AMIS-42675 High-Speed Low Power CAN Transceiver
For Long Networks
1.0 General Description
Data Sheet
The AMIS-42675 CAN transceiver is the interface between a controller area network (CAN) protocol controller and the physical bus. It
may be used in both 12V and 24V systems. The transceiver provides differential transmit capability to the bus and differential receive
capability to the CAN controller.
The AMIS-42675 is the low power member of the CAN high-speed transceiver family and offers the following additional features:
•
•
•
Ideal passive behaviour when supply voltage is removed
Wake-up over bus
Extremely low current standby mode
Due to the wide common-mode voltage range of the receiver inputs, the AMIS-42675 is able to reach outstanding levels of electro-
magnetic susceptibility (EMS). Similarly, extremely low electromagnetic emission (EME) is achieved by the excellent matching of the
output signals.
The AMIS-42675 is the industrial version of the AMIS-42665 and primarily for applications where long network lengths are mandatory.
Examples are elevators, in-building networks, process control and trains. To cope with the long bus delay the communication speed
needs to be low. AMIS-42675 allows low transmit data rates down 10 Kbit/s or lower.
2.0 Key Features
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Compatible with the ISO 11898 standard (ISO 11898-2, ISO 11898-5 and SAE J2284)
Wide range of bus communication speed (0 up to 1 Mbit/s)
Ideally suited for 12V and 24V industrial and automotive applications
Allows low transmit data rate in networks exceeding 1 km
Extremely low current standby mode with wake-up via the bus
Low electromagnetic emission (EME): common-mode choke is no longer required
Differential receiver with wide common-mode range (+/- 35V) for high EMS
Voltage source via V
SPLIT
pin for stabilizing the recessive bus level (further EMC improvement)
No disturbance of the bus lines with an un-powered node
Thermal protection
Bus pins protected against transients
Power down mode in which the transmitter is disabled
Bus and V
SPLIT
pins short circuit proof to supply voltage and ground
Logic level inputs compatible with 3.3V devices
At least 110 nodes can be connected to the same bus
3.0 Ordering Information
Table 1: Ordering Information
Ordering Code (Tubes)
0ICAA-001-XTD
Ordering Code (Tape)
0ICAA-001-XTP
Marketing Name
AMIS 42675AGA
Package
SOIC-8 GREEN
Temp. Range
-40°C…125°C
AMI Semiconductor
–October 07, Rev. 1.0
www.amis.com
Specifications subject to change without notice
1
AMIS-42675 High-Speed Low Power CAN Transceiver
For Long Networks
4.0 Technical Characteristics
Table 2: Technical Characteristics
Symbol
Parameter
V
CC
Power supply voltage
V
STB
DC voltage at pin STB
V
TxD
DC voltage at pin TxD
V
RxD
DC voltage at pin RxD
V
CANH
DC voltage at pin CANH
V
CANL
DC voltage at pin CANL
V
SPLIT
DC voltage at pin V
SPLIT
V
O(dif)(bus_dom)
Differential bus output voltage in dominant state
CM-range
Input common-mode range for comparator
V
CM-peak
C
load
t
pd(rec-dom)
t
pd(dom-rec)
V
CM-step
T
junc
Common-mode peak
Load capacitance on IC outputs
Propagation delay TxD to RxD
Propagation delay TxD to RxD
Common-mode step
Junction temperature
Data Sheet
Conditions
0 < V
CC
< 5.25V; no time limit
0 < V
CC
< 5.25V; no time limit
0 < V
CC
< 5.25V; no time limit
42.5Ω < R
LT
< 60Ω
Guaranteed differential receiver threshold and
leakage current
Note
See Figure 5
See Figure 5
Note
Min.
4.75
-0.3
-0.3
-0.3
-35
-35
-35
1.5
-35
-500
70
100
-150
-40
Max.
