注：根据试验的结果，可以认为，只要Vdda电源的纹波不是太差，就能得到很好的AD测量结果，大家的担心我看大多是多余的。
这个老外用ST的STM32官方评估板做到了+/- 1LSB，而且没有使用软件滤波：
more news, compared the KEIL MCBSTM32 board and
the ST board STM32F10F10X-128K-EVAL to really cool one with TFT LCD
the ST board have TONS more ADC noise, removed LCD and have now IMPRESSIVE low noise !
only +/- one LSB wow !!
so the switchmode supply on the back side of the LCD is one nasty noise source to the ADC :-)
be warned if you design with switchmodes and need a clean ADC, add extra coils and caps near the noise source to isoilate it.
Now I am investigating the KEIL board, the capacitors for VDDA and analog GND are placed too far away from IC,
this gives poor decoubling to the analog section, it is hard to fix on that board.
Last edited by ThomasScherrer (2008-02-12 16:11:51)
链接：http://www.stm32circle.com/forum/viewtopic.php?id=161
其中还有图形 |
