MCZ33989EG Freescale Semiconductor, MCZ33989EG Datasheet - Page 52

• Manufacturer Part Number: MCZ33989EG
• Description: IC SYSTEM BASIS CHIP CAN 28-SOIC
• Manufacturer: Freescale Semiconductor

Specifications of MCZ33989EG

• Applications: *
• Interface: *
• Voltage - Supply: *
• Package / Case: 28-SOIC (7.5mm Width)
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

CAN Driver Overtemperature:
CANL driver, the driver will be automatically disabled and the
THERM bit set in the CAN register. If enabled, an interrupt
will be signalled. The GFAIL flag is set in the MCR register.
device is no longer able to transmit. As soon as the
temperature is below the overtemperature level minus
hysteresis, the CAN driver is automatically re-enabled.
necessary to clear it:
Overcurrent Detection:
condition, occurring for instance in case of CANL shorted to
VBAT. This is signalled by the bit CUR in the CAN register.
An INT can be enabled, and GFAIL bit is set. The CUR bit is
latched and two conditions are necessary to clear it:
Protection
environments.
overcurrent.
52
33989
TYPICAL APPLICATIONS
SUPPLEMENTAL APPLICATION NOTES
In case of an overtemperature condition at the CANH or
When the CAN is in an overtemperature situation, the
The THERM bit is latched and two conditions are
• No longer “CAN overtemperature situation” AND
• Read operation of the CAN register.
The CAN interface can detect and signal over current
• No longer “CAN over current situation” AND
• Read operation of the CAN register.
The MC33989 CAN output is protected for automotive
The CAN driver is protected against overtemperature and
Figure 44. Current in Case of Bus Short Conditions
V2 Terminal
CANL
CANH
60 ohms
I_TERM
I_H
I_L
ISO7637 Transient
This means that the MC33989 CAN output can handle failure
situations like the bus directly shorted to the battery line in a
load dump situation (+40 V).
and CANL line floating high to the VBAT supply. The rest of
the network will not be affected. However the CANH and
CANL lines of the ungrounded module will see a negative
voltage of the VBAT value, with respect to their gnd level.
Such situations can be handled by the CAN interface of the
MC33989, but also in cases of a jump start (battery at 27 V)
and gnd disconnection.
maximum rating of the CANH and CANL lines of +40 Vdc and
-27 Vdc must be respected.
ESD
±4 kV. An external capacitor between CANH and CANL to
gnd or a zener diode suppressor can be added to ensure a
higher module resistance to ESD.
Current in Case of Bus Short Conditions
current in the CAN supply, the CAN line can be different from
the nominal case. The
various cases.
CAN L line
CANH line
The CANH and CANL are rated from +40 Vdc to -27 Vdc.
Ground disconnection of the module will lead to the CANH
Fast transient pulses, ISO7637-3. During these pulses, the
The CANH and CANL line of the MC33989 are rated at
In case of short circuit condition on the CAN bus the
VBAT
5V
VBAT
5V
Analog Integrated Circuit Device Data
Figure 44
and
Freescale Semiconductor
Table 35
describe the