High-precision large-current constant current source suitable for three-super platform voice coil motor drive

Abstract

A high-precision large-current constant current source suitable for three-super platform voice coil motor driving comprises a master constant current module, a slave constant current module, a reference voltage source and a load, a master-slave parallel connection or master-slave cascade connection circuit structure is adopted, the master constant current module forms a high-precision power Howland constant current source through a high-precision device and a power operational amplifier, and the slave constant current module forms a high-precision power Howland constant current source through a high-precision device and a power operational amplifier. The slave constant-current module forms a common-precision power Howland constant-current source through a common-precision device and a power operational amplifier, the master constant-current module and the slave constant-current module are connected in parallel or in cascade to form a high-precision large-current constant-current source, the current driving capability of the high-precision large-current constant-current source is jointly determined by the master constant-current module and the slave constant-current module, and the driving current precision mainly depends on the master constant-current module.

Description

Technical Field

[0001] The invention relates to a high-precision large-current constant-current source suitable for driving a triple-super-platform voice coil motor, and belongs to the field of constant-current driving. Background Art

[0002] High-performance optical payloads require ultra-high precision, ultra-high stability, and ultra-high agility from the satellite platform. The three-super control system uses voice coil motors as actuators. Their control accuracy and driving capability directly affect the control accuracy and payload driving capability of the control system, while the control accuracy and driving capability of the voice coil motors directly depend on the current accuracy and current capability of the driver. Therefore, improving the driving current accuracy and driving current capability of the voice coil motor is the key to improving the control accuracy and payload driving capability of the three-super platform.

[0003] In the prior art, the three-super platform voice coil motor uses a power op amp to form a power Howland constant current source for driving. However, the output current capability of existing aerospace-grade power op amps is limited. In practical applications, in addition to meeting the first-level derating, factors such as the safe operating area and optimal operating point of the device must also be considered, resulting in the actual maximum current that can be used being only about 1 / 3 of the peak current of the device. In the future, the load driving capability of the three-super platform will be greatly improved, and the current driving capability of the power Howland constant current source formed by a single power op amp can no longer meet the driving capability requirements of the future three-super platform voice coil motor.

[0004] In the prior art, in order to improve the current driving capability, two or more power Howland constant current sources can be used in parallel. Since the power Howland constant current sources used in parallel share the same reference voltage source and have the same composition structure and circuit parameters, the output current is the sum of the output currents of the power Howland constant current sources used in parallel, thereby achieving the purpose of expanding the output current capability. However, the prior art has the following problems:

[0005] (1) It is difficult to achieve both high precision and high current. Compared with precision op amps, power op amps have higher output power (current and voltage), but smaller open-loop gain and larger offset temperature drift, resulting in poor output accuracy of the power Howland constant current source and severe temperature effects. In aerospace environments with severe ambient temperature changes, it is difficult to achieve ultra-high precision with existing technologies.

[0006] (2) It is difficult to achieve both high precision and small size, light weight and low cost. In order to maximize the output current accuracy, the power Howland constant current sources used in parallel are required to have the same output current accuracy. This requires that all key components of each power Howland constant current source, including sampling resistors and proportional resistors, should be high-precision devices. However, such devices are usually bulky and expensive, so they do not conform to the design concept of small size, light weight and low cost of future aerospace products. Summary of the invention

[0007] The technical problem solved by the present invention is: in view of the problem that it is difficult to take into account both large current and high precision as well as high precision and small size, light weight and low cost in the traditional technology in the current existing technology, a high-precision large current constant current source suitable for driving a three-super platform voice coil motor is proposed.

[0008] The present invention solves the above technical problems by the following technical solutions:

[0009] A high-precision high-current constant current source suitable for driving a three-super platform voice coil motor, comprising a main constant current module, N slave constant current modules, a reference voltage source, and a load module;

[0010] The main constant current module is provided with a reference voltage by a reference voltage source, receives the output current of N slave constant current modules through a sampling resistor, performs sampling feedback processing, and outputs the motor drive current with a specified current accuracy to the load module;

[0011] The slave constant current module is provided with a reference voltage by a reference voltage source, generates a current signal according to the reference voltage and inputs the current signal into the master constant current module; the slave constant current module and the master constant current module form a master-slave parallel structure or a master-slave cascade structure;

[0012] A reference voltage source, providing a reference voltage for the master constant current module and N slave constant current modules;

[0013] The load module receives the motor drive current of the specified current accuracy output by the main constant current module, selects the working mode and works according to the output mode of the motor drive current; the output mode of the motor drive current is adjusted according to the connection settings of the load module and the reference voltage source.

[0014] The output mode of the motor driving current includes a common-phase output mode and an anti-phase output mode;

[0015] The reference voltage source includes a common terminal A, a positive common terminal P, an inverting reference common terminal C, and a negative common terminal N; when the common terminal A and the positive common terminal P, the inverting reference common terminal C and the negative common terminal N are short-circuited at the same time, the motor drive current is in a common output mode; when the common terminal A and the negative common terminal N, the inverting reference common terminal C and the positive common terminal P are short-circuited at the same time, the motor drive current is in an inverting output mode.

[0016] The main constant current module includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a main constant current module sampling resistor RSM, a composite operational amplifier OP-M11, a main constant current module in-phase reference input terminal IP-M11, a main constant current module inverting reference input terminal IN-M11, a main constant current module common terminal C-M11 and a main constant current module output terminal O-M11, wherein:

[0017] One end of the first resistor R1 is connected to the inverting reference input terminal IN-M11 of the main constant current module, the other end of the first resistor R1 is connected to the inverting input terminal of the composite operational amplifier OP-M11 and one end of the second resistor R2 at the same time, the other end of the second resistor R2 is connected to the output end of the composite operational amplifier OP-M11 and one end of the main constant current module sampling resistor RSM, forming the main constant current module common terminal C-M11; the other end of the main constant current module sampling resistor RSM is connected to one end of the fourth resistor R4, forming the main constant current module output terminal O-M11;

[0018] The other end of the fourth resistor R4 is connected to the in-phase input terminal of the composite operational amplifier OP-M11 and one end of the third resistor R3 at the same time, and the other end of the third resistor R3 is connected to the in-phase reference input terminal IP-M11 of the main constant current module.

[0019] The composite operational amplifier OP-M11 includes a precision operational amplifier OP1 and a power operational amplifier PA1, which are connected in series, the non-inverting input terminal and the inverting input terminal of the precision operational amplifier OP1 are respectively used as the non-inverting input terminal and the inverting input terminal of the composite operational amplifier OP-M11, and the output terminal of the power operational amplifier PA1 is used as the output terminal of the composite operational amplifier OP-M11.

