CN215576335U - Trimming circuit and integrated circuit - Google Patents

Abstract

The application provides a trimming circuit and integrated circuit, trimming circuit includes: a bandgap reference module for generating an internal reference voltage; the positive input end of the comparator module is connected with the output end of the band-gap reference module, and the negative input end of the comparator module inputs external standard voltage; the logic judgment module is connected with the test signal, and the output end of the comparator module is connected with the logic judgment module; the logic judgment module is used for judging whether the internal reference voltage currently output by the band gap reference module is the target reference voltage according to the output result of the comparator module and outputting a logic control signal according to the judgment result; and the trimming and burning module is respectively connected with the output end of the logic judgment module and the band gap reference module and is used for generating a trimming signal according to the logic control signal so as to control the band gap reference module to automatically adjust the currently output internal reference voltage. The problem that the finished product yield can be reduced in the trimming mode of the conventional integrated circuit is solved.

Description

Trimming circuit and integrated circuit

Technical Field

The present disclosure relates to integrated circuits, and particularly to a trimming circuit and an integrated circuit.

Background

In the production of integrated circuits, there is usually a problem of chip-to-chip variation, and in order to ensure the product yield, the chips need to be tested and repaired. At present, in a finished product test, two ports are usually needed, one port is filled with a clock signal, the other port is filled with a trimming signal, the trimming signal is used for carrying out a finished product parameter test on a chip, a trimming logic value is calculated according to the comparison between the tested value and an actual required value, the chip is filled with the trimming signal, and the chip is trimmed through an internal trimming circuit.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides a trimming circuit and an integrated circuit, and solves the problem that the finished product yield is reduced by the trimming mode of the conventional integrated circuit.

The present invention is achieved as such, and a trimming circuit includes:

a bandgap reference module for generating an internal reference voltage;

the positive input end of the comparator module is connected with the output end of the band-gap reference module, and the negative input end of the comparator module inputs external standard voltage;

the logic judgment module is connected with a test signal, and the output end of the comparator module is connected with the logic judgment module;

the logic judgment module is used for judging whether the internal reference voltage currently output by the band gap reference module is a target reference voltage according to the output result of the comparator module and outputting a logic control signal according to the judgment result;

and the trimming and burning module is respectively connected with the output end of the logic judgment module and the band-gap reference module, and is used for generating a trimming signal according to the logic control signal so as to control the band-gap reference module to automatically adjust the currently output internal reference voltage.

According to the trimming circuit provided by the embodiment of the application, the internal reference voltage output by the band gap reference module enters the comparator module, the comparator module compares the internal reference voltage with the external standard voltage, the logic judgment module judges whether the output result of the comparator module is a high level or a low level, judges whether the current internal reference voltage is a target reference voltage, obtains a logic control signal, and the trimming and burning module generates a trimming signal according to the logic control signal to control the current output internal reference voltage to be adjusted; this application only need insert test signal all the way and can get into the maintenance mode, and accomplish the maintenance of inside reference voltage automatically, has removed traditional finished product test step from to can repair the regulation after circuit package, very big improvement the finished product yield.

In one embodiment, the test signal is a clock signal.

In one embodiment, the logic judgment module includes a plurality of shift registers connected in series, and the clock signal is connected to the shift registers.

In one embodiment, the trimming burning module comprises a fuse, and the band-gap reference module comprises a variable trimming resistor;

and the trimming signal output by the trimming and burning module is used for controlling the fuse to be blown or adjusting the resistance value of the variable trimming resistor, so that the internal reference voltage currently output by the band-gap reference module is adjusted.

In one embodiment, the number of adjustable gears of the internal reference voltage output by the bandgap reference module is equal to the number of the shift registers.

In one embodiment, during the trimming process, the internal reference voltages output by the bandgap reference module increase sequentially from the minimum value.

In one embodiment, the trimming circuit further comprises a sampling voltage dividing module, the sampling voltage dividing module is used for generating an external standard voltage, and the sampling voltage dividing module is connected with the negative input end of the comparator module.

In one embodiment, the logic judgment module comprises a plurality of shift registers and oscillators connected in series, and the oscillators are connected with the shift registers;

the test signal is connected to the oscillator, and the oscillator is used for generating a clock signal.

An embodiment of the present application further provides an integrated circuit, including the trimming circuit according to any of the above embodiments.

