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13.7 EMC CHARACTERISTICS
Susceptibility tests are performed on a sample ba-
sis during product characterization.
13.7.1 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).
s
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.
s
FTB: Burst of Fast Transient voltage (positive
and negative) is applied to VDD and VSS through
a 100pF capacitor, until a functional disturbance
occurs. This test conforms with the IEC 1000-4-
4 standard.
A device reset allows normal operations to be re-
sumed.
Figure 79. EMC Recommended star network power supply connection 2)
Notes:
1. Data based on characterization results, not tested in production.
2. The suggested 10
F and 0.1F decoupling capacitors on the power supply lines are proposed as a good price vs. EMC
performance tradeoff. They have to be put as close as possible to the device power supply pins. Other EMC recommen-
dations are given in other sections (I/Os, RESET, OSCx pin characteristics).
Symbol
Parameter
Conditions
Neg 1)
Pos 1)
Unit
VFESD
Voltage limits to be applied on any I/O pin
to induce a functional disturbance
VDD=5V, TA=+25°C, fOSC=8MHz
conforms to IEC 1000-4-2
-1
>1.5
kV
VFFTB
Fast transient voltage burst limits to be ap-
plied through 100pF on VDD and VDDA pins
to induce a functional disturbance
VDD=5V, TA=+25°C, fOSC=8MHz
conforms to IEC 1000-4-4
-2
2
VDD
VSS
0.1
F
10
F
VDD
ST72XXX
VSSA
VDDA
0.1
F
POWER
SUPPLY
SOURCE
ST7
DIGITAL NOISE
FILTERING
EXTERNAL
NOISE
FILTERING