[0020] The circuit structures of the slave constant current modules are the same, including a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a slave constant current module sampling resistor and a power amplifier PA1, a sampling resistor RS1 N, an Nth slave constant current module in-phase reference input terminal IP-S1 N, an Nth slave constant current module inverting reference input terminal IN-S1 N, an Nth slave constant current module common terminal C-S1N and an Nth slave constant current module output terminal O-S1 N, wherein:

[0021] One end of the fifth resistor R5 is connected to the inverting reference input terminal IN-S1 N of the Nth slave constant current module, the other end of the fifth resistor R5 is simultaneously connected to the inverting input terminal of the power amplifier PA1 and one end of the sixth resistor R6, the other end of the sixth resistor R6 is connected to the output terminal of the power amplifier PA1 and one end of the slave constant current module sampling resistor RS1 N, forming the Nth slave constant current module common terminal C-S1 N, the other end of the slave constant current module sampling resistor RS1 N is connected to one end of the eighth resistor R8, forming the Nth slave constant current module output terminal O-S1 N, the other end of the eighth resistor R8 is simultaneously connected to the in-phase input terminal of the power amplifier PA1 and one end of the seventh resistor R7, and the other end of the seventh resistor R7 is connected to the in-phase reference input terminal IP-S1 N of the slave constant current module.

[0022] The number N of the slave constant current modules is a positive integer greater than or equal to 1, and is determined according to the current value range required by the motor drive current; the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 are high-precision resistors; the value constraints of the high-precision resistors are: R1=R3 and R2=R4, initial accuracy ≤0.1%, temperature coefficient ≤10ppm / ℃; the key parameter value constraints of the precision operational amplifier OP1 are: open-loop gain ≥120dB, offset voltage temperature drift ≤1μV / ℃, offset current temperature drift ≤50pA / ℃.

[0023] The fifth resistor R5, the sixth resistor R6, the seventh resistor R7 and the eighth resistor R8 are ordinary precision resistors; the value constraints of the ordinary precision resistors are: R5=R7, R6=R8, initial accuracy ≤1%, temperature coefficient ≤100ppm / ℃.

[0024] The positive electrode of the reference voltage source VR is connected to the positive common terminal P, and the negative electrode of the reference voltage source VR is connected to the negative common terminal N and the ground at the same time; the output terminal O-M11 of the main constant current module is grounded through the load RL, and the load current IL flows through the load RL.

[0025] In the master-slave parallel structure, the common terminal C-M11 of the master constant current module is connected to the output terminals of N slave constant current modules at the same time; the output terminals of the N slave constant current modules include the output terminal O-S11 of the first slave constant current module, the output terminal O-S12 of the second slave constant current module...the output terminal O-S1 N of the Nth slave constant current module; the common terminals of the N slave constant current modules are suspended, and the common terminals of the N slave constant current modules include the common terminal C-S11 of the first slave constant current module, the common terminal C-S12 of the second slave constant current module...the common terminal C-S1 N of the Nth slave constant current module;

[0026] In the master-slave cascade structure, the common terminal C-M11 of the master constant current module is connected to the output terminal O-S11 of the first slave constant current module, the common terminal C-S11 of the first slave constant current module is connected to the output terminal O-S12 of the second slave constant current module, the common terminal C-S12 of the second slave constant current module is connected to the output terminal of the next level slave constant current module, until the output terminal O-S2N of the Nth slave constant current module is connected to the common terminal of the previous level slave constant current module, and the common terminal C-S2N of the Nth slave constant current module is left floating.

[0027] When the master constant current module M11 and the N slave constant current modules form a master-slave parallel structure, the sampling resistors of the slave constant current modules are the same, and the constraint relationship with the master constant current module sampling resistor RSM is:

[0028]

[0029] Wherein, RS11 is the first slave constant current module sampling resistor, RS12 is the second slave constant current module sampling resistor…RS1 N is the Nth slave constant current module sampling resistor;

[0030] In the master-slave parallel structure, the output current of N slave constant current modules and the load current IL satisfy the constraint relationship as follows:

[0031]

[0032] Wherein, IS11 is the output current of the first slave constant current module, IS12 is the output current of the second slave constant current module…IS1 N is the output current of the Nth slave constant current module; IL is the load current, which is equal to the current flowing through the sampling resistor RSM of the main constant current module.

[0033] When the master constant current module M11 and the N slave constant current modules form a master-slave cascade structure, the slave constant current module sampling resistors are different, and the constraint relationship with the master constant current module sampling resistor RSM is:

[0034]

[0035] …

[0036]

[0037] Wherein, RS11 is the first slave constant current module sampling resistor, RS12 is the second slave constant current module sampling resistor…RS1 N is the Nth slave constant current module sampling resistor;

[0038] In the master-slave cascade structure, the output current flowing through N slave constant current modules and the load current IL satisfy the constraint relationship:

[0039]

[0040] …

[0041]

[0042] Wherein, IS11 is the output current of the first slave constant current module, IS12 is the output current of the second slave constant current module, IS1 N is the output current of the Nth slave constant current module; IL is the load current, which is equal to the current flowing through the sampling resistor RSM of the main constant current module.

[0043] In the in-phase output mode, the load current IL and the reference voltage source VR have the same phase, and the load current IL is:

[0044]

[0045] Wherein, R1, R2, R3 and R4 are respectively the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4, VR is the reference voltage source, RSM is the main constant current module sampling resistor RSM, and the load current constraint condition is: R1 = R3 and R2 = R4;

[0046] In the inverting output mode, the load current IL and the reference voltage source VR have opposite phases, and the load current IL is:

[0047]

[0048] Wherein, the load current constraint condition is: R1=R3 and R2=R4.

[0049] The reference voltage source VR is one of a fixed voltage source, an adjustable voltage source, a unipolar positive voltage source, a unipolar negative voltage source or a bipolar voltage source; the load RL is one of a voice coil motor, a resistive load or an inductive load.

[0050] The advantages of the present invention compared with the prior art are:

[0051] (1) The present invention provides a high-precision, high-current constant current source suitable for driving a three-super platform voice coil motor. The main circuit is composed of high-precision devices and power amplifiers to form a high-precision power Howland constant current source, and the slave circuit is composed of ordinary precision devices and power amplifiers to form an ordinary precision power Howland constant current source. The main circuit and the slave circuit are connected in parallel or cascade to form a high-precision, high-current constant current source. The originality of the present invention is mainly reflected in that the output current flowing through the sampling resistor of the slave circuit flows through the sampling resistor of the main circuit and participates in the closed-loop feedback of the main circuit, which can ensure the output current accuracy while expanding the driving current, and has the advantages of small size, light weight, and low cost.

