FUNCTIONAL DESCRIPTION
The L9615 is used as an interface between a
CAN controller and the physical bus. The device
provides transmitting capability to the CAN con-
troller.
The transmitter outputs C_H and C_L are pro-
tected against short circuits and electrical tran-
sients which may occur in an automotive environ-
ment. In case of short circuit (C_H to C_L, C_H to
B) the protection circuit recognizes this fault con-
ditionand the transmitter output stages are dis-
abled with a delay of max. 10
µ
s to prevent de-
struction of the IC and high consumption of
supply current I
S
. If V
C_L
>V
C_Lmax
the transmitter
output stages would be disabled immediately.
Pin ASC makes it possible to select two different
modes of operation: High speed (
≤
500kBaud) and
low speed (
≤
125kBaud).
The ASC pin is tied to GND for normal operation
at
≤
500kBaud. For slower speed operation at
≤
125kBaud the rise and fall slope of the bus out-
put can be decreased to reduce EMI by connect-
ingg the ASC pin to V
S
.
FUNCTIONAL TABLE
TXO C_H C_L Bus State RXO
L H L Dominant L
H or
Floating
Floating
V
S
/2
Floating
V
S
/2
Recessive H
DINAMIC CHARACTERISTICS
(C
A
= 47pF between C_H and C_L; V
S
= 5V; t
R
< 5ns;
C
RXO
= 20pF between RXO and B; R
A
= 60
Ω
between C_H and C_L)
Symbol Parameter Test Condition Min. Typ. Max. Unit
t
OT
Signal Delay TXO to C_H, C_L 50 ns
S
R
Differential Output Slew Rate
(Transmitter)
V
ASC
= 0V 20 50 V/µs
V
ASC
= V
S
520V/µs
t
OR
Signal Delay C_H, C_L to R
XO
V
ASC
= 0V 150 ns
t
OTR
Signal Delay T
XO
to R
XO
V
ASC
= 0V 300 ns
CONTROLLER L9615 L9615 CONTROLLER
CAN BUS
SYSTEM n
V
COM
R
A
V
Sn
V
GNDn
V
GNDD
V
GNDm
R
A
V
Diff
C_H
C_L
SYSTEM m
V
GNDm
V
Sm
D96AT247A
TYPICAL APPLICATION
L9615
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