请问一下STM32F103C8T6的PA0脚 做AD用途有什么特殊配置吗?

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 楼主| dl_shuang 发表于 2012-11-15 12:39 | 显示全部楼层 |阅读模式
STM32F103C8T6 的PA0和PA1 测量同一个信号。PA0 的噪声在5Bit左右,而PA1则在1BIT左右。
PA0即使用2K电阻接地,也会有5BIT。
airwill 发表于 2012-11-15 16:55 | 显示全部楼层
2.1  Voltage glitch on ADC input 0
Description
A low-amplitude voltage glitch may be generated (on ADC input 0) on the PA0 pin, when the ADC is converting with injection trigger. It is generated by internal coupling and synchronized to the beginning and the end of the injection sequence, whatever the channel(s) to be converted.
The glitch amplitude is less than 150 mV with a typical duration of 10 ns (measured with the I/O configured as high-impedance input and left unconnected). If PA0 is used as a digital output, this has no influence on the signal. If PA0 is used has a digital input, it will not be detected as a spurious transition, providing that PA0 is driven with an impedance lower than 5 kΩ. This glitch does not have any influence on the remaining port A pin or on the ADC conversion injection results, in single ADC configuration.
When using the ADC in dual mode with injection trigger, and in order to avoid any side effect, it is advised to distribute the analog channels so that Channel 0 is configured as an injected channel.
 楼主| dl_shuang 发表于 2012-11-16 19:44 | 显示全部楼层
太感谢了,看来我需要重新改板了。
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