CN117013975A

CN117013975A - Fuse trimming method and fuse trimming circuit

Info

Publication number: CN117013975A
Application number: CN202310545274.8A
Authority: CN
Inventors: 程武
Original assignee: Joulwatt Technology Co Ltd
Current assignee: Joulwatt Technology Co Ltd
Priority date: 2023-05-12
Filing date: 2023-05-12
Publication date: 2023-11-07

Abstract

The utility model discloses a fuse trimming method and a fuse trimming circuit, wherein the physical quantity is trimmed by the resistor trimming circuit, the resistor trimming circuit comprises n+1 connected resistor networks and n fuses, each fuse is connected with one resistor network, and the fuse trimming method repeatedly executes the following steps for i times: obtaining an actually measured resistance value in a resistance trimming circuit; taking the difference between the target reference resistance value and the actual measured resistance value as a compensation resistance value; calculating an n-bit binary number according to the compensation resistance value to represent the fuse wire to be blown at the time; and selecting whether to blow fuses of corresponding bits in the resistance trimming circuit according to the value of at least one binary number selected from the currently output n-bit binary numbers. According to the fuse trimming method, at least one fuse is trimmed each time, then the compensation resistance value is calculated for multiple times to trim gradually, trimming precision is improved, and the problem that trimming precision is not high due to the fact that the resistance of an access circuit is too large or too small through one trimming is avoided.

Description

Fuse trimming method and fuse trimming circuit

Technical Field

The application relates to the technical field of integrated circuits, in particular to a fuse trimming method and a fuse trimming circuit.

Background

With the development of integrated circuit design and process technology, the higher the circuit performance requirement is. However, circuit performance is always affected by non-ideal factors of the semiconductor manufacturing process, so that actual output of the product deviates from a predetermined standard to a different extent, and thus, trimming of the physical quantity of the output by a trimming tool is generally required in the chip manufacturing process.

Fuse trimming technology has wide application in integrated circuits, and unlike conventional circuit board repair, fuses used in integrated circuits are micro fuses with wire diameters of only a few microns to tens of microns. By connecting micro fuses to devices such as transistors, capacitors, etc., the physical characteristics of these devices can be changed to adjust the parameters of the circuit. For example, in the fabrication of analog integrated circuits, some device parameters may be out of the specified range due to batch differences in device parameters, errors in lithography exposure, and the like. In this case, the devices may be trimmed using fuse trimming techniques to meet design requirements and thereby improve integrated circuit performance.

Most of the current trimming methods add corresponding components into a circuit according to the deviation of parameters or physical quantities as compensation quantities, but the trimming method has low trimming precision, poor trimming effect and even trimming failure possibly caused by too much added compensation quantities.

Disclosure of Invention

In order to solve the technical problems, the application provides a fuse trimming method and a fuse trimming circuit, which are used for solving the problems in the prior art.

According to an aspect of the present application, there is provided a method for trimming a fuse, wherein a physical quantity to be trimmed on paths of two potential ends is trimmed by a resistor trimming circuit, the resistor trimming circuit includes n+1 connected resistor networks and n fuses connected between the two potential ends, each fuse is connected with one resistor network, n is an integer greater than or equal to 1, and the method for trimming a fuse is repeatedly performed i times by: obtaining an actually measured resistance value in the resistance trimming circuit; taking the difference between the target reference resistance value and the measured resistance value as a compensation resistance value; calculating an n-bit binary number according to the compensation resistance value to represent the fuse wire to be blown at this time; and selecting whether to blow fuses of corresponding bits in the resistance trimming circuit according to the value of at least one bit binary number selected from the n-bit binary numbers currently output, wherein at least one bit is selected from the n-bit binary numbers according to a set sequence, the at least one bit binary number selected each time is not repeated, and i is larger than 1.

Optionally, the fuse trimming method further includes: and obtaining a physical quantity target value of the physical quantity, and converting the physical quantity target value to obtain the target reference resistance value.

Optionally, the target reference resistance value is a maximum resistance value corresponding to a margin range allowed by the physical quantity target value or any value within a range of plus or minus 20% of the maximum resistance value.

Alternatively, as i gradually increases, the margin range gradually decreases, and the value of the physical quantity corresponding to the target reference resistance value gradually approaches the physical quantity target value.

Optionally, the n-bit binary number is obtained through calculation according to the compensation resistance value, wherein the actual resistance value of the resistance network combination corresponding to the n-bit binary number meets a preset condition.

Optionally, when i is 1, the preset condition is: the actual resistance value of the resistor network combination does not exceed the difference between the target reference resistance value and the measured resistance value.

Optionally, when i is 2 to n-1, the preset condition is: the actual resistance value of the resistor network combination is greater than the compensation resistance value.

Optionally, when i is n and the compensation resistance value is greater than half of the actual resistance value of the n+1th resistance network, the resistance networks are combined into the n+1th resistance network.

Optionally, the step of calculating an n-bit binary number according to the compensation resistance value to characterize the fuse to be blown at this time includes: obtaining an integer interval in which the ratio of the compensation resistance value to the step distance value is located; selecting an integer from the integer interval according to a preset condition; and outputting the n-bit binary number corresponding to the selected integer.

Optionally, the step distance value is the nominal resistance value of the n+1th resistance network, and an integer is selected from the integer interval by adopting a table look-up mode and output as an n-bit binary number.

Optionally, the step of obtaining the measured resistance value in the resistance trimming circuit includes: obtaining an actual measurement value of the physical quantity to be repaired by an auxiliary circuit; and converting the measured value of the physical quantity into the measured resistance value according to the relation between the physical quantity and the resistance value.

Optionally, the auxiliary circuit comprises a current mirror, and the measured value of the physical quantity is proportional to the value of the physical quantity on the current mirror.

Optionally, the fuse trimming method further includes: acquiring an actual resistance value of a first resistance network which is not connected with the fuse in the resistance trimming circuit; and calculating and obtaining the actual resistance values of the 2 nd to n+1st resistor networks according to the actual resistance value of the first resistor network.

