AD ADM3483E Full-duplex, rs-485/rs-422 transceiver Datasheet

3.3 V, ±15 kV ESD-Protected, Half- and
Full-Duplex, RS-485/RS-422 Transceivers
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
TIA/EIA RS-485/RS-422 compliant
±15 kV ESD protection on RS-485 input/output pins
Data rates
ADM3483E/ADM3488E: 250 kbps
ADM3486E: 2.5 Mbps
ADM3490E/ADM3491E: 12 Mbps
Half- and full-duplex options
Up to 32 nodes on the bus
Receiver open-circuit, fail-safe design
Low power shutdown current
(ADM3483E/ADM3486E/ADM3491E only)
Outputs high-Z when disabled or powered off
Common-mode input range: −7 V to +12 V
Thermal shutdown and short-circuit protection
Industry-standard 75176 pinout
8-lead and 14-lead narrow SOIC packages
FUNCTIONAL BLOCK DIAGRAMS
VCC
ADM3483E/
ADM3486E
RO
R
RE
A
DE
B
DI
D
06284-001
FEATURES
GND
Figure 1.
VCC
ADM3488E/
ADM3490E
R
RO
A
B
APPLICATIONS
Z
Y
GND
Figure 2.
VCC
GENERAL DESCRIPTION
The ADM3483E/ADM3486E/ADM3488E/ADM3490E/
ADM3491E are 3.3 V, low power data transceivers with
±15 kV ESD protection suitable for full- and half-duplex
communication on multipoint bus transmission lines. They
are designed for balanced data transmission, and they
comply with TIA/EIA standards RS­485 and RS-422. The
ADM3483E/ADM3486E are half-duplex transceivers that
share differential lines and have separate enable inputs for
the driver and receiver. The full-duplex ADM3488E/
ADM3490E/ADM3491E transceivers have dedicated
differential line driver outputs and receiver inputs. The
ADM3491E also features separate enable inputs for the
driver and receiver.
D
06284-002
DI
ADM3491E
RO
R
A
B
RE
DE
DI
D
GND
Z
Y
06284-003
Power/energy metering
Telecommunications
EMI-sensitive systems
Industrial control
Local area networks
Figure 3.
The devices have a 12 kΩ receiver input impedance,
which allows up to 32 transceivers on a bus. Because only
one driver should be enabled at any time, the output of a
disabled or powered-down driver is tristated to avoid
overloading the bus.
(continued on Page 3)
Rev. A
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Fax: 781.461.3113
©2006 Analog Devices, Inc. All rights reserved.
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications....................................................................................... 1
General Description ......................................................................... 1
Functional Block Diagrams............................................................. 1
Revision History ............................................................................... 2
Specifications..................................................................................... 4
Driver Timing Specifications...................................................... 5
Receiver Timing Specifications .................................................. 6
Absolute Maximum Ratings............................................................ 7
ESD Caution.................................................................................. 7
Pin Configurations and Function Descriptions ........................... 8
Test Circuits and Switching Characteristics.................................. 9
Devices Without Receiver/Driver Enable―ADM3488E/
ADM3490E ................................................................................. 14
Low Power Shutdown Mode—ADM3483E/ADM3486E /
ADM3491E ................................................................................. 14
Driver Output Protection.......................................................... 14
Propagation Delay ...................................................................... 14
Line Length vs. Data Rate ......................................................... 14
±15 kV ESD Protection ............................................................. 15
Human Body Model .................................................................. 15
Typical Applications................................................................... 15
Outline Dimensions ....................................................................... 18
Ordering Guide .......................................................................... 18
Typical Performance Characteristics ........................................... 11
Circuit Description......................................................................... 14
Devices with Receiver/Driver Enable—ADM3483E/
ADM3486E/ADM3491E ........................................................... 14
REVISION HISTORY
10/06—Rev. 0 to Rev. A
Added ADM3483E and ADM3488E ...............................Universal
Changes to Figure 1 and Figure 2................................................... 1
Inserted Table 3................................................................................. 5
Changes to Figure 4 and Figure 5................................................... 8
Inserted Figure 28 and Figure 29.................................................. 13
Changes to Figure 31 and Figure 32............................................. 16
Changes to Figure 34...................................................................... 17
Updated Outline Dimensions ....................................................... 18
Changes to Ordering Guide .......................................................... 18
8/06—Revision 0: Initial Version
Rev. A | Page 2 of 20
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
GENERAL DESCRIPTION
(continued from Page 1)
The driver outputs of the ADM3483E/ADM3486E/
ADM3488E are slew rate limited, in order to reduce EMI
and data errors caused by reflections from improperly
terminated buses. The receiver has a fail-safe feature that
ensures a logic high output when the inputs are floating.
