STMICROELECTRONICS L9637

L9637

ISO 9141 INTERFACE
OPERATING POWER SUPPLY VOLTAGE
RANGE 4.5V ≤ VS ≤ 36V (40V FOR TRANSIENTS)
REVERSE SUPPLY (BATTERY) PROTECTED DOWN TO VS ≥ -24V
STANDBY MODE WITH VERY LOW CURRENT CONSUMPTION ISSB 1µA @ VCC 0.5V
LOW QUIESCENT CURRENT IN OFF CONDITION ISOFF = 120µA
TTL COMPATIBLE TX INPUT
BIDIRECTIONAL K-I/O PIN WITH SUPPLY
VOLTAGE DEPENDENT INPUT THRESHOLD
OVERTEMPERATURE SHUT DOWN FUNCTION SELECTIVE TO K-I/O PIN
WIDE INPUT AND OUTPUT VOLTAGE
RANGE -24V ≤ VK ≤ VS
K OUTPUT CURRENT LIMITATION, TYP IK =
60mA
DEFINED OFF OUTPUT STATUS IN UNDERVOLTAGE CONDITION AND VS OR GND INTERRUPTION
CONTROLLED OUTPUT SLOPE FOR LOW
EMI
HIGH INPUT IMPEDANCE FOR OPEN VS OR
GND CONNECTION
SO8
Minidip
ORDERING NUMBERS:
L9637D
L9637
DEFINED OUTPUT ON STATUS OF LO OR
RX FOR OPEN LI OR K INPUTS
DEFINED K OUTPUT OFF FOR TX INPUT
OPEN
INTEGRATED PULL UP RESISTORS FOR
TX, RX AND LO
EMI ROBUSTNESS OPTIMIZED
DESCRIPTION
The L9637 is a monolithic integrated circuit containing standard ISO 9141 compatible interface
functions.
BLOCK DIAGRAM
VCC
VS
RTX
K
IK
+
OFF
IL I
RRX
TX
1, 75 V
+
LI
RL O
+
RX
LO
GND
December 1998
1/11
L9637
ABSOLUTE MAXIMUM RATINGS (No damage or latch)
Symbol
Parameter
Value
Unit
VS
Supply Voltage
ISO transients t = 400ms
-24 to +36
-24 to +40
V
V
VCC
Stabilized Voltage
-0.3 to +7
V
∆VS/dt
Supply Voltage transient
-10 to +10
V/µs
VLI, K
Pin Voltage
-24 to VS
V
VLO, RX, TX
Pin Voltage
-24 to VCC
V
Note: Max. ESD voltages are ±2kV with human body model C = 100pF, R = 1.5k corresponds to maximum energy dissipation 0.2mJ according
to MIL883C.
PIN CONNECTION (Top view)
RX
1
8 LI
LO
2
7 VS
U537
VCC
3
6 K
TX
4
5 GND
THERMAL DATA
Symbol
Parameter
Min.
TJSDon
TJSDoff
Temperature K shutdown switch on threshold
Temperature K shutdown switch off threshold
160
150
Rth j-amb
Thermal steady state junction to ambient resistance for SO8
Thermal steady state junction to ambient resistance for Minidip
130
80
PIN DESCRIPTION
N.
Name
1
RX
Output for K as input
Function
2
LO
Output L comparator
3
VCC
Stabilized voltage supply
4
TX
5
GND
Common GND
6
K
Bidirectional I/O
7
VS
Supply voltage
8
LI
Input L comparator
2/11
Input for K as output
Typ.
155
100
Max.
Unit
200
200
°C
°C
180
120
°C/W
°C/W
L9637
ELECTRICAL CHARACTERISTICS (The electrical characteristics are valid within the below defined operating conditions, unless otherwise specified. The function is guaranteed by design until TJSDon temperature shutdown switch-on-threshold.)
Symbol
Parameter
Max.
Unit
4.5
36
V
3
7
V
-40
150
°C
1.4
2.3
mA
<1
5
µA
VS ≤ 16V; VLI, VTX = 0V
1.2
3
mA
ISOFF
VK ≥ VKhigh; VLI ≥ VLIhigh
VTX ≥ VTXhigh @ VS ≤ 12V
120
220
µA
ISSB
VCC ≤ 0.5V @ VS ≤ 12V
<1
VS
Supply Voltage
VCC
Stabilized Voltage
Tj
Junction temperature
ICC
Supply VCC Current
ISON
VKlow
VKhigh
VK hys
IKoff
Supply VS Current
Input Voltage Low state
Input Voltage High state
Test Condition
VCC ≤ 5.5V; VLI,VTX = 0V
VK ≥ VKhigh; VLI ≥ VLIhigh
VTX = VCC @ VCC ≤ 5.5V
RX output status LOW
4.5V ≤ VS ≤ 18V
-24
0.45VS
RX output status LOW
18V < VS
-24
8
V
RX output status HIGH
4.5V ≤ VS ≤ 18V
0.55VS
VS
V
RX output status HIGH
18V < VS
12
VS
V
0.025
VS
0.8
V
4
25
µA
10
30
Ω
60
VKhigh - VKlow
Input Current
@ VTX ≥ VTXhigh
VK ≤ VS VS, VCC ≥ 0
VS, VCC = open
Output ON Impedance
IKSC
-5
Typ.
