possible to include wave filter.Here filtering Device is primarily to the noise etc. filtered in set of cells disturbs, and the circuit work making the present invention is more stable reliably.
In Fig. 1, leftmost VCELL is that (battery here refers to: set of cells or single for battery to be detected Battery, lower same).Battery connects high pressure sampling module, and the high-voltage signal of battery is defeated after high pressure sampling module is sampled Go out to low pressure processing module.The output of low pressure processing module is to comparator.Result of the comparison is given number by comparator Word processing and control module.Digital processing controls D/A switch module with control module.D/A switch module is divided It is not connected with high pressure sampling module and low pressure processing module.
After result of the comparison is given digital processing and control module by comparator, digital processing is passed through with control module D/A switch module control and regulation electric charge is in D/A switch module, high pressure sampling module and low pressure processing module Distribution, electric charge is redistributed rear comparator and is compared, by charge distributing repeatedly, compares, finally Obtain the magnitude of voltage of set of cells.The magnitude of voltage obtained is exported with control module by digital processing.The present invention's is upper State detection process and can be understood as the worked of successive approximation register type (SAR) analog-digital converter (ADC) Journey.
In order to make circuit overall work more stable, wave filter is arranged between set of cells and high pressure sampling module, I.e. give high pressure sampling module after the filtering of the high-voltage signal of set of cells filtered device.It addition, in order to measure battery The low-voltage signal such as electric current, temperature, is provided with low pressure sampling module, low pressure sampling module and D/A switch module phase Even.
In order to illustrate further the present invention, as Fig. 2 present invention is applied to the fully differential modulus of battery cell monitoring chip Sample with shown in the concrete structure block diagram of change-over circuit: high pressure sampling module includes the submodule that two structures are the same Block: high pressure sampling module P and high pressure sampling module N；Low pressure processing module includes the submodule that two structures are the same Block: low pressure processing module P and low pressure processing module N；D/A switch module includes the submodule that two structures are the same Block: D/A switch P and D/A switch N；The positive and negative electrode of battery connect respectively wave filter input INP and INN；Output INP and INN of wave filter connects IN end and the high pressure sampling module of high pressure sampling module P respectively The IN end of N.Need exist for it is emphasised that: it has been observed that wave filter is not necessarily.Without wave filter The positive and negative electrode of battery connects IN end and the IN end of high pressure sampling module N of high pressure sampling module P respectively.
Connected by switch S2 between SW end and the SW end of high pressure sampling module N of high pressure sampling module P； The OUT terminal of high pressure sampling module P, the LSB end of low pressure processing module P and the LSB of D/A switch P End links together；The OUT terminal of high pressure sampling module N, the LSB end of low pressure processing module N and number/ The LSB end of mould conversion N links together；The MSB end of low pressure processing module P and the MSB of D/A switch P End connects；The MSB end of low pressure processing module N and the MSB end of D/A switch N connect；Low pressure processes mould The COMP end of block P is connected with the positive terminal of comparator；The COMP end of low pressure processing module N and comparator End of oppisite phase be connected.Switch in modules is also controlled by digital processing and control module, in Fig. 2 also Do not illustrate.
It addition, it has been observed that in order to measure the electric current of battery, temperature etc., the low pressure sampling module of setting is respectively First low pressure sampling module and the second low pressure sampling module.If for the temperature measuring battery, the first low pressure Sampling module and the second low pressure sampling module are provided with critesistor；If for the electric current measuring battery, First low pressure sampling module and the second low pressure sampling module are provided with hall device.
Below modules is described in detail.
Wave filter:
Wave filter can be electric capacity C, inductance L, resistance R composition.But according to actual needs, here Wave filter is preferably RC wave filter.As Fig. 3 present invention is applied to the fully differential modulus sampling of battery cell monitoring chip Shown in the Filter Principle figure of change-over circuit: one end of port INP connecting resistance Rfi1, resistance Rfi1's is another One end of one termination capacitor Cfi1 and port OUTP；One end of port INN connecting resistance Rfi2, resistance Rfi2 The other end of another termination capacitor Cfi1 and port OUTN.
