AD ADM483AR-REEL 5v low power, slew-rate limited Datasheet

5 V Low Power, Slew-Rate Limited
RS-485/RS-422 Transceiver
ADM483
EIA RS-485/RS-422-compliant
Data rates up to 250 kbps
Slew-rate limited for low EMI
100 nA supply current in shutdown mode
Low power consumption (120 µA)
Up to 32 transceivers on one bus
Outputs high-z when disabled or powered off
–7 V to +12 V bus common-mode range
Thermal shutdown and short-circuit protection
Pin-compatible with MAX483
Specified over –40°C to +85°C temperature range
Available in 8-lead SOIC package
FUNCTIONAL BLOCK DIAGRAM
VCC
ADM483
RO
R
A
RE
B
DE
DI
D
GND
05079-001
FEATURES
Figure 1.
APPLICATIONS
Low power RS-485 applications
EMI sensitive systems
DTE-DCE interfaces
Industrial control
Packet switching
Local area networks
Level translators
GENERAL DESCRIPTION
The ADM483 is a low power differential line transceiver suitable
for half-duplex data communication on multipoint bus transmission lines. It is designed for balanced data transmission, and
complies with EIA Standards RS-485 and RS-422.The part
contains a differential line driver and a differential line receiver.
Both share the same differential pins, with either the driver or
the receiver being enabled at any given time.
The receiver contains a fail-safe feature that results in a logic
high output state if the inputs are unconnected (floating).
The device has an input impedance of 12 kΩ, allowing up to
32 transceivers on one bus. Since only one driver should be
enabled at any time, the output of a disabled or powered-down
driver is three-stated to avoid overloading the bus. This high
impedance driver output is maintained over the entire
common-mode voltage range from –7 V to +12 V.
The part is fully specified over the industrial temperature range,
and is available in an 8-lead SOIC package.
The driver outputs are slew-rate limited to reduce EMI and data
errors caused by reflections from improperly terminated buses.
Excessive power dissipation caused by bus contention or by
output shorting is prevented by a thermal shutdown circuit.
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.326.8703
© 2004 Analog Devices, Inc. All rights reserved.
ADM483
TABLE OF CONTENTS
Specifications..................................................................................... 3
Applications..................................................................................... 11
Timing Specifications....................................................................... 4
Differential Data Transmission ................................................ 11
Absolute Maximum Ratings............................................................ 5
Cable and Data Rate................................................................... 11
ESD Caution.................................................................................. 5
Thermal Shutdown .................................................................... 12
Pin Configuration and Function Descriptions............................. 6
Receiver Open-Circuit Fail-Safe............................................... 12
Test Circuits....................................................................................... 7
Outline Dimensions ....................................................................... 13
Switching Characteristics ................................................................ 8
Ordering Guide .......................................................................... 13
Typical Performance Characteristics ............................................. 9
REVISION HISTORY
10/04—Revision 0: Initial Version
Rev. 0 | Page 2 of 16
ADM483
SPECIFICATIONS
VCC = 5 V ± 5%, TA = TMIN to TMAX, unless otherwise noted.
Table 1.
