阅读说明：本技术 一种数字示波器和用于数字示波器的增益自校正方法 (Digital oscilloscope and gain self-correction method for digital oscilloscope ) 是由 周旭鑫 唐尧江 朱宇通 于 2019-12-13 设计创作，主要内容包括：一种数字示波器和用于数字示波器的增益自校正方法,通过按预设顺序依次切换衰减倍数和增益放大倍数,当切换到任一个增益放大倍数时,控制产生一偏置调节信号。依据当前衰减倍数和当前偏置调节信号获取第二显示信号,根据当前的增益放大倍数对第二显示信号进行增益放大,以获取第一显示信号,显示当前的第一显示信号和偏置调节信号的电压值。控制调节偏置调节信号的电压,使第一显示信号被显示在预设的显示范围内,以获取当前增益放大倍数的电压档和零电平偏置值。由于可对数字示波器所有电压档位的增益精度和偏置精度进行校正,以减少数字示波器在细调电压档位下进行测量时的误差。(A digital oscilloscope and a gain self-correction method for the digital oscilloscope sequentially switch attenuation times and gain amplification times according to a preset sequence, and when any gain amplification time is switched, a bias adjusting signal is controlled and generated. And acquiring a second display signal according to the current attenuation multiple and the current bias adjusting signal, performing gain amplification on the second display signal according to the current gain amplification multiple to acquire a first display signal, and displaying the current voltage values of the first display signal and the bias adjusting signal. And controlling and adjusting the voltage of the offset adjusting signal to enable the first display signal to be displayed in a preset display range so as to obtain a voltage level of the current gain amplification factor and a zero level offset value. The gain precision and the offset precision of all voltage gears of the digital oscilloscope can be corrected, so that the error of the digital oscilloscope in measurement under the condition of fine adjustment of the voltage gears is reduced.)

1. A method of gain self-correction for a digital oscilloscope, comprising:

responding to an attenuation multiple switching instruction, and sequentially switching attenuation multiples according to a preset sequence;

when the attenuation multiple is switched to any one attenuation multiple, responding to a gain multiple switching instruction, and sequentially switching gain amplification multiples according to a preset sequence;

when the gain is switched to any gain amplification factor, generating a bias adjusting signal;

displaying voltage values of a first display signal and a bias adjusting signal, wherein the first display signal is obtained by gain amplifying a second display signal according to the current gain amplification factor, and the second display signal is obtained based on the current attenuation factor and the current bias adjusting signal;

responding to a bias adjusting instruction, adjusting the voltage of the bias adjusting signal to update the displayed first display signal, so that the first display signal is displayed in a preset display range;

acquiring the actual voltage value of the current bias adjusting signal and the voltage value of the displayed bias adjusting signal;

and acquiring a voltage level of the current gain amplification factor and a zero level offset value based on the actual voltage value of the current offset adjusting signal and the voltage value of the displayed offset adjusting signal.

2. The method of claim 1, wherein the preset display range is within ± N Div of a display screen of the digital oscilloscope, wherein a value of N is a value not greater than half of a vertical display grid number of the display screen.

3. The method of claim 2, wherein obtaining the current actual voltage value of the bias adjustment signal and the displayed voltage value of the bias adjustment signal comprises:

acquiring a positive offset adjusting value and a negative offset adjusting value of a current offset adjusting signal; wherein the positive bias adjustment value is a voltage value of the bias adjustment signal when the first display signal is displayed within a + N Div range of the display screen, and the negative bias adjustment value is a voltage value of the bias adjustment signal when the first display signal is displayed within a-N Div range of the display screen;

acquiring a positive display voltage value and a negative display voltage value of the displayed bias adjusting signal; wherein the positive display voltage value is a display value when the first display signal is displayed within a + N Div range of the display screen, and the negative display voltage value is a display value when the first display signal is displayed within a-N Div range of the display screen.

