Philips AU5783 Datasheet

INTEGRATED CIRCUITS
AU5783
J1850/VPW transceiver with supply control function
Objective specification 1999 May 11
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Philips Semiconductors Objective specification
TYPE NUMBER
FEATURES
Supports SAE/J1850 VPW standard for in-vehicle class B
multiplexing
Bus speed 10.4 kbit/s nominal
Drive capability 32 bus nodes
Low RFI due to output waveshape function
Direct battery operation with protection against +40V load dump
and 8 kV ESD
Bus terminals proof against automotive transients up to
+100V/–150V and 8kV ESD
Power supply enable function
Very low sleep mode power consumption
4X transmission mode (41.6 kbit/s)
Diagnostic loop-back mode
Thermal overload protection
14-pin SOIC
ORDERING INFORMATION
NAME DESCRIPTION VERSION
AU5783D SO14
AU5783D-T SO14
plastic small outline package; 14 leads; body width 3.9 mm; packed in tubes
plastic small outline package; 14 leads; body width 3.9 mm; shipped on tape and reel
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.
PACKAGE
SOT108-1 –40 to +125 °C
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 7 12 16 V Operating ambient temperature range –40 +125 °C Battery voltage load dump, 1s +40 V Bus output voltage 250 < RL < 1.6 k 6.5 8.0 V Bus input threshold 3.55 4.2 V Sleep mode supply current 90 µA Propagation delay Tx to Rx 25 µs Bus output rise time 14 µs
1999 May 11
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Philips Semiconductors Objective 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
1999 May 11
GND
SL01224
Figure 1. Block diagram
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Philips Semiconductors Objective 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
GND 2 Ground 4X/LOOP 3 Tx mode control input; low: normal mode;
NSTB 4 Network ST andBy power control input;
TX 5 Transmit data input; low: transmitter
RX 6 Receive data output; low: active bus
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
LOAD 11 Bus load in/output BUS 12 Bus line transmit/receive input/output,
N.C. 13 Not connected GND 14 Ground
ground potential via a resistor
high: 4X mode; float: loopback
low: transmit function disabled (low power modes); high: transmit function enabled
passive; high: transmitter active
condition detected; high: otherwise
side driver; e.g., to control a voltage regulator. Active high enables the regulator
active 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.
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 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
. The load resistor pulls the bus line to
ld
1999 May 11
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Philips Semiconductors Objective specification
AU5783J1850/VPW transceiver with supply control function
essentially disconnecting an electronic control unit from the J1850 bus line. The TX signal is internally looped back to the RX output.
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 BAT input is protected against 40V 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.
Table 1. Control input summary
Z = Input connected to high impedance permitting it to float. Typically accomplished by turning off the output of a microcontroller. X = Don’t care; The input may be at either logic level.
NSTB 4X/LOOP TX Mode Bus
1 0 1 normal operation active high low high 1 0 0 normal operation passive float bus state,
1 1 1 4X transmit active high low high 1 1 0 4X transmit passive float bus state,
1 Z 1 loop-back passive float low high 1 Z 0 loop-back passive float high high
0 or Z X X standby (default state after power on),
Note 1
1 –> 0 X X go to sleep command, Note 4 off float bus state,
0 or Z X X sleep, Note 4 off float bus state,
NOTES:
1. After power-on, the AU5783 enters standby mode since the input pins NSTB and 4X/LOOP are assumed to be floating. In standby mode the voltage regulator is enabled via the INH output, and therefore power is supplied to the microcontroller. When the microcontroller begins operation it will normally set the control inputs NSTB high and 4X/LOOP to low state in order to start normal operation of the AU5783.
2. RX outputs the bus state. If the bus level is below the receiver threshold (i.e., all transmitters passive), then RX will be high. Otherwise, if the bus level is above the receiver threshold (i.e., at least one transmitter is active), then RX will be low.
3. INH is turned off after a time-out period.
4. For entering the sleep mode (e.g., to deactivate INH), the “Go To Sleep” command needs to be applied. The “Go To Sleep” command is a high-to-low transition on the NSTB input. When the “Go To Sleep” command is present, the INH flag is deactivated. This signal can be used to turn-off the voltage regulator of an electronic module. After the voltage regulator is turned off the microcontroller is no longer supplied and the NSTB input will be floating. The INH output will be set again upon detection of bus activity or occurrence of a local wake-up event.
5. In standby and sleep mode, the detection of a wake-up condition (e.g., high level on BUS) will be signalled on the output RX.
transmitter
off float bus state,
BUS RX (out) INH
high
Note 2
high
Note 2
high
Note 5
float, Note 3
Note 5
float
Note 5
1999 May 11
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