Trimming circuit, method, control chip and trimming system

Abstract

The application provides a trimming circuit, a method, a control chip and a trimming system. The trimming circuit is applied to a feedback loop and comprises a resistance module, a fuse module, a switch module and a control module. The resistance module is connected with a voltage output and an input end of the feedback loop respectively. The switch module is connected with the resistance module and the fuse module respectively. The control module controls the switch module to be turned off, so that the resistance module and the fuse module are disconnected, so that a test device detects a test output voltage of the voltage output end of the feedback loop, and determines a trimming signal according to the test output voltage and a target output voltage. According to the trimming signal, corresponding fuses in the fuse module are fused. After the corresponding fuses are fused, the control module controls the switch module to be turned on, so as to adjust an effective resistance of the resistance module, and to trim the output voltage of the feedback loop. The application can avoid the problems of low trimming precision and low stability of the feedback loop caused by large leakage current and parasitic capacitance in the wafer test process.

Description

Technical Field

[0001] This application relates to the field of integrated circuit technology, and more specifically, to a tuning circuit, method, control chip, and tuning system. Background Technology

[0002] To ensure the accuracy of the output voltage of the feedback loop (such as a low-dropout voltage regulator circuit, a DC-DC converter circuit, etc.), it is usually necessary to adjust the test output voltage of the feedback loop.

[0003] Currently, related technologies typically employ adjustment circuits composed of resistors and metal fuses. During wafer testing, current is applied to the adjustment voltage bonding points of the adjustment circuit by connecting probes to the circuit, melting the metal fuse and thus changing the effective resistance value, thereby altering the test voltage to achieve the adjustment purpose. However, since probes are usually connected by long leads, parasitic capacitance may exist between the leads. Large parasitic capacitances can affect the stability during testing. Furthermore, when probes and the test system are connected to the adjustment circuit, a large leakage current is introduced, which in turn affects the adjustment accuracy of the circuit. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a trimming circuit, method, control chip, and trimming system. This trimming circuit avoids the problems of low trimming accuracy and low feedback loop stability caused by large leakage current and parasitic capacitance during wafer testing. Furthermore, the trimming circuit provided in this application ensures the stability of the feedback loop, thus eliminating the need for additional compensation circuitry and reducing chip manufacturing costs.

[0005] In a first aspect, this application provides a trimming circuit, comprising: a resistor module, a fuse module, a switch module, and a control module; a first terminal of the resistor module is connected to the voltage output terminal of the feedback loop, and a second terminal of the resistor module is connected to the input terminal of the feedback loop; the fuse module is connected to a test device via a probe, and the fuse module is used to adjust the effective resistance value of the resistor module; a switch module is connected to both the resistor module and the fuse module; the control module has its output terminal connected to the controlled terminal of the switch module, and is used to output a control signal to the switch module to control the switching of the switch module; the control module is used to control the switch module to turn off, thereby disconnecting the resistor module and the fuse module, so that the test device can detect the test output voltage at the voltage output terminal of the feedback loop, and determine a trimming signal based on the test output voltage and the target output voltage, and blow the corresponding fuse in the fuse module according to the trimming signal; after the corresponding fuse is blown, the control module is also used to control the switch module to turn on, so as to adjust the effective resistance value of the resistor module to trim the output voltage of the feedback loop.

[0006] Based on the trimming circuit provided in this application, before measuring the output voltage of the feedback loop, the trimming circuit can control the resistor module and fuse module to be open-circuited. This avoids the problems of low trimming accuracy and low feedback loop stability caused by large leakage current and parasitic capacitance during wafer testing, ensuring the measurement reliability and accuracy of the trimming circuit, and thus ensuring the trimming reliability and accuracy of subsequent trimming. Furthermore, the trimming circuit provided in this application ensures the stability of the feedback loop, therefore eliminating the need for additional compensation circuits. This allows chips using this trimming circuit to be miniaturized and lightweight, while reducing chip manufacturing costs and saving on production costs.

[0007] In one possible design, the control module includes a control unit and an inverter; the control unit has an input terminal for receiving test signals; the inverter has an input terminal connected to the output terminal of the control unit for outputting control signals.

[0008] In one possible design, the control unit includes a comparator, with its inverting input for receiving a test signal, its non-inverting input for receiving a reference voltage signal, and its output connected to the input of the inverter.

