High-precision oscillator circuit based on temperature compensation array

Abstract

The high-precision oscillator circuit based on the temperature compensation array comprises an operational amplifier OP1, a transistor MN1, a comparator array, a reference voltage setting resistor array and an oscillator module, the positive input end of the operational amplifier OP1 is connected with a band-gap reference voltage source VREF, the output end of the operational amplifier OP1 is connected with the transistor MN1, and the output end of the operational amplifier OP1 is connected with the comparator array. The inverted input end of the operational amplifier OP1 is connected with the reference voltage setting resistor array and the source electrode of the transistor MN1, the drain electrode of the transistor MN1 is connected with voltage VI N, and the reference voltage setting resistor array is formed by connecting a plurality of resistors in series. According to the utility model, the positive temperature coefficient resistor and the negative temperature coefficient resistor are cooperatively used, the temperature detection array is combined, the two temperature coefficients are adjusted, the whole temperature coefficient is compensated, and the zero temperature coefficient characteristic is theoretically realized, so that the low temperature drift characteristic is obtained.

Description

Technical Field

[0001] This utility model relates to the field of oscillator technology, and in particular to a high-precision oscillator circuit based on a temperature compensation array. Background Technology

[0002] The output frequency accuracy of an oscillator affects the functionality and performance of various modules in a system, thus significantly impacting equipment use. In current designs, the effects of input voltage variations and temperature variations on frequency accuracy are two major considerations. This patented technology corrects for the impact of temperature variations by employing an array-based compensation method to achieve high-precision frequency characteristics, making the oscillator output frequency insensitive to temperature changes. The array design allows for more finely segmented temperature zones; theoretically, with a sufficiently large and numerous array, temperature compensation can approach linearity, achieving theoretically zero temperature drift. In practical designs, complexity and cost factors are considered to determine an appropriate array size. Utility Model Content

[0003] In order to overcome the shortcomings of the prior art, this application proposes a high-precision oscillator circuit based on a temperature compensation array to solve the problems existing in the prior art.

[0004] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0005] A high-precision oscillator circuit based on a temperature-compensated array includes an operational amplifier OP1, a transistor MN1, a comparator array, a reference voltage setting resistor array, and an oscillator module. The non-inverting input of the operational amplifier OP1 is connected to a bandgap reference voltage source VREF, the output of the operational amplifier OP1 is connected to the transistor MN1, the inverting input of the operational amplifier OP1 is connected to the reference voltage setting resistor array and the source of the transistor MN1, and the drain of the transistor MN1 is connected to voltage VI. N, the reference voltage setting resistor array is composed of multiple resistors connected in series, the voltages collected between two adjacent resistors are VR1-VRn respectively, VR1-VRn are the positive input signals of N comparators in the comparator array, the negative input signals of N comparators are the voltage V_Temp obtained by the temperature detection module, the output terminals of N comparators are all connected to corresponding MOSFETs, some of the MOSFETs are connected in parallel with the positive temperature system resistor array, and the other part of the MOSFETs are connected in parallel with the negative temperature system resistor array. Both the positive temperature system resistor array and the negative temperature system resistor array are composed of multiple resistors connected in series, the source and drain of each MOSFET are connected to the two ends of a resistor, one end of the positive temperature system resistor array is connected to the oscillator module, the other end of the positive temperature system resistor array is connected to the negative temperature system resistor array, and the other end of the negative temperature system resistor array is grounded.

[0006] As a further technical solution of this utility model: the operational amplifier OP1 is model OP07.

[0007] As a further technical solution of this utility model: the transistor MN1 is a MOSFET.

[0008] As a further technical solution of this utility model: the resistors in the voltage sampling resistor array have the same resistance value.

[0009] As a further technical solution of this utility model: the resistance values ​​in the resistor array of the positive temperature system are the same.

[0010] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0011] 1. By using a combination of positive temperature coefficient resistors and negative temperature coefficient resistors, along with a temperature detection array, the two temperature coefficients are adjusted to compensate for the overall temperature coefficient, theoretically achieving zero temperature coefficient characteristics and thus obtaining low temperature drift characteristics.

[0012] 2. A compatible design is adopted, allowing the temperature compensation array to be implemented using either the internal temperature detection circuitry of the chip or an external thermistor. Internal detection offers lower cost and higher integration, while external detection provides higher accuracy and greater flexibility. Attached Figure Description

[0013] Figure 1 This is an overall structural diagram of the present invention. Detailed Implementation