The application provides a trimming circuit and integrated circuit's beneficial effect lies in: according to the method, the middle test step is directly skipped, the test and the trimming can be carried out after the circuit is packaged, and the trimming function can be automatically realized only by injecting a test signal through one pin, so that the product development period is shortened, and the yield of finished products is improved; the number of pins needed is reduced, and the method is also suitable for products with few pins.

Drawings

Fig. 1 is a block diagram of a trimming circuit according to an embodiment of the present disclosure.

Fig. 2 is a schematic circuit diagram of a comparator module, a bandgap reference module, and a sampling voltage-dividing module of the trimming circuit according to an embodiment of the present disclosure.

Fig. 3 is a schematic circuit diagram of a logic determining module and a trimming writing module of a trimming circuit according to an embodiment of the present disclosure.

Fig. 4 is a circuit diagram of a logic determination module and a trimming programming module including three shift registers connected in series according to an embodiment of the present disclosure.

Fig. 5 is a block diagram of a trimming circuit according to a second embodiment of the present disclosure.

Reference numerals: 10. a band gap reference module; 11. a variable trimming resistor;

20. a comparator module;

30. a logic judgment module; 31. a shift register; 32. an oscillator;

40. modifying and debugging the burning module; 41. a fuse;

50. and a sampling voltage division module.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model.

The embodiment of the application provides a trimming circuit, which solves the problem that the finished product yield is reduced in the trimming mode of the conventional integrated circuit.

Example one

Referring to fig. 1-2, a trimming circuit provided in an embodiment of the present application includes a bandgap reference module 10, where the bandgap reference module 10 is configured to generate an internal reference voltage; a positive input end of the comparator module 20 is connected with an output end of the bandgap reference module 10, and a negative input end of the comparator module 20 inputs an external standard voltage; the logic judgment module 30, the logic judgment module 30 accesses the test signal, and the output end of the comparator module 20 is connected with the logic judgment module 30; the logic judgment module 30 is configured to judge whether the internal reference voltage currently output by the bandgap reference module 10 is the target reference voltage according to the output result of the comparator module 20, and output a logic control signal according to the judgment result; and the trimming and burning module 40, the trimming and burning module 40 is respectively connected with the output end of the logic judgment module 30 and the band-gap reference module 10, and the trimming and burning module 40 is used for generating a trimming signal according to the logic control signal so as to control the band-gap reference module 10 to automatically adjust the currently output internal reference voltage.

According to the trimming circuit provided by the embodiment of the application, the internal reference voltage output by the bandgap reference module 10 enters the comparator module 20, the comparator module 20 compares the internal reference voltage with the external standard voltage, the logic judgment module 30 judges whether the output result of the comparator module 20 is a high level or a low level, and then judges whether the current internal reference voltage is a target reference voltage, so as to obtain a logic control signal, and the trimming and burning module 40 generates a trimming signal according to the logic control signal to control the currently output internal reference voltage to be adjusted; this application only need insert test signal all the way and can get into the maintenance mode, and accomplish the maintenance of inside reference voltage automatically, has removed traditional finished product test step from to can repair the regulation after circuit package, very big improvement the finished product yield.

The test signal is a clock signal. A Clock Signal (CLK) is the basis of sequential logic, which is a Signal quantity having a fixed period and being independent of operation, and is used to determine when the state in the logic unit is updated. The clock signal CLK is connected to the logic determination module 30, so that the logic determination module 30 enters the next state after determining that the current internal reference voltage is not the target reference voltage, that is, the current internal reference voltage is adjusted, and the logic determination module 30 determines whether the adjusted internal reference voltage is the target reference voltage again, so that the internal reference voltages of all the gears can be automatically traversed, and the automatic trimming function is realized.

Optionally, the logic determining module 30 includes a plurality of shift registers 31 connected in series, and the clock signal is connected to the shift registers 31.

In digital circuits, the circuitry used to store binary data or codes is called a register. The data in the shift register can be shifted to the right or left bit by bit in sequence under the action of shift pulses, and the data can be input in parallel and output in parallel, can be input in series and output in series, can be input in parallel and output in series, and can be input in series and output in parallel, so that the method is very flexible and has wide application. The shift register 31 can not only register data, but also shift the data therein to the left or right in sequence under the action of a clock signal. The setting of the shift register 31 can make the logic judgment module 30 sequentially reach the values traversing all the gears of the internal reference voltage from small to small, thereby automatically trimming the internal reference voltage.