[0009] In one possible design, the input terminal of the control unit is set as a test solder joint, which is connected to the test equipment via a probe to receive the test signal input from the test equipment. The control unit also includes a first current source, one end of which is connected to the input terminal of an inverter, and the other end is grounded. When the test signal received by the test solder joint is high, the control signal output by the control module is low; when the test solder joint does not receive a test signal, the control signal output by the control module is high.

[0010] In one possible design, the resistor module includes N trimming resistors connected in series and a sampling resistor; the fuse module includes N fuses connected in series; and the switch module includes (N+1) first switches, where N is a positive integer. The first end of each of the N trimming resistors is connected to the voltage output terminal, and the second end is connected to the first end of the sampling resistor. The second end of the sampling resistor is grounded, and the third end is connected to the input terminal of the feedback loop. Both ends of each fuse are configured as trimming voltage solder joints, which are connected to the test equipment via probes. Each fuse is connected to both ends of a trimming resistor, and the (N+1) first switches are respectively located on each branch where the fuses and trimming resistors are connected.

[0011] In one possible design, the sampling resistor includes a first resistor and a second resistor; the first end of the first resistor is connected to the second end of N trimming resistors, the second end of the first resistor is connected to the first end of the second resistor, and is also connected to the input of the feedback loop, and the second end of the second resistor is grounded.

[0012] In one possible design, the switch module further includes a second switch; the second switch is connected in parallel across the first trimming resistor, which is one of the N trimming resistors connected to the voltage output terminal; the controlled terminal of the second switch is connected to the first trimming voltage solder joint of the first fuse, which is a fuse connected in parallel across the first trimming resistor, and the first trimming voltage solder joint is a trimming voltage solder joint connected to the voltage output terminal through the first switch; when the first switch is off and the fuse module is not blown, the second switch is on, used to determine the voltage difference between the output voltage of the trimmed feedback loop and the target output voltage based on the trimming signal.

[0013] Based on the above optional method, the first switch is turned off, and the adjustment signal is measured. When the fuse module is not blown, the second switch is turned on to determine the voltage difference between the output voltage of the adjusted feedback loop and the target output voltage according to the adjustment signal. This determines whether the output voltage of the adjusted feedback loop conforms to the target output voltage. In this way, pre-adjustment measurement can be realized, that is, the amount of change in the effect of the adjustment circuit on the output voltage of the feedback loop according to the adjustment signal can be simulated to determine the adjustment accuracy of the adjustment circuit in adjusting the output voltage of the feedback loop.

[0014] Secondly, embodiments of this application provide a tuning method, including the tuning circuit described in any optional manner of the first aspect; the method includes: a control module controlling a switch module to turn off, thereby disconnecting the resistor module and the fuse module, so that a test device can detect the test output voltage at the voltage output terminal of the feedback loop; determining a tuning signal based on the test output voltage and the target output voltage; blowing the corresponding fuse in the fuse module according to the tuning signal; and the control module controlling the switch module to turn on, after the fuse module blows the corresponding fuse, adjusting the effective resistance value of the resistor module to tune the output voltage of the feedback loop.

[0015] Thirdly, embodiments of this application provide a control chip, including the tuning circuit and feedback loop described in any of the optional embodiments of the first aspect.

[0016] Thirdly, embodiments of this application provide a tuning system, including a control chip, a probe, and a testing device as described in any of the optional embodiments of the third aspect; the testing device is connected to the control chip via the probe. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the framework structure of a tuning circuit in related technologies; Figure 2 This is a schematic diagram of the circuit structure of a trimming circuit in related technologies; Figure 3 This is a schematic diagram of the frame structure of a trimming circuit provided in an embodiment of this application; Figure 4 This is a schematic diagram of the circuit structure of an adjustment circuit provided in an embodiment of this application; Figure 5 This is a schematic diagram of the circuit structure of another adjustment circuit provided in an embodiment of this application; Figure 6 This is a schematic diagram of the circuit structure of another adjustment circuit provided in the embodiments of this application; Figure 7 This is a schematic diagram of the framework structure of another adjustment circuit provided in the embodiments of this application; Figure 8 This is a schematic diagram of the framework structure of another adjustment circuit provided in the embodiments of this application; Figure 9 This is a flowchart of the adjustment method provided in the embodiments of this application.