Optionally, the fuse trimming method further includes: measuring the trimming value of the trimmed physical quantity to obtain a difference value between the trimming value of the physical quantity and the target value of the physical quantity; judging whether the difference value is within an error range or not; and if the difference value is within the error range, outputting the actual binary numbers corresponding to all the trimming fuses, otherwise, outputting a prompt of trimming failure.

Optionally, when the value of the binary number is 1, it indicates that the corresponding fuse needs to be blown, and when the binary number is 0, it indicates that the corresponding fuse is not processed.

According to another aspect of the present invention, there is provided a fuse trimming device for trimming a physical quantity to be trimmed of a path from a power supply terminal to a ground terminal through a resistor trimming circuit, the fuse trimming device comprising: the resistor trimming circuit comprises n+1 connected resistor networks and n fuses, wherein the n+1 connected resistor networks and the n fuses are connected between the power supply end and the grounding end, each fuse is connected with one resistor network, and n is an integer greater than or equal to 1; the test circuit is connected with the resistance trimming circuit and is used for acquiring an actual measured resistance value and an actual measured value of the physical quantity in the resistance trimming circuit; the execution circuit is connected with the resistance trimming circuit and fuses corresponding fuses in the resistance trimming circuit according to the control of a host; and the host is connected with the resistance trimming circuit, the execution circuit and the test circuit, and is used for storing computer instructions, executing the fuse trimming method based on the stored computer instructions and controlling the execution circuit to blow corresponding fuses.

According to the fuse trimming method and the fuse trimming circuit, the compensation quantity of the physical quantity is converted into the compensation quantity of the resistor, different fuses are blown according to the compensation quantity of the resistor, and the compensation quantity brought by the corresponding resistor network can be connected onto a path from a power supply end to a grounding end, so that the resistance value on the path to be connected can be intuitively and conveniently obtained directly according to the compensation quantity of the resistor, the trimming of the physical quantity is realized by continuously adjusting the resistance value, and the trimming of the physical quantity is realized faster and better; the compensation resistance value is converted into binary numbers through a certain algorithm, whether the corresponding fuse is blown or not can be judged according to the numerical value of the binary numbers, trimming can be realized through the set algorithm, and the method is efficient and reliable; in addition, at least one binary number is selected according to the compensation quantity of the resistor to repair at least one fuse wire each time, and then repair is performed step by step for multiple times, namely, each time only a part of resistance values are connected into a path, then different resistance networks are connected into the path in a sequence from big to small according to the resistance values which are added multiple times, and the different resistance networks are connected into the path step by step, so that repair precision can be greatly improved, and repair failure caused by overlarge or overlarge adjustment quantity due to the fact that a plurality of resistance networks are added at one time only according to one repair result is avoided.

Further, resistance values corresponding to values of different physical quantities are selected as target reference resistance values within the margin range of the physical quantity target value, the size of the reference resistance values can be flexibly adjusted, and the method is suitable for different trimming schemes. And when the fact that the final trimming resistance value is reduced due to the fact that residual resistance possibly exists after fuse breaking is considered, the corresponding maximum resistance value in the margin range and any resistance value in a certain range around the maximum resistance value are selected as target reference resistance values, so that the influence of the fuse residual resistance on trimming can be reduced, the current change amplitude after trimming is small, the trimming yield and precision are improved, the safety is better, and the risks of system damage caused by the fact that the trimming resistance is reduced due to the residual resistance and the path current is overlarge are reduced. In addition, as the trimming frequency increases, the resistance value required to be added into the circuit to be trimmed gradually becomes smaller, and at the moment, the target reference resistance value is gradually adjusted to enable the value of the corresponding physical quantity to gradually approach the physical quantity target value, so that the trimming precision is higher, the trimming precision is continuously improved in the process of changing the value of the compensation resistance value from larger to smaller, the trimming result is enabled to be closer to the physical quantity target value, the deviation is extremely small, and the accuracy is higher.

Further, a certain algorithm can be adopted to flexibly output different n-bit binary numbers according to the compensation resistance value, the trimming precision is improved, in the trimming process of different times, preset conditions which need to be met when the combined resistance of the fuse wire to be blown, which is represented by the n-bit binary numbers, is calculated, the actual resistance value corresponding to the combined resistance cannot exceed the resistance value corresponding to the physical quantity target value in the first trimming process, the problem that the value of the physical quantity and the target value are excessively offset when the resistance is excessively large can be avoided, in the subsequent trimming process, the actual resistance value of the resistor combination is larger than the compensation resistance value to efficiently and quickly finish trimming, the resistance value to be increased in the trimming process is limited in a reasonable range, the trimming accuracy is ensured, the preset conditions can be adjusted in real time according to the actual situation, the resistance value increased each time is in accordance with the actual requirement, and the trimming reliability is improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.

Drawings

FIGS. 1a and 1b show two schematic circuit diagrams of a resistance trimming circuit according to the invention;

FIG. 2 shows a schematic flow chart of a fuse trimming method according to a first embodiment of the invention;

FIG. 3 shows a schematic flow chart of a fuse trimming method according to a second embodiment of the invention;

fig. 4 shows a schematic block diagram of a fuse trimming device according to an embodiment of the invention.

Detailed Description

In order that the invention may be readily understood, a more complete description of the invention will be rendered by reference to the appended drawings. Preferred embodiments of the present invention are shown in the drawings. The invention may, however, be embodied in different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Fig. 1a and 1b show two schematic circuit diagrams of a resistance trimming circuit according to the invention.