Parameter
DRIVER
Differential Output Voltage, VOD
Min
Typ
2.0
1.5
1.5
∆ |VOD| for Complementary Output States
Common-Mode Output Voltage, VOC
∆ |VOC| for Complementary Output States
Output Short-Circuit Current, VOUT = High
Output Short-Circuit Current, VOUT = Low
DRIVER INPUT LOGIC
CMOS Input Logic Threshold Low
CMOS Input Logic Threshold High
CMOS Logic Input Current (DI)
DE Input Resistance to GND
RECEIVER
Differential Input Threshold Voltage, VTH
Input Hysteresis
Input Resistance (A, B)
Input Current (A, B)
CMOS Logic Input Current (RE)
CMOS Output Voltage Low
CMOS Output Voltage High
Output Short-Circuit Current
Three-State Output Leakage Current
POWER SUPPLY CURRENT
Max
Unit
Test Conditions/Comments
5
V
V
V
V
V
V
V
mA
mA
R = ∞, Figure 3
R = 50 Ω (RS-422), Figure 3
R = 27 Ω (RS-485), Figure 3
VTST = –7 V to 12 V, Figure 4
R = 27 Ω or 50 Ω, Figure 3
R = 27 Ω or 50 Ω, Figure 3
R = 27 Ω or 50 Ω, Figure 3
–7 V < VOUT < +12 V
–7 V < VOUT < +12 V
5
5
0.2
3
0.2
250
250
35
35
0.8
2.0
±2
220
–200
+200
70
12
1
–0.8
±2
0.4
3.5
7
0.1
120
350
Rev. 0 | Page 3 of 16
95
±2
10
250
650
V
V
µA
kΩ
mV
mV
kΩ
mA
mA
µA
V
V
mA
µA
µA
µA
µA
–7 V < VCM < +12 V
VCM = 0V
–7 V < VCM < +12 V
VIN = +12 V
VIN = –7 V
IOUT = 4 mA
IOUT = –4 mA
0 V < VOUT < VCC
0.4 ≤ VOUT ≤ 2.4 V
DE = 0 V, RE = VCC (shutdown)
DE = 0 V, RE = 0 V
DE = VCC
ADM483
TIMING SPECIFICATIONS
VCC = 5 V ± 5%, TA = TMIN to TMAX, unless otherwise noted.
Table 2.
Parameter
DRIVER
Maximum Data Rate
Propagation Delay tPLH, tPHL
Skew tSKEW
Rise/Fall Time tR, tF
Enable Time
Disable Time
Enable Time from Shutdown
RECEIVER
Propagation Delay tPLH, tPHL
Differential Skew tSKEW
Enable Time
Disable Time
Enable Time from Shutdown
Time to Shutdown1
1
Min
250
250
Typ
Max
Unit
Test Conditions/Comments
800
100
2000
800
2000
2000
3000
5000
kbps
ns
ns
ns
ns
ns
ns
RLDIFF = 54 Ω, CL1 = CL2 = 100 pF, Figure 5
RLDIFF = 54 Ω, CL1 = CL2 = 100 pF, Figure 5
RLDIFF = 54 Ω, CL1 = CL2 = 100 pF, Figure 5
RL = 500 Ω, CL = 100 pF, Figure 6
RL = 500 Ω, CL = 15 pF, Figure 6
RL = 500 Ω, CL = 100 pF, Figure 6
200
125
125
250
2000
100
20
20
50
330
50
50
5000
3000
ns
ns
ns
ns
ns
ns
CL = 15 pF, Figure 7
CL = 15 pF, Figure 7
RL = 1 kΩ, CL = 15 pF, Figure 8
RL = 1 kΩ, CL = 15 pF, Figure 8
RL = 1 kΩ, CL = 15 pF, Figure 8
The device is put into shutdown mode by driving RE high and DE low. If these inputs are in this state for less than 50 ns, the device is guaranteed not to enter
shutdown mode. If the enable inputs are in this state for at least 3000 ns, the device is guaranteed to have entered shutdown mode.
Rev. 0 | Page 4 of 16
ADM483
ABSOLUTE MAXIMUM RATINGS
TA = 25°C, unless otherwise noted.
Table 3.
Parameter
VCC to GND
Digital I/O Voltage (DE, RE, DI, ROUT)
Driver Output/Receiver Input Voltage
Operating Temperature Range
Storage Temperature Range
θJA Thermal Impedance (SOIC)
Lead Temperature
Soldering (10 s)
Vapor Phase (60 s)
Infrared (15 s)
Rating
6V
–0.3 V to VCC + 0.3 V
–9 V to +14 V
–40°C to +85°C
–65°C to +125°C
110°C/W
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
300°C
215°C
220°C
ESD CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on
the human body and test equipment and can discharge without detection. Although this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance
degradation or loss of functionality.
