Datasheet

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ST7LITE20F2 ST7LITE25F2 ST7LITE29F2 Electrical characteristics
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A device reset allows normal operations to be resumed. The test results are given in the
Table 76 based on the EMS levels and classes defined in application note AN1709.
Designing hardened software to avoid noise problems
EMC characterization and optimization are performed at component level with a typical
application environment and simplified MCU software. It should be noted that good EMC
performance is highly dependent on the user application and the software in particular.
Therefore it is recommended that the user applies EMC software optimization and
prequalification tests in relation with the EMC level requested for his application.
Software recommendations
The software flowchart must include the management of runaway conditions such as:
• Corrupted program counter
• Unexpected reset
• Critical data corruption (control registers...)
Prequalification trials
Most of the common failures (unexpected reset and program counter corruption) can be
reproduced by manually forcing a low state on the RESET pin or the Oscillator pins for 1
second.
To complete these trials, ESD stress can be applied directly on the device, over the range of
specification values. When unexpected behavior is detected, the software can be hardened
to prevent unrecoverable errors occurring.
Note: For more details, refer to the application note AN1015.
13.7.2 Electro Magnetic Interference (EMI)
Based on a simple application running on the product (toggling 2 LEDs through the I/O
ports), the product is monitored in terms of emission. This emission test is in line with the
norm SAE J 1752/3 which specifies the board and the loading of each pin.
Table 76. Test results
Symbol Parameter Conditions Level/Class
V
FESD
Voltage limits to be applied on any I/O pin to
induce a functional disturbance
V
DD
=5V, T
A
=+25°C, f
OSC
=8MHz
conforms to IEC 1000-4-2
3B
V
FFTB
Fast transient voltage burst limits to be applied
through 100pF on V
DD
and V
DD
pins to induce a
functional disturbance
V
DD
=5V, T
A
=+25°C, f
OSC
=8MHz
conforms to IEC 1000-4-4
3B