NCV7361A ON Semiconductor, NCV7361A Datasheet - Page 18

• Manufacturer Part Number: NCV7361A
• Description: Voltage Regulator
• Manufacturer: ON Semiconductor

LIN System Parameter
Bus Loading Requirements
Recommendations for System Design
universal definition of the LIN system for plug and play
solutions in LIN networks up to 20 kbd bus speeds.
recommended to adjust the total network capacitance to at
least 4.0 nF for good EMC and EMI behavior. This can be
done by setting only the master node capacitance. The
slave node capacitance should have a unit load of typically
220 pF for good EMC/EMI behavior.
number of nodes, some system parameters can exceed the
defined limits and the LIN system designer must intervene.
load capacitor itself. Additionally, there is the capacitance
of wires and connectors, and the internal capacitance of the
LIN transmitter. This internal capacitance is strongly
dependent on the technology of the IC manufacturer and
should be in the range of 30 pF to 150 pF. If the bus lines
have a total length of nearly 40m, the total bus capacitance
can exceed the LIN system limit of 10 nF.
termination resistor tolerance. If most of the slave nodes
have a slave termination resistance near by the allowed
maximum of 60 kW, the total network resistance is more
Operating Voltage Range
Voltage Drop of Reverse Protection Diode
Voltage Drop at the Series Diode in Pull Up Path
Battery Shift Voltage
Ground Shift Voltage
Master Termination Resistor
Slave Termination Resistor
Number of System Nodes
Total Length of Bus Line
Line Capacitance
Capacitance of Master Node
Capacitance of Slave Node
Total Capacitance of the Bus including Slave and Master Capacitance
Network Total Resistance
Time Constant of Overall System
The goal of the LIN physical layer standard is to have a
In case of small and medium LIN networks, it’s
In large networks with long bus lines and the maximum
The whole capacitance of a slave node is not only the unit
A second parameter of concern is the integrated slave
Parameter
APPLICATION HINTS
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NCV7361A
18
than 700 W. Even if the total network capacitance is below
or equal to the maximum specified value of 10 nF, the
network time constant is higher than 7.0 ms.
termination resistor to the required maximum network time
constant of 5.0 ms (max).
higher drive capability than necessary (40 mA @ 1.2 V)
within the LIN standard (33.6 mA @ 1.2 V). With this
driver stage the system designer can increase the maximum
LIN networks with a total network capacitance of more
than 10 nF. The total network resistance can be
decreased to:
NOTE: The NCV7361A meets the requirements for
implementation in RC−based slave nodes. The LIN
Protocol Specification requires the deviation of the slave
node clock to the master node clock after synchronization
must not differ by more than "2%.
Setting the network time constant is necessary in large
networks (primary resistance) and also in small networks
(primary capacitance).
This problem can be solved only by adjusting the master
The LIN bus output driver of the NCV7361A provides a
V
V
V
V
R
Symbol
LEN
Shift_GND
R
C
Shift_BAT
SerDiode
C
R tl_min + (V Bat_max * V BUSdom ) I BUS_max
Drop_rev
R
C
C
Network
V
master
Master
Slave
slave
LINE
BAT
BUS
N
t
BUS
+ (18 V * 1.2 V) 40 mA + 420 W
Min
900
537
8.0
0.4
0.4
1.0
1.0
20
0
0
2
−
−
−
−
1000
Typ
100
220
220
0.7
0.7
4.0
30
−
−
−
−
−
−
−
1100
Max
150
250
863
1.0
1.0
0.1
0.1
5.0
18
60
16
40
10
−
V
V
pF/m
Unit
kW
pF
pF
nF
ms
BAT
BAT
W
m
W
V
V
V
−