As shown in fig. 1a, a resistor trimming circuit is connected between two potential ends, such as a power supply end VDD and a ground end GND, and trims a physical quantity to be trimmed on a path between the two potential ends (such as the power supply end and the ground end) according to the resistor trimming circuit. The resistor trimming circuit comprises n+1 resistor networks and n fuses which are connected in series between a power supply end VDD and a ground end GND, wherein each fuse is connected with one resistor network, and n is more than or equal to 1. The resistor network may comprise only a single resistor or a resistor network comprising a plurality of components. Taking n=5 as an example in fig. 1, the resistance trimming circuit includes 6 resistor networks and 5 fuses connected in series, where R0-R5 may represent only one single resistor or an equivalent resistor of a resistor network composed of a plurality of electronic components, and the resistor values of R0-R5 gradually decrease. The other resistor networks except the first resistor network R0 are all connected with the fuse in parallel, and of course, other resistor networks R0 at other positions can be selected to be not connected with the fuse. In this embodiment, for example, the two ends of the resistor network R1 are connected in parallel to the Fuse1, the two ends of the resistor network R2 are connected in parallel to the Fuse2, the two ends of the resistor network R3 are connected in parallel to the Fuse3, the two ends of the resistor network R4 are connected in parallel to the Fuse4, and the two ends of the resistor network R5 are connected in parallel to the Fuse 5. R1-R5 may each be a single resistor, with R0 being the equivalent resistance of the resistor network. When a fuse is blown, a resistor network connected in parallel with the fuse is connected in series to a path between a power supply terminal and a ground terminal, so that the value of the corresponding physical quantity outputted is changed.

As shown in fig. 1b, the resistor trimming circuit may also include 1 resistor network R0 connected to the power supply terminal VDD and n resistor networks connected in parallel between the resistor network R0 and the ground terminal GND. Or may directly comprise n+1 resistor networks connected in parallel between the supply terminal VDD and the ground terminal GND. The n resistor networks are all connected with fuses in series, for example, R1-R5 are all connected with a fuse in series, the corresponding resistor network after the fuse is melted is disconnected with the power supply end and the grounding end, the total parallel resistance value of the resistor networks can be increased, and the resistor compensation is added on the path between the power supply end and the grounding end. The resistor network here can still represent a single resistor or an equivalent resistor of a resistor network consisting of a plurality of electronic components. R0 can be considered as the first resistor network, and R1-R5 can be considered as the 2 nd to nth resistor networks in turn, with the resistance values of R0-R5 gradually decreasing.

The two embodiments of the possible resistance trimming circuit of the present invention are given here only as limitations of the resistance trimming circuit of the present invention. The invention mainly introduces how to control the blowing of a plurality of fuses by a fuse trimming method so as to trim the physical quantity to be trimmed. In the following embodiments, the resistor trimming circuit of fig. 1a or fig. 1b is taken as an example, and in practice, other trimming circuits, such as a capacitor trimming circuit, may be applied to the fuse trimming method of the present invention, and the resistor trimming circuit may be disposed in a manner that does not adopt the examples of fig. 1a and fig. 1 b.

Fig. 2 shows a schematic flow chart of a fuse trimming method according to a first embodiment of the present invention.

As shown in fig. 2, the trimming method of the fuse wire of the present embodiment trims the circuit to be trimmed by the resistor trimming circuit of fig. 1a or 1b, and the trimming method of the fuse wire repeatedly executes steps S101-S104, i is greater than 1, and the specific steps are as follows:

in step S101, an actual measured resistance value in the resistance trimming circuit is obtained.

In the step, the resistor trimming circuit adds compensation quantity brought by the corresponding resistor network into the path through the fuse wire, and the trimming of the physical quantity to be trimmed needs to judge which resistor network needs to be connected into the circuit or which fuse wire needs to be blown, so that the actually measured resistor value of the resistor trimming circuit needs to be obtained.

In some cases, it is difficult to obtain the resistance by direct test, and other physical quantity measurement can be performed by an auxiliary circuit and then converted into a resistance value. For example, an actually measured value of the physical quantity is obtained by the auxiliary circuit, and the actually measured value of the physical quantity is converted into an actually measured resistance value based on a relationship between the physical quantity and the resistance value. The auxiliary circuit may include a current mirror in this embodiment, and the value of the physical quantity obtained by the current mirror is proportional to the measured value of the physical quantity. The physical quantity may be a current, and the current value itself is obtained by a current mirror, the current value is converted into an actual measurement value of the current on the path by the above ratio, and the actual measurement value of the current on the path is converted into an actual measurement resistance value according to the relationship between the current and the resistance.

Further, when all fuses are not blown, it can be considered that only the resistor network R0 is connected in series in the path between the two potential ends, then the actual resistance value at this time is the actual resistance value of the resistor network R0, and the resistor networks R0 to R5 all have nominal resistance values when shipped from the factory, and the actual resistance values of the other resistor networks R1 to R5 can be obtained according to the same proportional relationship with the actual resistance value and the nominal resistance value of the resistor network R0. When one or more fuses are blown, the measured resistance value is the total resistance value of the resistor network and the fuse residual resistance which are really connected in the circuit.

In this embodiment, the physical quantity may include a current, a voltage, a temperature, and the like, and the following embodiment is described by taking the current as an example. When the current on the path needs to be adjusted, the reference value and the actual measurement value of the current need to be known first, then the compensation amount of the current can be known, and the step S101 converts the measurement of the current into the measurement of the resistance, so that the subsequent steps are the same, and the current value needing to be compensated is represented according to the resistance value needing to be compensated. By converting the compensation amount of the current into the compensation amount of the resistor, the resistor value to be compensated can be intuitively obtained, and the resistor network to be accessed to the path can be quickly obtained, so that the fuse to be blown can be found.

In step S102, the difference between the acquired target reference resistance value and the measured resistance value is used as the compensation resistance value.

In the previous step, the measured resistance value has been obtained, so that the target reference resistance value needs to be obtained in the present step, and the difference between the obtained target reference resistance value and the measured resistance value is the compensation resistance value, that is, the total resistance value of the path needs to be accessed. In an alternative embodiment, the target reference resistance value is different each time the compensation resistance value is obtained, i.e., the target reference resistance value and the measured resistance value may be constantly changing with the number of trimming.