Excessive power dissipation caused by bus contention
or by output shorting is prevented with a thermal shutdown circuit.
The parts are fully specified over the industrial temperature range
and are available in 8-lead and 14-lead narrow SOIC packages.
Table 1. Selection Table
Part No.
ADM3483E
ADM3486E
ADM3488E
ADM3490E
ADM3491E
Guaranteed Data
Rate (Mbps)
0.25
2.5
0.25
12
12
Supply
Voltage (V)
3.0 to 3.6
3.0 to 3.6
3.0 to 3.6
3.0 to 3.6
3.0 to 3.6
Half/Full
Duplex
Half
Half
Full
Full
Full
Slew Rate
Limited
Yes
Yes
Yes
No
No
Rev. A | Page 3 of 20
Driver/Receiver
Enable
Yes
Yes
No
No
Yes
±15 kV ESD Protection
on Bus Pins
Yes
Yes
Yes
Yes
Yes
Pin Count
8
8
8
8
14
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
SPECIFICATIONS
VCC = 3.3 V ± 0.3 V, TA = TMIN to TMAX, unless otherwise noted.
Table 2. ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
Parameter
DRIVER
Differential Outputs
Differential Output Voltage
Symbol
Min
VOD
2.0
1.5
1.5
Δ|VOD| for Complementary Output States1
Common-Mode Output Voltage
Δ|VOC| for Complementary Output States1
Short-Circuit Output Current
∆VOD
VOC
∆VOC
IOSD
Output Leakage (Y, Z) (ADM3491E Only)
Normal Mode
IO
Typ
Max
Unit
Test Conditions/Comments
250
V
V
V
V
V
V
mA
mA
RL = 100 Ω (RS-422) (see Figure 7)
RL = 54 Ω (RS-485) (see Figure 7)
RL = 60 Ω (RS-485) (see Figure 8)
RL = 54 Ω or 100 Ω (see Figure 7)
RL = 54 Ω or 100 Ω (see Figure 7)
RL = 54 Ω or 100 Ω (see Figure 7)
VOUT = −7 V
VOUT = 12 V
20
μA
DE = 0 V, RE = 0 V, VCC = 0 V or 3.6 V,
VOUT = 12 V
DE = 0 V, RE = 0 V, VCC = 0 V or 3.6 V,
VOUT = −7 V
DE = 0 V, RE = VCC, VCC = 0 V or 3.6 V,
VOUT = 12 V
DE = 0 V, RE = VCC, VCC = 0 V or 3.6 V,
VOUT = −7 V
0.2
3
0.2
−250
−20
μA
Shutdown Mode
1
−1
Logic Inputs
Input High Voltage
Input Low Voltage
Logic Input Current
RECEIVER
Differential Inputs
Differential Input Threshold Voltage
Input Hysteresis
Input Resistance (A, B)
Input Current (A, B)
VIH
VIL
IIN1
2.0
VTH
∆VTH
RIN
IIN2
−0.2
μA
V
V
μA
DE, DI, RE
DE, DI, RE
DE, DI, RE
V
mV
kΩ
mA
mA
−7 V < VCM < +12 V
VCM = 0 V
−7 V < VCM < +12 V
DE = 0 V, VCC = 0 V or 3.6 V, VIN = 12 V
DE = 0 V, VCC = 0 V or 3.6 V, VIN = −7 V
0.4
±60
±1
V
V
mA
μA
IOUT = −1.5 mA, VID = 200 mV (see Figure 9)
IOUT = 2.5 mA, VID = 200 mV (see Figure 9)
0 V < VRO < VCC
VCC = 3.6 V, 0 V < VOUT < VCC
1.1
3.6
2.2
V
mA
0.95
1.9
mA
0.002
1
μA
No load, DI = 0 V or VCC, DE = VCC,
RE = 0 V or VCC
No load, DI = 0 V or VCC, DE = 0 V,
RE = 0 V
DE = 0 V, RE = VCC, DI = 0 V or VCC
kV
kV
Human body model
Human body model
0.8
±2
0.2
50
12
1.0
−0.8
RO Logic Output
Output High Voltage
Output Low Voltage
Short-Circuit Output Current
Tristate Output Leakage Current
POWER SUPPLY
Voltage Range
Supply Current
Shutdown Current
ESD PROTECTION
A, B, Y, Z Pins
All Pins Except A, B, Y, Z Pins
1
VOH
VOL
IOSR
IOZR
VCC − 0.4
VCC
ICC
3.0
ISHDN
μA
±8
±15
±4
Δ|VOD| and Δ|VOC| are the changes in VOD and VOC, respectively, when DI input changes state.
