AU5790D14-T [PHILIPS]
CAN Transceiver, 1-Trnsvr, PDSO14,;
| 型号： | AU5790D14-T |
| 厂家： | 
PHILIPS SEMICONDUCTORS |
| 描述： | CAN Transceiver, 1-Trnsvr, PDSO14, 电信 光电二极管 电信集成电路 |
| 文件： | 总25页 (文件大小：127K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
INTEGRATED CIRCUITS
The AU5790 single wire CAN transceiver is a line transceiver intended primarily for
in-vehicle class B multiplexing applications. This device provides interfacing between
a CAN data link controller and a single wire physical bus system with ground return.
AN2005
AU5790 Single wire CAN transceiver
Bin Lin
2001 Apr 16
Philips
Semiconductors
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
CONTENTS
1.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
2.
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
2
2.1
CAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bit Timing and Propagation Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Arbitration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Single Wire CAN Transceiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AU5790 in CAN Node Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AU5790 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Features List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Block Diagram and Function Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Mode and Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sleep Mode and Power Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wake-up Mode and Bus Signal Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
High Speed Data Download . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Normal Mode and Wave-shaping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loss of Ground Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AU5790 Application Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Node and Bus Load Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Basic Node Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CAN Bus Line Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
An Example of CAN Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermal Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermal Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Selecting a Package and Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1.1
2.1.2
2.2
2
3
4
2.3
4
3.
5
3.1
5
3.2
6
3.3
7
3.3.1
3.3.2
3.3.3
3.3.4
3.4
7
8
9
9
10
12
12
14
14
14
14
15
15
18
19
4.
4.1
4.2
4.2.1
4.2.2
4.2.3
4.3
4.3.1
4.3.2
4.3.3
i
2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
1. INTRODUCTION
The AU5790 single wire CAN transceiver is a line transceiver intended primarily for in-vehicle class B multiplexing applications. This device
provides interfacing between a CAN data link controller and a single wire physical bus system with ground return.
This application note is intended to explain AU5790 functions and benefits, and to guide the user in applying the AU5790 in a vehicle network
environment.
2. OVERVIEW
2.1 CAN
The Controller Area Network (CAN) is a serial communication protocol widely used in Automotive and Industrial applications for interconnecting
control units, sensors, actuators, etc.
There are two relevant CAN message formats in use today. One is the standard message format which is defined in CAN Specification 1.2. The
other one is the extended message format which is described in CAN Specification 2.0 Part B.
Primarily the two differ in that the standard message frame has 11 identifier bits, where the extended frame has 29 identifier bits.
STANDARD DATA FORMAT
IDENTIFIER
DLC
4
DATA
CRC
15
ACK
1
EOF
7
1
11
3
0 .. 8 BYTES
1
–
EXTENDED DATA FORMAT
IDENTIFIER
IDENTIFIER
DLC
4
DATA
CRC
ACK
1
EOF
7
1
11
2
18
3
0 .. 8 BYTES
15
1
1
SL01257
Figure 1. CAN message frames
2.1.1 Bit Timing and Propagation Delay
By the CAN bit timing definition, the Nominal Bit Time (NBT), with time duration t consists of three non-overlapping segments: SYNC_SEG,
bit,
TSEG1, and TSEG2, with time duration t
t
and t
respectively, as shown in Figure 2. Each of these segments may be
SYNC_SEG, seg1,
seg2,
programmed to be an integral number of the Time Quantum (TQ), whose time duration, t is derived from the oscillator. The sample point
Q,
usually is located at the end of TSEG1.
SYNCH_SEG
TSEG1
TSEG2
SAMPLE POINT
t
t
t
SEG2
SYNCH_SEG
SEG1
NBT, t
BIT
SL01258
Figure 2. CAN bit time definition
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2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
Within CAN each node must synchronize to each other’s message on the first recessive to dominant edge of the message and all the other
recessive to dominant edges in the message waveform. Because each node has its own clock reference, the oscillator tolerance, ∆f, will affect
the bit time and the sample time, so ∆f has big impact on the synchronization. Meanwhile, CAN supports arbitration and in-frame
acknowledgment, which means after sending out a data bit the transceiver needs to read back the bus level, so the propagation delay between
nodes in the network must be limited to guarantee synchronization.
The propagation delay from node A to node B includes all the device delays in the transmission path from A to B, CAN controller A delay time,
transceiver A transmit delay, transceiver B receive delay, and bus line delay, etc. Since all nodes must receive each other’s signal, and
synchronize to it, then send them back during arbitration, the total propagation delay in the network should be the round trip delay.
Dietmayer and Overberg analyzed CAN bit timing requirements in detail in their SAE technical paper #970295[1]. By summarizing their analysis,
we can find that in order to guarantee CAN bit time requirement, the total propagation delay has to satisfy following equations:
t
(max) < t – t
– ( 25t – t
)* ∆f (1)
seg2
prop
bit
seg2
bit
t
(max) < t – t
– ( 25t – t
)* ∆f + t
(min)/2 – t (1- ∆f) (2)
prop Q
prop
bit
seg2
bit
seg2
The requirement on Equation (1) is more severe than that on Equation (2) if the minimum propagation delay is larger than 2* t .
Q
2.1.2 Arbitration
If no device is transmitting a message, the network bus is in a recessive state, and any device may start to transmit a message. If more than
one device starts to transmit a message at the same time, only one device gets bus access successfully by bit arbitration using the identifier.
All devices on the bus are connected to the bus in a wired OR configuration. During arbitration, every device compares the read-back bus level
with the transmitted data level. If these levels are the same, the transmission continues. If a device sends a recessive level, and reads back a
dominant level, it has lost arbitration and has to stop sending any more bits, and becomes a receiver.