µA
V
Input Threshold Hysteresis
RKON
Min.
-5
or
@ VS ≥ 6.5V
VTX ≤ VTXlow
IK ≥ 7mA
1)
Short Circuit Current
30
100
mA
VTXlow
Input voltage LOW state
-24
1
V
VTXhigh
Input voltage HIGH state
2.5
VCC
V
RRXON
RLOON
Output ON Impedance
IRXSC
ILOSC
Output Short Circuit Current
VRX H
VLOH
Output Voltage HIGH state
RLO
RRX
Output pull-up resistance
VK ≤ VKlow; VLI ≤ VLIlow
VS ≥ 6.5V IRX, LO ≥ 1mA
40
90
9
20
35
Ω
mA
VCC 0.25
VCC 0.1
VCC
V
Output status = (HIGH)
-0.15V ≤ VLO ≤ VCC + 0.15V
-0.15V ≤ VRX ≤ VCC + 0.15V
5
10
20
KΩ
-0.15V ≤ VTX ≤ VCC + 0.15V
LO output status LOW
4.5V ≤ VS ≤ 18V
10
20
-24
1)
10MΩ ≤ R LRX
10MΩ ≤ R LLO
RTX
Input pull up resistance
VLIlow
Input voltage LOW state
VL high
Input voltage HIGH state
VLI hys
Input threshold hysteresis
VLIhigh - VLIlow
Input current
VLI ≤ VS VS, VCC ≥ 0
or
VS, VCC = open
LO output status LOW 18V < VS
LO output status HIGH
4.5V ≤ VS ≤ 18V
LO output status HIGH 18V < VS
ILI
40
KΩ
0.45VS
V
-24
8
V
0.55VS
VS
V
12
-5
VS
V
0.025V S
0.8
V
4
25
µA
3/11
L9637
ELECTRICAL CHARACTERISTIC (continued)
Symbol
Parameter
Test Condition
C Ki, LO, RX
Internal output capacities
fLI-LO
fK-RX
fTX-k
Transmission Frequency
trLI-LO
trK-RX
trTX-K
Rise Time
tfLI-LO
tfK-RX
tfTX-K
Fall Time
tOFF,LI-LO
tOFF,K-RX
tOFF,TX-K
Switch OFF time
tON,LI-LO
tON,K-RX
tON,TX-K
Switch ON time
Min.
9V < VS < 16V
(external loads)
R KO = 510Ω, CK ≤ 1.3nF
in active mode see Fig. 3
50
Typ.
kHz
6
µs
9V < VS < 16V (external loads)
R KO = 510Ω, CK ≤ 1.3nF
2
6
µs
for the definition of ton, tOFF see
Fig.1.
4
17
µs
4
17
µs
I
t
VOUT
80%
80%
20%
20%
tf
tr
4/11
pF
2
Figure 1: Input to Output Timings and Output Pulse Shape.
OFF
20
for the definition of tr, tf see
Fig.1.
9V < VS < 16V (external loads)
R KO = 510Ω, CK ≤ 1.3nF
(inactive mode see Fig. 3)
t
Unit
100
1) For output currents lower than this value a series protection diode can become active. See also Fig. 4 and 5.
V
Max.
t ON
t
L9637
Figure 2: ISO Application Circuit
VCC
VS
RTX
RLO
RRX
40V
VS
5V
R KO
TX
-
510 Ohm
0.4 Ohm
C K K
K
VCC
I/O
+
IK OFF
1,75V
RX
Diagnostic
-
Tester
I/O
uP
+
LI
LO
I/O
-
L
ILI
+
GND
VDD
L Line
K Line
ECU1
K
CK
LI
ECU2
FUNCTIONAL DESCRIPTION
The L9637 is a monolithic bus driver designed to
provide bidirectional serial communication in automotive diagnostic applications according to the
specification ”Diagnostic Systems ISO9141”.
The device provides a bidirectional link, called K,
to the VBat related diagnosis bus. It also includes
a separate comparator L which is also able to be
linked to the VBat bus. The input TX and output
RX of K are related to VCC with her integrated pull
up resistances. Also the L comparator output LO
has a pull up resistance connected to VCC.
The maximum external pull up resistance at K related to VS should not be higher than RKO ≤ 5KΩ
to achieve clear output ON conditions.