In step S103, an n-bit binary number is calculated according to the compensation resistance value to characterize the fuse that needs to be blown at this time.

In this step, after the compensation resistance value is obtained, the total resistance value of the path to be accessed can be known according to the compensation resistance value, a combination of multiple resistance networks can be obtained, then the combination of the most suitable resistance networks, namely the combination of fuses to be blown, is selected, and the result is output in the form of binary numbers. Alternatively, according to a specific calculation formula, the compensation resistance value may be taken as an input to obtain an output as an n-bit binary number corresponding to the n fuses. Or according to a certain algorithm, obtaining a proper n-bit binary number according to the compensation resistance value, wherein the output binary number represents the combination of fuses needing to be blown, namely the combination of resistor networks needing to be connected into the paths.

Further, the method comprises the following steps: obtaining an integer interval in which the ratio of the compensation resistance value to the step distance value is located; selecting an integer from the integer interval according to a preset condition; and outputting the n-bit binary number corresponding to the selected integer. The step distance value can be the nominal resistance value of the (n+1) th resistor, and a table look-up mode or other algorithms can be adopted to select an integer from the integer interval and output the integer as an n-bit binary number. The nominal resistance values of the 6 resistor networks, e.g. R0-R5, are: 70KΩ, 40KΩ, 20KΩ, 10KΩ, 5KΩ, 2.5KΩ, then the stride value may be 2.5, for example, the compensation resistance value is 23KΩ, then the ratio of 23 to 2.5 is 9.2, the obtained integer interval may be 8-12 or other values, then a most suitable integer is selected, and the corresponding n-bit binary number is output, for example, 01001. In this embodiment, the number of binary digits is n, which is matched with the number n of fuses. When the value of the binary number is 1, it indicates that the corresponding fuse needs to be blown, and when the value of the binary number is 0, it indicates that the corresponding fuse is not processed.

In step S104, whether to blow fuses of corresponding bits in the resistance trimming circuit is selected according to the value of at least one binary number selected from the currently output n-bit binary numbers.

In this step, it is determined whether to blow the fuse of the corresponding bit according to at least one binary number selected from the n-bit binary numbers outputted from the ith time. And at least one bit is selected from the n-bit binary numbers each time in a set order, for example, from left to right or from right to left, without repeating the at least one bit binary number selected each time. The selection sequence is related to the resistance value of the resistance network, and the resistance value of the resistance network at the position corresponding to each selected binary number gradually decreases along with the increase of i. Taking the resistor network of fig. 1a as an example, the resistance values of R1-R5 are gradually reduced, and the output binary numbers sequentially correspond to R1-R5, and the binary numbers need to be selected from left to right when the resistance value is selected to be large and then the resistance value is selected to be small. The fuses corresponding to the selected binary numbers are fuses to be trimmed, so that the binary numbers in different positions need to be selected each time, and the number of bits of the binary numbers selected each time can be the same or different.

For example, each time a binary number is sequentially selected from left to right, whether to blow the first Fuse is determined by the value of the first binary number in the n-bit binary numbers outputted for the first time, whether to blow the second Fuse is determined by the value of the second binary number of the second output result, and so on … …. Taking 01001 as an example, if this is the result of the first output, then the first bit value is 0, without blowing the first fuse, and if this is the result of the second output, then the second bit value is 1, with blowing the second fuse. For example, two fuses may be trimmed at a time, and then a two-bit binary number may be selected at a time. Alternatively, the selection of one-bit binary numbers and the selection of two-bit binary numbers can be performed at intervals.

In this embodiment, i gradually increases from 1, steps S101-S104 are a cyclic process, that is, each time, the target reference resistance value and the actual measurement resistance value are obtained to obtain the compensation resistance value, the corresponding binary number is output, then each time it is judged whether the selected at least one fuse needs to be blown, the first fuse is judged to the fifth fuse one by one, by means of such a stepping and iterative adjustment mode, a certain amount of resistance is only added in the path each time, so as to avoid the failure of trimming due to excessive adjustment amount, and the output binary number is continuously adjusted according to the continuous change of the compensation resistance value, so that trimming can be performed more accurately, the excessive or excessively small trimming amount caused by one trimming is avoided, and the trimming precision is very high.

And because the addition of the resistor network is performed according to the resistance value from large to small, the subsequent trimming of the resistor is only needed when the resistance value of the larger resistor is insufficient or too large, namely, the judgment of whether the rear fuse is blown or not is performed after the front fuse is processed, when the judgment of whether the i-th fuse is blown or not is performed, the judgment of the i-1-th fuse is completed, so that the value of the binary number of the i-1 bit is 0 in the output result of the corresponding binary number.

Therefore, the fuse trimming method of the embodiment of the invention converts the compensation quantity of the physical quantity into the compensation quantity of the resistor, and the trimming of the physical quantity is realized by continuously adjusting the resistor network of the access path, so that the resistor network of the access path can be intuitively and conveniently obtained according to the compensation quantity of the resistor, and the trimming of the physical quantity is realized faster and better; the compensation resistance value is converted into binary numbers through a certain algorithm, whether the corresponding fuse is blown or not can be judged according to the numerical value of the binary numbers, trimming can be realized through the algorithm, the algorithm is flexible, and the corresponding trimming scheme can be quickly and accurately obtained; in addition, at least one fuse wire is trimmed each time, different resistance networks are connected into the paths according to the resistance values from large to small, trimming precision can be greatly improved, trimming failure caused by overlarge or undersize adjustment quantity is avoided, real-time adjustment can be carried out on the connected resistance networks according to actual change of physical quantity in the process of trimming for many times, and a trimming plan is updated timely.

Fig. 3 shows a schematic flow chart of a fuse trimming method according to a second embodiment of the invention.