The following figure shows an arbitration example. Node 1, 2, and 3 start to send out message at the same time. At bit ID-23, node 2 sends a
recessive level, but the readback bus level is dominant, thus node 2 loses arbitration and becomes a receiver. Node 1 loses its arbitration at bit
ID-20. Node 3 finally wins bus access and continues message transmission.
ARBITRATION
CONTROL
DATA
ID 28 ... 18
R
T
R
S
O
F
RECEIVE
*
NODE 1
RECEIVE
NODE 2
*
NODE 3
DOMINANT
RECESSIVE
BUS-LEVEL
= ARBITRATION LOSS
BITS NOT SENT
*
SL01259
Figure 3. CAN bus arbitration
3
2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
2.2 Single Wire CAN Transceiver
Dual wire CAN transceivers are being extensively used in high speed (~1 Mbps) and medium speed (~125 Kbps) applications where data
transfer rate is the primary goal. The two wire approach lends itself well to high speed transmission while taking advantage of the inherent noise
cancellation associated with balanced twisted pair medium implementations.
In cost sensitive applications as in body electronics, where data rates can be reduced below 50 Kbps, single wire solutions provide a good
speed/cost alternative. In single wire systems EMC must be dealt with in the transceiver through wave-shaping to reduce frequency
components above the data rate.
The fundamental difference in network topology between the various types of transceivers offered by Philips is shown below.
A – HIGH SPEED
B – FAULT TOLERANT
C – SINGLE WIRE
(AU5790)
HS
LS
SW
HS
LS
SW
HS
LS
SW
Bus Voltage
Bus Voltage
Bus Voltage
5
4
5
4
CAN_L
CAN_H
4
2,5
CAN_L
1
1
0
CAN_H
CAN_H
0
t
t
t
Recessive
Dominant
Recessive
Recessive
Dominant
Recessive
Recessive
Dominant
Recessive
SL01260
Figure 4. CAN transceivers comparison
Figure 4(a) is a high speed CAN network with termination resistor to set the recessive level.
In Figure 4(b) a fault tolerant CAN network eliminates termination resistors and permits communication to continue under some fault conditions.
Resistors at each node set the recessive level.
The single wire CAN network shown at Figure 4(c) reduces the number of wires, and number of connectors or wire splices in half while also
reducing wiring harness weight. Resistors at each node set the recessive level.
2.3 AU5790 in CAN Node Architecture
A CAN node can be subdivided into three layers, as shown in Figure 5.
The object layer is concerned with message filtering as well as status and message handing.
The transfer layer represents the kernel of the CAN protocol. It presents messages received to the object layer and accepts message to be
transmitted from the object layer. The transfer layer is responsible for bit timing and synchronization, message framing, arbitration,
acknowledgement, error detection and signalling, and fault confinement.
The physical layer actually transmits signals. The AU5790 is a physical layer interface device in a CAN structure.
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2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
APPLICATION INTERFACE
OBJECT LAYER
µC
STAND-ALONE
CAN
CONTROLLER
(SJA1000)
TRANSFER LAYER
AU5790
PHYSICAL LAYER
CAN
TRANSCEIVER
SINGLE WIRE CAN BUS
SL01261
Figure 5. CAN node structure
3. AU5790 FEATURES
3.1 Feature list
• Supports in-vehicle class B multiplexing via a single bus line with ground return
• 33 kbps CAN bus transmission speed
• 83 kbps high-speed download mode
• Up to 32 bus nodes
• 70 µA power consumption in sleep mode
• Low electromagnetic emission due to output wave-shaping
• Direct battery operation with protection against load dump, jump start and transients
• Bus terminal protected against short-circuits and transients in the automotive environment
• Built in loss of ground protection
• Thermal overload protection
• Wake-up feature supports communication between control units even when network is in sleep state
• ± 8KV ESD protection on bus and battery pins
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Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
3.2 Block Diagram and Function Description
The AU7590 consists of several functional blocks shown in the block diagram below.
BATTERY (+12V)
BAT
1
VOLTAGE
TEMP.
PROTECTION
REFERENCE
L
BUS
CANH
TxD
7
OUTPUT
BUFFER
CAN
CONTROLLER
AND
µC
C
UL
3
NSTB
(Mode 0)
MODE
BUS
CONTROL
6
RECEIVER
EN
(Mode 1)
R
T
RxD
5
4
LOSS OF
GROUND
RTH
(LOAD)
PROTECTION
AU5790
8
GND
SL01306
Figure 6. AU5790 block diagram
The protocol controller feeds the transmit data stream to the transceiver’s TxD input. The AU5790 transceiver converts the TxD data input to a
bus signal with controlled slew rate and wave-shaping to minimize electromagnetic emissions. The bus output signal is transmitted via the
CANH in/output pin, which is connected to the physical bus medium. If TxD is low, then a typical voltage of 4 V is output at the CANH pin. If TxD
is high then the CANH output is pulled passive low via the local bus load resistance R . The physical bus lines for all transceivers on the bus are
T
connected in a wired-OR configuration, therefore the bus will be at a dominant level unless all nodes in network are passive.
To provide protection against a disconnection of the module ground wire the resistor R is connected to the RTH pin of the AU5790. The RTH
T
pin is connected to ground via the loss of ground protection circuit in the AU5790. By providing this switched ground pin, no current can flow
from the floating module ground to the bus via load resistor R .
T
The bus receiver detects the data stream at the bus line. The data signal is output at the RxD pin, which should be connected to a CAN
controller. If the bus level is recessive, i.e. all transmitters are passive, then RxD is floating or High with external pull-up resistance. If the bus
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2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
level is dominant, i.e. at least one transmitter is active, then RxD is Low. The RxD is an open drain output, and needs an external pull-up
resistance. To insure the RxD has the same voltage swing as other digital signal, the RxD pin should be pulled-up to the digital power supply
Vcc. The AU5790 provides appropriate high frequency filtering to ensure minimum susceptibility against electromagnetic interference. Further
enhancement is possible by applying an external inductor L and a capacitor C at the CANH pin as shown in Figure 6.
UL
The AU5790 features special robustness at its BAT and CANH pins. Hence the device is well suited for applications in the automotive
environment. The BAT input is protected against 40V load dump, jump start conditions and all the conventional Automotive transients as defined
in SAE J1113/ISO7637. In addition the CANH output pin is protected against ESD transients of at least 8KV without any external device
protection. Protection against wiring fault conditions e.g. short circuit to ground or battery voltage is also included in the design.
A thermal protection shutdown function with hysteresis is incorporated aimed at protecting the device against system fault conditions leading to
excessive operating junction temperature. In case the chip junction temperature reaches the trip point (>155 _C), the temperature protection
circuit will turn-off the transmit function. The transmit function is available again after a small decrease of the junction temperature. The thermal
shutdown hysteresis is about 5 _C.
NSTB and EN are mode control input pins. They are typically provided by a controller device. The AU5790 has four operation modes: sleep
mode, wake-up mode, high-speed transmission mode, and normal transmission mode.
3.3 Operating Mode and Control
The microcontroller controls the transceiver’s operating mode via the EN and NSTB pins. It is the microcontroller’s responsibility to insure that
the mode changes take place between the message frames. The following is the mode control summary table.
Table 1. Mode Control Summary
NSTB
EN
0
1
0
T D
X
don’t care
Description
sleep mode
wake-up mode
high-speed mode
normal mode
CANH
0 V
0 V, 12 V
0 V, 4 V
0 V, 4 V
R D
X
0
0
1
1
float(high)
bus state
bus state
bus state
T D-data
X
T D-data
X
T D-data
X
1
Times that the transceiver needs to change its operation mode are shown in following table.
Table 2. Mode Switching Time
From Mode
Normal
Normal
Normal
High speed
Wake-up
Sleep
To Mode
High speed
Wake-up
Sleep
Normal
Normal
Mode Switching Time (µs)
<30
<30
<500
<30
<30
<50
Normal
3.3.1 Sleep Mode and Power Management
Battery power management is extremely important while there are more and more electronic components on the in-vehicle network. The
AU5790 supports partial networking, i.e. individual nodes can communicate in normal and/or high-speed mode without disturbing the sleep
nodes in the network.
If the NSTB and EN control inputs are both pulled low or floating, the AU5790 enters a low-power or “sleep” mode. This mode is dedicated to
minimizing ignition-off current drain, to enhance system efficiency. In sleep mode, the typical quiescent current is 70 uA, and the transmit
function is disabled, e.g. the CANH output is inactive even when TxD is pulled low.
Sleeping nodes will ignore normal and/or high-speed communication on the bus, i.e. for 4.0 V dominant bus level, the RxD is still floating or
High. Sleeping nodes may be activated using the dedicated wake-up mode. An internal network active detector monitors the bus for any
occurrence of higher voltage signal level, typically 12 V, on the bus line with normal battery levels. If such levels are detected, a message will be
passed on to the CAN controller via the RxD output. Since the receive delay in sleep mode is much longer than that in normal or high speed
mode, the first wake-up message may be lost within the system. The controller should switch the transceiver to normal mode after it receives
the wake-up signal even though the message itself may be corrupt, otherwise the node will be back to sleep mode after the wake-up message.
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Application note
AU5790 Single wire CAN transceiver
AN2005
3.3.2 Wake-up Mode and Bus Signal Levels
When NSTB is low and EN is high the AU5790 enters wake-up mode i.e. it sends data with an increased signal level. This will result in an
activation of all sleeping bus nodes within the network.
A wake-up message has a much higher signal level than the normal and/or high-speed data. The following figure shows the transmitted, bus
and receive signals. The wake-up signal has a 12 V dominant level on the bus line while the normal signal level is 4 V, as shown in Figure 7.
Sleeping bus nodes will ignore normal 4.0 V dominant bus levels, and only respond to high voltage wake-up signals.
Since the thresholds of the receiver are different, the receive delay in sleep mode (T
) is much longer than that in normal mode (T ) in
TrN
TrW-S
Figure 7. The first wake-up message may be lost within the system. But a wake-up message is not require to be received correctly by sleeping
nodes. It is only required that all sleeping nodes detect this high voltage signal and set a High signal on RxD, and the controller may start the
oscillator for its time base, set transceiver to normal mode, etc.
In the meantime this high voltage wake-up signal has the same delay time at the normal signal threshold voltage, 3 V typical, as the normal
voltage signal. So the normal mode nodes still can interpret this high voltage signal correctly.
The high-speed and the wake-up features should not be active at the same time within the network.
TxD
1
0
12 V
WAKE UP
DOMINANT
t
TrW-S
4 V
NORMAL
DOMINANT
3 V
t
TrN
1 V
BUS
0 V
EFFECT OF LONG TIME
CONSTANT FROM LOAD
t
TfN
RxD
t
TfW
RECEIVING WHILE IN
NORMAL MODE
RxD
RECEIVING WHILE IN
SLEEP MODE
SL01262
Figure 7. Bus voltage levels and delay time at normal and wake-up mode, not to scale
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Application note
AU5790 Single wire CAN transceiver
AN2005
3.3.3 High Speed Data Download
The AU5790 also provides a high-speed transmission mode for software or diagnostic data download with bit rates up to 83 kbps. Usually an
external node is attached to the network as the data source. If the NSTB input is pulled high and the EN input is low, then the internal
wave-shaping function is disabled, i.e. the bus driver is turned on and off as fast as possible to support high-speed transmission of data.
