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Is there a safe negative input-pin current ?

BNord
Associate

I am using an STM32F205RGY6 and looking at possible fault conditions in my circuit.  With the MCU powered down, is there a safe maximum negative current I could apply to PC5 ? Under fault conditions I could see -4.1mA relative to Vss (-3.3v and 796 Ohms).

2 REPLIES 2
Uwe Bonnes
Principal III

Look in the data sheet, Tabel 11 and 12. -5 mA is possible, but observe remark 2 :

2. Negative injection disturbs the analog performance of the device. See note in Section 6.3.20: 12-bit ADC

  characteristics.

BNord
Associate

Thanks, I was hoping that's what the table meant. I was worried that I might be exceeding the minimum input voltage spec., Vss-0.3 . And since I' was looking at a powered-down situation performance is not an issue.

Appreciate the help.