As shown in fig. 3, the method for trimming a fuse in this embodiment is to trim a circuit to be trimmed by the resistor trimming circuit in fig. 1, and includes steps S201 to S211, which are more complete than the first embodiment, and steps S203 to S207 are repeatedly performed n times, specifically as follows:

In step S201, an actual resistance value of a first resistor network of the resistor trimming circuit, to which the fuse is not connected, is obtained.

This step is the actual resistance value detected when all fuses of the resistor trimming circuit have not been blown, so the actual resistance value is the actual resistance value of the resistor network not connected to the fuses, and is used as the actual resistance value of the first resistor network, for example, the first resistor network R0 in fig. 1a or 1 b. In this step, the actual measurement value of the physical quantity may be obtained by the auxiliary circuit, and the actual measurement value of the physical quantity may be converted into the actual measurement resistance value based on the relationship between the physical quantity and the resistance value. The auxiliary circuit may include a current mirror, the measured value of the physical quantity being proportional to the value of the physical quantity on the current mirror. For example, the current value detected by the current mirror is A1, the measured current value A0 of the physical quantity is obtained by a ratio of 100 to 10, and then the measured resistance value R0 is represented by the ratio of the fixed voltage value V0 to the current value A0.

In step S202, the actual resistance values of the 2 nd to n+1st resistor networks are calculated and obtained according to the actual resistance value of the first resistor network.

In this step, the actual resistance value of each resistor network is obtained according to the ratio of the nominal resistance value of each resistor network to the nominal resistance value of the first resistor network R0 and the measured resistance value. For example, the nominal resistance value of the resistor network R0 is 75kΩ, the nominal resistance value of the resistor network R1 is 40kΩ, and the actual resistance value of the resistor network R0 is 80kΩ, so that the actual resistance value of the resistor network R1 is 85×40/75kΩ. Similarly, the actual resistance value of the residual resistance network can be obtained according to the same calculation mode.

In step S203, an actual measured resistance value in the resistance trimming circuit is obtained.

In this step, the measured resistance value of the resistance trimming circuit is obtained in each trimming process from the 2 nd time to the i th time, and the step is the same as the step S101, and will not be repeated here.

In step S204, a physical quantity target value of the physical quantity is acquired, and converted into a target reference resistance value.

In this step, the target reference resistance value is a resistance value corresponding to a value of any physical quantity within a margin range allowed by the physical quantity target value, and may be, for example, a maximum resistance value corresponding to a value of a physical quantity within a margin range, or any value within a range of plus or minus 20% of the maximum resistance value. When the fuse is blown, there may be a residual resistance, so that the parallel connection relation between the resistor and the residual resistance in parallel connection with the fuse in fig. 1a is formed, the resistance of the actual resistance of the resistor is reduced, or the resistance after parallel connection cannot be expected due to the influence of the residual resistance of the fuse in fig. 1b, so that the trimming result is influenced, and in order to avoid the influence of the residual resistance, the target reference resistance is set to be slightly larger, that is, the compensation resistance is slightly larger, so as to adjust the influence caused by the residual resistance.

In an alternative embodiment, as i increases gradually, the margin range decreases gradually, and the value of the physical quantity corresponding to the target reference resistance value approaches the physical quantity target value gradually. Namely, as the trimming frequency increases, the value of the physical quantity corresponding to the target reference resistance value gradually approaches to the physical quantity target value, the margin range is reduced, and the variable range of the target reference resistance value is reduced, so that the adjustment precision is higher.

In this embodiment, resistance values corresponding to values of different physical quantities are selected as target reference resistance values within a margin range of a physical quantity target value, the size of the target reference resistance values can be flexibly adjusted, when the final resistance value becomes smaller due to the fact that residual resistance possibly exists after fuse melting is considered, any resistance value in a certain range around the maximum resistance value corresponding to the margin range is selected as the target reference resistance value, the compensation quantity of the resistance in the added path is guaranteed to meet the requirement, the current is not too large, and therefore the influence of the residual resistance of the fuse on trimming can be reduced, the trimming yield is greatly improved, the safety is better, and the problem that the whole system is damaged due to the too large current is avoided. In addition, as the trimming frequency increases, the resistance value required to be added into the circuit to be trimmed gradually becomes smaller, and at the moment, the target reference resistance value is gradually adjusted to enable the value of the corresponding physical quantity to gradually approach the physical quantity target value, so that the trimming precision is higher, the trimming precision is continuously improved in the process of changing the value of the compensation resistance value from larger to smaller, the trimming result is enabled to be closer to the physical quantity target value, the deviation is extremely small, and the accuracy is higher.

In step S205, the difference between the acquired target reference resistance value and the measured resistance value is used as the compensation resistance value.

The present step is the same as step S102, and will not be described here again.

In step S206, an n-bit binary number is calculated according to the compensation resistance value to characterize the fuse that needs to be blown at this time.

In this step, the resistor combination is calculated according to the compensation resistance value to obtain a corresponding n-bit binary number, and the binary number can be output by using the ratio of the compensation resistance value to the step distance value, which can be the same as step S103, and the same points are not described herein.

In an alternative embodiment, when calculating the n-bit binary number according to the compensation resistance value, the actual resistance value of the resistor network combination corresponding to the n-bit binary number meets a preset condition. In the process of trimming at different times, the preset conditions can be different, so that different resistor network combinations can be obtained in the process of trimming at different times. For example, when i is 1, the preset condition may be: the actual resistance value of the resistor network combination does not exceed the compensation resistance value. And when i is 2 to n-1, the preset conditions may be: the actual resistance value of the resistor network combination is larger than the compensation resistance value, namely the actual resistance value corresponding to the combined resistor network is the smallest, and the compensation resistance value is required to be exceeded. And when i is n and the compensation resistance value is greater than half of the actual resistance value of the n+1th resistance network, the resistance networks are combined into the n+1th resistance network. I.e. the compensation resistance value needs to be greater than half the actual resistance value of the last resistor network to blow the fuse corresponding to the last resistor network.