[0052] (2) The present invention has the advantages of high precision, small size, light weight and low cost. To achieve the same current driving capability and current accuracy, the high-precision devices used in the present invention are significantly less than those in the prior art. Generally, the volume, weight and cost of high-precision devices such as precision resistors and precision op amps are significantly higher than those of ordinary precision devices. Therefore, the present invention is more likely to achieve small size, light weight and low cost, and the more the number of slave constant current modules connected in parallel or cascaded, the more obvious the effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 A schematic diagram of a master-slave parallel structure of a high-precision, high-current constant-current source provided by the present invention;

[0054] Figure 2 A schematic diagram of a master-slave cascade structure of a high-precision, high-current constant-current source provided by the present invention;

[0055] Figure 3 A schematic diagram showing the effect of the change in sampling resistance of the constant current module on the accuracy index provided by the present invention;

[0056] Figure 4 A schematic diagram showing the effect of the offset voltage change of the power amplifier of the constant current module on the accuracy index provided by the present invention;

[0057] Figure 5 This is a schematic diagram of the effect of the sixth resistance change on the accuracy index provided by the present invention. DETAILED DESCRIPTION

[0058] A high-precision large-current constant current source suitable for driving a three-super-platform voice coil motor comprises a master constant current module, a slave constant current module, a reference voltage source and a load, and adopts a master-slave parallel or master-slave cascade circuit structure. The master constant current module is composed of high-precision devices and a power operational amplifier to form a high-precision power Howland constant current source, and the slave constant current module is composed of ordinary precision devices and a power operational amplifier to form an ordinary precision power Howland constant current source. The master and slave constant current modules are connected in parallel or cascade to form a high-precision large-current constant current source, and its current driving capability is jointly determined by the master constant current module and the slave constant current module, while the driving current accuracy mainly depends on the master constant current module.

[0059] The specific structure of high-precision large current constant current source includes:

[0060] Main constant current module, slave constant current module, reference voltage source, load module;

[0061] The input end of the master constant current module and the input ends of the N slave constant current modules are connected to a reference voltage source, and the reference voltage source provides a reference voltage; the master constant current module and the N slave constant current modules form a master-slave parallel structure or a master-slave cascade structure. In the master-slave parallel structure, the sampling resistor of the master constant current module receives the output current sampling feedback processing of the N slave constant current modules and outputs the motor drive current with a specified current accuracy; in the master-slave cascade structure, each slave constant current module is connected to the upper-level slave constant current module through the output end, and the output current of the first-level slave constant current module outputs the motor drive current with a specified current accuracy after passing through the sampling resistor of the master constant current module; the load module and the reference voltage source are short-circuited to adjust the output mode of the motor drive current.

[0062] The output modes of the motor driving current include a common-phase output mode and an anti-phase output mode;

[0063] The reference voltage source includes a common terminal A, a positive common terminal P, an inverting reference common terminal C, and a negative common terminal N; when the common terminal A and the positive common terminal P, the inverting reference common terminal C and the negative common terminal N are short-circuited at the same time, the motor drive current is in a common output mode; when the common terminal A and the negative common terminal N, the inverting reference common terminal C and the positive common terminal P are short-circuited at the same time, the motor drive current is in an inverting output mode.

[0064] The main constant current module includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a main constant current module sampling resistor RSM, a composite operational amplifier OP-M11, a main constant current module in-phase reference input terminal IP-M11, a main constant current module inverting reference input terminal IN-M11, a main constant current module common terminal C-M11 and a main constant current module output terminal O-M11, wherein:

[0065] One end of the first resistor R1 is connected to the inverting reference input terminal IN-M11 of the main constant current module, the other end of the first resistor R1 is connected to the inverting input terminal of the composite operational amplifier OP-M11 and one end of the second resistor R2 at the same time, the other end of the second resistor R2 is connected to the output end of the composite operational amplifier OP-M11 and one end of the main constant current module sampling resistor RSM, forming the main constant current module common terminal C-M11; the other end of the main constant current module sampling resistor RSM is connected to one end of the fourth resistor R4, forming the main constant current module output terminal O-M11;

[0066] The other end of the fourth resistor R4 is connected to the in-phase input terminal of the composite operational amplifier OP-M11 and one end of the third resistor R3 at the same time, and the other end of the third resistor R3 is connected to the in-phase reference input terminal IP-M11 of the main constant current module.

[0067] The composite operational amplifier OP-M11 includes a precision operational amplifier OP1 and a power operational amplifier PA1. The precision operational amplifier OP1 and the power operational amplifier PA1 are connected in series. The non-inverting input terminal and the inverting input terminal of the precision operational amplifier OP1 serve as the non-inverting input terminal and the inverting input terminal of the composite operational amplifier OP-M11 respectively. The output terminal of the power operational amplifier PA1 serves as the output terminal of the composite operational amplifier OP-M11.

[0068] The circuit structure of each slave constant current module is the same, including a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a slave constant current module sampling resistor and a power amplifier PA1, a sampling resistor RS1 N, an Nth slave constant current module in-phase reference input terminal IP-S1 N, an Nth slave constant current module inverting reference input terminal IN-S1 N, an Nth slave constant current module common terminal C-S1 N and an Nth slave constant current module output terminal O-S1 N, wherein:

[0069] One end of the fifth resistor R5 is connected to the inverting reference input terminal IN-S1 N of the Nth slave constant current module, the other end of the fifth resistor R5 is simultaneously connected to the inverting input terminal of the power amplifier PA1 and one end of the sixth resistor R6, the other end of the sixth resistor R6 is connected to the output terminal of the power amplifier PA1 and one end of the slave constant current module sampling resistor RS1 N, forming the Nth slave constant current module common terminal C-S1 N, the other end of the slave constant current module sampling resistor RS1 N is connected to one end of the eighth resistor R8, forming the Nth slave constant current module output terminal O-S1 N, the other end of the eighth resistor R8 is simultaneously connected to the in-phase input terminal of the power amplifier PA1 and one end of the seventh resistor R7, and the other end of the seventh resistor R7 is connected to the in-phase reference input terminal IP-S1 N of the slave constant current module.

[0070] The number N of constant current modules is a positive integer greater than or equal to 1, and is determined according to the current value range required by the motor drive current; the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 are high-precision resistors; the value constraints of the high-precision resistors are: R1=R3 and R2=R4, initial accuracy ≤0.1%, temperature coefficient ≤10ppm / ℃; the key parameter value constraints of the precision operational amplifier OP1 are: open-loop gain ≥120dB, offset voltage temperature drift ≤1μV / ℃, offset current temperature drift ≤50pA / ℃.

[0071] The fifth resistor R5, the sixth resistor R6, the seventh resistor R7 and the eighth resistor R8 are ordinary precision resistors; the value constraints of the ordinary precision resistors are: R5=R7, R6=R8, initial accuracy ≤1%, temperature coefficient ≤100ppm / ℃.

[0072] The positive electrode of the reference voltage source VR is connected to the positive common terminal P, and the negative electrode of the reference voltage source VR is connected to the negative common terminal N and the ground at the same time; the output terminal O-M11 of the main constant current module is grounded through the load RL, and the load current IL flows through the load RL.

