CN-122026847-A - Zero-temperature drift resistance circuit and trimming method

CN122026847ACN 122026847 ACN122026847 ACN 122026847ACN-122026847-A

Abstract

The invention discloses a zero-temperature drift resistance circuit and a trimming method, relates to the technical field of integrated circuits, and aims to solve the problem that a resistance circuit in the prior art cannot realize low resistance, zero-temperature drift, high precision and reduced occupied area at the same time. The circuit comprises a main resistance network, a first trimming resistance network and a second trimming resistance network, wherein the main resistance network is connected with the first trimming resistance network in parallel and then is connected with the second trimming resistance network in series, the trimming precision of the first trimming resistance network is smaller than that of the second trimming resistance network, trimming resistance units in the main resistance network and the first trimming resistance network are zero temperature coefficient resistance units, so that the main resistance network, the first trimming resistance network and the second trimming resistance network can be utilized for carrying out step-by-step trimming to obtain a resistance value which is suitable for a target resistance and then output, and the chip occupation area is reduced while the low resistance value, zero temperature drift and high precision are realized.

Inventors

DAI ZHIMING
GUO GUILIANG

Assignees

北京中科银河芯科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260123

Claims (10)

1. A zero temperature drift resistance circuit, comprising: The system comprises a main resistance network, a first trimming resistance network and a second trimming resistance network; The trimming precision of the first trimming resistor network is smaller than that of the second trimming resistor network, and trimming resistor units in the main resistor network and the first trimming resistor network are zero temperature coefficient resistor units; The main resistance network is used for carrying out resistance networking of first trimming precision according to the target resistance value to obtain a first resistance value; the first trimming resistor network is used for performing resistor networking with second trimming precision according to the difference value between the target resistance value and the first resistance value to obtain a second resistance value; The second trimming resistor network is used for carrying out resistor networking with third trimming precision according to the difference value between the target resistance value and the second resistance value to obtain a third resistance value, and the third resistance value is used as an output resistance value of the zero-temperature drift resistance value circuit.
2. The zero temperature drift resistance circuit according to claim 1, wherein said main resistor network comprises a plurality of first-type trimming resistor units, wherein said plurality of first-type trimming resistor units comprises a positive temperature coefficient resistor and a negative temperature coefficient resistor; One end of the positive temperature coefficient resistor is connected with the first terminal, the other end of the positive temperature coefficient resistor is connected with one end of the negative temperature coefficient resistor, and one end of the negative temperature coefficient resistor, which is not connected with the positive temperature coefficient resistor, is connected with the second terminal.
3. The zero temperature drift resistance circuit of claim 1, wherein the first trimming resistor network comprises at least a second trimming resistor unit, a third trimming resistor unit and a plurality of first trimming resistor units; the first type trimming resistor units comprise a positive temperature coefficient resistor and a negative temperature coefficient resistor, wherein the positive temperature coefficient resistor and the negative temperature coefficient resistor are connected in series to form the first type trimming resistor units, one end of each first type trimming resistor unit is connected with one end of a first laser fuse, and the other end of each first type trimming resistor unit is connected with a second terminal; The second type trimming resistor unit comprises two positive temperature coefficient resistors and two negative temperature coefficient resistors; the second type trimming resistor unit is obtained by respectively connecting two positive temperature coefficient resistors and two negative temperature coefficient resistors in series and then connecting the two positive temperature coefficient resistors and the two negative temperature coefficient resistors in series, wherein one end of the second type trimming resistor unit is connected with one end of a second laser fuse, and the other end of the second type trimming resistor unit is connected with a second terminal; The third type trimming resistor unit comprises four positive temperature coefficient resistors and four negative temperature coefficient resistors, the four positive temperature coefficient resistors and the four negative temperature coefficient resistors are connected in series respectively and then connected in series to obtain the third type trimming resistor unit, one end of the third type trimming resistor unit is connected with one end of a third laser fuse, the other end of the third type trimming resistor unit is connected with a second terminal, and one end of the third laser fuse, which is not connected with the third type trimming resistor unit, is connected with a first terminal.
4. The zero temperature drift resistance circuit of claim 3, wherein the second type of trimming resistor unit has a resistance twice the resistance of the first type of trimming resistor unit and the third type of trimming resistor unit has a resistance four times the resistance of the first type of trimming resistor unit.
5. The zero temperature drift resistance circuit of claim 1, wherein the second trimming resistor network comprises at least a first target trimming resistor unit, a second target trimming resistor unit, and a third target trimming resistor unit; the first target trimming resistor unit is connected with the fourth laser fuse in parallel, the second target trimming resistor unit is connected with the fifth laser fuse in parallel, the third target trimming resistor unit is connected with the sixth laser fuse in parallel, and then the second trimming resistor network is formed by sequentially connecting the third target trimming resistor unit and the sixth laser fuse in series; one end of the second trimming resistor network is connected with the second terminal, and the other end of the second trimming resistor network is connected with the third terminal.
6. The zero temperature drift resistance circuit of claim 5, wherein the second target trim resistance unit resistance value is twice the first target trim resistance unit resistance value and the third target trim resistance unit resistance value is four times the first target trim resistance unit resistance value.
7. A method for trimming a zero temperature drift resistance circuit, wherein the method for trimming a zero temperature drift resistance circuit is applied to the zero temperature drift resistance circuit according to any one of claims 1 to 6, and comprises the steps of: obtaining a target resistance value; performing resistor networking with first trimming precision according to the target resistance value by using a main resistor network to obtain a first resistance value; Performing resistor networking with second trimming precision by using a first trimming resistor network according to the difference value between the target resistance value and the first resistance value to obtain a second resistance value; Performing resistor networking with third trimming precision by using a second trimming resistor network according to the difference value between the target resistor value and the second resistor value to obtain a third resistor value, wherein the trimming precision of the first trimming resistor network is smaller than that of the second trimming resistor network; and taking the third resistance value as an output resistance value of the zero temperature drift resistance value circuit.
8. The trimming method of the zero-temperature drift resistance circuit according to claim 7, wherein after the obtaining the target resistance value, before the resistor networking with the first trimming precision according to the target resistance value by using the main resistor network, the trimming method comprises: The method comprises the steps of determining networking parameters of a main resistance network, a first trimming resistance network and a second trimming resistance network, wherein the networking parameters at least comprise the number of first trimming resistance units in the main resistance network, the number of first trimming resistance units, the number of second to K trimming resistance units in the first trimming resistance network and the number of first to L target trimming resistance units in the second trimming resistance network, wherein K and L are positive integers which are more than or equal to 3; And networking the first trimming resistor network, the second trimming resistor network and the third trimming resistor network based on networking parameters of the main resistor network, the first trimming resistor network and the second trimming resistor network to obtain the zero-temperature drift resistance circuit.
9. The method for trimming a zero temperature drift resistance according to claim 8, wherein after said obtaining said zero temperature drift resistance comprises: Determining trimming values of a plurality of first-type trimming resistor units in a main resistor network; determining trimming values of a plurality of first-class trimming resistor units in a first trimming resistor network and trimming values of second-class to K-class trimming resistor units; determining trimming values from the first target trimming resistor unit to the L target trimming resistor unit in the second trimming resistor network; and trimming the zero-temperature drift resistance circuit based on trimming values of a plurality of first-class trimming resistance units in the main resistance network, trimming values of a plurality of first-class trimming resistance units in the first trimming resistance network, trimming values of second-class to K-class trimming resistance units and trimming values of first-target trimming resistance units to L-target trimming resistance units in the second trimming resistance network to obtain an output resistance value for the zero-temperature drift resistance circuit.
10. The trimming method of the zero temperature drift resistance circuit according to claim 9, wherein in the second trimming resistance network, the resistance value of the L-th target trimming resistance unit is 2 times of the resistance value of the L-1-th target trimming resistance unit.