Consequently the EMC performance in this mode is degraded compared to the normal transmission mode. In high-speed transmission mode
the AU5790 supports the same bus signal levels as in the normal mode.
For example, the user needs to download software from an external node or test tool.
1. Plug the external node on the bus, and the external node is in normal mode.
2. Sends ‘go to high speed mode’ message to all nodes. If some of nodes do not need to download the software, sends ‘go to sleep mode’
message to those nodes first, then sends ‘go to high speed mode’ message to the other nodes.
3. Controllers will set transceivers to high-speed mode (EN = 0, NSTB = 1) or sleep mode (EN = 0, NSTB = 0), respectively. The external
node also goes to high-speed mode.
4. The external node sends data at the high speed bit rate.
5. The external node goes to normal mode and sends a ‘go to normal mode’ message to all nodes, or goes to wake up mode and wakes up
all sleep nodes first, then put all nodes back to normal mode.
6. Unplug the external node.
The user should not allow high-speed mode nodes existing in the network at the same time with normal mode nodes, and wake-up mode nodes
because it will cause bit timing errors.
3.3.4 Normal Mode and Wave-shaping
The AU5790 is in normal transmission mode when EN = 1, and NSTB = 1. In this mode, the transceiver sends a normal voltage signal onto the
bus at a normal communication bit rate, typically 33.3 kbps.
Important contributors to the EM emissions are the rise and fall times during output transitions and the ‘corners’ of the voltage waveform. To
minimize EM emissions, the AU5790 integrates a wave-shaping feature. The slew rate and the shape of the signal rising edges are controlled,
as well as the onset of the falling edge. After the driver is off, the remaining fall time of the high to low transition is determined by the RC time
constant of the total bus load.
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Application note
AU5790 Single wire CAN transceiver
AN2005
3.4 Loss of Ground Protection
Figure 8 shows the currents flowing during normal operation. The modules ground is the same as the vehicle ground.
I
E
I
T
I
E
I
T
is the current flowing to ground through the other module circuits, represented by R .
E
is the current flowing to ground through the modules load resistor R .
T
VEHICLE BATTERY
BAT
CANH
R
E
AU5790
R
T
OTHER
MODULE
CIRCUIITS
LOSS OF
GROUND
R
L
PROTECTION
RTH
GND
MODULE
I
E
I
T
VEHICLE GROUND
Figure 8. Current flow at normal condition
SL01263
Figure 9 shows what happens when the ground connection between the module and the vehicle is broken, if there is no loss of ground
protection. When the module looses its ground connection, any other ciruits between the module’s internal ground and battery will act as a pull
up to raise the module ground toward the battery level. These circuits are shown by their equivalent resistance, R . Without loss of ground
E
protection, the current will flow through R and the termination resistor R which acts as pull up resistors, instead of the intended pull down.
IE
E
T
When the bus is in a recessive level, this current flowing through the load resistors of the other modules, will raise the voltage level on the bus.
This will degrade bus noise margins, and potentially will corrupt proper data transmission,
I
I
I
I
is the current flowing to the bus through the other module circuits, represented by R and the termination resistor R
E T
E
E
is the current flowing to the bus from the CANH driver during loss of ground without a loss of ground protection circuit. The
CANLG
CANLG
actual current entering the bus from this node would be the sum of I and I
E
.
CANLG
VEHICLE BATTERY
I
CANLG
BAT
CANH
R
E
AU5790
OTHER
MODULE
CIRCUIITS
R
T
I
E
R
L
RTH
GND
MODULE
OPEN GROUND PATH
VEHICLE GROUND
SL01264
Figure 9. Current flow at module without loss of ground protection
10
2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
Figure 10 shows operation when a loss of ground protect circuit is included. The aim of the loss of ground protection circuit is to open the
current path from battery to the bus via the other module circuits, R , and through the load resistor R . Instead of connection to GND directly,
E
T
RTH is connected to GND through a controlled switch. When the module looses its ground, the GND reference will float up toward the battery
level. When the voltage drop between BAT and GND is less than ~5 V, the switch is opened and there is no current flow from this path. The
AU5790 features a low leakage current of 50 µA max. to the bus during loss of ground. This low leakage current will keep the bus offset voltage
sufficiently low to maintain proper bus levels for normal operation.
I
I
is the current flowing to the bus from the CANH driver during loss of ground, as tested, this is the sum of the leakage currents
CANLG
CANLG
from both the CANH pin directly and from the RTH pin via the termination resistor, R .
T
VEHICLE BATTERY
I
< 50 µA
CANLG
BAT
CANH
R
E
OTHER
MODULE
CIRCUIITS
AU5790
R
T
LOSS OF
GROUND
R
L
PROTECTION
RTH
GND
MODULE
OPEN GROUND PATH
SL01265
VEHICLE GROUND
Figure 10. Loss of ground protection
11
2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
4. APPLICATION INFORMATION
4.1 AU5790 Application Circuit
CAN CONTROLLER
(e.g. SJA1000)
PORT
TX0
RX0
PORT
R
D
+5V
2.4 to
2.7kΩ
1N5060
or equiv.
TxD
RxD
NSTB
EN
+12V
BAT
AU5790
TRANSCEIVER
100 nF
1 to 4.7 µF
GND
CANH
RTH
9.1kΩ,
1%
R
T
R
L
270 Ω, 10%
47 µH
C
UL
10%
220 pF
CAN BUS LINE
Note 1 TX0 should be configured to push-pull operation, active low; e.g., Output Control Register = 1E hex.