The preset condition set when i is 1 is to ensure that the actual resistance value of the obtained resistance network combination is in a proper range, so that the deviation between the value of the physical quantity after trimming and the target value of the physical quantity is smaller, and the condition that the added resistance value is too large to cause smaller current and finally cause trimming failure due to failure of trimming is avoided. The preset condition for setting i from 2 to n-1 is that the compensation resistance is larger after the first trimming, so that the combined resistance network needs to be set larger to finish trimming as soon as possible with high precision. In the step, preset conditions can be selected according to actual conditions, and trimming precision and accuracy are improved.

Therefore, in this embodiment, in the trimming process of different times, the preset conditions to be met when calculating the combined resistance network are different, when the actual resistance value corresponding to the combined resistance network cannot exceed the compensation resistance value in the first trimming process, the deviation between the physical value and the target value is avoided being too large when the resistance is too large, and in the subsequent trimming process, the actual resistance value combined by the resistance network is larger than the compensation resistance value to efficiently and quickly read and complete trimming, so that the resistance value to be increased in the trimming process is limited in a reasonable range, the trimming accuracy is ensured, and the preset conditions can be adjusted in real time according to the actual situation, so that the resistance amount to be increased each time is in accordance with the actual requirement, and the trimming reliability is improved.

In step S207, whether to blow fuses of corresponding bits in the resistance trimming circuit is selected according to the value of at least one binary number selected from the currently output n-bit binary numbers.

The step is the same as step S104, and will not be described again.

In step S208, the trimming value of the physical quantity of the circuit to be trimmed after trimming is measured, and a difference between the trimming value of the physical quantity and the target value of the physical quantity is obtained.

In the step, after n trimming is completed, the actual measurement value of the physical quantity or the trimming value of the physical quantity of the circuit to be trimmed is measured, and the difference between the actual measurement value and the target value of the physical quantity is judged.

In step S209, it is determined whether the difference is within the error range. If the difference is within the error range, step S210 is performed, otherwise step S211 is performed.

In step S210, the actual binary numbers corresponding to all the trimmed fuses are output.

In step S211, a prompt for a repair failure is output.

The embodiment is a more perfect fuse trimming method, and the adjustment of the target reference resistance value and the adjustment of the combined resistance are added, so that the accuracy and the reliability can be further improved under the condition of ensuring high precision.

In the following, for example, the trimming circuit of fig. 1a is used to trim the physical quantity to be trimmed, and steps S301-S331 are included, where steps S301-S306 are steps of determining whether the first Fuse1 is blown, steps S307-S313 are steps of determining whether the second Fuse2 is blown, steps S314-S320 are steps of determining whether the third Fuse3 is blown, steps S321-S327 are omitted, steps of determining whether the fourth Fuse4 is blown are similar to steps S307-S313 or steps S314-S320, so that the description is not expanded, and steps S328-S331 are steps of determining whether the fifth Fuse5 is blown. In the following examples, RA0 to RA5 represent actual resistance values of 6 resistors, RL0 represents a target resistance value corresponding to a target value of a physical quantity, RL1 to RL5 represent a plurality of target reference resistance values, and R Add1 to R Add5 represent a plurality of compensation resistance values. In this example, when calculating the n-bit binary number according to the compensation resistance value, the actual resistance value of the resistor network combination corresponding to the n-bit binary number meets the preset condition. The following is a description of specific steps.

In step S301, an actual measurement value of the physical quantity is obtained by the auxiliary circuit, and the actual measurement resistance value RA0 of the resistor R0 in the resistor trimming circuit is obtained by conversion.

In step S302, a compensation resistance value radd 1 to be increased is calculated according to the target reference resistance value RL1 and the measured resistance value RA0 of the resistor R. R Add1 = RL1-RA0, where RL1 is the maximum resistance value corresponding to the value of the physical quantity within the physical quantity target value margin.

In step S303, an optimal trimming resistor combination (binary number is output) is calculated according to R Add1, and when trimming is performed according to this resistor combination, the series resistance is maximum and does not exceed RL0 to RA0. In this step, the resistor combination is obtained according to a preset condition of i=1.

In step S304, it is determined whether the highest digit value of the n-bit binary number is 1. If yes, go to step S305 to blow the first Fuse 1; otherwise, step S306 is executed, and the Fuse1 is not blown. Thus, trimming of the first fuse or the second resistor is completed.

In step S307, the measured resistance value in the resistance trimming circuit is obtained, and the compensation resistance value radd 2 to be increased is calculated according to the target reference resistance value RL2 and the measured resistance value.

In this step, if Fuse1 fuses and has a residual resistance in the previous step, the measured resistance value detected this time is the series resistance value of RA0 and the parallel resistance value of RA1 and the residual resistance. And when the fuse is blown later, calculating according to a similar calculation mode.

In step S308, it is determined whether the compensation resistance value radd 2 is greater than the sum of the actual resistance values of the remaining resistors (RA 2+ RA3+ RA4+ RA 5). If yes, go to step S309, otherwise go to step S310.

In step S309, the output binary number is 01111.

In step S310, an optimal trimming resistor combination (output binary number) is calculated according to R Add2, and the resistor combination is a minimum resistance value greater than R Add 2. The preset condition of i=2 is used in this step to calculate the resistance combination.

In step S311, it is determined whether the value of the second bit of the n-bit binary number is 1. If yes, go to step S312 to blow the second Fuse 2; otherwise, step S313 is executed, and the Fuse2 is not blown. Thus, trimming of the second fuse or the third resistor is completed.

In step S314, the measured resistance value in the resistance trimming circuit is obtained, and the compensation resistance value radd 3 to be increased is calculated according to the target reference resistance value RL3 and the measured resistance value. The actual measured resistance value also needs to consider the influence of the residual resistance after the fuse is blown.