[0073] In the master-slave parallel structure, the common terminal C-M11 of the master constant current module is connected to the output terminals of N slave constant current modules at the same time; the output terminals of the N slave constant current modules include the output terminal O-S11 of the first slave constant current module, the output terminal O-S12 of the second slave constant current module...the output terminal O-S1 N of the Nth slave constant current module; the common terminals of the N slave constant current modules are suspended, and the common terminals of the N slave constant current modules include the common terminal C-S11 of the first slave constant current module, the common terminal C-S12 of the second slave constant current module...the common terminal C-S1 N of the Nth slave constant current module;

[0074] In the master-slave cascade structure, the common terminal C-M11 of the master constant current module is connected to the output terminal O-S11 of the first slave constant current module, the common terminal C-S11 of the first slave constant current module is connected to the output terminal O-S12 of the second slave constant current module, the common terminal C-S12 of the second slave constant current module is connected to the output terminal of the next level slave constant current module, until the output terminal O-S2N of the Nth slave constant current module is connected to the common terminal of the previous level slave constant current module, and the common terminal C-S2N of the Nth slave constant current module is left floating.

[0075] When the master constant current module M11 and the N slave constant current modules form a master-slave parallel structure, the sampling resistors of the slave constant current modules are the same, and the constraint relationship with the master constant current module sampling resistor RSM is:

[0076]

[0077] Wherein, RS11 is the first slave constant current module sampling resistor, RS12 is the second slave constant current module sampling resistor…RS1 N is the Nth slave constant current module sampling resistor;

[0078] In the master-slave parallel structure, the output current of N slave constant current modules and the load current IL satisfy the constraint relationship as follows:

[0079]

[0080] Wherein, IS11 is the output current of the first slave constant current module, IS12 is the output current of the second slave constant current module…IS1 N is the output current of the Nth slave constant current module; IL is the load current, which is equal to the current flowing through the sampling resistor RSM of the main constant current module.

[0081] When the master constant current module M11 and the N slave constant current modules form a master-slave cascade structure, the slave constant current module sampling resistors are different, and the constraint relationship with the master constant current module sampling resistor RSM is:

[0082]

[0083] …

[0084]

[0085] Wherein, RS11 is the first slave constant current module sampling resistor, RS12 is the second slave constant current module sampling resistor…RS1 N is the Nth slave constant current module sampling resistor;

[0086] In the master-slave cascade structure, the output current flowing through N slave constant current modules and the load current IL satisfy the constraint relationship:

[0087]

[0088] …

[0089]

[0090] Wherein, IS11 is the output current of the first slave constant current module, IS12 is the output current of the second slave constant current module, IS1 N is the output current of the Nth slave constant current module; IL is the load current, which is equal to the current flowing through the sampling resistor RSM of the main constant current module.

[0091] In the in-phase output mode, the load current IL and the reference voltage source VR have the same phase, and the load current IL is:

[0092]

[0093] Wherein, R1, R2, R3 and R4 are respectively the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4, VR is the reference voltage source, RSM is the main constant current module sampling resistor RSM, and the load current constraint condition is: R1 = R3 and R2 = R4;

[0094] In the inverting output mode, the load current IL and the reference voltage source VR have opposite phases, and the load current IL is:

[0095]

[0096] Wherein, the load current constraint condition is: R1=R3 and R2=R4.

[0097] The reference voltage source VR is one of a fixed voltage source, an adjustable voltage source, a unipolar positive voltage source, a unipolar negative voltage source or a bipolar voltage source; the load RL is one of a voice coil motor, a resistive load or an inductive load.

[0098] The following is further described in conjunction with the accompanying drawings and preferred embodiments of the specification:

[0099] In the current embodiment, the main circuit is composed of high-precision devices and power amplifiers to form a high-precision power Howland constant current source, and the slave circuit is composed of ordinary precision devices and power amplifiers to form an ordinary precision power Howland constant current source. The main circuit and the slave circuit are connected in parallel or cascade to form a high-precision large current constant current source. The originality of the present invention is mainly reflected in that the output current flowing through the sampling resistor of the slave circuit flows through the sampling resistor of the main circuit and participates in the closed-loop feedback of the main circuit, which can ensure the output current accuracy while expanding the driving current, and has the advantages of small size, light weight and low cost.

[0100] High-precision high-current constant current source suitable for driving the three-super platform voice coil motor, including: main constant current module M11, slave constant current module, reference voltage source VR and load RL;

[0101] The main constant current module M11 has four terminals, namely, the main constant current module in-phase reference input terminal IP-M11, the main constant current module inverting reference input terminal IN-M11, the main constant current module common terminal C-M11 and the main constant current module output terminal O-M11;

[0102] The slave constant current module includes a first slave constant current module S11, a second slave constant current module S12, and so on, an Nth slave constant current module S1 to N, a total of N, where N is a positive integer greater than or equal to 1;

[0103] The first slave constant current module S11 has four terminals, namely, the first slave constant current module in-phase reference input terminal IP-S11, the first slave constant current module inverting reference input terminal IN-S11, the first slave constant current module common terminal C-S11 and the first slave constant current module output terminal O-S11; the second slave constant current module S12 has four terminals, namely, the second slave constant current module in-phase reference input terminal IP-S12, the second slave constant current module inverting reference input terminal IN-S12, the second slave constant current module common terminal C-S12 and the second slave constant current module output terminal O-S12; by analogy, the Nth slave constant current module S1 N has four terminals, namely, the Nth slave constant current module in-phase reference input terminal IP-S1N, the Nth slave constant current module inverting reference input terminal IN-S1 N, the Nth slave constant current module common terminal C-S1 N and the Nth slave constant current module output terminal O-S1 N;

[0104] The in-phase reference input terminal IP-M11 of the master constant current module is simultaneously connected to the in-phase reference input terminals of N slave constant current modules to form an in-phase reference common terminal A. The in-phase reference input terminals of the N slave constant current modules include the in-phase reference input terminal IP-S11 of the first slave constant current module, the in-phase reference input terminal IP-S12 of the second slave constant current module, and so on, the in-phase reference input terminal IP-S1 N of the Nth slave constant current module;

[0105] The inverting reference input terminal IN-M11 of the master constant current module is simultaneously connected to the inverting reference input terminals of N slave constant current modules to form an inverting reference common terminal C. The inverting reference input terminals of the N slave constant current modules include the inverting reference input terminal IN-S11 of the first slave constant current module, the inverting reference input terminal IN-S12 of the second slave constant current module, and so on, the inverting reference input terminal IN-S1 N of the Nth slave constant current module;

[0106] The positive electrode of the reference voltage source VR is connected to the positive common terminal P, and the negative electrode of the reference voltage source VR is connected to the negative common terminal N and the ground at the same time;

[0107] The output terminal O-M11 of the main constant current module is grounded through a load RL, and a load current IL flows through the load RL.