Rev. 0 | Page 5 of 16
ADM483
RO 1
RE 2
ADM483
8
VCC
7
B
6 A
TOP VIEW
(Not to Scale) 5 GND
DI 4
DE 3
05079-002
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
Figure 2. Pin Configuration
Table 4. Pin Function Descriptions
Pin No.
1
Mnemonic
RO
2
RE
3
DE
4
DI
5
6
7
8
GND
A
B
VCC
Description
Receiver Output. When enabled, if A > B by 200 mV, then RO = high.
If A < B by 200 mV, then RO = low.
Receiver Output Enable. A low level enables the receiver output, RO.
A high level places it in a high impedance state.
Driver Output Enable. A high level enables the driver differential inputs A and B.
A low level places it in a high impedance state.
Driver Input. When the driver is enabled, a logic low on DI forces A low and B high,
while a logic high on DI forces A high and B low.
Ground.
Noninverting Receiver Input A/Driver Output A.
Inverting Receiver Input B/Driver Output B.
5 V Power Supply.
Rev. 0 | Page 6 of 16
ADM483
TEST CIRCUITS
VCC
A
VOD
0V OR 3V
VOC
05079-003
R
DE
RL
S2
S1
B
CL
05079-006
R
VOUT
DE IN
Figure 3. Driver Voltage Measurement
Figure 6. Driver Enable/Disable
375Ω
VTST
A
375Ω
B
Figure 4. Driver Voltage Measurement over Common-Mode Voltage Range
VOUT
RE
CL
05079-007
60Ω
05079-004
VOD3
Figure 7. Receiver Propagation Delay
+1.5V
VCC
S1
CL1
RE
CL2
CL
05079-005
RLDIFF
B
RL
–1.5V
VOUT
RE IN
Figure 5. Driver Propagation Delay
Figure 8. Receiver Enable/Disable
Rev. 0 | Page 7 of 16
S2
05079-008
A
ADM483
SWITCHING CHARACTERISTICS
3V
3V
1.5V
0V
tPLH
1.5V
1.5V
0V
tPHL
tLZ
tZL
1/2VO
VO
2.3V
A, B
VOL +0.5V
A
VOL
tSKEW = |tPLH –tPHL|
5V
tZH
VOH
90% POINT
90% POINT
A, B
10% POINT
10% POINT
tR
tF
VOH –0.5V
2.3V
05079-009
0V
tHZ
0V
05079-011
B
DE
1.5V
Figure 11. Driver Enable/Disable Timing
Figure 9. Driver Propagation Delay, Rise/Fall Timing
3V
RE
0V
0V
tPLH
tPHL
1.5V
0V
tLZ
tZL
1.5V
R
VOL +0.5V
O/P LOW
VOL
VOH
RO
1.5V
tSKEW = |tPLH –tPHL|
1.5V
VOL
05079-010
tZH
Figure 10. Receiver Propagation Delay
R
O/P HIGH
1.5V
tHZ
VOH
VOH –0.5V
0V
Figure 12. Receiver Enable/Disable Timing
Rev. 0 | Page 8 of 16
05079-012
A, B
1.5V
ADM483
TYPICAL PERFORMANCE CHARACTERISTICS
0.40
350
250
200
DE = VCC
150
100
DE = GND
50
0
–50
–25
0
25
50
75
TEMPERATURE (°C)
100
0.30
0.25
0.20
0.15
–50
125
05079-016
OUTPUT LOW VOLTAGE (V)
0.35
300
05079-013
UNLOADED SUPPLY CURRENT (µA)
400
–25
0
25
50
TEMPERATURE (°C)
75
100
125
Figure 16. Receiver Output Low Voltage vs. Temperature
Figure 13. Supply Current vs. Temperature
4.6
50
4.5
OUTPUT HIGH VOLTAGE (V)
40
35
30
25
20
15
10
4.4
4.3
4.2
5
0
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
RECEIVER OUTPUT LOW VOLTAGE (V)
1.8
4.0
–50
2.0
Figure 14. Output Current vs. Receiver Output Low Voltage
05079-017
4.1
05079-014
RECEIVER OUTPUT CURRENT (mA)
45
–25
0
25
50
TEMPERATURE (°C)
75
100
125
Figure 17. Receiver Output High Voltage vs. Temperature
5
0
–5
–10
–15