In step S315, it is determined whether the compensation resistance value radd 3 is larger than the sum of the actual resistance values of the remaining resistors (RA 3+ RA4+ RA 5). If yes, step S316 is executed, otherwise step S317 is executed.

In step S316, the output binary number is 00111.

In step S317, an optimal trimming resistor combination (output binary number) is calculated according to R Add3, and the resistor combination is a minimum resistance value greater than R Add 3. The preset condition of i=3 is used in this step to calculate the resistance combination.

In step S318, it is determined whether the value of the third bit of the n-bit binary number is 1. If yes, go to step S319 to blow the third Fuse 3; otherwise, step S320 is executed, and the Fuse3 is not blown. Thus, trimming of the third fuse or the fourth resistor is completed.

The trimming process of the fourth fuse or the fifth resistor is similar to the trimming process of the second fuse and the third fuse, and will not be described here.

In step S328, the measured resistance value in the resistance trimming circuit is obtained, and the compensation resistance value radd 5 to be increased is calculated according to the target reference resistance value RL3 and the measured resistance value.

In step S329, it is determined whether the compensation resistance value radd 5 is greater than half RA 1. If yes, go to step S330 to blow the fifth Fuse 5; otherwise, step S331 is executed, and the Fuse5 is not blown. Thus, trimming of the fifth fuse or the sixth resistor is completed.

In this embodiment, when the compensation resistance value is greater than the sum of the actual resistance values of all the remaining unmodified resistors, the n-bit binary numbers indicate that all the unmodified fuses need to be blown, that is, all binary numbers corresponding to all the unmodified fuses are output as 1, and only the ith fuse is blown or not blown according to the ith output result. At this time, too much resistor needs to be connected into the circuit to be repaired, which is not in line with the original purpose of fine tuning, and corresponding prompt information needs to be sent out to remind operators to re-detect, so as to see whether the circuit to be repaired has a problem or other circuits have faults, and therefore the circuit to be repaired is timely adjusted.

As shown in fig. 4, the present invention further provides a fuse trimming device 400, which mainly trims a physical quantity to be trimmed by a resistor trimming circuit, where the fuse trimming device 400 includes: host 420, resistance trimming circuit 430, test circuit 440, execution circuit 450, and auxiliary circuit 460. The physical quantities to be trimmed include, for example, current, voltage, resistance, capacitance, etc., the resistance trimming circuit is illustrated in fig. 1a, and the power supply terminal VDD may be, for example, various circuits such as an oscillator, a bandgap reference, a current source, etc.

In this embodiment, the resistor trimming circuit 430 is connected between two potential ends, for example, the two potential ends may be a power supply end VDD and a ground end GND, and include n+1 resistor networks connected in series and n fuses, where two ends of each resistor network except the first resistor network are connected in parallel to one fuse, and n is an integer greater than or equal to 1. In fig. 4, n=5, the resistor trimming circuit 430 includes 6 resistor networks and 5 fuses connected in series, and the rest of resistors except the first resistor network R0 are connected in parallel with the fuses. For example, the Fuse1 is connected in parallel across the resistor network R1, the Fuse2 is connected in parallel across the resistor network R2, the Fuse3 is connected in parallel across the resistor network R3, the Fuse4 is connected in parallel across the resistor network R4, the two ends of the resistor network R5 are connected with the Fuse wire Fuse5 in parallel, and when one Fuse wire is blown, the resistor network connected with the Fuse wire Fuse is connected in parallel into the paths of the power supply end and the grounding end, and the corresponding physical quantity value is changed.

The test circuit 440 is connected to the resistance trimming circuit 430 for measuring the value of the physical quantity and the resistance value in the resistance trimming circuit 430. The test circuit 440 may also be connected to the resistance trimming circuit 430 through an auxiliary circuit 460, and the test circuit 440 may obtain the value of the physical quantity and the resistance value through the auxiliary circuit 460. For example, the auxiliary circuit 460 includes a current mirror, and by measuring the current on the current mirror, the current on the resistor trimming circuit 430, i.e., the current value on the path between the power supply terminal and the ground terminal, can be obtained according to the proportional relationship.

The execution circuit 450 is connected to the resistance trimming circuit 430, and blows corresponding fuses in the resistance trimming circuit 430 according to the control of the host 420. The execution circuit 450 is connected to each fuse, which may be, for example, a current generation circuit, and causes the fuse to blow due to a large current after generating a corresponding current.

The host 420 is coupled to the resistance trimming circuit 430, the execution circuit 450, and the test circuit 440, and may include a memory for storing computer instructions and a processor for executing the fuse trimming method of the embodiment depicted in fig. 2-3 based on the stored computer instructions and controlling the execution circuit 450 to operate to blow the corresponding fuses. Since the fuse trimming method has been described in detail in the above method embodiments, details are not repeated here.

In summary, the method and the circuit for trimming the fuse wire convert the compensation quantity of the physical quantity into the compensation quantity of the resistor, and blow different fuses according to the compensation quantity of the resistor, so that the compensation quantity brought by the corresponding resistor network can be connected to the path from the power supply end to the grounding end, the resistance value on the path to be connected can be intuitively and conveniently obtained directly according to the compensation quantity of the resistor, and the trimming of the physical quantity is realized by continuously adjusting the resistance value, so that the trimming of the physical quantity is faster and better realized; the compensation resistance value is converted into binary numbers through a certain algorithm, whether the corresponding fuse is blown or not can be judged according to the numerical value of the binary numbers, trimming can be realized through the set algorithm, and the method is efficient and reliable; in addition, at least one binary number is selected according to the compensation quantity of the resistor to repair at least one fuse wire each time, and then repair is performed step by step for multiple times, namely, each time only a part of resistance values are connected into a path, then different resistance networks are connected into the path in a sequence from big to small according to the resistance values which are added multiple times, and the different resistance networks are connected into the path step by step, so that repair precision can be greatly improved, and repair failure caused by overlarge or overlarge adjustment quantity due to the fact that a plurality of resistance networks are added at one time only according to one repair result is avoided.