High pressure sampling submodule:
Here high pressure sampling submodule i.e. high pressure sampling module P or high pressure sampling module N, they are the same Structure.It is applied to the fully differential modulus sampling of battery cell monitoring chip such as Fig. 4 present invention and the high pressure of change-over circuit is adopted Shown in appearance module principle figure: the port IN of high pressure sampling submodule connects one end of switch SW；Switch SW One end of the other end, switch one end of Sgnd and electric capacity Cs be connected together as high pressure sampling submodule Port S；Another termination port OUT of electric capacity Cs.
Low pressure process submodule:
Same, low pressure here processes submodule i.e. low pressure processing module P and low pressure processing module N, they It it is the same structure.As Fig. 5 present invention is applied to the sampling of fully differential modulus and the change-over circuit of battery cell monitoring chip Low pressure process shown in submodule schematic diagram: low pressure processes the MSB end of submodule and connects power supply by switch S3 VDDL, by switch S6 connect port COMP and switch S5 one end；Another termination voltage of switch S5 VCML；Low pressure processes the LSB end of submodule by switching S4 ground connection VSSL, connecing port by switch S7 COMP and one end of switch S5.
D/A switch submodule:
D/A switch module includes the submodule that two structures are the same: D/A switch P and D/A switch N；As Fig. 6 present invention is applied to the sampling of fully differential modulus and the D/A switch circuit of change-over circuit of battery cell monitoring chip Shown in module diagram: D/A switch circuit module includes the capacitor array module that two structures are identical, two electricity Hold array module to use respectively as high-order capacitor array module and bit capacitor array module.High-order capacitor array The port SB of module meets MSB, bit capacitor array module port SB and meets LSB.High-order capacitor array module Three inputs with bit capacitor array module connect VREF, VTEMP, VREFGND respectively.Port VREF, VTEMP, VREFGND will be connected with control module with digital processing.
As Fig. 7 present invention is applied to the sampling of fully differential modulus and the D/A switch of change-over circuit of battery cell monitoring chip In circuit module shown in capacitor array module schematic diagram, capacitor array module is mainly individual according to binary weighting by m The electric capacity composition of arrangement, a pole plate of all electric capacity links together and meets port SB, and the other end of electric capacity leads to Cross switch switching and can be alternatively coupled to REF, TEMP or REFGND end respectively.Here, m is big In the positive integer equal to 1.
Aforementioned comparator, digital processing are general module with control module, are the most just not described in detail.Right To be introduced in conjunction with specific embodiments below in the first low pressure sampling module and the second low pressure sampling module Bright.
Specific embodiment one (high pressure sample detecting):
As Fig. 8 present invention is applied to the sampling of fully differential modulus and the overall principle of change-over circuit of battery cell monitoring chip Figure one.It should be noted that the concrete port title being the most specifically illustrate each submodule aforementioned in Fig. 8, But may determine that each submodule and port thereof according to what circuit connected with earlier figures 2 corresponding relation.Scheme simultaneously The first low pressure sampling module and the concrete structure of the second low pressure sampling module is not comprised in 8.In figure, VSSH is The ground of high pressure；VDDL, VSSL are the ground of low-tension supply and low pressure respectively.It addition, D/A switch P or number/ Port VREF, VTEMP, VREFGND of mould conversion N close with the connection of digital processing with control module System the most specifically illustrates.
The process of high pressure sample detecting will be introduced below on the basis of shown in Fig. 8.Including battery voltage sampling and Cell voltage transformation process two parts.
Battery voltage sampling process:
Battery voltage sampling process such as Fig. 9 specific embodiment of the invention one: during battery voltage sampling, SW, S3 and S4 close, and other switches are opened.At this moment cell voltage is stored on sampling capacitance CS, compares The common-mode voltage of device is set to VCML (S5 Guan Bi), and a high position of DAC and bit capacitor store different respectively Initial charge.It should be noted that in Fig. 9 and distinguish and the connection shape in illustrative circuitry with the gray scale light and shade of line State (following identical).
