Datasheet

MAX13050/MAX13052/MAX13053/MAX13054
Industry-Standard High-Speed CAN
Transceivers with ±80V Fault Protection
11
Maxim Integrated
(Figure 3). The transmitter becomes enabled upon
detecting a rising edge at TXD.
Receiver
The receiver reads differential inputs from the bus lines
(CANH, CANL) and transfers this data as a single-
ended output (RXD) to the CAN controller. It consists of
a comparator that senses the difference V
DIFF
=
(CANH - CANL) with respect to an internal threshold of
0.7V. If this difference is positive (i.e., V
DIFF
> 0.7), a
logic-low is present at RXD. If negative (i.e., V
DIFF
<
0.7V), a logic-high is present.
The CANH and CANL common-mode range is greater
than ±12V. RXD is logic-high when CANH and CANL
are shorted or terminated and undriven.
+3.3V Logic Compatibility (MAX13054)
A separate input, V
CC
2, allows the MAX13054 to com-
municate with +3.3V logic systems while operating from
a +5V supply. This provides a reduced input voltage
threshold to the TXD and STBY inputs, and provides a
logic-high output at RXD compatible with the microcon-
troller’s system voltage. The logic compatibility elimi-
nates longer propagation delay due to level shifting.
Connect V
CC
2 to V
CC
to operate the MAX13054 with
+5V logic systems.
Driver Output Protection
The current-limiting feature protects the transmitter out-
put stage against a short circuit to a positive and nega-
tive battery voltage. Although the power dissipation
increases during this fault condition, current-limit pro-
tection prevents destruction of the transmitter output
stage. Upon removal of a short, the CAN transceiver
resumes normal operation.
Thermal Shutdown
If the junction temperature exceeds +165°C, the driver
is switched off. The hysteresis is approximately 13°C,
TXD RS CANH CANL BUS STATE RXD
Low V
RS
≤ 0.75 x V
CC
High Low Dominant Low
High or Open V
RS
≤ 0.75 x V
CC
V
CC
/ 2 V
CC
/ 2 Recessive High
XV
RS
≥ 0.75 x V
CC
R
ICM
to GND R
ICM
to GND Recessive High
TXD RS CANH CANL BUS STATE RXD
Low V
S
< 0.8V High Low Dominant Low
High or Open V
S
< 0.8V V
CC
/ 2 V
CC
/ 2 Recessive High
XV
S
> 2V V
CC
/ 2 V
CC
/ 2 Recessive High
Table 2. Transmitter and Receiver Truth Table (MAX13052)
TXD STBY CANH CANL BUS STATE RXD
Low
V
STBY
≤ 0.8V
*V
STBY
≤ 0.3 x V
CC
2
High Low Dominant Low
High or Open
V
STBY
≤ 0.8V
*V
STBY
≤ 0.3 x V
CC
2
V
CC
/ 2 V
CC
/ 2 Recessive High
X
V
STBY
≥ 2V
*V
STBY
≥ 0.7 x V
CC
2
R
ICM
to GND R
ICM
to GND Recessive High
Table 3. Transmitter and Receiver Truth Table
(MAX13053)
(MAX13050/MAX13054)
TRANSMITTER
DISABLED
TRANSMITTER
ENABLED
t
DOM
TXD
V
CANH
- V
CANL
Figure 3. Transmitter Dominant Timeout Timing Diagram
* For the MAX13054