str755fvx STMicroelectronics, str755fvx Datasheet - Page 50

• Manufacturer Part Number: str755fvx
• Description: Arm7tdmi-s, 32-bit Mcu With Flash, Smi, 3 Std 16-bit Timers Pwm Timer, Fast 10-bit Adc, I2c, Uart, Ssp, Usb And Can
• Manufacturer: STMicroelectronics

Electrical parameters
3.3.7
50/71
EMC characteristics
Susceptibilitytests are performed on a sample basis during product characterization.
Functional EMS (Electro Magnetic Susceptibility)
Based on a simple running application on the product (toggling 2 LEDs through I/O ports),
the product is stressed by two electro magnetic events until a failure occurs (indicated by the
LEDs).
G
G
A device reset allows normal operations to be resumed. The test results are given in the
table below 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:
G
G
G
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 behaviour is detected, the software can be
hardened to prevent unrecoverable errors occurring (see application note AN1015).
Table 27.
Symbol
V
V
FESD
EFTB
ESD: Electro-Static Discharge (positive and negative) is applied on all pins of the
device until a functional disturbance occurs. This test conforms with the IEC 1000-4-2
standard.
FTB: A Burst of Fast Transient voltage (positive and negative) is applied to V
V
conforms with the IEC 1000-4-4 standard.
Corrupted program counter
Unexpected reset
Critical Data corruption (control registers...)
SS
through a 100pF capacitor, until a functional disturbance occurs. This test
Voltage limits to be applied on any I/O pin to
induce a functional disturbance
Fast transient voltage burst limits to be applied
through 100pF on V
a functional disturbance
EMC characteristics
Parameter
DD
and V
SS
pins to induce
V
T
conforms to IEC 1000-4-2
V
T
conforms to IEC 1000-4-4
A
A
DD_IO
DD_IO
=+25° C, f
=+25° C, f
=3.3 V or 5 V,
=3.3 V or 5 V,
Conditions
CK_SYS
CK_SYS
=32 MHz
=32 MHz
DD
STR750F
Class A
Class A
Level/
Class
and