All VBat bus defined inputs LI and K have supply
voltage dependent thresholds together with suf-
ficent hysteresis to suppress line spikes. These
pins are protected against overvoltages, shorts to
GND and VS and can also be driven beyond VS
and GND. These features are also given for TX,
RX and LI only taking into account the behaviour
of the internal pull up resistances. The thermal
shut down function switches OFF the K output if
the chip temperature increases above the thermal
shut down threshold. To reactivate K again the
chip temperature must decrease below the K
switch ON temp. To achieve no fault for V S undervoltage conditions the outputs will be switched
OFF and stay at high impedance. The device is
also protected against reverse battery condition.
During lack of VS or GND all pins shows high impedance characteristic. To realize a lack of the VS
related bus line LI and K the outputs LO and RX
shows defined ON status.
5/11
L9637
Supressing all 4 classes of ”Schaffner” signals all
pins can be load with short energy pulses of max.
±0.2mJ. All these features together with a high
possible baud rate >50Kbaud, controlled output
slopes for low EMI, a wide power supply voltage
range and a very small quiescent current during
OFF (TX LI K=High) condition ISoff typ ≤ 120µA,
and a real standby function with zero power consumption ISSB typ ≤ 1µA during system depowering VCC ≤ 0.5V make this device high efficient for
automotive bus system.
After wake up of the system from OFF or SB
condition the first output signal will have an additional delay time tdtyp ≤ 5µs see also Fig. 3.
The typical output voltage behaviour for the K,
LO, RX outputs as a function of the output current
is shown in Fig.4. Fig.5 shows a waveform of the
output signal when the low level changes from
RON * IOUT to IOUT * 2 * RON + UBE state. This variation occurs due to too low output current or after
a negative transient forced to the output or to the
supply voltage line.
Figure 3: Typical timing for mode transitions.
O FF
a c tiv e
O FF
a c tiv e
LI
LO
TX
K
RX
t d t ON
LI - LO
6/11
td
t ON
TX - K
L9637
Figure 4: Output Characteristics at K, LO, RX.
IO UT
M IN
V OUT
= IO U T * R D S O N
V OUT
= IO U T * 2 * R D SO N + U B E
R
DS ON
IOUT
p ro te c tio n d i o d e
0 .8 V
VO UT
Figure 5: Output Signal Shape Related to Output Current.
V IN
t
VO UT
IOUT
* 2 * RDSON + U BE
IO UT
RDSON
*
IO U T > IO U T
M IN
t
IOUT > IOUT
M IN
I O U T < IO U T
M IN
7/11
L9637
Figure 6: EMS Performance (ISO 9141 BUS system).
=
VS = 12V
510 Ohm
VS
50 Ohm
TX
K
P ro b e
IS O i n te rf a c e
4 0dB
R h o d e & S c h w a rt z
136 Ohm
N A P - 73
SMG
10k Hz
1 . 5n F
P im a x = 5 W
0 .1 - 1 0 0 0M H z
68 Ohm
VS
Pi
D
RX
K
IS O i n te rf a c e
NAP
Signal comparison
∆≤±
D£ 10%
10 %
Figure 7.
P i(m W )
n o t i n c id e n t p o w e r re s i s ta n t
1 0000
50 00
in c id e n t p o w e r r e s is t a n t
10 00
10 0
1
8/11
10
10 0
1 0 00
f (M H z)
L9637
mm
DIM.
MIN.
TYP.
A
a1
inch
MAX.
MIN.
TYP.
1.75
0.1
0.25
a2
MAX.
0.069
0.004
0.010
0.065
1.65
a3
0.65
0.85
0.026
0.033
b
0.35
0.48
0.014
0.019
b1
0.19
0.25
0.007
0.010
C
0.25
0.5
0.010
0.020
c1
45° (typ.)
D (1)
4.8
5.0
0.189
0.197
E
5.8
6.2
0.228
0.244
e
1.27
0.050
e3
3.81
0.150
F (1)
3.8
4.0
0.15
0.157
L
0.4
1.27
0.016
0.050
M
S
OUTLINE AND
MECHANICAL DATA
0.6
0.024
SO8
8 ° (max.)
(1) D and F do not include mold flash or protrusions. Mold flash or
potrusions shall not exceed 0.15mm (.006inch).
9/11
L9637
mm
DIM.
MIN.
A
TYP.
inch
MAX.
MIN.
3.32
TYP.
MAX.
0.131
a1
0.51
B
1.15
1.65
0.045
0.065
b
0.356
0.55
0.014
0.022
b1
0.204
0.304
0.008
0.012
0.020
D
E
10.92
7.95
9.75
0.430
0.313
0.384
e
2.54
0.100
e3
7.62
0.300
e4
7.62
0.300
F
6.6
0.260
I
5.08
0.200
L
Z
10/11
3.18
OUTLINE AND
MECHANICAL DATA
3.81
1.52
0.125
0.150
0.060
Minidip
L9637
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences
of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is
granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specification mentioned in this publication are
subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products
are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
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 1998 STMicroelectronics – Printed in Italy – All Rights Reserved
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11/11