[0108] Preferably, the main constant current module M11 is a high-precision power Howland constant current source composed of a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a main constant current module sampling resistor RSM and a composite operational amplifier OP-M11;

[0109] The connection mode of the high-precision power Howland constant current source is as follows: one end of the first resistor R1 is connected to the inverting reference input terminal IN-M11 of the main constant current module, the other end of the first resistor R1 is simultaneously connected to the inverting input terminal of the composite operational amplifier OP-M11 and one end of the second resistor R2, the other end of the second resistor R2 is connected to the output terminal of the composite operational amplifier OP-M11 and one end of the main constant current module sampling resistor RSM, forming the main constant current module common terminal C-M11; the other end of the main constant current module sampling resistor RSM is connected to one end of the fourth resistor R4, forming the main constant current module output terminal O-M11, the other end of the fourth resistor R4 is simultaneously connected to the in-phase input terminal of the composite operational amplifier OP-M11 and one end of the third resistor R3, the other end of the third resistor R3 is connected to the in-phase reference input terminal IP-M11 of the main constant current module;

[0110] The composite operational amplifier OP-M11 is composed of a precision operational amplifier OP1 and a power operational amplifier PA1 connected in series. The non-inverting input terminal and the inverting input terminal of the precision operational amplifier OP1 serve as the non-inverting input terminal and the inverting input terminal of the composite operational amplifier OP-M11 respectively, and the output terminal of the power operational amplifier PA1 serves as the output terminal of the composite operational amplifier OP-M11.

[0111] The key parameter value constraints of precision op amp OP1 are: open-loop gain ≥ 120dB, offset voltage temperature drift ≤ 1μV / ℃, offset current temperature drift ≤ 50pA / ℃;

[0112] The first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 are high-precision resistors; the value constraints of the high-precision resistors are: R1 = R3 and R2 = R4, initial accuracy ≤ 0.1%, and temperature coefficient ≤ 10ppm / °C.

[0113] Preferably, the circuit structures of the N slave constant current modules are the same, and are all ordinary precision power Howland constant current sources composed of a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a slave constant current module sampling resistor and a power amplifier PA1;

[0114] The slave constant current module sampling resistors include a first slave constant current module sampling resistor RS11, a second slave constant current module sampling resistor RS12, and so on, an Nth slave constant current module sampling resistor RS1N;

[0115] The connection mode of the ordinary precision power Howland constant current source is as follows: one end of the fifth resistor R5 is connected to the inverting reference input end of the slave constant current module, the other end of the fifth resistor R5 is simultaneously connected to the inverting input end of the power amplifier PA1 and one end of the sixth resistor R6, the other end of the sixth resistor R6 is connected to the output end of the power amplifier PA1 and one end of the sampling resistor of the slave constant current module, forming the common end of the slave constant current module; the other end of the sampling resistor of the slave constant current module is connected to one end of the eighth resistor R8, forming the output end of the slave constant current module, the other end of the eighth resistor R8 is simultaneously connected to the in-phase input end of the power amplifier PA1 and one end of the seventh resistor R7, and the other end of the seventh resistor R7 is connected to the in-phase reference input end of the slave constant current module;

[0116] The fifth resistor R5, the sixth resistor R6, the seventh resistor R7 and the eighth resistor R8 are ordinary precision resistors; the value constraints of the ordinary precision resistors are: R5=R7, R6=R8, initial accuracy ≤1%, temperature coefficient ≤100ppm / ℃.

[0117] Preferably, the master constant current module M11 and N slave constant current modules can form a master-slave parallel structure, and the specific connection method is: the common terminal C-M11 of the master constant current module is simultaneously connected to the output terminals of N slave constant current modules; the output terminals of the N slave constant current modules include the first slave constant current module output terminal O-S11, the second slave constant current module output terminal O-S12, and so on, the Nth slave constant current module output terminal O-S1 N; the common terminals of the N slave constant current modules are suspended, and the common terminals of the N slave constant current modules include the first slave constant current module common terminal C-S11, the second slave constant current module common terminal C-S12, and so on, the Nth slave constant current module common terminal C-S1 N.

[0118] Preferably, the master constant current module M11 and N slave constant current modules can form a master-slave cascade structure, and the specific connection method is: the common terminal C-M11 of the master constant current module is connected to the output terminal O-S11 of the first slave constant current module, the common terminal C-S11 of the first slave constant current module is connected to the output terminal O-S12 of the second slave constant current module, the common terminal C-S12 of the second slave constant current module is connected to the output terminal of the next level slave constant current module, and so on, the output terminal O-S2N of the Nth slave constant current module is connected to the common terminal of the previous level slave constant current module, and finally, the common terminal C-S2N of the Nth slave constant current module is suspended.

[0119] Preferably, when the master constant current module M11 and N slave constant current modules form a master-slave parallel structure, the slave constant current module sampling resistors are the same and satisfy the following constraint relationship with the master constant current module sampling resistor RSM:

[0120]

[0121] Wherein, RS11 is the first slave constant current module sampling resistor, RS12 is the second slave constant current module sampling resistor, and so on, RS1 N is the Nth slave constant current module sampling resistor;

[0122] Under the above constraints, the output currents of the power amplifier PA1 constituting the master constant current module M11 and the N slave constant current modules are approximately equal, and the currents flowing through the sampling resistors of the N slave constant current modules are also approximately equal, that is, the output currents of the N slave constant current modules are approximately equal, and satisfy the following relationship with the load current IL:

[0123]

[0124] Wherein, IS11 is the output current of the first slave constant current module, IS12 is the output current of the second slave constant current module, and so on, IS1 N is the output current of the Nth slave constant current module; IL is the load current, which is approximately equal to the current flowing through the sampling resistor RSM of the main constant current module.

[0125] Preferably, when the master constant current module M11 and N slave constant current modules form a master-slave cascade structure, the sampling resistors of the slave constant current modules are different and satisfy the following relationship with the sampling resistor RSM of the master constant current module:

[0126]

[0127] And so on.

[0128]

[0129] Wherein, RS11 is the first slave constant current module sampling resistor, RS12 is the second slave constant current module sampling resistor, and so on, RS1 N is the Nth slave constant current module sampling resistor;

[0130] Under the above constraints, the output currents of the power amplifier PA1 constituting the master constant current module M11 and the N slave constant current modules are approximately equal; however, the currents flowing through the sampling resistors of the N slave constant current modules are not equal, and satisfy the following relationship with the load current IL:

[0131]

[0132] And so on.

[0133]

[0134] Wherein, IS11 is the output current of the first slave constant current module, IS12 is the output current of the second slave constant current module, and so on, IS1 N is the output current of the Nth slave constant current module; IL is the load current, which is approximately equal to the current flowing through the sampling resistor RSM of the main constant current module.