5.25
V
CC
V
CC
V
CC
+35
+35
+35
3
+35
500
15
230
245
150
150
Unit
V
V
V
V
V
V
V
V
V
mV
pF
ns
ns
mV
°C
Note:
The parameters V
CM-peak
and V
CM-step
guarantee low EME.
5.0 Block Diagram
V
CC
3
VCC
AMIS- 42675
POR
7
TxD
1
VCC
CANH
V
SPLIT
CANL
Thermal
shutdown
VCC
V
SPLIT
5
STB
8
Mode &
wake -up
control
Driver
control
6
RxD
GND
4
Wake - up
Filter
COMP
2
COMP
PC20071005.2
Figure 1: Block Diagram
AMI Semiconductor
–October 07, Rev. 1.0
www.amis.com
Specifications subject to change without notice
2
AMIS-42675 High-Speed Low Power CAN Transceiver
For Long Networks
6.0 Typical Application
6.1 Application Schematic
Data Sheet
VBAT
IN
5V-reg
OUT
V
CC
STB
3
8
4
V
CC
7
CANH
60
Ω
CAN
controller
RxD
TxD
AMIS-
42675
2
5
V
SPLIT
60
Ω
47 nF
CAN
BUS
1
6
CANL
PC20071005.3
GND
GND
Figure 2: Application Diagram
6.2 Pin Description
TxD
GND
V
CC
RxD
1
8
STB
CANH
CANL
V
SPLIT
AMIS-
42675
Figure 3: Pin Configuration
2
3
4
7
6
5
PC20071005.1
Table 3: Pin Out
Pin
Name
1
TxD
2
GND
3
V
CC
4
RxD
5
V
SPLIT
6
CANL
7
CANH
8
STB
Description
Transmit data input; low input => dominant driver; internal pull-up current
Ground
Supply voltage
Receive data output; dominant transmitter => low output
Common-mode stabilization output
Low-level CAN bus line (low in dominant mode)
High-level CAN bus line (high in dominant mode)
Stand-by mode control input
AMI Semiconductor
–October 07, Rev. 1.0
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www.amis.com
Specifications subject to change without notice
AMIS-42675 High-Speed Low Power CAN Transceiver
For Long Networks
7.0 Functional Description
7.1 Operating Modes
AMIS-42675 provides two modes of operation as illustrated in Table 4. These modes are selectable through pin STB.
Table 4: Operating Modes
Mode
Pin STB
Pin RXD
Low
High
Data Sheet
Normal
Standby
Low
High
Bus dominant
Wake-up request detected
Bus recessive
No wake-up request detected
7.1.1. Normal Mode
In the normal mode, the transceiver is able to communicate via the bus lines. The signals are transmitted and received to the CAN
controller via the pins TxD and RxD. The slopes on the bus lines outputs are optimized to give extremely low EME.
7.1.2. Stand-by Mode
In stand-by mode both the transmitter and receiver are disabled and a very low-power differential receiver monitors the bus lines for
CAN bus activity. The bus lines are terminated to ground and supply current is reduced to a minimum, typically 10µA. When a wake-up
request is detected by the low-power differential receiver, the signal is first filtered and then verified as a valid wake signal after a time
period of t
BUS
, the RxD pin is driven low by the transceiver to inform the controller of the wake-up request.
7.2 Split Circuit
The V
SPLIT
pin is operational only in normal mode. In standby mode this pin is floating. The V
SPLIT
is connected as shown in Figure 2 and
its purpose is to provide a stabilized DC voltage of 0.5 x V
CC
to the bus avoiding possible steps in the common-mode signal therefore
reducing EME. These unwanted steps could be caused by an un-powered node on the network with excessive leakage current from the
bus that shifts the recessive voltage from its nominal 0.5 x V
CC
voltage.
7.3 Wake-up
Once a valid wake-up (dominant state longer than t
BUS
) has been received during the standby mode the RxD pin is driven low.