Rev. A | Page 4 of 20
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
DRIVER TIMING SPECIFICATIONS
VCC = 3.3 V, TA = 25°C.
Table 3. ADM3483E/ADM3488E
Parameter
MAXIMUM DATA RATE
DIFFERENTIAL OUTPUT DELAY
DIFFERENTIAL OUTPUT TRANSITION TIME
PROPAGATION DELAY
From Low to High Level
From High to Low Level
|tPLH − tPHL| PROPAGATION DELAY SKEW1
ENABLE/DISABLE TIMING (ADM3483E ONLY)
Enable Time to Low Level
Enable Time to High Level
Disable Time from Low Level
Disable Time from High Level
Enable Time from Shutdown to Low Level
Enable Time from Shutdown to High Level
1
Symbol
tDD
tTD
tPLH
tPHL
tPDS
Min
250
600
400
Typ
Max
Unit
kbps
ns
ns
Test Conditions/Comments
900
740
1400
1200
700
700
930
930
±50
1500
1500
ns
ns
ns
RL = 27 Ω (see Figure 11)
RL = 27 Ω (see Figure 11)
RL = 27 Ω (see Figure 11)
900
600
50
50
1.9
2.2
1300
800
80
80
2.7
3.0
ns
ns
ns
ns
μs
μs
RL = 110 Ω (see Figure 13)
RL = 110 Ω (see Figure 12)
RL = 110 Ω (see Figure 13)
RL = 110 Ω (see Figure 12)
RL = 110 Ω (see Figure 13)
RL = 110 Ω (see Figure 12)
Min
2.5
20
15
Typ
Max
Test Conditions/Comments
42
28
70
60
Unit
Mbps
ns
ns
20
20
42
42
−6
75
75
±12
ns
ns
ns
RL = 27 Ω (see Figure 11)
RL = 27 Ω (see Figure 11)
RL = 27 Ω (see Figure 11)
52
52
40
40
700
700
100
100
80
80
1000
1000
ns
ns
ns
ns
ns
ns
RL = 110 Ω (see Figure 13)
RL = 110 Ω (see Figure 12)
RL = 110 Ω (see Figure 13)
RL = 110 Ω (see Figure 12)
RL = 110 Ω (see Figure 13)
RL = 110 Ω (see Figure 12)
tPZL
tPZH
tPLZ
tPHZ
tPSL
tPSH
RL = 60 Ω (see Figure 10)
RL = 60 Ω (see Figure 10)
Measured on |tPLH (Y) − tPHL (Y)| and |tPLH (Z) − tPHL (Z)|.
VCC = 3.3 V, TA = 25°C.
Table 4. ADM3486E
Parameter
MAXIMUM DATA RATE
DIFFERENTIAL OUTPUT DELAY
DIFFERENTIAL OUTPUT TRANSITION TIME
PROPAGATION DELAY
From Low to High Level
From High to Low Level
|tPLH − tPHL| PROPAGATION DELAY SKEW 1
ENABLE/DISABLE TIMING
Enable Time to Low Level
Enable Time to High Level
Disable Time from Low Level
Disable Time from High Level
Enable Time from Shutdown to Low Level
Enable Time from Shutdown to High Level
1
Symbol
tDD
tTD
tPLH
tPHL
tPDS
tPZL
tPZH
tPLZ
tPHZ
tPSL
tPSH
Measured on |tPLH (Y) − tPHL (Y)| and |tPLH (Z) − tPHL (Z)|.
Rev. A | Page 5 of 20
RL = 60 Ω (see Figure 10)
RL = 60 Ω (see Figure 10)
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
VCC = 3.3 V, TA = 25°C.