–20
3.5
4.0
4.5
5.0
RECEIVER OUTPUT HIGH VOLTAGE (V)
70
60
50
40
30
20
05079-018
DRIVER OUTPUT CURRENT (mA)
80
05079-015
RECEIVER OUTPUT CURRENT (mA)
90
10
0
5.5
0
Figure 15. Output Current vs. Receiver Output High Voltage
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
DIFFERENTIAL OUTPUT VOLTAGE (V)
4.5
5.0
Figure 18. Driver Output Current vs. Differential Output Voltage
Rev. 0 | Page 9 of 16
ADM483
800
120
700
600
PROPAGATION DELAY (ns)
80
60
40
500
400
300
200
20
05079-019
100
0
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
OUTPUT VOLTAGE (V)
4.0
4.5
05079-022
OUTPUT CURRENT (mA)
100
0
–50
5.0
Figure 19. Output Current vs. Driver Output Low Voltage
–25
0
25
50
75
TEMPERATURE (°C)
100
125
Figure 22. Receiver Propagation Delay vs. Temperature
–30
3
–50
–70
–90
05079-020
2
–110
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
OUTPUT VOLTAGE (V)
4.0
4.5
350
300
250
200
150
100
05079-021
PROPAGATION DELAY (ns)
400
–50
–25
0
25
50
75
TEMPERATURE (°C)
100
CH2 1.00VΩBW
CH4 5.00VΩ
M 400ns
CH3
Figure 23. Driver/Receiver Propagation Delay
450
0
4
CH1 1.00VΩBW
CH3 2.00VΩBW
5.0
Figure 20. Output Current vs. Driver Output High Voltage
50
05079-023
OUTPUT CURRENT (mA)
–10
125
Figure 21. Driver Propagation Delay vs. Temperature
Rev. 0 | Page 10 of 16
2.00V
ADM483
APPLICATIONS
DIFFERENTIAL DATA TRANSMISSION
Table 5. Comparison of RS-422 and RS-485 Interface Standards
Differential data transmission is used to reliably transmit
data at high rates over long distances and through noisy
environments. Differential transmission nullifies the effects
of ground shifts and noise signals that appear as commonmode voltages on the line. There are two main standards
approved by the Electronics Industries Association (EIA),
which specify the electrical characteristics of transceivers
used in differential data transmission.
Specification
Transmission Type
Maximum Cable Length
Minimum Driver Output Voltage
Driver Load Impedance
Receiver Input Resistance
Receiver Input Sensitivity
Receiver Input Voltage Range
Drivers/Receivers per Line
The RS-422 standard specifies data rates up to 10 Mbaud
and line lengths up to 4000 ft. A single driver can drive a
transmission line with up to 10 receivers.
CABLE AND DATA RATE
To achieve true multipoint communications, the RS-485
standard was defined. This standard meets or exceeds all the
requirements of RS-422, but also allows up to 32 drivers and 32
receivers to be connected to a single bus. An extended commonmode range of –7 V to +12 V is defined. The most significant
difference between RS-422 and RS-485 is that the drivers may
be disabled, allowing up to 32 to be connected to a single line.
Only one driver should be enabled at a time, but the RS-485
standard contains additional specifications to guarantee device
safety in the event of line contention.
