Gpio Electrical Characteristics And Definitions; Gpio General Information; Pad Leakage Current (Ilkg); Injected Current (Iinj) - ST STM32 Application Note

AN4899
5

GPIO electrical characteristics and definitions

This chapter defines and explains some of the electrical parameters in STM32 datasheets.
5.1

GPIO general information

The following sections detail some of the electrical parameters in the datasheets as a
function of their use from an application point of view.
AMR (absolute maximum ratings)
The absolute maximum ratings represent the values of voltages, current, temperatures,
power dissipations, and others which must never be exceeded. Exceeding these values can
lead to the deterioration or the destruction of the IC.
Operating conditions
The operating conditions represent the range of guaranteed values within which the IC
operates in proper conditions.
5.1.1 Pad leakage current (I
The pad leakage current is the current which is sourced from the input signal by the I/O pin
when it is configured in input mode. The value of the leakage current depends on the I/O
structure and on the voltage range of the V
Leakage currents are product dependent. Refer to the datasheets for their values.
5.1.2 Injected current (I
Injection current is the current that is being forced into a pin by an input voltage (V
positive supp
Injection current above the given specifications causes a current flow inside the device and
affects its reliability. Even a very small current exceeding the specified limit is not allowed.
STM32 datasheets specify injected current and V
Negative-injection current is the current induced when V
injected current is -5 mA and the minimum V
-0.3 V for TT and FT GPIO.
Positive-injection current is the current induced when V
maximum positive-injection current on TT and FT GPIO is defined as N/A or 0 mA.
•
N/A means that, as long as the input voltage is within the AMR range, and due to the
internal design of the GPIO, no current injection occurs. As a result, no corruption of
the GPIO and STM32 device operation is observed in such a case.
•
0 mA means that current injection can damage the GPIO and induce STM32
malfunction.
Warning:
)
lkg
)
INJ
ly (V + ∆V) or lower than ground (V
DD
positive current injection is prohibited for a TT or FT GPIO
defined as 0 mA
AN4899 Rev 3
GPIO electrical characteristics and definitions
signal applied to the I/O pin.
IN
).
SS
.
IN
< V
IN SS
voltage level acceptable on the GPIO is
IN
> V
IN DD
) higher than the
IN
. The maximum negative
. For STM32 devices, the
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