ST72C334J4TAE STMicroelectronics, ST72C334J4TAE Datasheet - Page 127

• Manufacturer Part Number: ST72C334J4TAE
• Description: 8-bit MCU for automotive with single voltage Flash/ROM memory, ADC, 16-bit timers, SPI, SCI interfaces
• Manufacturer: STMicroelectronics

EMC CHARACTERISTICS (Cont’d)
15.7.3 ESD Pin Protection Strategy
To protect an integrated circuit against Electrostat-
ic Discharge the stress must be controlled to pre-
vent degradation or destruction of the circuit ele-
ments. The stress generally affects the circuit ele-
ments which are connected to the pads but can
also affect the internal devices when the supply
pads receive the stress. The elements to be pro-
tected must not receive excessive current, voltage
or heating within their structure.
An ESD network combines the different input and
output ESD protections. This network works, by al-
lowing safe discharge paths for the pins subjected
to ESD stress. Two critical ESD stress cases are
presented in
pins and in
drain pins.
Figure 76. Positive Stress on a Standard Pad vs. V
Figure 77. Negative Stress on a Standard Pad vs. V
Main path
Path to avoid
Main path
Figure 78
Figure 76
V
V
V
V
DD
DD
SS
SS
and
and
Figure 79
Figure 77
(3a)
(3b)
(3a)
(3b)
for true open
for standard
ST72334xx-Auto, ST72314xx-Auto, ST72124Jx-Auto
OUT
OUT
SS
Standard Pin Protection
To protect the output structure the following ele-
ments are added:
To protect the input structure the following ele-
ments are added:
DD
– A diode to V
– A protection device between V
– A resistor in series with the pad (1)
– A diode to V
– A protection device between V
(4)
(4)
IN
IN
DD
DD
(3a) and a diode from V
(2a) and a diode from V
(2a)
(2b)
(2a)
(2b)
(1)
(1)
DD
DD
and V
and V
127/150
SS
SS
V
V
V
V
SS
SS
DD
SS
DD
SS
(3b)
(2b)
(4)
(4)