±60V Fault Protected 3.3V/5V CAN Transceiver

±60V Fault Protected 3.3V/5V
CAN Transceiver
Robust Communications for Automotive, Industrial and Medical Networks
The LTC®2875 is an exceptionally rugged, high voltage tolerant CAN transceiver that helps reduce field failures without the need
for costly external protection devices. ±60V overvoltage fault protection on the data transmission lines protects bus pins during
operation and shutdown, while an extended ±36V input common mode range improves data communication reliability in electrically
noisy environments and in the presence of ground loop voltages. Enhanced ESD protection allows the LTC2875 to withstand ±25kV
HBM on the transceiver pins without latchup or damage; all other pins are protected to ±8kV HBM.
Features
n
n
n
n
n
n
n
n
n
n
n
n
Protected from Overvoltage Line Faults to ±60V
3.3V or 5.5V Supply Voltage
High Speed Operation up to 4Mbps
±25kV ESD Interface Pins, ±8kV All Other Pins
Active Symmetry Driver with Variable Slew Rate and
SPLIT Pin for Low Electromagnetic Emission EME
Extended Common Mode Range (±36V)
Transmit Data (TXD) Dominant Timeout Function
Micropower Shutdown Mode
ISO 11898-2 Compliant
DeviceNet Compatible
MP-Grade Option Available (–55°C to 125°C)
3mm × 3mm DFN-8 and SO-8 Packages
LTC2875 Transmitting at
4Mbps from a 3.3V Supply
TXD
XD
2V/DIV
IV
RXD
XD
2V/DIV
IV
COMMON MODE
CANH
H
1V/DIV
IV
CANL
NL
1V/DIV
IV
100ns/DIV
L, LT, LTC, LTM, Linear Technology and the Linear logo are
registered trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
3.3V
3.3V or 5V Operation
The LTC2875 can be powered from either a 3.3V or 5V rail,
which is very useful in low power applications where a 5V rail
may not be present. A 3.3V powered LTC2875 may interoperate
with 5V-powered CAN transceivers on the same bus.
5V
CANH
LTC2875
LTC2875
CANL
Low EME
RSL = 0
The electromagnetic emissions (EME) spectrum of a differential
line transmitter is largely determined by the variation in the
common mode voltage during switching. The LTC2875 employs
a low EME driver with a maximum symmetry of ±500mV and
a transmit data dominant (TXD) timer that prevents faulty
controllers from clamping the bus. Optional split termination
provides further reduction of EME by dividing the single line-end
termination resistor (nominally 120Ω) into two series resistors of
half value.
0dB
20dB/DIV
RSL = 200k
0dB
20dB/DIV
500kHz/DIV
Power Spectrum of Common Mode Voltage Showing
High Frequency Reduction of Lowest Slew Rate
(RSL = 200k) Compared to Highest Slew Rate (RSL = 0).
MOV
Extended IEC Protection
±60V tolerance is easily extended to higher levels of protection
and makes extremely robust applications possible. This network
provides the highest specified level of IEC protection (Level 4)
against lightning surge, electrical fast transients (EFT) from
switching high current inductive loads, and electrostatic
discharge (ESD).
VCC
CANH_EXTERNAL
GDT
TBU
TVS
R
NH
CANH
GND
GDT
TBU
RXD
RX
CANL
NL
T
RS
LTC2875
TX
TXD
TVS
CANL_EXTERNAL
GND
MOV
DeviceNet Compatible
DeviceNet is a network standard based on the CAN bus and places requirements on the transceiver that exceed those of the ISO 11898-2
standard. The LTC2875 meets or exceeds the following ISO 11898-2 and DeviceNet requirements:
Parameter
Number of Nodes
ISO-11898-2 Requirement
N/A
Minimum Differential Input Resistance 10kΩ
DeviceNet Requirement
LTC2875
64
166
20kΩ
50kΩ
Differential Input Capacitance
10pF (Nom)
24pF (Max)
8.4pF (Typ)
Bus Pin Voltage Range (Survivable)
–3V to 16V (for 12V Battery)
–25V to 18V
–60V to 60V
Bus Pin Voltage Range (Operation)
–2V to 7V
–5V to 10V
–36V to 36V (VCC = 5V)
–25V to 25V (VCC = 3.3V)
Connector Mis-Wiring Tests,
All Pin-Pin Combinations
N/A
±18V
±60V
www.linear.com/2875 n 1-800-4-LINEAR
0215B