Note 2 Recommended range for the load resistor is 2k < R < 9.2k.
SL01311
T
Figure 11. AU5790 application circuit
The Microcontroller and CAN controller communicate with other nodes within the single wire can network via the transceiver.
The blocking diode between the battery and the AU5790 BAT pin protects the transceiver and all other module ICs from reverse battery
voltages. It should support reverse breakdown voltages of > 100 V, and should have a forward drop of < 1V at the maximum current required by
the module. The RxD pin is an open drain structure so it does not have an active pull up. A pull up resistor should be connected from RxD to the
digital power supply V , and a value of 2.4kΩ to 2.7kΩ should be used to meet the timing specified on the data sheet. This pull up allows the
CC
receive pin to drive the digital logic without having to supply V to the transceiver.
CC
R is the nodes load resistance within the module while C is the unit load capacitance of the node.
T
UL
The nodes loading components can have an effect on the modules EMC characteristics. An inductor, L, of 47 µH is required between the CANH
pin and the bus. A damping resistor R in parallel can further improve EMC characteristics. The impact of the L and R on the EMC characteristics
is dependent on the bus load and the frequency of interest. Figures 12 and 13 show the EM emissions with different combinations of total bus
load R(L), total bus capacitance C(L) and the local nodes R and L values. With a light total load R(L) = 5.1 kΩ as shown in Figure 13, the series
inductor, interacting with the load capacitance C(L) forms a tank circuit and including R decreases the Q of the tank circuit and hence the
amplitude of the EME. If required to minimize EME at < 1 MHz, a damping resistor R of 270 Ω ±10% should be inserted in parallel with
inductor L.
12
2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
50
40
30
20
10
0
R (L) = 301 Ω,
C(L) = 12 nF,
L = 47 µH
R (L) = 301 Ω,
C(L) = 12 nF,
L = 47 µH,
R = 274 Ω
5.0E+05
7.0E+05
9.0E+05
1.1E+06
1.3E+06
1.5E+06
1.7E+06
Frequency (Hz)
SL01266
Figure 12. The influence of external components on EME with heavy load
50
40
30
R(L) = 5.1 kΩ,
C(L) = 680 pF,
L = 47 µH
20
10
R(L) = 5.1 kΩ,
C(L) = 680 pF,
L = 47 µH,
R = 274 Ω
0
5.0E+05
7.0E+05
9.0E+05
1.1E+06
1.3E+06
1.5E+06
1.7E+06
Frequency (Hz)
SL01267
Figure 13. The influence of external components on EME with light load
13
2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
4.2 Node and Bus Load Effects
For the AU5790 the termination resistor R is needed to pull down the bus line to the recessive level as default. C is required to reduce
T
UL
interference caused by high frequency noise on the bus. A CAN node presents a R // C load to the bus.
T
UL
4.2.1 Basic Node Load
The basic node load R // C is:
T
UL
• C = 220 pF (+/- 10%)
UL
• 2 kΩ < R < 9.2 kΩ
T
- For a network of 32 nodes, R = 9.1 kΩ (+/- 1%). A smaller value for R will result in violating the requirement for the CAN bus line total
T
T
load, R .
L
4.2.2 CAN Bus Line Load
The total bus load R // C is:
L
L
• C < 13.7nF
L
- C = sum of all C + cable capacitance C
L
UL
C
- C = typically 100 pF/m * total length of all cable. Note the actual capacitance per meter is dependent on the cable chosen. Consult the
C
wire specification for this value.
• 270 Ω < R < 9.2 kΩ
L
- R is the all parallel equivalent of all the individual node resistors, R , between the CAN bus and ground.
L
T
- The 270 Ω minimum bus load resistance is limited by the CANH output capability.
• 1µs < R * C < 4 µs
L
L
- The bus time constant R * C determines the duration of the CANH signal’s falling edge.
L
L
- A small time constant may result in high EM emission. The bus time constant should not be less than 1µs in order to meet EMC
requirements.
- A large time constant may cause long transmit delay time, and violate CAN bit timing requirement. The bus time constant should not be
more than 4 µs.
4.2.3 An Example of CAN Network
A CAN network may consist of both standard nodes and optional nodes, and node loads may be different. The user has to consider the
minimum and maximum system, and all R
C and R * C have to be within the range. Bus wiring capacitance tends to increase the time
L, L, L L
constant. A lower value of R in standard modules may be used to counterbalance this increase.
T
The following is a CAN network example:
• 5 standard nodes, R = 3.9 kΩ
T
• 0 to 20 optional nodes, R = 9.1 kΩ
T
• Node capacitance C = 220 pF
UL
• 40 meters wiring
For minimum system with 5 standard nodes:
• R = 3.9 kΩ / 5 = 780 Ω
L
• C = (220 pF * 5 )+ (40 m * 100 pF/m) = 5.1 nF
L
• R * C = 3.98 µs
L
L
All parameters are within the requirement range, but the time constant R * C is near the maximum limit.
L
L
For maximum system with 5 standard and 20 optional nodes:
• R = 3.9 kΩ / 5 // 9.1 kΩ /20 = 287 Ω
L
• C = (220 pF * 25) + (40 m * 100 pF/m) = 9.5 nF
L
• R * C = 2.73 µs
L
L
All parameters are within the requirement range, but the load resistance R is near the minimum limit.
L
So this system is OK with all requirement. This example demonstrates that a lower value of R may be needed in standard nodes to keep the
T
time constant within the spec, especially when the wiring in minimum system and maximum system are comparable, but the maximum number
of 32 nodes can not be reached with this configuration.
14
2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
4.3 Thermal Management
The AU5790 provides protection from thermal overload. When the IC junction temperature reaches the threshold (>155 _C), the AU5790 will
disable the transmitter drivers, reducing power dissipation to protect the device. The transmit function will be available again after the junction
temperature drops. The thermal shutdown hysterisis is about 5 _C.
In order to avoid this transmit function shutdown, care must be taken to not overheat the IC during normal operation. The relationship among the
junction temperature, the ambient temperature, the dissipated power, and the thermal resistance can be expressed as:
T =T + P * θ
ja
j
a
d
where:
T is junction temperature (_C);
a
j
T is ambient temperature (_C);
P is dissipated power (W);
d
θ
is thermal resistance (_C/W).
ja
4.3.1 Thermal Resistance
Thermal resistance is the ability of a subject to dissipate heat to its environment. In semiconductor applications, it is highly dependant on the IC
package, PCBs, and airflow. Thermal resistance also varies slightly with input power, the difference between ambient and junction temperature,
and soldering material, etc.
Figures 14 and 15 show the thermal resistance as a function of IC package and PCB configuration assuming no airflow.
The high/low conductance board is the JEDEC standard high/low effective thermal conductive test board. The JESD51-7 and EIA/JESD51-3
specifications are available from: http://www.jedec.org. The high conductance board contains two 1 oz thick Cu ground planes, and 2 oz
(0.071 mm) thick Cu top and bottom trace layers. The low conductance board does not contain any ground planes, and has 2 oz (0.071 mm)
thick Cu top and bottom trace layers. The very low conductance board is the PCB with EIA/JESD51-3 standard trace configuration, but the
traces are 1 oz thick Cu instead of standard 2 oz Cu.
15
2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
200
150
100
50
very low
conductance
board
low
conductance
board
high
conductance
board
0
0
50
100
150
200
250
Cu area on fused pin(mm2)
SL01268
Figure 14. SO-8 thermal resistance vs. PCB configuration
150
100
50
very low
conductance
board
low
conductance
board
high
conductance
board
0
0
100
200
300
400
500
Cu area on fused pins (mm2)
SL01269
Figure 15. SO-14 thermal resistance vs. PCB configuration
Both the SO-8 and SO-14 have one or more pins which are directly connected, or fused, to the die bonding pad to provide an improved thermal
path from the die to the pin. Normally the die pad and the lead frame are stamped from the same copper sheet during manufacture. Wire bonds
connect from bonding pads on the die to the lead frame and the die attach pad supports the die. By making the copper continuous from the die
attach pad to the lead frame these fused pins have lower thermal resistance than normal pins which rely on wire bonds to make electrical
connections. Figure 16 shows sketches of both the SO-8 and SO-14 package construction. On the SO-8 package, pin 8 is directly fused with
the die attach pad. On the SO-14 package all 4 corner pins are fused to the die attach pad. The thermal resistance from die to ambient can be
further improved by putting an area of copper foil on the board connected to the fused pins. This copper area acts as a heat sink. The “Cu area
on fused pin(s) (mm2)” shown on Figures 14 and 15 refers to the total area of copper connected to the fused pins.
16
2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
COPPER AREA
ON BOARD
GND
FOR HEAT
DISSIPATION
GND
N.C.
PINS FUSED
TO
DIE PAD
TxD
NSTB
EN
BONDING
WIRE
CANH
RTH
DIE
RxD
N.C.
BAT
TYPICAL EXTERNAL PIN
AND INTERNAL LEAD FRAME
DIE PAD
N.C.
GND
GND
PACKAGE BODY
(a). SO-14 CONFIGURATION
COPPER AREA
ON BOARD FOR
HEAT DISSAPATION
TxD
GND
PIN FUSED TO
DIE PAD
CANH
RTH
NSTB
EN
DIE
DIE PAD
RxD
BAT
BONDING WIRE
TYPICAL EXTERNAL PIN AND
INTERNAL LEAD FRAME
PACKAGE BODY
(b). SO-8 CONFIGURATION
SL01270
Figure 16. Package heat conductor configuration
17
2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
4.3.2 Power Dissipation
The power dissipation of an IC is the major factor determining junction temperature. The AU5790 power dissipations in active and passive
states are different. The average power dissipation is:
P
tot
= P *Dy + P
* (1-Dy)
INT
PNINT
where:
P
P
P
is total dissipation power;
tot
is dissipation power in an active state;
INT
is dissipation power in a passive state;
PNINT
Dy is duty cycle, which is the percentage of time that TxD is in an active state during any given time duration.
At passive state there is no current going into the load. So all of the supply current is dissipated inside the IC.
P
PNINT
= V
* I
BAT BATPN
where:
V
BAT
is the battery voltage;
I
is the passive state supply current in normal mode.
BATPN
In an active state, part of the supply current goes to the load, and only part of the supply current dissipates inside the IC, causing an
incremental increase in junction temperature.
P
INT
= P
– P
BATAN LOADN
where:
where:
P
P
is active state battery supply power in normal mode;
BATAN
P
BATAN
= V
* I
BAT BATAN
is load power consumption in normal mode.
LOADN
P
= V
* I
CANHN LOADN
LOADN
I
is active state supply current in normal mode;
BATAN
V
is bus output voltage in normal mode;
CANHN
I
is current going through load in normal mode.
LOADN
I
= V
/R
CANHN LOAD
LOAD
I
= I
+ I
LOAD INT
BATN
where:
I
I
is an active state current dissipated within the IC in normal mode.
INT
will decrease slightly when the node number decreases. To simplify this analysis, we will assume I
is fixed.
INT
INT
I
= I
(32 nodes) – I
(32 nodes)
LOAD
INT
BATN
I
(32 nodes) may be found in the DC Characteristics table.
BATN
A power dissipation example follows. The assumed values are chosen from specification and typical applications.
Assumptions:
V
BAT
= 13.4 V
R
T
= 9.1 kΩ
32 nodes
= 2 mA
I
BATPN
I
(32 nodes) = 35 mA
BATN
V
= 4.55 V
CANHN
Duty cycle = 50%
Computations:
R
= 9.1 kΩ / 32 = 284.4 Ω
LOAD
P
I
= 13.4 V × 2 mA = 26.8 mW
= 4.55 V / 284.4 Ω = 16mA
= 4.55 V × 16 mA = 72.8 mW
= 35 mA - 16 mA = 19 mA
= 13.4 V × 35 mA = 469 mW
PNINT
LOAD
P
LOADN
I
INT
P
BATAN
P
INT
= 469 mW - 72.8 mW = 396.2 mW
P
tot
= 396.2 mW × 50% + 26.8 mW × (1-50%) = 211.5 mW
Additional examples with various node counts are shown in Tables 3, 4, and 5 for operation at 13.4 V, 18 V, and 26.5 V respectively.
18
2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
Table 3. Power Dissipation At 13.4 V Battery Voltage Vs. Node Count
I
P
V
I
I
I
P
P
tot
BATPN
(mA)
PNINT
CANHN
(V)
LOADN
(mA)
BATN
INT
INT
Nodes
R
(Ω)
V
(V)
Dcycle
L
BAT
(mW)
26.8
26.8
26.8
26.8
(mA)
(mA)
(mW)
263.5
298.9
343.1
396.2
(mW)
145.1
162.8
184.9
211.5
2
4550
13.4
13.4
13.4
13.4
2
2
2
2
4.55
4.55
4.55
4.55
1
5
20
19
0.5
0.5
0.5
0.5
10
20
32
910
455
24
19
10
16
29
19
284.4
35
19
Table 4. Power Dissipation At 18 V Battery Voltage Vs. Node Count
R
I
P
(mW)
V
I
I
I
P
P
tot
L
BATPN
(mA)
PNINT
CANHN
(V)
LOADN
(mA)
BATN
INT
INT
Nodes
V
(V)
Dcycle
BAT
(Ω)
4550
910
(mA)
(mA)
(mW)
355.5
409.3
476.5
557.2
(mW)
195.7
222.6
256.3
296.6
2
18
18
18
18
2
2
2
2
36
4.55
4.55
4.55
4.55
1
5
20
19
0.5
0.5
0.5
0.5
10
20
32
36
24
19
455
36
10
16
29
19
284.4
36
35
19
Table 5. Power Dissipation At 26.5 V Battery Voltage Vs. Node Count
R
I
P
(mW)
V
I
I
I
P
P
tot
L
BATPN
(mA)
PNINT
CANHN
(V)
LOADN
(mA)
BATN
INT
INT
Nodes
V
(V)
Dcycle
BAT
(Ω)
4550
910
455
284
(mA)
(mA)
(mW)
525.5
613.3
723
(mW)
289.2
333.1
388
2
26.5
26.5
26.5
26.5
2
2
2
2
53
4.55
4.55
4.55
4.55
1
5
20
19
0.5
0.5
0.5
0.5
10
20
32
53
24
19
53
10
16
29
19
53
35
19
854.7
453.8
4.3.3 Selecting a Package and Board
In a user’s application, the following are usually known or can be calculated from circuit parameters;
Tj(max) = 150 _C from the data sheet.
This is the maximum allowed junction temperature.
Ta(max) is known from the user’s application.
Typically the maximum ambient temperature, Ta, it will be 85 _C for most body multiplexing nodes, however some nodes such as those
in the instrument cluster may require operation at 105 _C and any nodes in the engine compartment will most likely require operation in
a 125 _C ambient.
Pd(max) is the power dissipation for the worst case combination of load and supply voltage.
It can be calculated as described in the previous section for any application. Several summaries of calculated Pd are shown in Tables 3,
4, and 5 at the end of the previous section.
This leaves only the thermal resistance, θja, as an unknown. The thermal equation can be solved for θja.
Tj = Ta + Pd*θja Becomes; θja = (Tj–Ta)/Pd
With θja calculated, Figures 14 and 15 may be used to determine a package and PC board configuration that will provide a thermal resistance,
θja, less than the required value.
For example assume; θja(max) = 125 _C/W
Examining Figure 14 for the SO-8 package we find that a high conductance board with just the normal signal traces will provide approximately
100 _C/W and hence exceeds the requirements with margin to spare. The low conductance board will also work if 225-sq. mm of foil area is
included on pin 8, the fused pin, to act as a heat sink providing approximately 120 _C/W. It can also be seen that the very low thermal
conductance board will not support this application using an SO-8 package. If we now examine the SO-14 curves in Figure 15 we find even the
very low conductance board will meet the needs of the application with minimal additional copper foil for heat dissipation, and the low and high
conductance boards do not require any extra foil area.
For selected operating voltages Figures 17 through 22 shows plots that allow the user to select a board type if the number of standard nodes,
operating voltage, and ambient temperature are known. These plots were created using the data and equations from the previous two sections.
Select the plot for the operating voltage and package type being considered, and then find the intersection of the maximum node count and the
highest ambient temperature required. Any curve which is above the intersection point represents a board type and possible area of heat
dissipating copper foil which will provide a low enough thermal resistance to meet the applications needs. These plots assume all nodes use the
normal unit load resistance of 9.1 kΩ, and insure that the junction temperature, Tj, will not exceed 150 _C.