It can be understood that the number of adjustable steps of the internal reference voltage output by the bandgap reference module 10 is equal to the number of the shift registers 31. The shift registers 31 are provided with a plurality of circuits, each shift register 31 is connected to the trimming and burning module 40, the formed circuits correspond to the logic determination module 30 for determining whether the internal reference voltages at different gears are the target reference voltages, and the shift registers 31 are sequentially triggered, that is, the logic determination module 30 sequentially determines whether the internal reference voltages at different gears are the target reference voltages. Referring to fig. 4, three shift registers 31 are provided, and three shift registers 31 are connected in series, each shift register 31 is connected to the trimming and burning module 40, in fig. 4, the clock signal CLK and the signal VOC output by the comparator module 20 are input to the logic determination module 30, the shift registers 31 output the signal PT, the logic determination module 30 generates the logic control signal Trim, the PT signal and the Trim signal Trim are input to the trimming and burning module 40 to generate the trimming signal Tx, exemplarily, three shift registers 31 in fig. 4 output the signals PT1, PT2 and PT3 respectively, only one output signal of the shift register 31 is input to the trimming and burning module 40 at a time, the trimming and burning module 40 generates the trimming signals Tx1, Tx2 and Tx3 respectively, so that the internal reference voltage of each tap can be independently determined, and when the internal reference voltage of a tap is the target reference voltage, the internal reference voltage can be kept constant, not disturbed by powering up and down or any other state.

Referring to fig. 3, the trimming burning module 40 includes a fuse 41, and the bandgap reference module 10 includes a variable trimming resistor 11; the trimming signal output by the trimming burning module 40 is used to control the blown fuse 41 or to adjust the resistance of the variable trimming resistor 11, so that the internal reference voltage currently output by the bandgap reference module 10 is adjusted.

Through the above arrangement, when the logic determination module 30 determines that the output signal VOC of the comparator module 20 is at a high level, which indicates that the current internal reference voltage is the target reference voltage, the trimming and programming module 40 will control the fuse 41 to be blown, so as to fix the internal reference voltage output by the bandgap reference module 10 as the target reference voltage, and complete trimming; when the logic determination module 30 determines that the output signal VOC of the comparator module 20 is at a low level, it indicates that the current internal reference voltage is not the target reference voltage, the trimming and burning module 40 will output the trimming signal Tx to control the variable trimming resistor 11 to change, so as to change the value of the internal reference voltage output by the bandgap reference module 10, and then the logic determination module 30 determines whether the adjusted internal reference voltage is the target reference voltage again, repeats the above steps until the target reference voltage is found, and then blows the fuse 41, fixes the internal reference voltage output by the bandgap reference module 10 as the target reference voltage, and completes trimming; the whole trimming process can be automatically completed in the circuit, and the development period of the product is greatly shortened.

Optionally, in the trimming process, the internal reference voltages output by the bandgap reference module 10 sequentially increase from the minimum value.

Through the above arrangement, when the trimming is started, the value of the internal reference voltage output by the bandgap reference module 10 for the first time is the internal reference voltage of the minimum gear output by the bandgap reference module 10, and the trimming process in this embodiment can be divided into three types, which are respectively: when the trimming is started, after the band gap reference module 10 outputs the internal reference voltage for the first time, the output signal VOC of the comparator module 20 is at a high level, which indicates that the current internal reference voltage is the target reference voltage, and the trimming and burning module 40 will control the fuse 41 to burn out, so that the internal reference voltage output by the band gap reference module 10 is fixed as the target reference voltage, and the trimming is completed. When trimming is started, after the bandgap reference module 10 outputs the internal reference voltage for the first time, the output signal VOC of the comparator module 20 is at a low level, which indicates that the current internal reference voltage is not the target reference voltage, the trimming and burning module 40 will control the variable trimming resistor 11 to change, so as to change the value of the internal reference voltage output by the bandgap reference module 10, the logic determination module 30 will jump to the next state to continue to determine, and thus the logic is traversed and repeated until the output signal VOC of the comparator module 20 changes from the low level to the high level, which is output to the trimming and burning module 40 after being determined by the logic determination module 30, the trimming and burning module 40 burns out the corresponding fuse 41, and keeps the current internal reference voltage fixed to the bandgap reference module 10, and the trimming operation is completed. After traversing the internal reference voltages of all the gears output by the bandgap reference module 10, the output signal VOC of the comparator module 20 is still at a low level, at this time, the internal reference voltage of the maximum gear output by the bandgap reference module 10 is determined as the target reference voltage, the fuse 41 is blown, and the internal reference voltage output by the bandgap reference module 10 is fixed as the internal reference voltage of the maximum gear, thereby completing trimming.