[0135] Preferably, the load current IL and the reference voltage source VR can form a common-phase output mode, and the specific connection method is: short-circuiting the common-phase reference terminal A and the positive common terminal P, and short-circuiting the inverse-phase reference common terminal C and the negative common terminal N;

[0136] When the in-phase output mode is formed, the load current IL and the reference voltage source VR have the same phase, and the expression of the load current IL is:

[0137]

[0138] The constraint conditions for the above formula to be valid are: R1=R3 and R2=R4, where R1, R2, R3 and R4 are respectively the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4, VR is the reference voltage source, and RSM is the main constant current module sampling resistor RSM.

[0139] Preferably, the load current IL and the reference voltage source VR can form an inverting output mode, and the specific connection method is: short-circuiting the in-phase reference common terminal A and the negative common terminal N, and short-circuiting the inverting reference common terminal C and the positive common terminal P;

[0140] When the inverting output mode is formed, the load current IL and the reference voltage source VR are in opposite phases, and the expression of the load current IL is:

[0141]

[0142] The constraint conditions for the above formula to be valid are: R1=R3 and R2=R4, where R1, R2, R3 and R4 are respectively the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4, VR is the reference voltage source, and RSM is the main constant current module sampling resistor RSM.

[0143] Preferably, the reference voltage source VR is one of a fixed voltage source, an adjustable voltage source, a unipolar positive voltage source, a unipolar negative voltage source or a bipolar voltage source; and the load RL is one of a voice coil motor, a resistive load or an inductive load.

[0144] like Figure 1 As shown, the master constant current module M11 and N slave constant current modules form a master-slave parallel structure, and the specific connection method is: the common terminal C-M11 of the master constant current module is connected to the output terminals of the N slave constant current modules at the same time, and the common terminals of the N slave constant current modules are suspended. The output terminals of the N slave constant current modules include the output terminal O-S11 of the first slave constant current module, the output terminal O-S12 of the second slave constant current module, and so on, the output terminal O-S1 N of the Nth slave constant current module; the common terminals of the N slave constant current modules include the common terminal C-S11 of the first slave constant current module, the common terminal C-S12 of the second slave constant current module, and so on, the common terminal C-S1 N of the Nth slave constant current module.

[0145] When the master constant current module M11 and N slave constant current modules form a master-slave parallel structure, the sampling resistors of the slave constant current modules are the same and satisfy the following constraint relationship with the sampling resistor RSM of the master constant current module:

[0146]

[0147] Wherein, RS11 is the first slave constant current module sampling resistor, RS12 is the second slave constant current module sampling resistor, and so on, RS1 N is the Nth slave constant current module sampling resistor;

[0148] Under the above constraints, the output currents of the power amplifier PA1 constituting the master constant current module M11 and the N slave constant current modules are approximately equal, and the currents flowing through the sampling resistors of the N slave constant current modules are also approximately equal, that is, the output currents of the N slave constant current modules are approximately equal, and satisfy the following relationship with the load current IL:

[0149]

[0150] Wherein, IS11 is the output current of the first slave constant current module, IS12 is the output current of the second slave constant current module, and so on, IS1 N is the output current of the Nth slave constant current module; IL is the load current, which is approximately equal to the current flowing through the sampling resistor RSM of the main constant current module.

[0151] During normal operation, the output currents of the N slave constant current modules all flow through the master constant current module sampling resistor RSM and participate in feedback. Therefore, the driving current capacity of the present invention is jointly determined by the master constant current module M11 and the N slave constant current modules, while the driving current accuracy mainly depends on the master constant current module M11. Therefore, the present invention can take into account both high current and high accuracy.

[0152] The main constant current module M11 uses high-precision devices and composite op amps to form a high-precision power Howland constant current source. Among them, the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4 and the main constant current module sampling resistor RSM are all high-precision resistors, and the main selection basis is: R1 = R3 and R2 = R4, initial accuracy ≤0.1%, temperature coefficient ≤10ppm / ℃. The composite op amp OP-M11 uses precision op amp OP1 and power op amp PA1 in series, among which the main selection basis of precision op amp OP1 is: open-loop gain ≥120dB, offset voltage temperature drift ≤1μV / ℃, offset current temperature drift ≤50pA / ℃.

[0153] N slave constant current modules use ordinary precision devices and power amplifiers to form ordinary precision power Howland constant current sources. Among them, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8 and the slave constant current module sampling resistor are all ordinary precision resistors, and the main selection basis is: R5 = R7 and R6 = R8, initial accuracy ≤ 1%, temperature coefficient ≤ 100ppm / ℃.

[0154] Generally, the volume, weight and cost of high-precision devices are significantly higher than those of ordinary precision devices, and in the present invention, only the main constant current module M11 is composed of high-precision devices. To achieve the same current driving capability and current accuracy, the high-precision devices used in the present invention are significantly less than those in the prior art. Therefore, the present invention is more likely to achieve small size, light weight and low cost, and the more the number of slave constant current modules, the more obvious the effect.

[0155] In addition, the load current IL and the reference voltage source VR can form a common-phase output mode and an inverting output mode. The specific connection method of the common-phase output mode is: short-circuiting the common-phase reference common terminal A and the positive common terminal P, and short-circuiting the inverting reference common terminal C and the negative common terminal N. The specific connection method of the inverting output mode is: short-circuiting the common-phase reference common terminal A and the negative common terminal N, and short-circuiting the inverting reference common terminal C and the positive common terminal P.

[0156] When the in-phase output mode is formed, the load current IL and the reference voltage source VR have the same phase, and the expression of the load current IL is:

[0157]

[0158] When the inverting output mode is formed, the load current IL and the reference voltage source VR are in opposite phases, and the expression of the load current IL is:

[0159]

[0160] The constraints for the above two equations to be valid are: R1=R3 and R2=R4, where R1, R2, R3 and R4 are respectively the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4, VR is the reference voltage source, and RSM is the main constant current module sampling resistor RSM.

[0161] In addition, the reference voltage source VR is one of a fixed voltage source, an adjustable voltage source, a unipolar positive voltage source, a unipolar negative voltage source or a bipolar voltage source, and the main selection basis is: initial accuracy ≤1%, temperature coefficient ≤10ppm / ℃. The load RL is one of a voice coil motor, a resistive load or an inductive load.

[0162] like Figure 2 As shown, the circuit structure of specific embodiment 2 is similar to that of specific embodiment 1, except that, in specific embodiment 2, the master constant current module M11 and N slave constant current modules form a master-slave cascade structure, and the specific connection method is: the common terminal C-M11 of the master constant current module is connected to the output terminal O-S11 of the first slave constant current module, the common terminal C-S11 of the first slave constant current module is connected to the output terminal O-S12 of the second slave constant current module, the common terminal C-S12 of the second slave constant current module is connected to the output terminal of the next level slave constant current module, and so on, the output terminal O-S2N of the Nth slave constant current module is connected to the common terminal of the previous level slave constant current module, and finally, the common terminal C-S2N of the Nth slave constant current module is suspended.

