Datasheet

DocID022152 Rev 8 113/202
STM32F405xx, STM32F407xx Electrical characteristics
Static latchup
Two complementary static tests are required on six parts to assess the latchup
performance:
• A supply overvoltage is applied to each power supply pin
• A current injection is applied to each input, output and configurable I/O pin
These tests are compliant with EIA/JESD 78A IC latchup standard.
5.3.15 I/O current injection characteristics
As a general rule, current injection to the I/O pins, due to external voltage below V
SS
or
above V
DD
(for standard, 3 V-capable I/O pins) should be avoided during normal product
operation. However, in order to give an indication of the robustness of the microcontroller in
cases when abnormal injection accidentally happens, susceptibility tests are performed on a
sample basis during device characterization.
Functional susceptibilty to I/O current injection
While a simple application is executed on the device, the device is stressed by injecting
current into the I/O pins programmed in floating input mode. While current is injected into
the I/O pin, one at a time, the device is checked for functional failures.
The failure is indicated by an out of range parameter: ADC error above a certain limit (>5
LSB TUE), out of conventional limits of induced leakage current on adjacent pins (out of
5
μA/+0 μA range), or other functional failure (for example reset, oscillator frequency
deviation).
Negative induced leakage current is caused by negative injection and positive induced
leakage current by positive injection.
The test results are given in Table 47.
Table 46. Electrical sensitivities
Symbol Parameter Conditions Class
LU Static latch-up class T
A
= +105 °C conforming to JESD78A II level A