Referring to fig. 1-2, the trimming circuit further includes a sampling voltage-dividing module 50, the sampling voltage-dividing module 50 is used for generating an external standard voltage, and the sampling voltage-dividing module 50 is connected to the negative input terminal of the comparator module 20.

The sampling voltage-dividing module 50 includes two resistors connected in series, one of the resistors is connected to a power supply, the other resistor is grounded, the negative input end of the comparator module 20 is connected to a connecting line between the two resistors, and the voltage input by the negative input end of the comparator module 20 can be changed by changing the resistance value of the resistor, so that the value of the internal reference voltage input by the positive input end of the comparator module 20 when the output signal VOC of the comparator module 20 is at a high level is changed, and the sampling voltage-dividing module can be suitable for trimming different products.

Example two

Referring to fig. 5, the logic determining module 30 includes several shift registers 31 and oscillators 32 connected in series, and the oscillators 32 are connected to the shift registers 31; the test signal is coupled to an oscillator 32, the oscillator 32 being arranged to generate a clock signal CLK.

In the second embodiment, the oscillator 32 is arranged in the logic determination module 30, a clock signal can be generated by the oscillator 32, but an external test signal needs to be provided to trigger the oscillator 32, the test signal can be a voltage signal, and the test signal can be accessed from a multiplexing pin of a product, so that the number of pins to be arranged is greatly reduced, and the trimming circuit of the second embodiment is more suitable for the product application with fewer pins.

EXAMPLE III

A third embodiment of the present application provides an integrated circuit, including the trimming circuit in any of the above embodiments.

The integrated circuit of the third embodiment of the application adopts the trimming circuit, so that the testing and trimming can be carried out after the integrated circuit is packaged, the middle testing step is directly skipped, and the trimming function can be automatically realized only by injecting a test signal through one pin, thereby shortening the product development period and improving the yield of finished products; the number of pins needed is reduced, and the method is also suitable for products with few pins.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (9)

1. A trimming circuit, comprising:

a bandgap reference module (10), the bandgap reference module (10) being configured to generate an internal reference voltage;

a positive input end of the comparator module (20) is connected with the output end of the bandgap reference module (10), and an external standard voltage is input to a negative input end of the comparator module (20);

the logic judgment module (30), the logic judgment module (30) accesses the test signal, and the output end of the comparator module (20) is connected with the logic judgment module (30);

the logic judgment module (30) is used for judging whether the internal reference voltage currently output by the band gap reference module (10) is a target reference voltage according to the output result of the comparator module (20), and outputting a logic control signal according to the judgment result;

the trimming and burning module (40) is respectively connected with the output end of the logic judgment module (30) and the band-gap reference module (10), and the trimming and burning module (40) is used for generating a trimming signal according to the logic control signal so as to control the band-gap reference module (10) to automatically adjust the currently output internal reference voltage.

2. The trimming circuit of claim 1, wherein the test signal is a clock signal.

3. Trimming circuit according to claim 2, characterized in that the logic decision module (30) comprises a number of shift registers (31) connected in series, the clock signal being coupled into the shift registers (31).

4. The trimming circuit according to claim 3, wherein the trimming burning module (40) comprises a fuse (41), and the bandgap reference module (10) comprises a variable trimming resistor (11);

the trimming signal output by the trimming and burning module (40) is used for controlling to blow the fuse (41) or adjusting the resistance value of the variable trimming resistor (11), so that the internal reference voltage currently output by the band-gap reference module (10) is adjusted.

5. The trimming circuit according to claim 3 or 4, wherein the number of adjustable steps of the internal reference voltage outputted by the bandgap reference module (10) is equal to the number of the shift registers (31).

6. The trimming circuit according to any one of claims 1 to 4, characterized in that during trimming, the internal reference voltage output by the bandgap reference module (10) increases sequentially from a minimum value.

7. The trimming circuit according to claim 6, further comprising a sampling voltage dividing module (50), wherein the sampling voltage dividing module (50) is configured to generate an external standard voltage, and the sampling voltage dividing module (50) is connected to a negative input terminal of the comparator module (20).

8. The trimming circuit according to claim 1, wherein the logic judgment module (30) comprises a plurality of shift registers (31) connected in series and an oscillator (32), the oscillator (32) is connected with the shift registers (31);

the test signal is coupled to the oscillator (32), and the oscillator (32) is used for generating a clock signal.

9. An integrated circuit comprising the trimming circuit of any one of claims 1-8.

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