阅读说明：本技术 一种芯片振荡器温度补偿控制系统 (Temperature compensation control system of chip oscillator ) 是由 朱晖 于 2021-09-26 设计创作，主要内容包括：本发明涉及温度补偿控制,具体涉及一种芯片振荡器温度补偿控制系统,包括数字控制单元、温度传感器、校准单元、补偿单元、电流源、比较单元和振荡器电路,校准单元根据温度传感器检测信号选择合适的校准曲线发送至补偿单元,补偿单元基于校准曲线分别向电流源、比较单元发送补偿控制信号,电流源的电流信号通过调节开关发送至振荡器电路、比较单元,数字控制单元接收比较单元的输出信号,并对调节开关进行控制；本发明提供的技术方案能够有效克服现有技术所存在的振荡器输出时钟信号的频率容易受温度影响出现较大波动、进行温度补偿时需要消耗较多硬件资源的缺陷。(The invention relates to temperature compensation control, in particular to a temperature compensation control system of a chip oscillator, which comprises a digital control unit, a temperature sensor, a calibration unit, a compensation unit, a current source, a comparison unit and an oscillator circuit, wherein the calibration unit selects a proper calibration curve according to a detection signal of the temperature sensor and sends the calibration curve to the compensation unit; the technical scheme provided by the invention can effectively overcome the defects that the frequency of the clock signal output by the oscillator is easily influenced by temperature to generate larger fluctuation and more hardware resources are required to be consumed when temperature compensation is carried out in the prior art.)

1. A chip oscillator temperature compensation control system is characterized in that: including digital control unit, temperature sensor, calibration unit, compensation unit, current source, comparing unit and oscillator circuit, the calibration unit selects suitable calibration curve to send to the compensation unit according to temperature sensor detected signal, the compensation unit sends compensation control signal to current source, comparing unit respectively based on the calibration curve, the current signal of current source sends oscillator circuit, comparing unit through regulating switch, the output signal of comparing unit is received to the digital control unit to control regulating switch.

2. The chip oscillator temperature compensation control system of claim 1, wherein: the digital control unit controls the regulating switch to be alternatively opened and closed so as to control the current source to charge the oscillator circuit and supply power to the comparison unit.

3. The chip oscillator temperature compensation control system of claim 2, wherein: the compensation unit adjusts the oscillation frequency of the output signal of the comparison unit by controlling the tail current in the comparison unit.

4. The chip oscillator temperature compensation control system of claim 2, wherein: the current source comprises sub current sources with various proportions, the current source selects different sub current sources according to the compensation control signal to form a total reference current IREF, and the total reference current IREF is sent to the oscillator circuit to adjust the oscillation frequency of the oscillator circuit.

5. The chip oscillator temperature compensation control system of any one of claims 1-4, wherein: the oscillator circuit comprises a capacitor C0 and a capacitor C1.

6. The chip oscillator temperature compensation control system of claim 1, wherein: different calibration curves are stored in the calibration unit, and a proper calibration curve is selected according to input information and sent to the compensation unit.

7. The chip oscillator temperature compensation control system of claim 6, wherein: the compensation unit carries out quantitative conversion on the calibration curve and sends the result to the current source and the comparison unit for calibration and compensation.

Technical Field

The invention relates to temperature compensation control, in particular to a temperature compensation control system of a chip oscillator.

Background

The microprocessor chip typically contains 1 or more internal RC oscillator circuits for outputting oscillator clock signals of different frequencies for application to the various sub-modules of the microprocessor. The RC oscillator circuit inside a general microprocessor has the advantages: the microprocessor can conveniently obtain output clock signals with different frequencies, an external crystal oscillator is not needed, the system cost is reduced, and the system volume is saved. The disadvantages are that: the RC oscillator occupies a chip area, and the output clock signal frequency of the RC oscillator varies significantly with temperature, and without compensation, the output clock signal frequency of the RC oscillator varies with temperature by about 30%.

The control principle of the conventional RC oscillator circuit of the microprocessor chip is shown in fig. 6, and the microprocessor chip can obtain oscillator output clock signals with different frequencies by controlling the currents of I _ charge and I _ discharge, and the sizes of the capacitor C and the reference levels VH and VL.

The control method has the advantages of simple circuit, but when the temperature inside the microprocessor changes, the current of the I _ charge and the I _ discharge changes obviously, and the frequency of the output clock signal of the oscillator changes obviously. Because the range of the frequency of the oscillator output clock signal changing with the temperature is large and has no obvious regularity, more hardware resources are consumed for temperature compensation of the currents of the I _ charge and the I _ discharge.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects in the prior art, the invention provides a temperature compensation control system of a chip oscillator, which can effectively overcome the defects that the frequency of an oscillator output clock signal is easily influenced by temperature to generate larger fluctuation and more hardware resources are required to be consumed during temperature compensation in the prior art.