[0018] The following are the labeling elements in the figure: 1. Adjustment circuit; 11. Resistor module; 12. Fuse module; 2. Feedback loop; 3. Adjustment circuit; 31. Resistor module; 32. Fuse module; 33. Switch module; 34. Control module; 341. Control unit; VO, Output Voltage; VR, Reference Voltage; TM, Test Signal; F, Fuse; F1, First Fuse; F2, Second Fuse; F3, Third Fuse; R1, Adjustment Resistor; R1a, First Adjustment Resistor; R1b, Second Adjustment Resistor; R1c, Third Adjustment Resistor; TP, Adjustment Voltage Solder Joint; TPa, First Adjustment Voltage Solder Joint; TPb, Second Adjustment Voltage Solder Joint; TPc, Third Adjustment Voltage Solder Joint; TPd, Fourth Adjustment Voltage Solder Joint; R2, Sampling Resistor; R2a, First Resistor; R2b, Second Resistor; EA, Amplifier; Q1, First MOSFET; Q2, Second MOSFET; I1, First Current Source; I2, Second Current Source; V, Voltage Source; S1, First Switch; S2, Second Switch; INV, Inverter; COMP, Comparator. Detailed Implementation

[0019] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, devices, and circuits have been omitted so as not to obscure the description of this application with unnecessary detail.

[0020] Currently, to ensure the accuracy of the output voltage of feedback loops (such as low-dropout voltage regulation circuits and DC-DC conversion circuits), it is usually necessary to adjust the output voltage of the feedback loop. Related technologies typically involve burning out a metal fuse to change its resistance value, thereby regulating the output voltage of the feedback loop. For example, ... Figure 1 As shown, the first input terminal of feedback loop 2 is connected to the reference voltage VR. The trimming circuit 1 in related technologies typically includes a resistor module 11 and a fuse module 12. The first terminal of resistor module 11 is connected to the voltage output terminal of feedback loop 2, the second terminal of resistor module 11 is connected to the second input terminal of feedback loop 2, and the second terminal of resistor module 11 is connected to fuse module 12. During trimming via wafer testing, a probe is first connected to the trim pad. By measuring the output voltage VO of the voltage output terminal of feedback loop 2, trimming information (e.g., trimming voltage, trimming ratio, etc.) is obtained. Then, current is applied through the probe to burn the corresponding fuse in fuse module 12 according to the trimming information. The burned fuse then adjusts the resistance value of resistor module 11, thereby regulating the output voltage VO of feedback loop 2.

[0021] like Figure 2 As shown, the resistor module 11 in the related technology may include multiple series-connected adjustment resistors R1, and the fuse module 12 may include multiple series-connected fuses F. The multiple adjustment resistors R1 correspond one-to-one with the multiple fuses F. Additionally, the adjustment circuit 1 in the related technology may also include two sampling resistors R2. See [link to related technology]. Figure 2 Taking resistor module 11, which includes three adjustment resistors R1, and fuse module 12, which includes three fuses F connected in series, as an example, assuming the target output voltage is 2V, and during wafer testing, the measured test output voltage VO is 2V, then the output voltage VO is the target output voltage and no adjustment is needed. Therefore, all three fuses F can be burned out. If the measured test output voltage VO is 2.02V, then the output voltage VO is not the target output voltage and adjustment is needed. Two fuses F can be burned out so that after the feedback circuit 2 is working normally, the adjustment resistor R1 corresponding to the unburned fuse F is short-circuited, thereby adjusting the resistance value of resistor module 11 and thus regulating the output voltage VO of feedback loop 2, reducing the output voltage VO from 2.02V to 2V.

[0022] However, when the probe and testing equipment test feedback loop 2, they introduce significant leakage current and parasitic capacitance. This large leakage current introduces errors in the measurement of the output voltage VO, affecting measurement accuracy and reducing the reliability and accuracy of the adjustment circuit 1 in adjusting feedback loop 2. During testing, the large parasitic capacitance leads to lower stability in feedback loop 2. To improve stability, additional phase compensation circuits or larger phase compensation components (such as compensation capacitors) are typically required. This results in excessively large compensation circuits or components, increasing manufacturing costs.

[0023] Therefore, embodiments of this application provide a trimming circuit, method, control chip, and trimming system. The trimming circuit can avoid the problems of low trimming accuracy and low feedback loop stability caused by large leakage current and parasitic capacitance during wafer testing. Furthermore, the trimming circuit provided by this application ensures the stability of the feedback loop, so there is no need to add an additional compensation circuit, thereby reducing the chip manufacturing cost.

[0024] The following description, in conjunction with the accompanying drawings, provides an exemplary account of the adjustment circuit, adjustment method, and control chip provided in this application.

[0025] like Figure 3 As shown, the adjustment circuit 3 provided in this embodiment may include a resistor module 31, a fuse module 32, a switch module 33, and a control module 34. The first end of the resistor module 31 is connected to the voltage output terminal of the feedback loop 2, and the second end of the resistor module 31 is connected to the input terminal of the feedback loop 2. The fuse module 32 is connected to the test equipment through a probe. The switch module 33 is connected to both the resistor module 31 and the fuse module 32. The output terminal of the control module 34 is connected to the controlled terminal of the switch module 22.

[0026] The fuse module 32 is used to adjust the effective resistance value of the resistor module 31 to adjust the feedback loop 2. The output terminal of the control module 34 is connected to the controlled terminal of the switch module 33 and is used to output a control signal to the switch module 33 to control the on / off state of the switch module 33.

[0027] For example, before wafer testing, the control module 34 controls the switch module 3 to turn off, causing the resistor module 31 and fuse module 32 to be open-circuited. This allows the test equipment to detect the test output voltage VO at the voltage output terminal of the feedback loop 2. At this time, because the resistor module 31 and fuse module 32 are open-circuited, the large leakage current introduced by the probe and test equipment will not affect the test accuracy, ensuring the accuracy and reliability of the measurement by the adjustment circuit 3. Simultaneously, because the resistor module 31 and fuse module 32 are open-circuited at this time, i.e., the probe fuse module 32 and the feedback loop 2 are short-circuited, the parasitic capacitance introduced by the test equipment will not affect the stability of the feedback loop 2. Thus, the stability of the feedback loop 2 is ensured, and no additional compensation circuit is needed, thereby reducing the chip manufacturing cost. Thus, before measuring the output voltage VO of the feedback loop 2, the adjustment circuit 3 in this application can control the resistor module 31 and the fuse module 32 to be disconnected. This avoids the problems of low adjustment accuracy and low feedback loop stability caused by large leakage current and parasitic capacitance during wafer testing, ensuring the measurement reliability and accuracy of the adjustment circuit 3, and consequently ensuring the adjustment reliability and accuracy of the subsequent adjustment by the adjustment circuit 3. Furthermore, the adjustment circuit 3 provided in this application ensures the stability of the feedback loop 2, thus eliminating the need for additional compensation circuits. This allows chips using this adjustment circuit 3 to be miniaturized and lightweight, while reducing chip manufacturing costs and saving on production costs.

[0028] After measuring the output voltage VO of feedback loop 2, control module 34 compares the measured output voltage VO with the target output voltage to determine the adjustment signal. It is worth noting that this adjustment signal may include the adjustment ratio for resistor module 31, or which fuses F in fuse module 32 are specifically burned. This application does not impose specific limitations on this. After receiving the adjustment signal, control module 34 burns the corresponding fuses in fuse module 32 according to the adjustment signal. After burning the corresponding fuse F, control module 34 controls switch module 33 to conduct. At this time, the effective resistance value of resistor module 31 is adjusted through the burned fuse L to adjust the output voltage VO of feedback loop 2, making the output voltage VO of feedback loop 2 the target output voltage.

[0029] After the corresponding fuse F is blown, the control chip using the feedback loop 2 and the adjustment circuit 3 is packaged. After packaging, the control chip can be tested to see if it is qualified.

[0030] Taking feedback loop 2 as an example of a low drop-out regulator (LDO regulator), the explanation will be as follows: Figure 4As shown, the LDO may include an amplifier EA, a first MOSFET Q1, a second MOSFET Q2, and a second current source I2. The first input terminal of the amplifier EA is connected to a reference voltage VR. The second input terminal of the amplifier EA is connected to the second terminal of the resistor module 31. The output terminal of the amplifier EA is connected to the controlled terminal of the first MOSFET Q1. The first terminal of the first MOSFET Q1 is connected to a power supply. The second terminal of the first MOSFET Q1 is connected to one end of the second MOSFET Q2 and one end of the second current source I2. The other end of the second current source I2 is grounded. The first terminal of the second MOSFET Q2 is connected to a power supply. The second terminal of the second MOSFET Q2 is connected to the first terminal of the resistor module 31.

