根据 STM32F10xx8 and STM32F10xxB Errata sheet.
Doc ID 14574 Rev 9 P11 2.1 描述:
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.
Workaround
中文翻译版是这么翻译的:
问题描述
当以注入触发进行ADC转换时,在PA0引脚(ADC输入0)上,可能会产生一个低振幅的电压毛刺。这个毛刺是由内部耦合和同步到注入序列的开始和结束产生的,与要转换的通道无关。
毛刺的振幅低于150mV,典型的持续时间是10ns(在I/O引脚配置为高阻输入并悬空时测量的)。如果PA0是作为数字输出,这将不会影响到输出信号。如果PA0是配置为数字输入,只要驱动PA0的另一端的阻抗低于5kΩ,这个毛刺将不会被检测为意外的转换。在单ADC配置时,这个毛刺不会对端口A的其它引脚产生影响,也不会对ADC注入转换的结果产生影响。
当使用ADC的双模式,并使用注入触发时,为了避免任何可能的副作用,建议分配模拟通道时,把通道0配置为注入通道。
我的疑问:
既然 ADC0 上会出现与注入触发转换同步的噪声. 为何还说 "为了避免任何可能的副作用,建议分配模拟通道时,把通道0配置为注入通道。"
应该是避免将 ADC0 分配为注入通道才是呀?
None. |