KV30F64的ADC外设,支持对差分输入和单端输入的模拟量采样,我的项目中先通过ADC0,ADC1采集两路差分输入,再通过ADC0采集一路单端输入,并且保持循环采样,循环周期为62.5us。ADC模块时钟为12MHZ(48MHZ进行4分频),不开启long sample time采样,分辨率都设置为16位,也不开启硬件平均功能。
ADC0的差分输入连接到管脚ADC0_DP1,ADC0_DM1,ADC1的差分输入连接到管脚ADC1_DP1,ADC1_DM1,ADC0的单端输入连接到管脚ADC0_SE23。
把单端信号通过100K电阻连接到Gnd上,外部只保留100PF电容,每次在对它进行采样时,发现信号上会出现接近200mv的电压跳变。检查ADC配置未发现明显异常,这种情况可能是什么原因?
Solved! Go to Solution.
Hi yaoXin,
100K电阻值太大了。 数据手册Kinetis KV30: 100MHz Cortex-M4F 64/128KB Flash 32-64pin
的Table 23. 16-bit ADC operating conditions 章节中可以看到RADIN Input series resistance 最大才5K
可以看一下这篇:ADC外部RC电路电阻和电容选取计算方法 https://mp.weixin.qq.com/s/l5afihUlRecSW0o7BOYJbA
Best Regards,
Robin
-------------------------------------------------------------------------------
Note:
- If this post answers your question, please click the "Mark Correct" button. Thank you!
- We are following threads for 7 weeks after the last post, later replies are ignored
Please open a new thread and refer to the closed one, if you have a related question at a later point in time.
-------------------------------------------------------------------------------
Hi yaoXin,
100K电阻值太大了。 数据手册Kinetis KV30: 100MHz Cortex-M4F 64/128KB Flash 32-64pin
的Table 23. 16-bit ADC operating conditions 章节中可以看到RADIN Input series resistance 最大才5K
可以看一下这篇:ADC外部RC电路电阻和电容选取计算方法 https://mp.weixin.qq.com/s/l5afihUlRecSW0o7BOYJbA
Best Regards,
Robin
-------------------------------------------------------------------------------
Note:
- If this post answers your question, please click the "Mark Correct" button. Thank you!
- We are following threads for 7 weeks after the last post, later replies are ignored
Please open a new thread and refer to the closed one, if you have a related question at a later point in time.
-------------------------------------------------------------------------------