4. The method of claim 3, wherein obtaining the voltage level of the current gain amplification and the zero level offset value based on the actual voltage value of the current bias adjustment signal and the voltage value of the displayed bias adjustment signal comprises obtaining the zero level offset value according to the following equation:

DAC₀=（-Offset_-nd）×（Offset_+nd- Offset_-nd）^-1×（DAC_+nd+DAC_-nd）+DAC_-nd

wherein, DAC₀At zero level offset, DAC_+ndFor positive bias adjustment values, DAC_-ndFor negative bias adjustment value, Offset_+ndFor positive display voltage values, Offset_-ndThe voltage values are shown negative.

5. The method of claim 4, wherein obtaining the voltage level of the current gain amplification and the zero level offset value based on the actual voltage value of the current bias adjustment signal and the voltage value of the displayed bias adjustment signal comprises obtaining the voltage level of the digital oscilloscope at the current gain amplification according to the following formula:

Volt_d=（Volt_+nd-Volt_-nd）×（Offset_+nd-Offset_-nd）^-1×Offset_d

wherein, Volt_dIs the voltage level, Offset of the digital oscilloscope under the current gain amplification factor_dFor each Div-represented voltage value, Offset, of the display screen at the current gain magnification_+ndFor positive display voltage values, Offset_-ndFor negative display of voltage value, Volt_-ndAdjusting a value DAC for negative bias_-ndCorresponding voltage value, Volt_+ndAdjusting a value DAC for positive bias_+ndThe corresponding voltage value.

6. The method of claim 1, wherein sequentially switching attenuation factors in a predetermined order comprises:

and sequentially switching attenuation multiples from large to small or from small to large.

7. The method of claim 1, wherein sequentially switching gain amplification factors in a predetermined order comprises:

the gain amplification factors are switched in sequence from large to small or from small to large.

8. The method of claim 1, wherein adjusting the voltage of the bias adjustment signal in response to the bias adjustment command to update the displayed first display signal such that the first display signal is displayed within a preset display range comprises:

and adjusting the voltage configuration value of the current bias adjusting signal and the voltage configuration value of the bias adjusting signal of the last gain amplification factor into an arithmetic series or an geometric series.

9. The method of claim 1, wherein adjusting the voltage of the bias adjustment signal in response to the bias adjustment command to update the displayed first display signal such that the first display signal is displayed within a preset display range comprises:

and adjusting the voltage range of the current bias adjusting signal within the voltage range of the bias adjusting signal of the last gain amplification factor.

10. A digital oscilloscope is characterized by comprising a controller, an attenuation network, an impedance transformation network, a digital gain amplifier, a bias adjusting circuit and a display module; the attenuation network is used for attenuating the input signal input into the digital oscilloscope; the bias adjusting circuit is used for generating a bias adjusting signal; the impedance transformation network is used for acquiring a second display signal according to the attenuated input signal and the bias adjusting signal; the digital gain amplifier is used for performing gain amplification on the second display signal to obtain a first display signal; the display module is used for displaying the voltage values of the first display signal and the bias adjusting signal; wherein:

the controller is used for sequentially switching the attenuation multiples of the attenuation network according to a preset sequence;

when the attenuation network is switched to any attenuation multiple, the controller sequentially switches the gain amplification multiples of the digital gain amplifier according to a preset sequence;

when the digital gain amplifier is switched to any gain amplification factor, the controller controls the bias adjusting circuit to generate a bias adjusting signal, and the impedance conversion network acquires a second display signal according to the current attenuation factor of the attenuation network and the current bias adjusting signal of the bias adjusting circuit; the digital gain amplifier performs gain amplification on the second display signal according to the current gain amplification factor to obtain a first display signal; the display module displays the current voltage values of the first display signal and the bias adjusting signal;

the controller controls the bias adjusting circuit to adjust the voltage of the bias adjusting signal to update the displayed first display signal so that the first display signal is displayed in the display range of the display module;

the controller acquires the actual voltage value of the current bias adjusting signal and the voltage value of the displayed bias adjusting signal;

and the controller acquires a voltage gear of the current gain amplification factor and a zero level bias value based on the actual voltage value of the current bias adjusting signal and the voltage value of the displayed bias adjusting signal.