MAX13050/MAX13052/MAX13053/MAX13054
Industry-Standard High-Speed CAN
Transceivers with ±80V Fault Protection
10
Maxim Integrated
rates of up to 500kbps. This reduces the effects of EMI,
thus allowing the use of unshielded-twisted or parallel
cable. The MAX13050/MAX13052 and MAX13054 stand-
by mode shuts off the transmitter and switches the
receiver to a low-current/low-speed state.
The MAX13050/MAX13052/MAX13053/MAX13054 input
common-mode range is greater than ±12V, exceeding
the ISO11898 specification of -2V to +7V, and feature
±8kV Contact Discharge protection, making these
devices ideal for harsh industrial environments.
±80V Fault Protected
The MAX13050/MAX13052/MAX13053/MAX13054 fea-
ture ±80V fault protection. This extended voltage range
of CANH, CANL, and SPLIT allows use in high-voltage
systems and communication with high-voltage buses.
Operating Modes
High-Speed Mode
The MAX13050/MAX13052/MAX13053/MAX13054 can
achieve transmission rates of up to 1Mbps when oper-
ating in high-speed mode. Drive STBY low to operate
the MAX13050 and MAX13054 in high-speed opera-
tion. Connect RS to ground to operate the MAX13052 in
high-speed mode.
Slope-Control Mode (MAX13052)
Connect a resistor from RS to ground to select slope-
control mode (Table 1). In slope-control mode, CANH
and CANL slew rates are controlled by the resistor
(16kΩ≤R
RS
≤ 200kΩ) connected between RS and
GND. Controlling the rise and fall slopes reduces high-
frequency EMI and allows the use of an unshielded-
twisted pair or a parallel pair of wires as bus lines. The
slew rate can be approximated using the formula below:
where, SR is the desired slew rate and R
RS
is in kΩ.
Standby Mode (MAX13050/MAX13052/MAX13054)
In standby mode (RS or STBY = high), the transmitter is
switched off and the receiver is switched to a low-cur-
rent/low-speed state. The supply current is reduced
during standby mode. The bus line is monitored by a
low-differential comparator to detect and recognize a
wake-up event on the bus line. Once the comparator
detects a dominant bus level greater than t
WAKE
, RXD
pulls low.
Drive STBY high for standby mode operation for the
MAX13050 and MAX13054. Apply a logic-high to RS to
enter a low-current standby mode for the MAX13052.
Silent Mode S (MAX13053)
Drive S high to place the MAX13053 in silent mode.
When operating in silent mode, the transmitter is dis-
abled regardless of the voltage level at TXD. RXD how-
ever, still monitors activity on the bus line.
Common-Mode Stabilization (SPLIT)
SPLIT provides a DC common-mode stabilization volt-
age of 0.5 x V
CC
when operating in normal mode.
SPLIT stabilizes the recessive voltage to 0.5 x V
CC
for
conditions when the recessive bus voltage is lowered,
caused by an unsupplied transceiver in the network
with a significant leakage current from the bus lines to
ground. Use SPLIT to stabilize the recessive common-
mode voltage by connecting SPLIT to the center tap of
the split termination, see the
Typical Operating Circuit
.
In standby mode or when V
CC
= 0, SPLIT becomes
high impedance.
Reference Output (MAX13053)
MAX13053 has a reference voltage output (REF) set to
0.5 x V
CC
. REF can be utilized to bias the input of a
CAN controller’s differential comparator, and to provide
power to external circuitry.
Transmitter
The transmitter converts a single-ended input (TXD)
from the CAN controller to differential outputs for the
bus lines (CANH, CANL). The truth table for the trans-
mitter and receiver is given in Table 2.
TXD Dominant Timeout
The CAN transceivers provide a transmitter dominant
timeout function that prevents erroneous CAN controllers
from clamping the bus to a dominant level by a continu-
ous low TXD signal. When the TXD remains low for the
1ms maximum timeout period, the transmitter becomes
disabled, thus driving the bus line to a recessive state
