st72324bk STMicroelectronics, st72324bk Datasheet - Page 126

• Manufacturer Part Number: st72324bk
• Description: 3 V/5 V Range 8-bit Mcu With 4/8 Kbyte Rom, 10-bit Adc, Four Timers And Spi
• Manufacturer: STMicroelectronics

Electrical characteristics
11.7
11.7.1
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EMC characteristics
Susceptibility tests are performed on a sample basis during product characterization.
Functional EMS (electromagnetic susceptibility)
Based on a simple running application on the product (toggling 2 LEDs through I/O ports),
the product is stressed by two electromagnetic events until a failure occurs (indicated by the
LEDs).
●
●
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:
●
●
●
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 from occurring (see application note AN1015)
Table 74.
1. Design target value only.
Symbol
.
V
V
FESD
FFTB
ESD: Electrostatic 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 100 pF on V
pins to induce a functional disturbance
EMS test results
Parameter
DD
and V
DD
f
IEC 1000-4-2
V
8 MHz
conforms to IEC 1000-4-4
V
OSC
DD
DD
= 5 V, T
= 8 MHz conforms to
= 5 V, T
Conditions
A
A
= +25 °C, f
= +25 °C,
OSC
ST72323 ST72323L
=
Level/Class
DD
4A
4A
and
(1)