STMICROELECTRONICS ST491ABDR

ST491A
LOW POWER HIGH SPEED RS-485/RS-422 TRANSCEIVER
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■
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LOW SUPPLY CURRENT: 5mA MAX
DESIGNED FOR RS485 INTERFACE
APPLICATIONS
-7 TO 12 COMMON MODE INPUT VOLTAGE
RANGE
70mV TYPICAL INPUT HYSTERESIS
DESIGNED FOR 25Mbps OPERATION
OPERATE FROM SINGLE 5 SUPPLY
±4kV ESD PROTECTION
CURRENT LIMITING AND THERMAL
SHUTDOWN FOR DRIVER OVERLOAD
PROTECTION
DESCRIPTION
The ST491A is a low power transceiver for
RS-485 and RS-422 communications. The device
contains one driver and one receiver in full duplex
configuration. The ST491A draws 5mA (typ.) of
supply current when unloaded and operates from
a single 5V supply.
DIP
SOP
Driver is short-circuit current limited and is
protected against excessive power dissipation by
thermal shutdown circuitry that place the driver
outputs into a high-impedance state. The receiver
input has a fail-safe feature that guarantees a
logic high output if both inputs are open circuit.
ORDERING CODES
Type
Temperature
Range
Package
ST491ACN
ST491ABN
ST491ACD
ST491ABD
ST491ACDR
ST491ABDR
0 to 70 °C
-40 to 85 °C
0 to 70 °C
-40 to 85 °C
0 to 70 °C
-40 to 85 °C
DIP-14
DIP-14
SO-14 (Tube)
SO-14 (Tube)
SO-14 (Tape & Reel)
SO-14 (Tape & Reel)
July 2003
Comments
25parts per tube / 40tube per
25parts per tube / 40tube per
50parts per tube / 20tube per
50parts per tube / 20tube per
2500 parts per reel
2500 parts per reel
box
box
box
box
1/12
ST491A
PIN CONFIGURATION
PIN DESCRIPTION
PlN N°
SYMBOL
1
2
3
4
5
6
7
8
9
10
11
12
13
NC
RO
RE
DE
DI
GND
GND
NC
Y
Z
B
A
NC
VCC
14
NAME AND FUNCTION
Not Connected
Receiver Output.
Receiver Output Enable
Driver Output Enable
Inverting Driver Input.
Ground
Ground
Not Connected
Non-inverting Driver Output
Inverting Driver Output
Inverting Receiver Input
Non-inverting Receiver Input
Not Connected
Supply Voltage
TRUTH TABLE (RECEIVER)
TRUTH TABLE (DRIVER)
INPUT
OUTPUTS
INPUT
OUTPUT
DI
DE
Y
Z
A-B
RE
RO
L
H
X
H
H
L
L
H
Z
H
L
Z
≥ -0.2V
between -0.2V to 0.2V
≤ -0.2V
OPEN
X
L
L
L
L
H
H
?
L
H
Z
X= Don’t Care; Z=High Impedance
?= Irrelevant; X= Don’t Care; Z=High Impedance
2/12
ST491A
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
VCC
Supply Voltage
VDI
Driver Input Voltage
Value
Unit
7
V
-0.5 to 7
V
VY, VZ
Driver Output Voltage
-7.5 to 12.5
V
VA, VB
Receiver Input Voltage
-7.5 to 12.5
V
VRO
Receiver Output Voltage
ESD
Human Body Model
-0.3 to (VCC + 0.3)
V
3.5
KV
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is
not implied.
ELECTRICAL CHARACTERISTICS
VCC = 4.5V to 5.5V, TA = -40 to 85°C, unless otherwise specified. Typical values are referred to TA = 25°C)
Symbol
Parameter
Test Conditions
Min.
ISUPPLY No Load Supply Current
Typ.
Max.
Unit
2
5
mA
CIN
Input Capacitance
1.8
pF
CYZ
Driver Output Capacitance
1.2
pF
Output Capacitance
2.3
pF
COUT
TRANSMITTER ELECTRICAL CHARACTERISTICS
VCC = 4.5V to 5.5V, TA = -40 to 85°C, unless otherwise specified. Typical values are referred to Ta = 25°C)
Symbol
Parameter
VOD1
Differential Drive Output
(No load)
Differential Drive Output
(With Load)
Differential Drive Output
(With Load)
Change in magnitude of
Driver Differential Output
Voltage for Complementary
Output States (Note1)
Driver Common Mode
Output Voltage
Change in magnitude of
Driver Common Mode
Output Voltage (Note1)
Power Off Output Current
VOD2
VOD3
∆VOD
VOC
∆VOC
IOFF
VIL
Driver Short Circuit Output
Current
Input Logic Threshold Low
VIH
Input Logic Threshold High
IOSD
Test Conditions
Min.
Typ.
RL= 54Ω (RS-422) (Figure 1)
1.5
2.6
RL= 100Ω (RS-422) (Figure 1)
2
3
RL= 54Ω or 100Ω (Figure 1)
RL= 54Ω (Figure 1)
0
1
RL= 54Ω (Figure 1)
VCC = 0V
0
VO=-7V to 12V
VO=-7V to 12V
± 35
Max.
Unit
VCC
V
5
V
V
0.2
V
3
V
0.2
V
± 100
µA
± 250
mA
0.8
2
V
V
3/12
ST491A
RECEIVER ELECTRICAL CHARACTERISTICS
VCC = 4.5V to 5.5V, TA = -40 to 85°C, unless otherwise specified. Typical values are referred to Ta = 25°C)
Symbol
IIN
VTH
∆VTH
VOH
VOL
RRIN
Parameter
Input Current (A, B)
Test Conditions
other input=0V
VCC= 0 or 5.25V
Receiver Differential
Threshold Voltage
Receiver Input Hysteresis
VCM = -7V to 12V
Receiver Output High
Voltage
Receiver Output Low
Voltage
Receiver Input Resistance
IOUT = -8mA, VID = 200mV
Min.
