NCV7361A_05 Datasheet, PDF (25/28 Pages) ON Semiconductor – Voltage Regulator with Integrated LIN Transceiver

NCV7361A
Connection to Flash−MCU
During programming of a flash MCU the NCV7361A
should be disconnected from the MCU. This can be done
by disconnecting the supply voltage of the NCV7361A or
by turning off the NCV7361A with the EN pin. A blocking
diode must be used between the MCU and the RxD pin to
avoid loading of the programming data.
The programming of the flash is also possible via the
LIN pin, if the MCU supports this kind of flash mode.
Prog.−Data
10mF...47mF
NCV7361A
V_OUT
47nF...100nF
mC
RESET
TxD
RxD
V_{high_RxD} > 4.7 V at V_DD = 5 V
V_{low_RxD} = 0.8 V
0.7 V
V_high = 4 V at V_DD = 5 V
Figure 38. Example Circuitry for Connection of RxD to MCU for Flash Programming
Operating During Disturbance
Operating Without V_SUP or GND
The BUS pin is designed for voltages of GND − 24 V up
to GND + 30 V. This prevents loss of communication
between other bus nodes with the loss of V_SUP or loss of
GND. The BUS pin will remain at V_BAT and current draw
will be minimal with the loss of GND or V_SUP.
Short Circuit BUS to V_BAT
• Recessive LIN bus is blocked, no influence to the
NCV7361A
• Dominant Current limit, thermal shutdown of
NCV7361A if power dissipation raises T_J
Short Circuit BUS to GND
The LIN bus is blocked. There is no influence to the
NCV7361A.
Short Circuit TxD to GND
The LIN transceiver is permanent in the dominant state
as is the LIN bus. This state can only be detected from the
LIN controller. In this case the controller must switch−off
the LIN node via the EN input of the NCV7361A and look
for a recessive state. A thermal shutdown of NCV7361A
will appear if the thermal shutdown threshold is exceeded.
TxD Open
The internal pullup resistor forces the LIN node to the
recessive state. The communication between the other
bus−nodes will not be disturbed.
Short Circuit V_OUT to GND
The V_OUT pin is protected via a current limit. This state
is comparable with the behavior in the sleep mode.
Overload of V_OUT
Thermal Switch−Off
The power dissipation is increasing if the load current is
between I_{VOUT_max} and I_LVOUT. If the IC exceeds the
thermal shutdown threshold of > 155°C, the transceiver
will be switched off. The voltage regulator will also be
switched off and a reset signal is forced.
Overcurrent
If the current limit is active the voltage on V_OUT drops
down. If this voltage is below the threshold V_RES, a reset
will be forced.
Undervoltage V_SUP, V_OUT
The reset circuit guarantees the correct behavior of the
driver during undervoltage. The BUS pin generates the
recessive state if V_OUT < V_MRes. The inputs EN and TxD
have pull−down and pull−up circuits respectively.
If V_MRes v V_OUT v 4.5 V the TxD signal is transmitted
to the bus. The receive mode is also active.
Short Circuit RxD, RESET to GND or V_OUT
Both outputs are short circuit proof to V_OUT and ground.
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