Table 5. ADM3490E/ADM3491E
Parameter
MAXIMUM DATA RATE
DIFFERENTIAL OUTPUT DELAY
DIFFERENTIAL OUTPUT TRANSITION TIME
PROPAGATION DELAY
From Low to High Level
From High to Low Level
|tPLH − tPHL| PROPAGATION DELAY SKEW1
ENABLE/DISABLE TIMING (ADM3491E ONLY)
Enable Time to Low Level
Enable Time to High Level
Disable Time from Low Level
Disable Time from High Level
Enable Time from Shutdown to Low Level
Enable Time from Shutdown to High Level
1
Symbol
tDD
tTD
tPLH
tPHL
tPDS
Min
12
1
3
Typ
15
22
11
Max
7
7
tPZL
tPZH
tPLZ
tPHZ
tPSL
tPSH
Test Conditions/Comments
35
25
Unit
Mbps
ns
ns
23
23
−1.4
35
35
±8
ns
ns
ns
RL = 27 Ω (see Figure 11)
RL = 27 Ω (see Figure 11)
RL = 27 Ω (see Figure 11)
42
42
35
35
650
650
90
90
80
80
900
900
ns
ns
ns
ns
ns
ns
RL = 110 Ω (see Figure 13)
RL = 110 Ω (see Figure 12)
RL = 110 Ω (see Figure 13)
RL = 110 Ω (see Figure 12)
RL = 110 Ω (see Figure 13)
RL = 110 Ω (see Figure 12)
RL = 60 Ω (see Figure 10)
RL = 60 Ω (see Figure 10)
Measured on |tPLH (Y) − tPHL (Y)| and |tPLH (Z) − tPHL (Z)|.
RECEIVER TIMING SPECIFICATIONS
VCC = 3.3 V, TA = 25°C.
Table 6. ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
Parameter
PROPAGATION DELAY
From Low to High Level
ADM3486E/ADM3490E/ADM3491E
ADM3483E/ADM3488E
From High to Low Level
ADM3486E/ADM3490E/ADM3491E
ADM3483E/ADM3488E
|tRPLH − tRPHL| PROPAGATION DELAY SKEW
ADM3486E/ADM3490E/ADM3491E
ADM3483E/ADM3488E
ENABLE/DISABLE TIMING (ADM3483E/ADM3486E/
ADM3491E ONLY)
Enable Time to Low Level
Enable Time to High Level
Disable Time from Low Level
Disable Time from High Level
Enable Time from Shutdown to Low Level
Enable Time from Shutdown to High Level
Time to Shutdown1
1
Symbol
Min
Typ
Max
Unit
Test Conditions/Comments
25
25
62
75
90
120
ns
ns
VID = 0 V to 3.0 V, CL = 15 pF (see Figure 14)
VID = 0 V to 3.0 V, CL = 15 pF (see Figure 14)
25
25
62
75
90
120
ns
ns
VID = 0 V to 3.0 V, CL = 15 pF (see Figure 14)
VID = 0 V to 3.0 V, CL = 15 pF (see Figure 14)
+6
+12
±10
±20
ns
ns
VID = 0 V to 3.0 V, CL = 15 pF (see Figure 14)
VID = 0 V to 3.0 V, CL = 15 pF (see Figure 14)
25
25
25
25
720
720
190
50
50
45
45
1400
1400
300
ns
ns
ns
ns
ns
ns
ns
CL = 15 pF (see Figure 15)
CL = 15 pF (see Figure 15)
CL = 15 pF (see Figure 15)
CL = 15 pF (see Figure 15)
CL = 15 pF (see Figure 15)
CL = 15 pF (see Figure 15)
tRPLH
tRPHL
tRPDS
tRPZL
tRPZH
tRPLZ
tRPHZ
tRPSL
tRPSH
tSHDN
80
The transceivers are put into shutdown mode by bringing the RE high and the DE low. If the inputs are in this state for less than 80 ns, the parts are guaranteed not to
enter shutdown. If the parts are in this state for 300 ns or more, the parts are guaranteed to enter shutdown.
Rev. A | Page 6 of 20
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
ABSOLUTE MAXIMUM RATINGS
TA = 25°C, unless otherwise noted.
Table 7.