7.4 Over-temperature Detection
A thermal protection circuit protects the IC from damage by switching off the transmitter if the junction temperature exceeds a value of
approximately 160°C. Because the transmitter dissipates most of the power, the power dissipation and temperature of the IC is
reduced. All other IC functions continue to operate. The transmitter off-state resets when pin TxD goes high. The thermal protection
circuit is particularly needed when a bus line short circuits.
7.5 High Communication Speed Range
The transceiver is primarily intended for industrial applications. It allows very low baud rates needed for long bus length applications.
But also high speed communication is possible up to 1Mbit/s.
7.6 Fail Safe Features
A current-limiting circuit protects the transmitter output stage from damage caused by accidental short circuit to either positive or
negative supply voltage, although power dissipation increases during this fault condition.
The pins CANH and CANL are protected from automotive electrical transients (according to ISO 7637; see Figure 4). Pins TxD and
STB are pulled high internally should the input become disconnected. Pins TxD, STB and RxD will be floating, preventing reverse
supply should the V
CC
supply be removed.
AMI Semiconductor
–October 07, Rev. 1.0
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www.amis.com
Specifications subject to change without notice
AMIS-42675 High-Speed Low Power CAN Transceiver
For Long Networks
8.0 Electrical Characteristics
8.1 Definitions
Data Sheet
All voltages are referenced to GND (pin 2). Positive currents flow into the IC. Sinking current means the current is flowing into the pin;
sourcing current means the current is flowing out of the pin.
8.2 Absolute Maximum Ratings
Stresses above those listed in the following table may cause permanent device failure. Exposure to absolute maximum ratings for
extended periods may affect device reliability.
Table 5: Absolute Maximum Ratings
Symbol
Parameter
Supply voltage
V
CC
DC voltage at pin CANH
V
CANH
DC voltage at pin CANL
V
CANL
DC voltage at pin VSPLIT
V
SPLIT
DC voltage at pin TxD
V
TxD
DC voltage at pin RxD
V
RxD
DC voltage at pin STB
V
STB
Transient voltage at pin CANH
V
tran(CANH)
Transient voltage at pin CANL
V
tran(CANL)
Transient voltage at pin VSPLIT
V
tran(VSPLIT)
Conditions
Min.
-0.3
-50
-50
-50
-0.3
-0.3
-0.3
-300
-300
-300
Max.
+7
+50
+50
+50
V
CC
+ 0.3
V
CC
+ 0.3
V
CC
+ 0.3
+300
+300
+300
Unit
V
V
V
V
V
V
V
V
V
V
0 < V
CC
< 5.25V; no time limit
0 < V
CC
< 5.25V; no time limit
0 < V
CC
< 5.25V; no time limit
Note 1
Note 1
Note 1
Note 2
Note 4
Note 3
V
esd(
Latch-up
Electrostatic discharge voltage at all pins
Static latch-up at all pins
Storage temperature
Ambient temperature
Maximum junction temperature
-5
-750
-55
-40
-40
T
stg
T
amb
T
junc
+5
+750
120
+150
+125
+170
kV
V
mA
°C
°C
°C
Notes:
1) Applied transient waveforms in accordance with ISO 7637 part 3, test pulses 1, 2, 3a, and 3b (see Figure 4).
2) Standardized human body model electrostatic discharge (ESD) pulses in accordance to MIL883 method 3015.7.
3) Static latch-up immunity: Static latch-up protection level when tested according to EIA/JESD78.
4) Standardized charged device model ESD pulses when tested according to EOS/ESD DS5.3-1993.
8.3 Thermal Characteristics
Table 6: Thermal Characteristics
Symbol
Parameter
Thermal resistance from junction to ambient in SO8 package
R
th(vj-a)
Thermal resistance from junction to substrate of bare die
R
th(vj-s)
Conditions
In free air
In free air
Value
145
45
Unit
K/W
K/W
AMI Semiconductor
–October 07, Rev. 1.0
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www.amis.com
Specifications subject to change without notice
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