(II) technical scheme

In order to achieve the purpose, the invention is realized by the following technical scheme:

the utility model provides a chip oscillator temperature compensation control system, includes digital control unit, temperature sensor, calibration unit, compensation unit, current source, comparing element and oscillator circuit, the calibration unit selects suitable calibration curve to send to the compensation unit according to temperature sensor detected signal, the compensation unit sends compensation control signal to current source, comparing element respectively based on the calibration curve, the current signal of current source sends oscillator circuit, comparing element through regulating switch, the digital control unit receives comparing element's output signal to control regulating switch.

Preferably, the digital control unit is alternately opened and closed by controlling the regulating switch to control the current source to charge the oscillator circuit and supply power to the comparison unit.

Preferably, the compensation unit adjusts the oscillation frequency of the output signal of the comparison unit by controlling the magnitude of the tail current inside the comparison unit.

Preferably, the current source comprises sub-current sources with various proportions, and the current source selects different sub-current sources according to the compensation control signal to form a total reference current IREF which is sent to the oscillator circuit to adjust the oscillation frequency of the oscillator circuit.

Preferably, the oscillator circuit comprises a capacitor C0, a capacitor C1.

Preferably, different calibration curves are stored in the calibration unit, and an appropriate calibration curve is selected according to the input information and sent to the compensation unit.

Preferably, the compensation unit performs quantization conversion on the calibration curve, and sends the result to the current source and the comparison unit for calibration and compensation.

(III) advantageous effects

Compared with the prior art, the temperature compensation control system of the chip oscillator provided by the invention has the following beneficial effects:

1) the hardware resources required to be added are less when the temperature compensation is carried out, a large amount of memory and logic calculation resources are not required, compensation data are stored, logic calculation processing is carried out, and only a few internal logic circuits are required to be added;

2) the frequency fluctuation of the oscillator output clock signal after temperature compensation is extremely small along with the temperature change, and the application scene with higher requirement on the frequency stability of the oscillator can be met.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a schematic diagram of the system of the present invention;

FIG. 2 is a diagram illustrating a calibration curve stored in the calibration unit according to the present invention;

FIG. 3 is a schematic diagram of a current source according to the present invention;

FIG. 4 is a schematic diagram of a comparison unit according to the present invention;

FIG. 5 is a schematic diagram of the frequency and temperature of the output clock signal of the temperature compensated oscillator according to the present invention;

fig. 6 is a schematic diagram of a prior art RC oscillator control circuit.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

A temperature compensation control system of a chip oscillator is shown in figures 1 to 4 and comprises a digital control unit, a temperature sensor, a calibration unit, a compensation unit, a current source, a comparison unit and an oscillator circuit, wherein the calibration unit selects a proper calibration curve according to a detection signal of the temperature sensor and sends the calibration curve to the compensation unit, the compensation unit sends compensation control signals to the current source and the comparison unit respectively based on the calibration curve, a current signal of the current source is sent to the oscillator circuit and the comparison unit through an adjusting switch, and the digital control unit receives an output signal of the comparison unit and controls the adjusting switch.

As shown in fig. 2, different calibration curves are stored in the calibration unit, and an appropriate calibration curve is selected according to input information (different temperature process and voltage conditions) and sent to the compensation unit.

The compensation unit carries out quantitative conversion on the calibration curve and sends the result to the current source and the comparison unit for calibration and compensation.

The digital control unit controls the regulating switches (all the regulating switches are in three dotted line boxes in fig. 1, and a cmos switch can be adopted) to be alternately switched on and switched off so as to control the current source to charge the oscillator circuit and supply power to the comparison unit.

As shown in fig. 4, the compensation unit adjusts the oscillation frequency of the output signal of the comparison unit by controlling the magnitude of Itail tail current inside the comparison unit. For example, Itail tail current increases, the switching speed of the comparison unit increases, and the oscillation frequency of the output signal increases.

As shown in fig. 3, the current source includes sub-current sources with various ratios, and the current source selects different sub-current sources according to the compensation control signal to form a total reference current IREF to be sent to the oscillator circuit to adjust the oscillation frequency of the oscillator circuit.

In the technical scheme of the application, the oscillator circuit comprises a capacitor C0 and a capacitor C1, and the frequency of the output clock signal can be changed through the capacitor C0 and the capacitor C1. For example, the capacitance C0 and the capacitance C1 increase, and the oscillation frequency decreases. The digital control unit can respectively charge the capacitor C0 and the capacitor C1 by controlling the regulating switch to be alternatively opened and closed, so that the oscillator circuit can be ensured to normally work.

The calibration unit selects a proper calibration curve to be sent to the compensation unit through processing and calculation of a compensation function according to an output signal of a temperature sensor in the microprocessor, the compensation unit carries out quantization conversion on the calibration curve, and sends a result to the current source, the comparison unit carries out calibration and compensation, the current output from the current source to the capacitor C0 and the capacitor C1 is adjusted, and the oscillation frequency of the output signal of the comparison unit is adjusted by controlling the Itail tail current in the comparison unit, so that a stable oscillator output clock signal with extremely small fluctuation along with temperature change is obtained.

The relationship between the frequency of the oscillator output clock signal and the temperature at this time is approximated to a simple function curve shape such as a 2-order curve or a parabola as shown in fig. 5, and the difference between the frequency fluctuation range freqmax and freqmin with the temperature is small.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions.