Philips AU5783D Datasheet
INTEGRATED CIRCUITS
AU5783
J1850/VPW transceiver with
supply control function
Preliminary specification
Supersedes data of 2000 Nov 29
2001 Feb 15
Philips Semiconductors Preliminary specification
TYPE NUMBER
AU5783J1850/VPW transceiver with supply control function
FEATURES
•Supports SAE/J1850 VPW standard for in-vehicle class B
multiplexing
•Bus speed 10.4 kbit/s nominal
•4X transmission mode (41.6 kbit/s)
•Drive capability 32 bus nodes
•Low RFI due to output waveshape function
•Direct battery operation with protection against +40 V load dump
and 8 kV ESD
•Bus terminals proof against automotive transients up to
+100 V/–150 V and 8 kV ESD
•Power supply enable function
DESCRIPTION
The AU5783 is a line transceiver being primarily intended for
in-vehicle multiplex applications. It provides interfacing between a
J1850 link controller and the physical bus wire. The device supports
the SAE/J1850 VPWM standard with a nominal bus speed of
10.4 kbit/s. For data upload and download purposes the 4X
transmission mode is supported with a nominal bus speed of
41.6 kbit/s. The AU5783 provides protection against loss of ground
conditions, thus ensuring the network will be operational in case of
an electronic control unit loosing connection to ground potential. Low
power operation is supported through provision of a sleep mode with
very low power consumption. In addition an external voltage
regulator can be turned off via the AU5783 transceiver to further
reduce the overall power consumption. The voltage regulator will be
activated again upon detection of bus activity or upon a local
wake-up event.
•Very low sleep mode power consumption
•Diagnostic loop-back mode
•Thermal overload protection
•14-pin SOIC
ORDERING INFORMATION
PACKAGE
NAME DESCRIPTION VERSION
AU5783D SO14 plastic small outline package; 14 leads; body width 3.9 mm SOT108-1 –40 to +125°C
TEMPERATURE
RANGE
QUICK REFERENCE DATA
SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT
V
BAT.op
T
amb
V
BAT.ld
V
BOH
V
BI
I
BAT.lp
t
P
t
r
Operating supply voltage, including low battery
operation
Operating ambient temperature range –40 +125 °C
Battery voltage load dump, 1s +40 V
Bus output voltage 250 Ω < RL < 1.6 kΩ 6.7 8.0 V
Bus input threshold 3.4 4.2 V
Sleep mode supply current 90 µA
Propagation delay Tx to Rx 25 µs
Bus output rise time 14 µs
5.5 12 16 V
2001 Feb 15
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Philips Semiconductors Preliminary specification
AU5783J1850/VPW transceiver with supply control function
BLOCK DIAGRAM
BATTERY (+12V)
BAT
Rs
4X/LOOP
Vcc (+5V)
LWAKE
R/F
NSTB
Rd
RX
INH
VOLTAGE
REFERENCE
1.6V
Vbat
TX–
BUFFER
MODE
CONTROL
VOLTAGE
REFERENCE
WAKE-UP
CONTROL
TX
TEMP.
PROTECTION
OUTPUT
BUFFER
LOAD
SWITCH
AU5783
BUS
Rld
LOAD
2001 Feb 15
GND
SL01224
Figure 1. Block diagram
3
Philips Semiconductors Preliminary specification
AU5783J1850/VPW transceiver with supply control function
PINNING
Pin configuration
R/F
GND
4X/LOOP
NSTB
RX
N.C.
1
2
3
4
5
TX
6
7
AU5783
Figure 2. Pin configuration
SO14
14
13
12
10
9
8
11
GND
N.C.
BUS
LOAD
INH
LWAKE
BAT
SL01225
Pin description
SYMBOL PIN DESCRIPTION
R/F 1 Rise/fall time control input; connect to ground
GND 2 Ground
4X/LOOP 3 Tx mode control input; low: normal mode;
NSTB 4 Network STandBy power control input; low:
TX 5 Transmit data input; low: transmitter passive;
RX 6 Receive data output; low: active bus condition
N.C. 7 Not connected
BAT 8 Battery supply input, 12V nominal
LWAKE 9 Local wake-up input, edge sensitive
INH 10 Activity indication flag (inhibit) output high side
LOAD 11 Bus load in/output
BUS 12 Bus line transmit/receive input/output, active
N.C. 13 Not connected
GND 14 Ground
potential via a resistor
high: 4X mode; float: loopback
transmit function disabled (low power modes);
high: transmit function enabled
high: transmitter active
detected; high: otherwise
driver; e.g., to control a voltage regulator.
Active high enables the regulator
high side driver
FUNCTIONAL DESCRIPTION
The AU5783 is an integrated line transceiver IC that interfaces an
SAE/J1850 protocol controller IC to the vehicle’s multiplex bus line.
It is primarily intended for automotive “Class B” multiplexing
applications in passenger cars using VPW (Variable Pulse Width)
modulated signals with a nominal transmission speed of 10.4 kbit/s.
The device provides transmit and receive capability as well as
protection to a J1850 electronic module.
A J1850 link controller feeds the transmit data stream to the
transceiver’s TX input. The AU5783 transceiver waveshapes the TX
data input signal so as to minimize electromagnetic emission. The
bus output signal features controlled rise & fall characteristic
including rounded shape. A resistance being connected to the R/F
control input sets the bus output slew rate.
The LOAD output is connected to the physical bus line via an
external load resistor R
ground potential being the default state, e.g., when no transmitter
outputs an active state. This output ensures the J1850 network will
not be affected by a potential loss of ground condition at an
individual electronic control unit.
The AU5783 includes a bus receiver with filter function to minimize
susceptibility against interference. The logic state of the J1850 bus
signal is indicated at the RX output being connected to the J1850
link controller.
The AU5783 also provides advanced low-power modes to help
minimize ignition-off power consumption of an electronic control unit.
The bus receiver function is kept alive in the low-power modes. If an
active state is being detected on the bus line this will be indicated
via the RX output. By default the AU5783 enters the low-power
standby mode when the mode control inputs NSTB and 4X/LOOP
are not driven. A 100 kΩ pull down resistor is required on NSTB.
Ignition-off current draw can be reduced further by turning off the
voltage regulator being typically provided in an electronic control
unit. This is supported by the activity indication function of the
AU5783. In this application the activity indication flag INH will control
external devices such as a voltage regulator. To turn-off the INH flag
and thus the voltage regulator, the go to sleep command needs to
be applied to the Network Standby power control input,
e.g., NSTB = 0. The INH output is turned off after the sleep time-out
period thereby , reducing the power consumption of an electronic
control unit to an extremely low level.
The activity indication flag INH will be turned on again upon
detection of a remote wake-up condition (i.e. bus activity) or upon
detection of a local wake-up condition or a respective command
from the microcontroller. A local wake-up condition is detected
when an edge occurs at the wake-up input LWAKE. The INH flag
will also be turned on upon detection of a high input level at the
mode control input NSTB. Activation of the INH output enables
external devices, e.g., a voltage regulator. This condition will power-up
logic devices, e.g., a microcontroller in order to perform appropriate
action, e.g., activation of the AU5783 and the J1850 network.
The AU5783 contain a power on reset (POR) circuit, which is active
at low voltages. This circuit insures that if the control input NSTB is
at 0 V or floating during power up, the device will be forced into the
standby mode by the time the battery voltage rises to 4.4 V. This will
also insure that the INH pin is in the high state to turn on the local
voltage regulator. If there is a dip going below 4.4 V in battery
voltage while in the sleep mode, the device may return to the
. The load resistor pulls the bus line to
ld
2001 Feb 15
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Philips Semiconductors Preliminary specification
AU5783J1850/VPW transceiver with supply control function
standby mode if the POR is tripped. Even if the device is not in
sleep mode the INH output will turn off at some battery voltages
below 4.4 V when the internal POR circuit is active. At still lower
voltages where the POR circuit does not operate, the INH may
again pull up toward the battery level, typically with battery voltages
below approximately 3.6 V. The operation of the POR circuit can be
verified by placing the device in the sleep mode while the battery
voltage is above 4.4 V. The INH output, which is a high side driver,
should turn off when the sleep mode is entered. Next ramp the
battery voltage down to 2.0V and finally return the battery voltage to
4.4 V . When the battery supply is returned to 4.4V, the INH output
will pull high since the device enters standby mode. The actual
voltages at which the POR engages and releases will vary from part
to part. The lowest voltage at which the POR will be active is 2.6 V
and it will always release below 4.4 V .
The AU5783 provides a high-speed data transmission mode where
the bus output waveshape function is disabled. In this mode transmit
signals are output as fast as possible thus allowing higher data
rates, e.g., the so-called 4X mode with 41.6 kbit/s nominal speed.
The AU5783 also provides a loop-back mode for diagnostic
purpose, e.g., self-test of an electronic control unit. In loop-back
mode the bus transmit and receive functions are disabled thus
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essentially disconnecting an electronic control unit from the J1850
bus line. The TX signal is internally looped back to the RX output.
The AU5783 only requires one power supply V
BAT
. Bus
transmissions can continue with battery voltage down to 5.5 V . The
bus output voltage will track 1.3V bellow the battery voltage. The
bus input voltage threshold will also follow the battery voltage going
down as shown in Figure 3. This ratio metric behavior of the input
threshold partially compensates for the reduced dominant level
transmitted during low battery operation.
The AU5783 features special robustness at its BAT and BUS pins
hence the device is well protected for applications in the automotive
environment. Specifically the BA T input is protected against 40 V
load dump and jump start condition. The BUS output is protected
against wiring fault conditions, e.g., short circuit to ground and
battery voltage as well as typical automotive transients and
electrostatic discharge. In addition, an over-temperature shutdown
function with hysteresis is incorporated which protects the device
under network fault conditions. In case of the die temperature
reaching the trip point, the AU5783 will latch-off the transceiver
function. The device is reset on the first rising edge on the TX input
after a decrease in the junction temperature.
~
~
Bus Voltage (V)
6.7
5.5
4.2
3.9
3.4
1.9
5.5 5.8 7 8 16
Battery Voltage (V)
Figure 3. Bus voltage vs battery voltage
~
~
bus output
~
~
~
~
bus input
SL01254
2001 Feb 15
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