what is the minimum saadc working freq,5us?

[wen]

i use the saadc as well as ble.the saadc dose not working on 200k hz(5us) as the Product Specification says.what is the wrong?

[zhwzh308]

If your samples are dithering, it could be because you have too much impedance at the port. Is AIN attached to a high impedance circuit? the specification has some recommended impedance values, such as 3us less than 10k ohms, 5us less than 40k ohms.