[0031] Optionally, resistor module 31 may include sampling resistor R2 and N series-connected trimming resistors R1, fuse module 32 may include N series-connected fuses F, and switch module may include (N+1) first switches S, where N is a positive integer. The first ends of the N trimming resistors R1 are connected to the voltage output terminal of the LDO, the second ends of the N trimming resistors R1 are connected to the first end of the sampling resistor R2, the second end of the sampling resistor R2 is grounded, and the sampling resistor R2 is also connected to the input terminal of the feedback loop 2. Both ends of each fuse F are configured as trimming voltage solder joints TP, which are connected to the test equipment via probes. Both ends of each fuse F are connected to both ends of a trimming resistor R1. The (N+1) first switches S1 are respectively set on each branch where the fuse F is connected to the trimming resistor TP. Multiple sampling resistors R2 may be included.

[0032] by Figure 4For example, the resistor module 31 provided in this application embodiment may include three trimming resistors R1, namely the first trimming resistor R1a, the second trimming resistor R1b and the third trimming resistor R1c. The fuse module 32 may include three fuses F, namely the first fuse F1, the second fuse F2 and the third fuse F3. The first switch S1 is provided with four, namely the first switch S1(ad). The fuse module 32 is provided with four trimming voltage solder points TP, namely the first trimming voltage solder point TPa, the second trimming voltage solder point TPb, the third trimming voltage solder point TPc and the fourth trimming voltage solder point TPd. The sampling resistor R2 may include the first resistor R2a and the second resistor R2b. The first end of the first resistor R2a is connected to the second end of the third trimming resistor R1c. The second end of the first resistor R2a is connected to the first end of the second resistor R2b and is also connected to the input end of the feedback loop 2. The second end of the second resistor R2b is grounded. The following description uses the resistor module 31 provided in this application, which includes three adjustment resistors R1, the fuse module 32, which includes three fuses F, the first switch S1, which is provided with four adjustment voltage solder points TP, and the sampling resistor R2, which is provided with two, as an example. The specific number of settings can be set according to actual needs. This application does not impose specific limitations on this.

[0033] Initially, the output voltage VO of feedback loop 2, measured before the fuse F burns out during wafer testing, can be obtained from formula (1): (1) Where V1 is the initial output voltage VO, VR is the reference voltage, R4 is the resistance of the first resistor R2a, and R5 is the resistance of the second resistor R2b.

[0034] During wafer testing, when all the unburned fuses F are connected one-to-one with the adjustment resistor R1, the measured output voltage VO of feedback loop 2 can be obtained from formula (2): (2) Wherein, V2 is the output voltage VO, VR is the reference voltage, R1 is the resistance of the first adjustment resistor R1a, R2 is the resistance of the second adjustment resistor R1b, R3 is the resistance of the third adjustment resistor R1c, R4 is the resistance of the first resistor R2a, and R5 is the resistance of the second resistor R2b.

[0035] For example, assuming VR is 1V, the resistance of the second resistor R2b is 1MΩ, the resistance of the first resistor R2a is 1MΩ, the resistance of the first adjustment resistor R1a is 0.02MΩ, the resistance of the second adjustment resistor R1b is 0.02MΩ, and the resistance of the third adjustment resistor R1c is 0.02MΩ, the voltage value can be increased by 1% by blowing the first fuse F1, the second fuse F2, or the third fuse F3.

[0036] Specifically, assuming the target output voltage is 2.02V, during wafer testing, if the measured test output voltage VO is 2.02V, then the output voltage VO is the target output voltage and no adjustment is needed. Therefore, the first fuse F1, the second fuse F2, and the third fuse F3 can all be burned out. If the measured test output voltage VO is 2.04V, then the output voltage VO is not the target output voltage and adjustment is needed. In this case, the first fuse F1 and the second fuse F2 can be burned out, while the third fuse F3 remains intact. After the first switch S1 (ad) is turned on and the feedback circuit 2 is operating normally, the third adjustment resistor R1c corresponding to the intact third fuse F3 will be short-circuited, thus adjusting the resistance value of the resistor module 31. This adjusts the output voltage VO of the feedback loop 2, reducing it from 2.04V to 2.02V, achieving the adjustment function.

[0037] In one example, such as Figure 5 As shown, the control module 34 may include a control unit 341 and an inverter INV. The input terminal of the control unit 341 is used to receive the test signal TM, and the input terminal of the inverter INV is connected to the output terminal of the control unit 341 to output a control signal.