[0014] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0015] like Figure 1As shown, a high-precision oscillator circuit based on a temperature-compensated array includes an operational amplifier OP1, a transistor MN1, a comparator array, a reference voltage setting resistor array, and an oscillator module. The positive input terminal of the operational amplifier OP1 is connected to a bandgap reference voltage source VREF, the output terminal of the operational amplifier OP1 is connected to the transistor MN1, the inverting input terminal of the operational amplifier OP1 is connected to the reference voltage setting resistor array and the source of the transistor MN1, and the drain of the transistor MN1 is connected to voltage VI. N, the reference voltage setting resistor array is composed of multiple resistors connected in series, the voltages collected between two adjacent resistors are VR1-VRn respectively, VR1-VRn are the positive input signals of N comparators in the comparator array, the negative input signals of N comparators are the voltage V_Temp obtained by the temperature detection module, the output terminals of N comparators are all connected to corresponding MOSFETs, some of the MOSFETs are connected in parallel with the positive temperature system resistor array, and the other part of the MOSFETs are connected in parallel with the negative temperature system resistor array. Both the positive temperature system resistor array and the negative temperature system resistor array are composed of multiple resistors connected in series, the source and drain of each MOSFET are connected to the two ends of a resistor, one end of the positive temperature system resistor array is connected to the oscillator module, the other end of the positive temperature system resistor array is connected to the negative temperature system resistor array, and the other end of the negative temperature system resistor array is grounded.

[0016] The working principle is as follows:

[0017] The circuit structure is mainly divided into three parts:

[0018] (1) Reference voltage array generation circuit:

[0019] VREF is a bandgap reference voltage source that provides a precise reference voltage. A source follower array of reference voltages, VR1, VR2, VR3...VRn, is generated by using operational amplifiers OP1 and MN1 and resistors.

[0020] The reference voltage does not change with the operating voltage, and its accuracy is limited by the accuracy of VREF itself and the accuracy of the resistor connected in series with MN1.

[0021] (2) Temperature comparator array:

[0022] The reference voltage array generated in (1) above is compared with the voltage V_Temp obtained by the temperature detection module. The comparator array compares the V_Temp voltage obtained at different temperatures with the reference voltage and outputs the comparison result (CTRL1, CTRL2...CTRLn) as high level or low level.

[0023] (3) Temperature coefficient compensation of resistance of oscillator module:

[0024] This module uses both positive and negative temperature coefficient resistors in combination. The control signal CTRLn generated in (2) above controls the MOSFET switch. When the MOSFET is turned on, the resistor connected in parallel with it is short-circuited, and the resistor corresponding to the temperature coefficient will increase or decrease. This achieves temperature compensation of the overall equivalent resistance R (including the positive and negative temperature coefficient resistors).

[0025] In summary, when the array of components (1), (2), and (3) is large enough, the temperature compensation effect can be sufficiently refined and accurate. In practical design, factors such as design requirements and cost constraints should be considered.

[0026] This invention employs a design that combines built-in and external components. The overall compensation design utilizes a multi-mode fusion technology: (1) a temperature-independent reference voltage to reduce the impact of voltage variations on the oscillator frequency; (2) a combination of positive and negative temperature coefficient resistors for temperature coarsening compensation; and (3) a temperature detection and comparator array to control compensation switching. Combining these methods yields superior performance and allows for flexible cost control by tailoring the design to specific requirements.

[0027] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention.

[0028] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment have been appropriately combined to form other embodiments that are easy for those skilled in the art to understand.

Claims

1. A high-precision oscillator circuit based on a temperature-compensated array, comprising an operational amplifier OP1, a transistor MN1, a comparator array, a reference voltage setting resistor array, and an oscillator module, characterized in that: The positive input terminal of the operational amplifier OP1 is connected to the bandgap reference voltage source VREF, and the output terminal of the operational amplifier OP1 is connected to the transistor MN1. The inverting input terminal of the operational amplifier OP1 is connected to the reference voltage setting resistor array and the source of the transistor MN1. The drain of the transistor MN1 is connected to the voltage VIN. The reference voltage setting resistor array is composed of multiple resistors connected in series. The voltages sampled between two adjacent resistors are VR1-VRn, which serve as the positive input signals of N comparators in the comparator array. The inverting input signals of the N comparators are the voltage V_Temp obtained by the temperature detection module. The output terminals of the N comparators are all connected to corresponding MOSFETs. Some of the MOSFETs are connected in parallel with the positive temperature system resistor array, and the other part of the MOSFETs are connected in parallel with the negative temperature system resistor array. Both the positive temperature system resistor array and the negative temperature system resistor array are composed of multiple resistors connected in series. The source and drain of each MOSFET are connected to the two ends of a resistor. One end of the positive temperature system resistor array is connected to the oscillator module, and the other end of the positive temperature system resistor array is connected to the negative temperature system resistor array. The other end of the negative temperature system resistor array is grounded.

2. The high-precision oscillator circuit based on a temperature-compensated array according to claim 1, characterized in that, The operational amplifier OP1 is model OP07.

3. The high-precision oscillator circuit based on a temperature-compensated array according to claim 1, characterized in that, The transistor MN1 is a MOSFET.

4. A high-precision oscillator circuit based on a temperature-compensated array according to claim 1, characterized in that, The resistors in the voltage sampling resistor array have the same resistance value.

5. A high-precision oscillator circuit based on a temperature-compensated array according to claim 4, characterized in that, The resistors in the positive temperature system resistor array have the same resistance value.

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