Description

Zero-temperature drift resistance circuit and trimming method Technical Field The invention relates to the technical field of integrated circuits, in particular to a zero-temperature drift resistance circuit and a trimming method. Background In analog integrated circuit designs, high precision resistors are the core element of many critical circuits. To achieve accurate circuit function, the resistor needs to have not only an accurate absolute resistance, which is able to resist deviations from different process corners, but also a low temperature drift coefficient (Temperature coefficient, TC). For example, in high voltage processes, achieving the above requirements presents a serious challenge, and high resistance limits, devices under high voltage processes are large in size, their intrinsic resistance is typically high, and it is difficult to directly achieve low resistance (e.g., below 1kΩ) resistors. Temperature drift-a single type of resistor typically has a large positive or negative temperature coefficient, making it difficult to meet zero temperature drift requirements. Process variations-process angle fluctuations during the manufacturing process can cause significant variations in the absolute value of the resistance (e.g., ±30%), which makes it extremely difficult to obtain accurate resistance values by the design itself. The trimming dilemma is that the trimming circuit taking the traditional MOS tube as the switch causes huge area cost under the high-voltage process because the MOS tube has larger size than the low-voltage process. Conventional laser trimming is to cut a single resistor to increase the resistance (incremental trimming), or to use a series fuse. The traditional MOS tube is not suitable for the scene that the resistance value is required to be accurately adjusted by reducing, and the traditional laser trimming faces the contradiction between the area and the precision when the low resistance value is realized, so that the resistance value circuit cannot realize the low resistance value, zero temperature drift and high precision at the same time, and the problem that the occupied chip area is small, and the actual requirement of the high-precision resistor in the design of an analog integrated circuit cannot be met. In view of this, a more advanced resistance circuit is needed to solve the problem that the conventional resistance circuit cannot realize low resistance, zero temperature drift, high precision and reduced occupied area at the same time. Disclosure of Invention The invention aims to provide a zero-temperature drift resistance circuit and a trimming method, which are used for solving the problems that the resistance circuit in the prior art cannot realize low resistance, zero-temperature drift, high precision and reduced occupied area at the same time. In order to achieve the above object, the present invention provides the following technical solutions: In a first aspect, the present invention provides a zero temperature drift resistance circuit, which may include: The system comprises a main resistance network, a first trimming resistance network and a second trimming resistance network; The trimming precision of the first trimming resistor network is smaller than that of the second trimming resistor network, and trimming resistor units in the main resistor network and the first trimming resistor network are zero temperature coefficient resistor units; The main resistance network is used for carrying out resistance networking of first trimming precision according to the target resistance value to obtain a first resistance value; the first trimming resistor network is used for performing resistor networking with second trimming precision according to the difference value between the target resistance value and the first resistance value to obtain a second resistance value; The second trimming resistor network is used for carrying out resistor networking with third trimming precision according to the difference value between the target resistance value and the second resistance value to obtain a third resistance value, and the third resistance value is used as an output resistance value of the zero-temperature drift resistance value circuit. Preferably, the main resistor network comprises a plurality of first type trimming resistor units, wherein the first type trimming resistor units comprise a positive temperature coefficient resistor and a negative temperature coefficient resistor; One end of the positive temperature coefficient resistor is connected with the first terminal, the other end of the positive temperature coefficient resistor is connected with one end of the negative temperature coefficient resistor, and one end of the negative temperature coefficient resistor, which is not connected with the positive temperature coefficient resistor, is connected with the second terminal. Preferably, the first trimming resistor network at least comprises a second trimmi