19
2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
145
125
105
85
VERY LOW CONDUCTANCE BOARD,
NORMAL TRACE
VERY LOW CONDUCTANCE BOARD,
2
225 MM Cu ON FUSED PIN
LOW CONDUCTANCE BOARD,
NORMAL TRACE
LOW CONDUCTANCE BOARD,
2
225 MM Cu ON FUSED PIN
HIGH CONDUCTANCE BOARD,
NORMAL TRACE
HIGH CONDUCTANCE BOARD,
2
225 MM Cu ON FUSED PIN
0
10
20
30
40
NODE COUNT
SL01271
Figure 17. Maximum ambient temperature SO-8 may support vs. node count at 13.4 V battery voltage
145
125
105
85
VERY LOW CONDUCTANCE BOARD,
NORMAL TRACE
VERY LOW CONDUCTANCE BOARD,
2
417.6 MM Cu ON FUSED PIN
LOW CONDUCTANCE BOARD,
NORMAL TRACE
LOW CONDUCTANCE BOARD,
2
417.6 MM Cu ON FUSED PIN
HIGH CONDUCTANCE BOARD,
NORMAL TRACE
HIGH CONDUCTANCE BOARD,
2
417.6 MM Cu ON FUSED PIN
0
10
20
30
40
NODE COUNT
SL01274
Figure 18. Maximum ambient temperature SO-14 may support vs. node count at 13.4 V battery voltage
20
2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
145
125
105
85
VERY LOW CONDUCTANCE BOARD,
NORMAL TRACE
VERY LOW CONDUCTANCE BOARD,
2
225 MM Cu ON FUSED PIN
LOW CONDUCTANCE BOARD,
NORMAL TRACE
LOW CONDUCTANCE BOARD,
2
225 MM Cu ON FUSED PIN
HIGH CONDUCTANCE BOARD,
NORMAL TRACE
HIGH CONDUCTANCE BOARD,
2
225 MM Cu ON FUSED PIN
0
10
20
30
40
NODE COUNT
SL01272
Figure 19. Maximum ambient temperature SO-8 may support vs. node count at 18 V battery voltage
145
125
105
85
VERY LOW CONDUCTANCE BOARD,
NORMAL TRACE
VERY LOW CONDUCTANCE BOARD,
2
417.6 MM Cu ON FUSED PIN
LOW CONDUCTANCE BOARD,
NORMAL TRACE
LOW CONDUCTANCE BOARD,
2
417.6 MM Cu ON FUSED PIN
HIGH CONDUCTANCE BOARD,
NORMAL TRACE
HIGH CONDUCTANCE BOARD,
2
417.6 MM Cu ON FUSED PIN
0
10
20
30
40
NODE COUNT
SL01275
Figure 20. Maximum ambient temperature SO-14 may support vs. node count at 18 V battery voltage
21
2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
145
125
105
85
VERY LOW CONDUCTANCE BOARD,
NORMAL TRACE
VERY LOW CONDUCTANCE BOARD,
2
225 MM Cu ON FUSED PIN
LOW CONDUCTANCE BOARD,
NORMAL TRACE
LOW CONDUCTANCE BOARD,
2
225 MM Cu ON FUSED PIN
HIGH CONDUCTANCE BOARD,
NORMAL TRACE
HIGH CONDUCTANCE BOARD,
2
225 MM Cu ON FUSED PIN
0
10
20
30
40
NODE COUNT
SL01273
Figure 21. Maximum ambient temperature SO-8 may support vs. node count at 26.5 V battery voltage
145
125
105
85
VERY LOW CONDUCTANCE BOARD,
NORMAL TRACE
VERY LOW CONDUCTANCE BOARD,
2
417.6 MM Cu ON FUSED PIN
LOW CONDUCTANCE BOARD,
NORMAL TRACE
LOW CONDUCTANCE BOARD,
2
417.6 MM Cu ON FUSED PIN
HIGH CONDUCTANCE BOARD,
NORMAL TRACE
HIGH CONDUCTANCE BOARD,
2
417.6 MM Cu ON FUSED PIN
0
10
20
30
40
NODE COUNT
SL01276
Figure 22. Maximum ambient temperature SO-14 may support vs. node count at 26.5 V battery voltage
Reference
[1]
K. Dietmayer, K. W. Overberg, ‘CAN Bit Timing Requirements’, SAE Technical Paper Series, #970295.
22
2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
NOTES
23
2001 Apr 16
Philips Semiconductors
Application note
AU5790 Single wire CAN transceiver
AN2005
Definitions
Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For
detailed information see the relevant data sheet or data handbook.
Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one
or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or
at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended
periods may affect device reliability.
Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips
Semiconductors make no representation or warranty that such applications will be suitable for the specified use without further testing or
modification.
Disclaimers
Life support — These products are not designed for use in life support appliances, devices or systems where malfunction of these products can
reasonably be expected to result in personal injury. Philips Semiconductors customers using or selling these products for use in such applications
do so at their own risk and agree to fully indemnify Philips Semiconductors for any damages resulting from such application.
Righttomakechanges—PhilipsSemiconductorsreservestherighttomakechanges, withoutnotice, intheproducts, includingcircuits,standard
cells, and/or software, described or contained herein in order to improve design and/or performance. Philips Semiconductors assumes no
responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright, or mask work right to these
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otherwise specified.
Philips Semiconductors
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Copyright Philips Electronics North America Corporation 2001
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Date of release: 04-01
Document order number:
9397-750-08258
Philips
Semiconductors
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