Typ.
Max.
Unit
VIN=12V
0.5
1
mA
VIN=-7V
-0.35
-0.8
mA
0.2
V
-0.2
VCM = 0V
3.5
IOUT = 8mA, VID = -200mV
VCM = -7V to 12V
70
mV
4.7
V
0.3
12
0.5
24
V
KΩ
DRIVER SWITCHING CHARACTERISTICS
VCC = 4.5V to 5.5V, TA = -40 to 85°C, unless otherwise specified. Typical values are referred to Ta = 25°C)
Symbol
Parameter
Test Conditions
Min.
Typ.
25
50
Max.
Unit
DR
Maximum Data Rate
Jitter <5%
tPLH
tPHL
Propagation Delay Input to
Output
RL= 54Ω
CL1=CL2=50pF, (Figure 1)
10
16
ns
RL= 54Ω
CL1=CL2=50pF, (Figure 1)
1
3
ns
tTLH
tTHL
Differential Output Delay
Skew
Rise or Fall Differential
Time
RL= 54Ω
CL1=CL2=50pF, (Figure 1)
8
12
ns
tPZL
Output Enable Time
CL= 50pF
S1 Closed
14
25
ns
tPZH
Output Enable Time
CL= 50pF
S2 Closed
14
25
ns
tPHZ
Output Disable Time
CL= 15pF
S2 Closed
10
25
ns
tPLZ
Output Disable Time
CL= 15pF
S1 Closed
16
25
ns
tSKEW
Mbps
RECEIVER SWITCHING CHARACTERISTICS
VCC = 4.5V to 5.5V, TA = -40 to 85°C, unless otherwise specified. Typical values are referred to Ta = 25°C)
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
tPLH
tPHL
Propagation Delay Input to
Output
CL = 15pF
(Figures 2,4)
19
30
ns
tSKD
|tPLH - tPHL| Receiver Output CL = 15pF
Skew
Rise or Fall Time
CL = 15pF
(Figures 2,4)
1
3
ns
(Figures 2,4)
6
tTLH
tTHL
ns
tPZL
Output Enable Time
CRL = 15pF S1 Closed
6
12
ns
tPZH
Output Enable Time
CRL = 15pF S2 Closed
7
12
ns
tPHZ
Output Disable Time
CRL = 15pF S2 Closed
6
12
ns
tPLZ
Output Disable Time
CRL = 15pF S1 Closed
6
12
ns
4/12
ST491A
TEST CIRCUITS AND TYPICAL CHARACTERISTICS
Figure 1 : Driver DC Test Load
Figure 2 : Receiver Timing Test Load
Figure 3 : Driver/Receiver Timing Test Circuit
5/12
ST491A
Figure 4 : Driver Timing Test Load
Figure 5 : Driver Propagation Delay
6/12
ST491A
Figure 6 : Receiver Propagation Delay
Figure 7 : Receiver Output Current vs Output
Voltage (Output Low)
Figure 9 : Driver Diff. Output Voltage vs Common
Mode Voltage (Diff. Output Low)
Figure 8 : Receiver Output Current vs Output
Voltage (Output High)
Figure 10 : Driver Diff. Output Voltage vs
Common Mode Voltage (Diff. Output High)
7/12
ST491A
Figure 11 : Driver Short Circuit Current vs Line
Voltage (Output High)
Figure 12 : Driver Short Circuit Current vs. Line
Voltage (Output Low)
8/12
Figure 13 : Receiver Input Current vs Input
Voltage
ST491A
Plastic DIP-14 MECHANICAL DATA
mm.
inch
DIM.
MIN.
a1
0.51
B
1.39
TYP
MAX.
MIN.
TYP.
MAX.
0.020
1.65
0.055
0.065
b
0.5
0.020
b1
0.25
0.010
D
20
0.787
E
8.5
0.335
e
2.54
0.100
e3
15.24
0.600
F
7.1
0.280
I
5.1
0.201
L
Z
3.3
1.27
0.130
2.54
0.050
0.100
P001A
9/12
ST491A
SO-14 MECHANICAL DATA
DIM.
mm.
MIN.
TYP
A
a1
inch
MAX.
MIN.
TYP.
1.75
0.1
0.068
0.2
a2
MAX.
0.003
0.007
1.65
0.064
b
0.35
0.46
0.013
0.018
b1
0.19
0.25
0.007
0.010
C
0.5
0.019
c1
45˚ (typ.)
D
8.55
8.75
0.336
0.344
E
5.8
6.2
0.228
0.244
e
1.27
0.050
e3
7.62
0.300
F
3.8
4.0
0.149
0.157
G
4.6
5.3
0.181
0.208
L
0.5
1.27
0.019
0.050
M
S
0.68
0.026
8 ˚ (max.)
PO13G
10/12
ST491A
Tape & Reel SO-14 MECHANICAL DATA
mm.
inch
DIM.
MIN.
A
TYP
MAX.
MIN.
330
MAX.
12.992
C
12.8
D
20.2
0.795
N
60
2.362
T
13.2
TYP.
0.504
22.4
0.519
0.882
Ao
6.4
6.6
0.252
0.260
Bo
9
9.2
0.354
0.362
Ko
2.1
2.3
0.082
0.090
Po
3.9
4.1
0.153
0.161
P
7.9
8.1
0.311
0.319
11/12
ST491A
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. Specifications
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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