Parameter
VCC to GND
Digital Input/Output Voltage (DE, RE, DI)
Receiver Output Voltage (RO)
Driver Output (A, B, Y, Z)/Receiver Input
(A, B) Voltage
Driver Output Current
Operating Temperature Range
Storage Temperature Range
θJA Thermal Impedance
8-Lead SOIC_N
14-Lead SOIC_N
Lead Temperature, Soldering (20 sec)
Rating
−0.3 V to +6 V
−0.3 V to +6 V
−0.3 V to (VCC + 0.3 V)
−8 V to +13 V
±250 mA
−40°C to +85°C
−65°C to +150°C
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.
ESD CAUTION
158°C/W
120°C/W
260°C
Rev. A | Page 7 of 20
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
NC 1
14 VCC
RO 2
RE 3
13 VCC
ADM3491E
12 A
DE 3
DI 4
VCC 1
ADM3483E/
ADM3486E
8
VCC
7
B
RO 2
TOP VIEW
(Not to Scale)
6
A
DI 3
5
GND
GND 4
Figure 4. ADM3483E/ADM3486E
Pin Configuration
ADM3488E/
ADM3490E
8
A
7
B
GND 6
9
Y
TOP VIEW
(Not to Scale)
6
Z
GND 7
8
NC
5
Y
06284-005
RE 2
06284-004
RO 1
11 B
TOP VIEW
DI 5 (Not to Scale) 10 Z
Figure 5. ADM3488E/ADM3490E
Pin Configuration
NC = NO CONNECT
06284-006
DE 4
Figure 6. ADM3491E
Pin Configuration
Table 8. Pin Function Descriptions
ADM3483E/
ADM3486E
Pin No.
1
ADM3488E/
ADM3490E
Pin No.
2
ADM3491E
Pin No.
2
Mnemonic
RO
2
N/A
3
RE
3
N/A
4
DE
4
3
5
DI
5
N/A
6
N/A
N/A
7
N/A
8
N/A
4
5
N/A
8
6
N/A
7
1
N/A
6, 7
9
N/A
12
10
N/A
11
13, 14
1, 8
GND
Y
A
A
Z
B
B
VCC
NC
Description
Receiver Output. If A > B by 200 mV, RO is high; if A < B by 200 mV,
RO is low.
Receiver Output Enable. A low level enables the receiver output. A high
level places it in a high impedance state. If RE is high and DE is low, the
device enters a low power shutdown mode.
Driver Output Enable. A high level enables the driver differential A and B
outputs. A low level places it in a high impedance state. If RE is high and DE
is low, the device enters a low power shutdown mode.
Driver Input. With a half-duplex part when the driver is enabled, a logic low
on DI forces A low and B high; a logic high on DI forces A high and B low.
With a full-duplex part when the driver is enabled, a logic low on DI forces Y
low and Z high; a logic high on DI forces Y high and Z low.
Ground.
Noninverting Driver Output.
Noninverting Receiver Input A and Noninverting Driver Output A.
Noninverting Receiver Input A.
Inverting Driver Output.
Inverting Receiver Input B and Inverting Driver Output B.
Inverting Receiver Input B.
Power Supply, 3.3 V ± 0.3 V. Bypass VCC to GND with a 0.1 μF capacitor.
No Connect. Not internally connected. Can be connected to GND.
Rev. A | Page 8 of 20
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
TEST CIRCUITS AND SWITCHING CHARACTERISTICS
VOM
Y
RL = 27Ω
RL/2
S1
VOD
Z
OUT
D
06284-007
VOC
RL/2
GENERATOR1
CL = 15pF2
50Ω
VCC
Figure 7. Driver Differential Output Voltage and
Common-Mode Output Voltage
VOM =
VOH + VOL
375Ω
VOD
RL
VCC
≈ 1.5V
1PPR = 250kHz, 50% DUTY CYCLE, t ≤ 6.0ns, Z = 50Ω.
R
O
2C INCLUDES PROBE AND STRAY CAPACITANCE.
L
VCM =
–7V TO +12V
3V
06284-008
D
2
375Ω
IN
1.5V
1.5V
0V
Figure 8. Driver Differential Output Voltage with
Varying Common-Mode Voltage
tPLH
tPHL
VOH
Y
OUT
VOM
VOM
VOL
tPHL
R
tPLH
VOH
IOL
VOL
VOH
IOH
(–)
(+)
Z
OUT
VOM
VOL
Figure 11. Driver Propagation Delays
Figure 9. Receiver Output Voltage High and Output Voltage Low
S1
CL
0V OR 3V
RL =
OUT
60Ω
D
GENERATOR1
VOM
06284-011
0
06284-009
VID
OUT
D
CL = 50pF2
RL = 110Ω
50Ω
VCC
GENERATOR1
CL = 15pF2
50Ω
VOM =
1PPR = 250kHz, 50% DUTY CYCLE, t ≤ 6.0ns, Z = 50Ω.