In this stage, the electric charge with VINP and VINN as reference point is:
QP1=VDDL(CMSBP)+VSSL(CLSBP)-AINP(2CS)-VREF(CMSBPF+CLSBPF)-
VREFGND(CMSBP+CLSBP-CMSBPF-CLSBPF)
QN1=VDDL(CMSBN)+VSSL(CLSBN)-AINN(2CS)-VREF(CMSBNF+CLSBNF)-
VREFGND(CMSBN+CLSBN-CMSBNF-CLSBNF)
Wherein for reference port VINP, CMSBP and CLSBP is high-order total capacitance in D/A switch P With low level total capacitance, CMSBPF and CLSBPF is the high-order electric capacity being connected to VREF with low level respectively. For reference port VINN, CMSBN and CLSBN is high-order total capacitance and low level in D/A switch N Total capacitance, CMSBNF and CLSBNF is the high-order electric capacity being connected to VREF with low level respectively.CS is Sampling capacitance.
Cell voltage transformation process:
As shown in the cell voltage transformation process of Figure 10 specific embodiment of the invention one: at cell voltage transformation process In, S2, S6 and S7 Guan Bi, other switches are opened.The capacitance switch battle array of D/A switch module (DAC) Electric charge on sampling capacitance is carried out charge distributing by row.In this stage, with VINP and VINN as reference point Electric charge be:
Q P 2 = P I N P ( 2 C S + C M S B P + C L S B P ) - A I N P + A I N N 2 ( 2 C S ) - V R E F ( C M S B P F , + C L S B P F , ) - V R E F G N D ( C M S B P + C L S B P - C M S P F , - C L S B P F , )
Q N 2 = V I N N ( 2 C S + C M S B N + C L S B N ) - A I N P + A I N N 2 ( 2 C S ) - V R E F ( C M S B N F , + C L S B N F , ) - V R E F G N D ( C M S B N + C L S B N - C M S B N F , - C L S B N F , )
Wherein for reference port VINP, CMSBPF ' and CLSBPF ' is to connect in D/A switch P respectively Receive the switch arrays electric capacity of VREF；For reference port VINN, CMSBNF ' and CLSBNF ' point It not the switch arrays electric capacity being connected to VREF in D/A switch N.
According to principle of charge conservation, the voltage of QP2=QP1, QN2=QN1, VINP and VINN can be derived For:
V I N P = ( A I N N - A I N P ) C S + V D D L ( C M S B P ) + V S S L ( C L S B P ) + ( V R E F - V R E F G N D ) ( C M S B P F , - C M S B P F + C L S B P F , - C L S B P F ) ( 2 C S + C M S B P + C L S B P )
V I N N = ( A I N P - A I N N ) C S + V D D L ( C M S B N ) + V S S L ( C L S B N ) + ( V R E F - V R E F G N D ) ( C M S B N F , - C M S B N F + C L S B N F , - C L S B N F ) ( 2 C S + C M S B N + C L S B N )
Due to:
CMSBP=CMSBN=CMSB；
CLSBP=CLSBN=CLSB；
CMSBPF=CMSB-CMSBNF；
CLSBPF=CLSB-CLSBNF；
CMSBPF '=CMSB-CMSBNF '；
CLSBPF '=CLSB-CLSBNF '；
Thus it is as follows with the relational expression of input cell voltage to derive comparator both end voltage:
V I N P - V I N N = ( 2 ( A I N N - A I N P ) C S + 2 ( V R E F - V R E F G N D ) ( C M S B P F , - C M S B P F + C L S B P F , - C L S B P F ) ) ( 2 C S + C M S B P + C L S B P )
From above formula it will be seen that this structure shows good symmetry, thus there is the highest common mode and press down System is than (CMRR, Common Mode Rejection Ratio).
Specific embodiment two (low pressure sample detecting):
As aforementioned: in order to measure the electric current of battery, temperature etc., it is low that the low pressure sampling module of setting is respectively first Pressure sampling module and the second low pressure sampling module.If for the temperature measuring battery, the first low pressure sampling mould Block and the second low pressure sampling module are provided with critesistor；If for the electric current measuring battery, first is low Pressure sampling module and the second low pressure sampling module are provided with hall device.
The process of low pressure detection is the most specifically described as a example by the temperature measuring battery.Measure the main of battery temperature Thought is by attaching critesistor on battery, critesistor being connected as partial-pressure structure, passes through critesistor It is voltage signal by the temperature transition of battery, voltage signal is detected it is thus possible to obtain the temperature letter of battery Breath.