[0163] When the master constant current module M11 and N slave constant current modules form a master-slave cascade structure, the sampling resistors of the slave constant current modules are different and satisfy the following relationship with the sampling resistor RSM of the master constant current module:

[0164]

[0165] And so on.

[0166]

[0167] Wherein, RS11 is the first slave constant current module sampling resistor, RS12 is the second slave constant current module sampling resistor, and so on, RS1 N is the Nth slave constant current module sampling resistor;

[0168] Under the above constraints, the output currents of the power amplifier PA1 constituting the master constant current module M11 and the N slave constant current modules are approximately equal; however, the currents flowing through the sampling resistors of the N slave constant current modules are not equal, and satisfy the following relationship with the load current IL:

[0169]

[0170] And so on.

[0171]

[0172] Wherein, IS11 is the output current of the first slave constant current module, IS12 is the output current of the second slave constant current module, and so on, IS1 N is the output current of the Nth slave constant current module; IL is the load current, which is approximately equal to the current flowing through the sampling resistor RSM of the main constant current module.

[0173] Except for the above differences, the specific embodiment 2 is exactly the same as the specific embodiment 1 and has the same advantages, which will not be described in detail. Figure 1 and Figure 2 Only the contents directly related to the present invention are given, and other contents which are necessary in practical application but belong to the known technology are not given.

[0174] Figures 3 to 5 The simulation comparison results of the present invention and the prior art are shown in FIG. Figure 1 and Figure 2 circuit as an example, assuming that the number of constant current modules N = 1, at this time, Figure 1 The master-slave parallel structure shown and Figure 2 The master-slave cascade structure shown is completely equivalent. The circuit parameters used in the simulation are as follows: R1 = R3 = R5 = R7 = 100kΩ, R2 = R4 = R6 = R8 = 10kΩ, RSM = 0.1Ω, RS11 = 0.2Ω, VR = 4V. The open-loop gain of the precision op amp OP1 = 120dB, the offset voltage temperature drift = 0.1μA / ℃, and the offset current temperature drift = 1.5pA / ℃. The offset voltage of the power op amp PA1 = 2mV, the open-loop gain = 90dB, and the offset voltage temperature drift = 20μV / ℃. The initial accuracy of R1-R4 and RSM is 0.01%, and the temperature coefficient is 5ppm / ℃; the initial accuracy of R5-R8 and RS11 is 1%, and the temperature coefficient is 100ppm / ℃.

[0175] During the simulation, the circuit parameters of the main constant current module are fixed, and only the circuit parameters of the slave constant current module are changed, including the parameter value of the slave constant current module sampling resistor RS11, the offset voltage of the power amplifier PA1 and the sixth resistor R6, which are used to simulate the change caused by a temperature change of 100°C.

[0176] like Figure 3 The figure shows the influence of the change of sampling resistor RS11 of the constant current module on the accuracy index of the present invention and the prior art. The results show that when the sampling resistor changes by 2mΩ, the output current of the prior art changes by about 20mA, while the output current change of the present invention is almost negligible, and the effect is obvious.

[0177] like Figure 4The figure shows the influence of the offset voltage change of the constant current module power amplifier PA1 on the accuracy index of the present invention and the prior art. The results show that the offset voltage changes by 4mV, the output current of the prior art changes by about 22mA, while the output current change of the present invention is almost negligible, and the effect is obvious.

[0178] like Figure 5 The figure shows the effect of the change of the sixth resistor R6 on the accuracy index of the present invention and the prior art. The results show that when the sixth resistor changes by 100Ω, the output current of the prior art changes by about 38mA, while the output current change of the present invention is almost negligible, and the effect is obvious.

[0179] Figures 3 to 5 The simulation results shown show that under the same conditions, the current accuracy index of the present invention is significantly better than that of the prior art.

[0180] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0181] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A high-precision, high-current constant current source suitable for driving a three-super platform voice coil motor, characterized in that: It includes a main constant current module, N slave constant current modules, a reference voltage source, and a load module; The main constant current module is provided with a reference voltage by a reference voltage source, receives the output current of N slave constant current modules through a sampling resistor, performs sampling feedback processing, and outputs the motor drive current with a specified current accuracy to the load module; The slave constant current module is provided with a reference voltage by a reference voltage source, generates a current signal according to the reference voltage and inputs it into the master constant current module; The slave constant current module and the master constant current module form a master-slave parallel structure or a master-slave cascade structure; A reference voltage source, providing a reference voltage for the master constant current module and N slave constant current modules; The load module receives the motor drive current with the specified current accuracy output by the main constant current module, selects the working mode according to the output mode of the motor drive current, and operates; The output mode of the motor drive current is adjusted according to the connection settings of the load module and the reference voltage source.

2. A high-precision, high-current constant current source suitable for driving a triple-super-platform voice coil motor according to claim 1, characterized in that: The output mode of the motor driving current includes a common-phase output mode and an anti-phase output mode; The reference voltage source includes an in-phase reference common terminal A, a positive common terminal P, an inverting reference common terminal C, and a negative common terminal N; When the in-phase reference common terminal A and the positive common terminal P, the inverting reference common terminal C and the negative common terminal N are short-circuited at the same time, the motor drive current is in the in-phase output mode; When the in-phase reference common terminal A and the negative common terminal N, the inverting reference common terminal C and the positive common terminal P are short-circuited at the same time, the motor drive current is in the inverting output mode.

3. A high-precision, high-current constant current source suitable for driving a triple-super-platform voice coil motor according to claim 1, characterized in that: The main constant current module includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a main constant current module sampling resistor RSM, a composite operational amplifier OP-M11, a main constant current module in-phase reference input terminal IP-M11, a main constant current module inverting reference input terminal IN-M11, a main constant current module common terminal C-M11 and a main constant current module output terminal O-M11, wherein: One end of the first resistor R1 is connected to the inverting reference input terminal IN-M11 of the main constant current module, the other end of the first resistor R1 is connected to the inverting input terminal of the composite operational amplifier OP-M11 and one end of the second resistor R2 at the same time, the other end of the second resistor R2 is connected to the output end of the composite operational amplifier OP-M11 and one end of the main constant current module sampling resistor RSM, forming the main constant current module common terminal C-M11; the other end of the main constant current module sampling resistor RSM is connected to one end of the fourth resistor R4, forming the main constant current module output terminal O-M11; The other end of the fourth resistor R4 is connected to the in-phase input terminal of the composite operational amplifier OP-M11 and one end of the third resistor R3 at the same time, and the other end of the third resistor R3 is connected to the in-phase reference input terminal IP-M11 of the main constant current module.

4. A high-precision, high-current constant current source suitable for driving a triple-super-platform voice coil motor according to claim 3, characterized in that: The composite operational amplifier OP-M11 includes a precision operational amplifier OP1 and a power operational amplifier PA1, which are connected in series, the non-inverting input terminal and the inverting input terminal of the precision operational amplifier OP1 are respectively used as the non-inverting input terminal and the inverting input terminal of the composite operational amplifier OP-M11, and the output terminal of the power operational amplifier PA1 is used as the output terminal of the composite operational amplifier OP-M11.