R
O
2C INCLUDES PROBE AND STRAY CAPACITANCE.
L
VOH + VOL
2
≈ 1.5V
1PPR = 250kHz, 50% DUTY CYCLE, t ≤ 6.0ns, Z = 50Ω.
R
O
2C INCLUDES PROBE AND STRAY CAPACITANCE.
L
+3V
+1.5V
+1.5V
3V
0V
OUT
50%
10%
90%
tTD
1.5V
1.5V
tDD
90%
0V
tPZH
≈ +2V
50%
10%
tTD
≈ –2V
OUT
06284-010
tDD
IN
tPHZ
0.25V
VOH
VOM
0V
Figure 10. Driver Differential Output Delay and Transition Times
Figure 12. Driver Enable and Disable Times (tPZH, tPSH, tPHZ)
Rev. A | Page 9 of 20
06284-012
IN
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
VCC
RL = 110Ω
S1
0V OR 3V
OUT
D
VID
GENERATOR1
CL = 50pF2
OUT
CL = 15pF2
50Ω
1.5V
VOM =
0V
1PPR = 250kHz, 50% DUTY CYCLE, t ≤ 6.0ns, Z = 50Ω.
R
O
2C INCLUDES PROBE AND STRAY CAPACITANCE.
L
VCC
1PPR = 250kHz, 50% DUTY CYCLE, t ≤ 6.0ns, Z = 50Ω.
R
O
2C INCLUDES PROBE AND STRAY CAPACITANCE.
L
3V
1.5V
3V
1.5V
0V
tPSL
1.5V
0V
tPLZ
tRPLH
VCC
tRPHL
VCC
VOM
0.25V
06284-013
OUT
1.5V
IN
VOL
VOM
OUT
0V
Figure 14. Receiver Propagation Delays
Figure 13. Driver Enable and Disable Times (tPZL, tPSL, tPLZ)
S1
S3
+1.5V
VOM
VID
–1.5V
VCC
1kΩ
R
S2
CL2
GENERATOR1
50Ω
1PPR = 250kHz, 50% DUTY CYCLE, t ≤ 6.0ns, Z = 50Ω.
R
O
2C INCLUDES PROBE AND STRAY CAPACITANCE.
L
+3V
+1.5V
IN
0V
tRPZH
tRPSH
OUT
S1 OPEN
S2 CLOSED
S3 = +1.5V
+3V
IN
+1.5V
VOH
VCC
OUT
+1.5V
+1.5V
0V
+3V
+1.5V
IN
0V
VOL
S1 OPEN
S2 CLOSED
S3 = +1.5V
+3V
+1.5V
IN
0V
tRPHZ
S1 CLOSED
S2 OPEN
S3 = –1.5V
tRPLZ
VOH
OUT
0V
tRPZL
tRPSL
S1 CLOSED
S2 OPEN
S3 = –1.5V
VCC
OUT
+0.25V
0V
VOL
+0.25V
Figure 15. Receiver Enable and Disable Times
Rev. A | Page 10 of 20
06284-015
IN
2
06284-014
GENERATOR1
R
50Ω
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
TYPICAL PERFORMANCE CHARACTERISTICS
25
0.8
IRO = 2.5mA
0.7
OUTPUT LOW VOLTAGE (V)
OUTPUT CURRENT (mA)
20
15
10
5
0.6
0.5
0.4
0.3
0.2
0
0.5
1.0
1.5
2.0
2.5
3.5
3.0
OUTPUT LOW VOLTAGE (V)
0
–40
06284-021
Figure 16. Output Current vs. Receiver Output Low Voltage
100
–16
90
OUTPUT CURRENT (mA)
–12
–10
–8
–6
–4
70
60
50
40
30
20
–2
10
0.5
1.0
1.5
2.0
2.5
3.5
3.0
OUTPUT HIGH VOLTAGE (V)
0
06284-022
0
0.5
1.0
1.5
2.0
2.5
3.5
3.0
DIFFERENTIAL OUTPUT VOLTAGE (V)
Figure 17. Output Current vs. Receiver Output High Voltage
Figure 20. Driver Output Current vs. Differential Output Voltage
2.6
3.30
DIFFERENTIAL OUTPUT VOLTAGE (V)
IRO = –1.5mA
3.25
3.20
3.15
3.10
–25
0
25
50
75
TEMPERATURE (°C)
06284-023
3.05
3.00
–50
0
06284-025
OUTPUT CURRENT (mA)
85
80
–14
OUTPUT HIGH VOLTAGE (V)
60
Figure 19. Receiver Output Low Voltage vs. Temperature