As Figure 11 present invention is applied to the sampling of fully differential modulus and the arrangement principle of change-over circuit of battery cell monitoring chip Shown in figure two: add the first low pressure sampling module and the second low pressure sampling module unlike Fig. 8.First Although the internal structure of low pressure sampling module and the second low pressure sampling module is different, but it is first in connection Low pressure sampling module and the second low pressure sampling module can exchange.In figure, resistance RNTC is critesistor.
It should be noted that the concrete port title being the most specifically illustrate each submodule aforementioned in Figure 11, but It is can to specify each submodule and port thereof according to what circuit connected with earlier figures 2 corresponding relation.In figure VSSH is the ground of high pressure；VDDL, VSSL are the ground of low-tension supply and low pressure respectively.It addition, D/A turns Change port VREF, VTEMP, VREFGND and digital processing and the control module of P or D/A switch N Annexation the most specifically illustrate.
Low pressure sample detecting (being specially temperature acquisition process here) will be introduced below on the basis of shown in Figure 11 Process.Including battery temperature sampling process and battery temperature transformation process two parts.
Battery temperature sampling process:
As shown in the battery voltage sampling process of Figure 12 specific embodiment of the invention two: in battery temperature sampling process Middle Sgnd, SVT, S3 and S4 close, and other switches are opened.At this moment battery temperature is stored in D/A switch P With on the high-order electric capacity of two capacitor array module in D/A switch N, the common-mode voltage of comparator is set to VCML (S5 Guan Bi), two capacitor array module in D/A switch P and D/A switch N a high position Different initial charges is stored respectively with bit capacitor.
In this stage, the electric charge with VINP and VINN as reference point is:
QP1=VDDL(CMSBP)+VSSL(CLSBP)-VTP(CMSBPT)-VREF(CMSBPR+CLSBPF)-
VREFGND(CMSBP+CLSBP-CMSBPT-CLSBPF-CMSBPR)
QN1=VDDL(CMSBN)+VSSL(CLSBN)-VTN(CMSBNT)-VREF(CMSBNR+CLSBNF)-
VREFGND(CMSBN+CLSBN-CMSBNT-CLSBNF-CMSBNR)
Wherein for reference port VINP, CMSBP and CLSBP is high-order total capacitance in D/A switch P With low level total capacitance, CMSBPR and CLSBPR is high-order in D/A switch P respectively and low level is connected to The electric capacity of VREF.
For reference port VINN, CMSBN and CLSBN is high-order total capacitance and low in D/A switch N Position total capacitance, CMSBNF and CLSBNF is high-order in D/A switch N respectively and low level is connected to VREF Electric capacity.CMSBPT is temperature sampling electric capacity.
Battery temperature transformation process:
As shown in the cell voltage transformation process of Figure 13 specific embodiment of the invention two: at battery temperature transformation process In, S6 and S7 closes, and other switches are opened.Capacitance switch battle array in D/A switch P and D/A switch N Electric charge on sampling capacitance is carried out charge distributing by row.
In this stage, the electric charge with VINP and VINN as reference point is:
QP2=VINP(CMSBP+CLSBP)-VREF(CMSBPF'+CLSBPF')-VREFGND(CMSBP+CLSBP-CMSBPF'-CLSBPF')
QN2=VINN(CMSBN+CLSBN)-VREF(CMSBNF'+CLSBNF')-VREFGND(CMSBN+CLSBN-CMSBNF'-CLSBNF')
Wherein for reference port VINP, CMSBPF ' and CLSBPF ' is to connect in D/A switch P respectively Receive the switch arrays electric capacity of VREF.
It is that D/A switch N is connected to respectively for reference port VINN, CMSBNF ' and CLSBNF ' The switch arrays electric capacity of VREF.