[0038] For example, the input terminal of the control unit 341 is set as a test pad, which is connected to the test equipment via a probe. The test pad is used to receive the test signal TM input by the test equipment. For example, before testing, the test equipment applies a high level (e.g., 5V) to the test pad via the probe, meaning the test signal TM is high at this time. The control unit 341 outputs a high level to the inverter INV. After the inverter INV is inverted, the output control signal is low, which controls the first switch S1 to turn off, thus disconnecting the resistor module 31 and the fuse module 32. When the resistor module 31 and the fuse module 32 are disconnected, the output voltage VO of the test feedback loop 2 avoids the problems of low adjustment accuracy and low feedback loop stability caused by the large leakage current and parasitic capacitance introduced by the probe during the test, ensuring the measurement reliability and accuracy of the adjustment circuit 3, and thus ensuring the adjustment reliability and accuracy of the subsequent adjustment circuit 3.

[0039] Optional, in this example, such as Figure 6As shown, the control unit 341 may include a first current source I1, one end of which is connected to the input terminal of the inverter INV, and the other end of which is grounded. When the test signal TM received by the test bonding pad is high, the control signal output by the control module 34 is low; when the test bonding pad does not receive the test signal TM, the control signal output by the control module is high. For example, when no test signal TM is applied to the test bonding pad, the current node is pulled down to ground by the first current source I1, that is, the input to the inverter INV is low, and the control signal output after inversion by the inverter INV is high, thus controlling the first switch S1 to conduct, so that the resistor module 31 and the fuse module 32 are connected. Here, it can be understood that when the chip is working normally and when the feedback loop 2 is being adjusted, the test signal TM is low, so that the chip can work normally or the fuse module 32 can adjust the effective resistance value of the resistor module 31 accordingly, so as to adjust the output voltage VO of the feedback loop 2.

[0040] Optional, such as Figure 7 As shown, the control unit 341 may include a comparator COMP, and the inverting input of the comparator COMP (such as...) Figure 6 The test signal is connected to the "-" terminal shown in the figure, and the non-inverting input terminal of the comparator COMP (as shown in the figure) is connected to the test signal. Figure 6 The "+" sign indicates that a reference voltage signal is being input. This reference voltage signal can be provided by a voltage source V. One end of the voltage source V is connected to the non-inverting input of the comparator COMP, and the other end is grounded. The output of the comparator COMP is connected to the input of the inverter INV. It's worth noting that the test signal at this time can be the enable signal EN. When the enable signal EN connected to the comparator COMP is lower than the reference voltage signal, it indicates that a test is required. This necessitates that resistor module 31 and fuse module 32 be disconnected, and comparator COMP outputs a high-level signal. This high-level signal can be understood as the aforementioned test signal TM. After the test signal TM is inverted by the inverter INV, the output control signal is low, which controls the first switch S1 to turn off, thus disconnecting resistor module 31 and fuse module 32. When the chip is working normally, the enable signal EN connected to the comparator COMP is greater than or equal to 0V. Assuming the reference voltage signal is -0.3V, the enable signal EN is higher than the reference voltage signal, and the comparator COMP outputs a low-level signal. This low-level signal is the aforementioned test signal TM. After the test signal TM is inverted by the inverter INV, the output control signal is high-level, which controls the first switch S1 to turn on, so that the resistor module 31 and the fuse module 32 are connected. This allows the fuse module 32 to adjust the effective resistance value of the resistor module 31, thereby adjusting the output voltage VO of the feedback loop 2.

[0041] Here, it can be understood that when the control unit 341 includes a comparator COMP, the control unit 341 can obtain the corresponding test signal according to the input enable signal EN. That is, at this time, the enable signal EN input to the control unit 341 is the test signal for whether to perform a test. At the same time, the control unit 341 can also output the corresponding test signal TM based on the enable signal EN to control the on / off state of the first switch S1.