R
The ADM483 is designed for bidirectional data communications on multipoint transmission lines. A typical application
showing a multipoint transmission network is shown in
Figure 24. An RS-485 transmission line can have as many as
32 transceivers on the bus. Only one driver can transmit at a
particular time, but multiple receivers can be enabled simultaneously. As with any transmission line, it is important to
minimize reflections. This can be done by terminating the
extreme ends of the line by using resistors equal to the characteristic impedance of the line. Stub lengths of the main
line should also be kept as short as possible. A properly
terminated transmission line appears purely resistive to
the driver.
ADM483
A
A
R
RO
RE
RE
DE
DE
D
B
B
A
A
B
DI
B
ADM483
ADM483
R
R
D
D
RO RE DE
D
DI
RO RE DE
DI
MAXIMUM NUMBER OF TRANSCEIVERS ON BUS: 32
Figure 24. Typical Half-Duplex RS-485 Network Topology
Rev. 0 | Page 11 of 16
05079-024
DI
RS-485
Differential
4000 ft.
±1.5 V
54 Ω
12 kΩ min
±200 mV
–7 V to +12 V
32/32
The preferred transmission line for RS-485 communications
is a twisted pair. Twisted pair cable tends to cancel commonmode noise and the magnetic fields generated by the current
flowing through each wire, thereby reducing the effective
inductance of the pair.
ADM483
RO
RS-422
Differential
4000 ft.
±2 V
100 Ω
4 kΩ min
±200 mV
–7 V to +7 V
1/10
ADM483
THERMAL SHUTDOWN
RECEIVER OPEN-CIRCUIT FAIL-SAFE
The ADM483 contains thermal shutdown circuitry that
protects the part from excessive power dissipation during
fault conditions. Shorting the driver outputs to a low
impedance source can result in high driver currents. The
thermal sensing circuitry detects the increase in die temperature and disables the driver outputs. The thermal sensing
circuitry is designed to disable the driver outputs when a die
temperature of 150°C is reached. As the device cools, the
drivers are re-enabled at 140°C.
The receiver input includes a fail-safe feature that guarantees
a logic high on the receiver when the inputs are open circuit
or floating.
Rev. 0 | Page 12 of 16
ADM483
OUTLINE DIMENSIONS
5.00 (0.1968)
4.80 (0.1890)
8
5
4.00 (0.1574)
3.80 (0.1497) 1
4
1.27 (0.0500)
BSC
0.25 (0.0098)
0.10 (0.0040)
6.20 (0.2440)
5.80 (0.2284)
1.75 (0.0688)
1.35 (0.0532)
0.51 (0.0201)
COPLANARITY
SEATING 0.31 (0.0122)
0.10
PLANE
0.50 (0.0196)
× 45°
0.25 (0.0099)
8°
0.25 (0.0098) 0° 1.27 (0.0500)
0.40 (0.0157)
0.17 (0.0067)
COMPLIANT TO JEDEC STANDARDS MS-012AA
CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN
Figure 25. 8-Lead Standard Small Outline Package [SOIC]
(R-8)
Dimensions shown in millimeters and (inches)
ORDERING GUIDE
Model
ADM483AR
ADM483AR-REEL
ADM483AR-REEL7
ADM483JR
ADM483JR-REEL
ADM483JR-REEL7
Temperature Range
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
0°C to 70°C
0°C to 70°C
0°C to 70°C
Package Description
8-Lead Standard Small Outline Package
8-Lead Standard Small Outline Package
8-Lead Standard Small Outline Package
8-Lead Standard Small Outline Package
8-Lead Standard Small Outline Package
8-Lead Standard Small Outline Package
Rev. 0 | Page 13 of 16
Package Option
R-8
R-8
R-8
R-8
R-8
R-8
ADM483
NOTES
Rev. 0 | Page 14 of 16
ADM483
NOTES
Rev. 0 | Page 15 of 16
ADM483
NOTES
© 2004 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D05079-0-10/04(0)
Rev. 0 | Page 16 of 16