According to principle of charge conservation:
QP2=QP1, QN2=QN1；
The voltage of VINP and VINN can be derived as:
V I N P = V D D L ( C M S B P ) + V S S L ( C L S B P ) + ( V R E F - V R E F G N D ) ( C M S B P F , - C M S B P F + C L S B P F , - C L S B P F ) - V T N ( C M S B P T ) ( C M S B P + C L S P B )
V I N N = V D D L ( C M S B N ) + V S S L ( C L S B N ) + ( V R E F - V R E F G N D ) ( C M S B N F , - C M S B N F + C L S B N F , - C L S B N F ) - V T P ( C M S B N T ) ( C M S B N + C L S B N )
Due to:
CMSBP=CMSBN=CMSB；
CLSBP=CLSBN=CLSB；
CMSBPT=CMSBNT=CT=CMSB/2；
CLSBPF=CLSB CLSBNF；
CMSBNR=CMSB-CMSBPT CMSBPR；
CMSBPF '=CMSB-CMSBNF '；
CLSBPF '=CLSB-CLSBNF '；
Thus it is as follows with the relational expression of input cell voltage to derive comparator both end voltage:
V I N P - V I N N = ( V T P - V T N ) C M S B 2 + 2 ( V R E F - V R E F G N D ) ( C M S B P F , - C M S B P F + C L S B P F , - C L S B P F - C M S B 4 ) ( C M S B P + C L S B P )
Whereby it can be detected that voltage.
Compared with prior art:
The present invention uses high pressure and low tension switch directly to gather the voltage of cascade battery in combination with high-voltage capacitance, Without voltage conversion unit, battery voltage is converted to low pressure and carries out voltage conversion again, thus improve sampling Speed and sampling precision.
High pressure pressure measures the structure using fully differential, can effectively eliminate common mode disturbances, have good common mode Rejection ratio (CMRR, Common Mode Rejection Ratio).
For the temperature survey of low pressure, the structure of the present invention equally realizes perfect symmetry, presses down in common mode System ratio has advantage equally on (CMRR).

Claims (10)

1. the fully differential modulus sampling being applied to battery cell monitoring chip and change-over circuit, it is characterised in that Including: high pressure sampling module, low pressure processing module, comparator, digital processing and control module and D/A switch； Battery connects high pressure sampling module, and the high-voltage signal of battery exports after high pressure sampling module is sampled and processes mould to low pressure Block；The output of low pressure processing module is to comparator；Result of the comparison is given digital processing and controls mould by comparator Block；Digital processing controls D/A switch module with control module；D/A switch module respectively with high pressure sample mould Block is connected with low pressure processing module.
It is applied to the sampling of fully differential modulus and the conversion electricity of battery cell monitoring chip the most as claimed in claim 1 Road, it is characterised in that: high pressure sampling module includes the submodule that two structures are the same: high pressure sampling module P and High pressure sampling module N；Low pressure processing module includes the submodule that two structures are the same: low pressure processing module P and Low pressure processing module N；D/A switch module includes the submodule that two structures are the same: D/A switch P sum/ Mould conversion N；The positive and negative electrode of battery connects the IN end of high pressure sampling module P and high pressure sampling module N's respectively IN end；Between SW end and the SW end of high pressure sampling module N of high pressure sampling module P by switch S2 even Connect；The OUT terminal of high pressure sampling module P, the LSB end of low pressure processing module P and D/A switch P's LSB end links together；The OUT terminal of high pressure sampling module N, low pressure processing module N LSB end with And the LSB end of D/A switch N links together；The MSB end of low pressure processing module P and D/A switch P MSB end connect；The MSB end of low pressure processing module N and the MSB end of D/A switch N connect；Low The COMP end of pressure processing module P is connected with the positive terminal of comparator；The COMP end of low pressure processing module N It is connected with the end of oppisite phase of comparator.
3. the fully differential modulus sampling being applied to battery cell monitoring chip as described in as arbitrary in claim 1 and 2 And change-over circuit, it is characterised in that: also including filter module, wave filter is arranged on battery and high pressure sampling mould Between block.
It is applied to the sampling of fully differential modulus and the conversion electricity of battery cell monitoring chip the most as claimed in claim 3 Road, it is characterised in that: the positive and negative electrode of battery connects input INP and INN of wave filter respectively；Wave filter Output INP and INN connects IN end and the IN end of high pressure sampling module N of high pressure sampling module P respectively.
It is applied to the sampling of fully differential modulus and the conversion electricity of battery cell monitoring chip the most as claimed in claim 2 Road, it is characterised in that: also include low pressure sampling module；Low pressure sampling module is connected with D/A switch module.
