MAX13051_14 Datasheet, PDF (8/12 Pages) Maxim Integrated Products – ±80V Fault-Protected Can Transceiver with Autobaud

MAX13051
±80V Fault-Protected Can Transceiver
with Autobaud
V_CC
RS
V_CC
TXD
AUTOBAUD
CIRCUITRY
MAX13051
TIMEOUT
AND SLOPE-
CONTROL
MODE
THERMAL
SHUTDOWN
DRIVER
WAKE-UP MODE
CONTROL
RXD
WAKE-UP
FILTER
CANH
CANL
GND
AUTOBAUD
ENABLE
MUX
Figure 3. MAX13051 Functional Diagram
Detail Description
±80V Fault Tolerant
The MAX13051 features ±80V fault protection. This
extended voltage range of CANH and CANL allows
communication in high-voltage systems up to 80V.
Operating Modes
High-Speed Mode
The MAX13051 can achieve transmission rates of up to
1Mbps when operating in high-speed mode. To oper-
ate in high-speed mode, short RS to ground.
Slope-Control Mode
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:
SR (V / µs) ≈ 250
R_RS
where, SR is the desired slew rate and R_RS is in kΩ.
Standby Mode
In standby mode (RS = high), the transmitter is
switched off and the receiver is switched to a low-cur-
rent/low-speed state. The supply current reduces to
15µA to detect and recognize a wake-up event on the
bus line. During standby mode, the bus line is moni-
tored with a low-differential comparator. Once the com-
parator detects a dominant bus level greater than
t_WAKE, RXD pulls low.
Autobaud Mode
The MAX13051 logic-controlled autobaud input allows
a microcontroller to compute the incoming baud rate
without destroying CAN protocol communication. When
operating in autobaud mode, TXD is looped back to
RXD without applying a differential signal at CANH and
CANL. See Figure 4.
8
Maxim Integrated