TI中文支持网AMP_Project.pdf
guiqi zhou：
datasheet里有相关说明，加上RS（10k）此现象依旧存在。。。
The inputs of the INA826 are individually protected for voltages up to ±40 V. For example, a condition of –40 V
on one input and 40 V on the other input does not cause damage. However, if the input voltage exceeds (V–) –
2 V and the signal source current drive capability exceeds 3.5 mA, the output voltage switches to the opposite
polarity; see Figure 17. This polarity reversal can easily be avoided by adding resistance of 10 kΩ in series with
both inputs.
Internal circuitry on each input provides low series impedance under normal signal conditions. If the input is
overloaded, the protection circuitry limits the input current to a safe value of approximately 8 mA. Figure 17 and
Figure 18 illustrate this input current limit behavior. The inputs are protected even if the power supplies are
disconnected or turned off.
Amy Luo：
您好，
可以把您输入的波形和相应输出的波形贴出来吗
guiqi zhou：
回复 Amy Luo:
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guiqi zhou：
回复 Amy Luo:
加大输入信号，失真更加严重。已确认芯片和供电正常
大信号失真图
小信号信号正常图
待测电流回路
ina826电路配置
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guiqi zhou：
回复 Amy Luo:
会是输入信号极性与接入放大器IN+、IN-相反的问题吗？
Amy Luo：
回复 guiqi zhou:
小信号输入正常时，输入信号是-4V~4.2V，输出是-148.8mV~260.4mV，怎么与放大倍数22对不上呢，示波器是怎么测的输入输出信号呢
guiqi zhou：
回复 Amy Luo:
黄色信号是lm1875的输出电压，OUT1和GND间有20Ω的负载，INA826的输入信号是在R2 （50mΩ）上取得，LM1875输出电压RMS为2.88v时电流约为144mA，故INA826输入信号约为72uV，输出信号约为158.2mV