It is applied to the sampling of fully differential modulus and the conversion electricity of battery cell monitoring chip the most as claimed in claim 5 Road, it is characterised in that: low pressure sampling module is respectively the first low pressure sampling module and the second low pressure sampling module.
It is applied to the sampling of fully differential modulus and the conversion electricity of battery cell monitoring chip the most as claimed in claim 2 Road, it is characterised in that: the structure of high pressure sampling submodule is: port IN connects one end of switch SW；Switch One end of the other end of SW, one end of switch Sgnd and electric capacity Cs is connected together as high pressure sampling The port S of module；Another termination port OUT of electric capacity Cs.
It is applied to the sampling of fully differential modulus and the conversion electricity of battery cell monitoring chip the most as claimed in claim 2 Road, it is characterised in that: low pressure process submodule structure be: MSB end by switch S3 connect power vd DL, Port COMP and one end of switch S5 is met by switch S6；Another termination voltage VCML of switch S5； Low pressure processes the LSB end of submodule by switching S4 ground connection VSSL, meeting port COMP by switch S7 One end with switch S5.
It is applied to the sampling of fully differential modulus and the conversion electricity of battery cell monitoring chip the most as claimed in claim 2 Road, it is characterised in that: D/A switch submodule includes the capacitor array module that two structures are identical, two electric capacity Array module uses respectively as high-order capacitor array module and bit capacitor array module；High-order capacitor array mould The port SB of block meets MSB, bit capacitor array module port SB and meets LSB.
It is applied to the sampling of fully differential modulus and the conversion electricity of battery cell monitoring chip the most as claimed in claim 9 Road, it is characterised in that: capacitor array module is formed according to the electric capacity of binary weighting arrangement by m, all electricity The pole plate held links together and meets port SB, and the other end of electric capacity is switched by switch and can select respectively Being connected to REF, TEMP or REFGND end, m is the positive integer more than or equal to 1.
CN201610318022.1A 2016-05-15 2016-05-15 Fully differential analog/digital sampling and conversion circuit applied to battery monitoring chip Pending CN105954681A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106842046A (en) * 2017-01-21 2017-06-13 深圳市沃特玛电池有限公司 battery capacity detection circuit
CN111934035A (en) * 2020-09-22 2020-11-13 深圳英集芯科技有限公司 Voltage detection chip, battery and electronic equipment

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102478631A (en) * 2010-11-26 2012-05-30 比亚迪股份有限公司 Battery performance parameter measuring device and measuring method thereof
CN104617627A (en) * 2015-02-12 2015-05-13 山东申普交通科技有限公司 Battery charging and discharging management system
CN105044607A (en) * 2015-07-01 2015-11-11 中国电力科学研究院 Battery module multichannel synchronous detection device
CN205608161U (en) * 2016-05-15 2016-09-28 西安矽源半导体有限公司 Be applied to full difference mould data acquisition appearance and converting circuit of battery monitoring chip

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102478631A (en) * 2010-11-26 2012-05-30 比亚迪股份有限公司 Battery performance parameter measuring device and measuring method thereof
CN104617627A (en) * 2015-02-12 2015-05-13 山东申普交通科技有限公司 Battery charging and discharging management system
CN105044607A (en) * 2015-07-01 2015-11-11 中国电力科学研究院 Battery module multichannel synchronous detection device
CN205608161U (en) * 2016-05-15 2016-09-28 西安矽源半导体有限公司 Be applied to full difference mould data acquisition appearance and converting circuit of battery monitoring chip

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
QIDONG ZHANG ETAL.: "An area-efficient and high speed multiplexer for battery monitor system", 《IEICE ELECTRONICS EXPRESS》 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106842046A (en) * 2017-01-21 2017-06-13 深圳市沃特玛电池有限公司 battery capacity detection circuit
CN106842046B (en) * 2017-01-21 2022-01-07 深圳安鼎新能源技术开发有限公司 Battery capacity detection circuit
CN111934035A (en) * 2020-09-22 2020-11-13 深圳英集芯科技有限公司 Voltage detection chip, battery and electronic equipment

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Application publication date: 20160921