It should be noted that, the numerical values herein are only used for illustrative purposes, and in other embodiments of the present invention, other numerical values may be sampled to implement the present solution, and the present invention is not limited to this, and should be reasonably set according to practical situations.

Finally, it should be noted that: it is apparent that the above examples are only illustrative of the present invention and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. And obvious variations or modifications thereof are contemplated as falling within the scope of the present invention.

It is also to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. The use of these terms and expressions is not meant to exclude any equivalents of the features shown and described (or portions thereof), and it is recognized that various modifications are possible and are intended to be included within the scope of the claims. Other modifications, variations, and alternatives are also possible. Accordingly, the claims should be looked to in order to cover all such equivalents.

Claims

1. The utility model provides a method for trimming fuses, is through the resistance trimming circuit to the physical quantity of waiting to transfer on the route of two potential ends, resistance trimming circuit includes that connect between two potential ends n+1 link resistance network and n fuses, every fuse link a resistance network, n is greater than or equal to 1 integer, the method for trimming fuses repeatedly carries out i times following steps:

Obtaining an actually measured resistance value in the resistance trimming circuit;

taking the difference between the target reference resistance value and the measured resistance value as a compensation resistance value;

calculating an n-bit binary number according to the compensation resistance value to represent the fuse wire to be blown at this time; and

selecting whether to blow fuses of corresponding bits in the resistance trimming circuit according to the value of at least one binary number selected from the n-bit binary numbers currently output,

at least one bit is selected from the n-bit binary numbers according to a set sequence, and at least one bit binary number selected each time is not repeated, wherein i is larger than 1.

2. The fuse trimming method of claim 1, further comprising:

and obtaining a physical quantity target value of the physical quantity, and converting the physical quantity target value to obtain the target reference resistance value.

3. The fuse trimming method according to claim 2, wherein the target reference resistance value is a corresponding maximum resistance value within a margin range allowed by the physical quantity target value or any value within plus or minus 20% of the maximum resistance value.

4. The fuse trimming method according to claim 3, wherein the margin range gradually decreases as i gradually increases, and the value of the physical quantity corresponding to the target reference resistance value gradually approaches the physical quantity target value.

5. The method for trimming a fuse according to claim 1, wherein the n-bit binary number is obtained by calculating according to the compensation resistance value, wherein an actual resistance value of a resistor network combination corresponding to the n-bit binary number meets a preset condition.

6. The fuse trimming method of claim 5, wherein when i is 1, the preset condition is: the actual resistance value of the resistor network combination does not exceed the difference between the target reference resistance value and the measured resistance value.

7. The fuse trimming method according to claim 5, wherein when i is 2 to n-1, the preset condition is: the actual resistance value of the resistor network combination is greater than the compensation resistance value.

8. The fuse trimming method of claim 5, wherein when i is n and the compensation resistance value is greater than half of an actual resistance value of an n+1th resistance network, the resistance networks are combined into the n+1th resistance network.

9. The method of trimming a fuse according to claim 1, wherein the step of calculating an n-bit binary number to characterize the fuse to be blown this time based on the compensation resistance value comprises:

obtaining an integer interval in which the ratio of the compensation resistance value to the step distance value is located;

Selecting an integer from the integer interval according to a preset condition; and

and outputting the n-bit binary number corresponding to the selected integer.

10. The method of trimming a fuse according to claim 9, wherein the step size is a nominal resistance of the n+1th resistor network, and the step size is an integer selected from the integer interval by using a table look-up method and output as an n-bit binary number.

11. The fuse trimming method of claim 1, wherein the step of obtaining the measured resistance value in the resistance trimming circuit comprises:

obtaining an actual measurement value of the physical quantity to be repaired by an auxiliary circuit;

and converting the measured value of the physical quantity into the measured resistance value according to the relation between the physical quantity and the resistance value.

12. The fuse trimming method of claim 11, wherein the auxiliary circuit comprises a current mirror, the measured value of the physical quantity being proportional to a value of the physical quantity on the current mirror.

13. The fuse trimming method of claim 1, further comprising:

acquiring an actual resistance value of a first resistance network which is not connected with the fuse in the resistance trimming circuit;

and calculating and obtaining the actual resistance values of the 2 nd to n+1st resistor networks according to the actual resistance value of the first resistor network.

14. The fuse trimming method of claim 2, further comprising:

measuring the trimming value of the trimmed physical quantity to obtain a difference value between the trimming value of the physical quantity and the target value of the physical quantity;

judging whether the difference value is within an error range or not;

and if the difference value is within the error range, outputting the actual binary numbers corresponding to all the trimming fuses, otherwise, outputting a prompt of trimming failure.

15. The fuse trimming method according to claim 1, wherein when the value of the binary number is 1, it indicates that the corresponding fuse needs to be blown, and when the binary number is 0, it indicates that the corresponding fuse is not processed.

16. A fuse trimming device for trimming a physical quantity to be trimmed of a path from a power supply end to a ground end through a resistor trimming circuit, the fuse trimming device comprising:

the resistor trimming circuit comprises n+1 connected resistor networks and n fuses, wherein the n+1 connected resistor networks and the n fuses are connected between the power supply end and the grounding end, each fuse is connected with one resistor network, and n is an integer greater than or equal to 1;

the test circuit is connected with the resistance trimming circuit and is used for acquiring an actual measured resistance value and an actual measured value of the physical quantity in the resistance trimming circuit;

The execution circuit is connected with the resistance trimming circuit and fuses corresponding fuses in the resistance trimming circuit according to the control of a host; and

a host connected to the resistance trimming circuit, the execution circuit and the test circuit for storing computer instructions and executing the fuse trimming method according to any one of claims 1 to 15 based on the stored computer instructions, and controlling the execution circuit to blow the corresponding fuse.