MAX3058 Datasheet, PDF (11/12 Pages) Maxim Integrated Products – 5V, 1Mbps, Low Supply Current CAN Transceivers

5V, 1Mbps, Low Supply Current
CAN Transceivers
Applications Information
Reduced EMI and Reflections
In slope-control mode, the CANH and CANL outputs
are slew-rate limited, minimizing EMI and reducing
reflections caused by improperly terminated cables.
In multidrop CAN applications, it is important to main-
tain a direct point-to-point wiring scheme. A single pair
of wires should connect each element of the CAN bus,
and the two ends of the bus should be terminated with
120Ω resistors. A star configuration should never
be used.
Any deviation from the point-to-point wiring scheme
creates a stub. The high-speed edge of the CAN data
on a stub can create reflections back down the bus.
These reflections can cause data errors by eroding the
noise margin of the system.
Although stubs are unavoidable in a multidrop system,
care should be taken to keep these stubs as small as
possible, especially in high-speed mode. In slope-con-
trol mode, the requirements are not as rigorous, but
stub length should still be minimized.
Power Supply and Bypassing
The MAX3058/MAX3059 require no special layout con-
siderations beyond common practices. Bypass V_CC to
GND with a 0.1µF ceramic capacitor mounted close to
the IC with short lead lengths and wide trace widths.
Chip Information
TRANSISTOR COUNT: 1024
PROCESS: BiCMOS
CAN
CONTROLLER
TX0
RX0
GND
Typical Operating Circuit
V_CC
120Ω
0.1µF
V_CC
CANH
MAX3058
TXD
CANL
RXD
SHDN
RS
GND
25kΩ–200kΩ
120Ω
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