[0042] In summary, the adjustment circuit 3 provided in this embodiment controls the high and low levels of the test signal TM, thereby enabling the control module 34 to correspondingly control the switch module 3 to turn off, thus achieving the testing and adjustment of the output voltage VO of the feedback loop 2. Specifically, before wafer testing, the test signal TM is set to a high level, the control signal output by the control module 34 is set to a low level, the first switch S1 is opened, and the resistor module 31 and fuse module 32 are disconnected, so that the test equipment can detect the test output voltage VO at the voltage output terminal of the feedback loop 2. At this time, since the resistor module 31 and fuse module 32 are disconnected, the large leakage current introduced by the probe and test equipment will not affect the test accuracy, ensuring the accuracy and reliability of the measurement by the adjustment circuit 3. At the same time, since the resistor module 31 and fuse module 32 are disconnected at this time, that is, the probe fuse module 32 and the feedback loop 2 are short-circuited, the parasitic capacitance introduced by the test equipment will not affect the stability of the feedback loop 2. Thus, the stability of the feedback loop 2 is guaranteed, and no additional compensation circuit is required, thereby reducing the chip manufacturing cost. After measuring the output voltage VO of feedback loop 2, control module 34 compares the test output voltage VO with the target output voltage to determine the adjustment signal. Based on the adjustment signal, the corresponding fuse in fuse module 32 is blown. After the corresponding fuse F is blown, control module 34 controls switch module 33 to conduct. At this time, the effective resistance value of resistor module 31 is adjusted by adjusting the fuse L after it is blown, so that the output voltage VO of feedback loop 2 is adjusted to be the target output voltage, thus achieving precise adjustment of feedback loop 2.

[0043] Thus, before measuring the output voltage VO of the feedback loop 2, the adjustment circuit 3 in this application can control the resistor module 31 and the fuse module 32 to be disconnected. This avoids the problems of low adjustment accuracy and low feedback loop stability caused by large leakage current and parasitic capacitance during wafer testing, ensuring the measurement reliability and accuracy of the adjustment circuit 3, and consequently ensuring the adjustment reliability and accuracy of the subsequent adjustment by the adjustment circuit 3. Furthermore, the adjustment circuit 3 provided in this application ensures the stability of the feedback loop 2, thus eliminating the need for additional compensation circuits. This allows chips using this adjustment circuit 3 to be miniaturized and lightweight, while reducing chip manufacturing costs and saving on production costs.

[0044] After measuring the output voltage VO to obtain the adjustment signal, the adjustment circuit 3, in order to determine whether the output voltage VO of the feedback loop 2 after adjustment according to the adjustment signal conforms to the target output voltage, such as... Figure 8 As shown, the switch module 33 may further include a second switch S2, which is connected in parallel across the first adjustment resistor R1. The first adjustment resistor R1 is one of N adjustment resistors R1 connected to the voltage output terminal, for example, as... Figure 8 As shown, the second switch S2 can be connected in parallel across the first adjusting resistor R1a. The controlled terminal of the second switch S2 is connected to the first adjusting voltage solder joint TPa of the first fuse F1. The first fuse F1 is the fuse F connected in parallel across the first adjusting resistor R1a, and the first adjusting voltage solder joint TPa is the adjusting voltage solder joint TP connected to the voltage output terminal through the first switch S1a. When the first switch S1 is turned off and the adjustment signal is measured, and the fuse module 32 is not blown, the second switch S2 is turned on. The voltage difference between the output voltage VO of the adjusted feedback loop 2 and the target output voltage is determined according to the adjustment signal. This determines whether the output voltage VO of the adjusted feedback loop 2 conforms to the target output voltage. In this way, a pre-adjustment test can be achieved, which can simulate the change in the magnitude of the output voltage VO of the feedback loop 2 when the first fuse F1 is not blown (i.e., when the first switch S1 is turned on, causing the first adjustment resistor R1a to be short-circuited). This determines the adjustment accuracy of the adjustment circuit 3 in adjusting the output voltage VO of the feedback loop 2.

[0045] This application embodiment also provides an adjustment method, applied to the adjustment circuit 3 described in any of the above optional embodiments, such as... Figure 9 As shown, the adjustment methods may include: S101, The control module controls the switch module to turn off, thereby disconnecting the resistor module and fuse module so that the test equipment can detect the test output voltage at the voltage output terminal of the feedback loop. S102. Determine the adjustment signal based on the test output voltage and the target output voltage; S103. Deactivate the corresponding fuse in the fuse module according to the adjustment signal; S104: The control module controls the switch module to turn on. After the fuse module blows the corresponding fuse, it is used to adjust the effective resistance value of the resistor module to adjust the output voltage of the feedback loop.

[0046] The method provided in this application embodiment can achieve the effect of the above-mentioned adjustment circuit 3, which will not be described in detail here.

[0047] This application also provides a control chip, including a trimming circuit 3 of any of the above-mentioned optional methods and a feedback loop 2, wherein the feedback loop 2 can be a structure other than an LDO, and this application does not impose specific limitations on it.