5. The high-precision, high-current constant current source suitable for driving a triple-super-platform voice coil motor according to claim 3, characterized in that: The circuit structures of the slave constant current modules are the same, including a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a slave constant current module sampling resistor and a power amplifier PA1, a sampling resistor RS1 N, an Nth slave constant current module in-phase reference input terminal IP-S1 N, an Nth slave constant current module inverting reference input terminal IN-S1 N, an Nth slave constant current module common terminal C-S1 N and an Nth slave constant current module output terminal O-S1 N, wherein: One end of the fifth resistor R5 is connected to the inverting reference input terminal IN-S1 N of the Nth slave constant current module, the other end of the fifth resistor R5 is simultaneously connected to the inverting input terminal of the power amplifier PA1 and one end of the sixth resistor R6, the other end of the sixth resistor R6 is connected to the output terminal of the power amplifier PA1 and one end of the slave constant current module sampling resistor RS1 N, forming the Nth slave constant current module common terminal C-S1 N, the other end of the slave constant current module sampling resistor RS1 N is connected to one end of the eighth resistor R8, forming the Nth slave constant current module output terminal O-S1 N, the other end of the eighth resistor R8 is simultaneously connected to the in-phase input terminal of the power amplifier PA1 and one end of the seventh resistor R7, and the other end of the seventh resistor R7 is connected to the in-phase reference input terminal IP-S1 N of the slave constant current module.

6. A high-precision, high-current constant current source suitable for driving a triple-super-platform voice coil motor according to claim 5, characterized in that: The number N of the slave constant current modules is a positive integer greater than or equal to 1, and is determined according to the current value range required by the motor drive current; the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 are high-precision resistors; the value constraints of the high-precision resistors are: R1=R3 and R2=R4, initial accuracy ≤0.1%, temperature coefficient ≤10ppm / ℃; the key parameter value constraints of the precision operational amplifier OP1 are: open-loop gain ≥120dB, offset voltage temperature drift ≤1μV / ℃, offset current temperature drift ≤50pA / ℃.

7. The high-precision, high-current constant current source suitable for driving a triple-super-platform voice coil motor according to claim 5, characterized in that: The fifth resistor R5, the sixth resistor R6, the seventh resistor R7 and the eighth resistor R8 are ordinary precision resistors; the value constraints of the ordinary precision resistors are: R5=R7, R6=R8, initial accuracy ≤1%, temperature coefficient ≤100ppm / ℃.

8. The high-precision, high-current constant current source suitable for driving a triple-super-platform voice coil motor according to claim 1, characterized in that: The positive electrode of the reference voltage source VR is connected to the positive common terminal P, and the negative electrode of the reference voltage source VR is connected to the negative common terminal N and the ground at the same time; the output terminal O-M11 of the main constant current module is grounded through the load RL, and the load current IL flows through the load RL.

9. The high-precision, high-current constant current source suitable for driving a triple-super-platform voice coil motor according to claim 5, characterized in that: In the master-slave parallel structure, the common terminal C-M11 of the master constant current module is connected to the output terminals of N slave constant current modules at the same time; the output terminals of the N slave constant current modules include the output terminal O-S11 of the first slave constant current module, the output terminal O-S12 of the second slave constant current module...the output terminal O-S1 N of the Nth slave constant current module; the common terminals of the N slave constant current modules are suspended, and the common terminals of the N slave constant current modules include the common terminal C-S11 of the first slave constant current module, the common terminal C-S12 of the second slave constant current module...the common terminal C-S1 N of the Nth slave constant current module; In the master-slave cascade structure, the common terminal C-M11 of the master constant current module is connected to the output terminal O-S11 of the first slave constant current module, the common terminal C-S11 of the first slave constant current module is connected to the output terminal O-S12 of the second slave constant current module, the common terminal C-S12 of the second slave constant current module is connected to the output terminal of the next level slave constant current module, until the output terminal O-S2N of the Nth slave constant current module is connected to the common terminal of the previous level slave constant current module, and the common terminal C-S2N of the Nth slave constant current module is left floating.

10. A high-precision, high-current constant current source suitable for driving a triple-super-platform voice coil motor according to claim 9, characterized in that: When the master constant current module M11 and the N slave constant current modules form a master-slave parallel structure, the sampling resistors of the slave constant current modules are the same, and the constraint relationship with the master constant current module sampling resistor RSM is: Wherein, RS11 is the first slave constant current module sampling resistor, RS12 is the second slave constant current module sampling resistor…RS1 N is the Nth slave constant current module sampling resistor; In the master-slave parallel structure, the output current of N slave constant current modules and the load current IL satisfy the constraint relationship as follows: Wherein, IS11 is the output current of the first slave constant current module, IS12 is the output current of the second slave constant current module…IS1 N is the output current of the Nth slave constant current module; IL is the load current, which is equal to the current flowing through the sampling resistor RSM of the main constant current module.

11. The high-precision, high-current constant current source suitable for driving a triple-super-platform voice coil motor according to claim 9, characterized in that: When the master constant current module M11 and the N slave constant current modules form a master-slave cascade structure, the slave constant current module sampling resistors are different, and the constraint relationship with the master constant current module sampling resistor RSM is: Wherein, RS11 is the first slave constant current module sampling resistor, RS12 is the second slave constant current module sampling resistor…RS1 N is the Nth slave constant current module sampling resistor; In the master-slave cascade structure, the output current flowing through N slave constant current modules and the load current IL satisfy the constraint relationship: Wherein, IS11 is the output current of the first slave constant current module, IS12 is the output current of the second slave constant current module, and IS1 N is the output current of the Nth slave constant current module; IL is the load current, which is equal to the current flowing through the sampling resistor RSM of the main constant current module.

12. The high-precision, high-current constant current source suitable for driving a triple-super-platform voice coil motor according to claim 2, characterized in that: In the in-phase output mode, the load current IL and the reference voltage source VR have the same phase, and the load current IL is: Wherein, R1, R2, R3 and R4 are respectively the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4, VR is the reference voltage source, RSM is the main constant current module sampling resistor RSM, and the load current constraint condition is: R1 = R3 and R2 = R4; In the inverting output mode, the load current IL and the reference voltage source VR have opposite phases, and the load current IL is: Wherein, the load current constraint condition is: R1=R3 and R2=R4.

13. The high-precision, high-current constant current source suitable for driving a triple-super-platform voice coil motor according to claim 2, characterized in that: The reference voltage source VR is one of a fixed voltage source, an adjustable voltage source, a unipolar positive voltage source, a unipolar negative voltage source or a bipolar voltage source; the load RL is one of a voice coil motor, a resistive load or an inductive load.

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