[0048] This application also provides a tuning system, including the control chip, probe, and testing equipment described above, wherein the testing equipment is connected to the control chip via the probe.

[0049] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0050] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0051] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0052] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0053] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A tuning circuit for tuning the output voltage of a feedback loop, characterized in that, include: A resistor module, wherein the first end of the resistor module is connected to the voltage output terminal of the feedback loop, and the second end of the resistor module is connected to the input terminal of the feedback loop; A fuse module, which is connected to the test equipment via a probe, is used to adjust the effective resistance value of the resistor module; The switch module is connected to both the resistor module and the fuse module. as well as The control module has its output terminal connected to the controlled terminal of the switch module, and is used to output control signals to the switch module to control the on / off state of the switch module; The control module is used to control the switch module to turn off, thereby disconnecting the resistor module and the fuse module, so that the test equipment can detect the test output voltage at the voltage output terminal of the feedback loop, determine the adjustment signal based on the test output voltage and the target output voltage, and blow the corresponding fuse in the fuse module according to the adjustment signal. After the corresponding fuse is blown, the control module is also used to control the switching module to turn on, so as to adjust the effective resistance value of the resistor module and adjust the output voltage of the feedback loop.

2. The adjustment circuit according to claim 1, characterized in that, The control module includes: The control unit has an input terminal for receiving test signals; and An inverter, whose input is connected to the output of the control unit, is used to output the control signal.

3. The adjustment circuit according to claim 2, characterized in that, The control unit includes a comparator, the inverting input of which is used to receive the test signal, the non-inverting input of which is used to receive a reference voltage signal, and the output of which is connected to the input of the inverter.

4. The adjustment circuit according to claim 2, characterized in that, The input terminal of the control unit is set as a test bonding point, which is connected to the test equipment via a probe to receive the test signal input by the test equipment; The control unit further includes a first current source, one end of which is connected to the input terminal of the inverter, and the other end is grounded. When the test signal received by the test bonding joint is high, the control signal output by the control module is low. When the test bonding joint does not receive the test signal, the control signal output by the control module is high.

5. The adjustment circuit according to any one of claims 1-4, characterized in that, The resistor module includes a first resistor, a second resistor, and N adjustment resistors connected in series. The fuse module includes N fuses connected in series. The switch module includes (N+1) first switches, where N is a positive integer. The first end of each of the N adjustment resistors is connected to the voltage output terminal, and the second end is connected to the first end of the first resistor. The second end of the first resistor is connected to the first end of the second resistor and also to the input end of the feedback loop; the second end of the second resistor is grounded. Each of the fuses has two ends set as adjustment voltage solder joints, which are connected to the test equipment via probes; Each of the fuses is connected at both ends to the two ends of a trimming resistor, and (N+1) first switches are respectively disposed on each branch where the fuses are connected to the trimming resistors.

6. The adjustment circuit according to claim 5, characterized in that, The switch module also includes a second switch; The second switch is connected in parallel across the first adjustment resistor, which is one of the N adjustment resistors connected to the voltage output terminal. The controlled terminal of the second switch is connected to the first adjustment voltage solder joint of the first fuse. The first fuse is a fuse connected in parallel across the first adjustment resistor. The first adjustment voltage solder joint is an adjustment voltage solder joint connected to the voltage output terminal through the first switch. When the first switch is off and the fuse module is not blown, the second switch is on, used to determine the voltage difference between the output voltage of the adjusted feedback loop and the target output voltage based on the adjustment signal.

7. A method for adjusting settings, characterized in that, Applied to the tuning circuit as described in any one of claims 1-6, the method comprises: The control module controls the switch module to turn off, thereby breaking the circuit of the resistor module and fuse module, so that the test equipment can detect the test output voltage at the voltage output terminal of the feedback loop; The adjustment signal is determined based on the test output voltage and the target output voltage; The corresponding fuse in the fuse module is blown according to the adjustment signal; The control module controls the switch module to turn on, and after the fuse module blows the corresponding fuse, it is used to adjust the effective resistance value of the resistor module to adjust the output voltage of the feedback loop.

8. A control chip, characterized in that, Includes the tuning circuit as described in any one of claims 1-6 and the feedback loop.

9. A tuning system, characterized in that, Includes the control chip, probe, and testing equipment as described in claim 8; The testing equipment is connected to the control chip via the probe.

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