–18
0
10
TEMPERATURE (°C)
RL = 54Ω
2.5
2.4
2.3
2.2
2.1
2.0
1.9
1.8
1.7
1.6
–50
–25
0
25
50
75
TEMPERATURE (°C)
Figure 21. Driver Differential Output Voltage vs. Temperature
Figure 18. Receiver Output High Voltage vs. Temperature
Rev. A | Page 11 of 20
06284-026
0
06284-024
0.1
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
120
0.9
0.8
0.7
SHUTDOWN CURRENT (µA)
OUTPUT CURRENT (mA)
100
80
60
40
0.6
0.5
0.4
0.3
0.2
20
0
2
4
6
8
10
12
OUTPUT LOW VOLTAGE (V)
0
–50
06284-027
0
–25
0
25
50
06284-030
0.1
75
TEMPERATURE (°C)
Figure 22. Output Current vs. Driver Output Low Voltage
Figure 25. Shutdown Current vs. Temperature
120
DI
80
3
60
Y
40
20
–6
–5
–4
–3
–2
–1
0
1
2
3
4
OUTPUT HIGH VOLTAGE (V)
Z
CH1 1.0V Ω
CH3 2.0V Ω
06284-028
0
–7
CH1
CH2
Figure 23. Output Current vs. Driver Output High Voltage
CH2 1.0V Ω
IT 400ps/pt A CH3
M20ns 1.25GS/s
1.44V
06284-031
OUTPUT CURRENT (mA)
100
Figure 26. ADM3490E/ADM3491E Driver Propagation Delay
1.2
VA – VB
1.0
M1
0.9
0.8
0.7
RO
0.6
–10
20
50
TEMPERATURE (°C)
80
CH3 2.0V Ω M200ns 250MS/s
MATH1 2.01V 200ns
4ns/pt
A CH2
1.24V
06284-032
3
0.5
–40
06284-029
SUPPLY CURRENT (mA)
1.1
Figure 27. ADM3490E/ADM3491E Receiver Propagation Delay,
Driven by External RS-485 Device
Figure 24. Supply Current vs. Temperature
Rev. A | Page 12 of 20
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
DI
3
VA – VB
Y
1
M
RO
06284-033
06284-034
Z
CH1 500mV Ω
CH3 5.0V Ω
CH2 500mV Ω
M2.0µs 25.0MS/s
A CH3
2.4V
CH1 2.00V
MATH 2.00V 20.0ms
40.0ns/pt
Figure 28. ADM3483E/ADM3488E Driver Propagation Delay
M20.0ms
A CH1
40.0mV
Figure 29. ADM3483E/ADM3488E Receiver Propagation Delay
Rev. A | Page 13 of 20
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
CIRCUIT DESCRIPTION
The ADM34xxE are low power transceivers for RS-485 and RS­422
communications. The ADM3483E/ADM3488E operate at data
rates up to 250 kbps. The ADM3486E operates at data rates up
to 2.5 Mbps, and the ADM3490E/ADM3491E transmit at up to
12 Mbps. The ADM3488E/ADM3490E/ADM3491E are fullduplex transceivers, and the ADM3483E/ADM3486E are half
duplex. Driver enable (DE) and receiver enable (RE) pins are
included on the ADM3483E/ADM3486E/ADM3491E. When
disabled, the driver and receiver outputs are high impedance.
Table 12. Receiving Truth Table
DEVICES WITH RECEIVER/DRIVER ENABLE—
ADM3483E/ADM3486E/ADM3491E
The ADM3483E/ADM3486E/ADM3491E are put into a low
power shutdown mode by bringing both RE high and DE low.
The devices do not shut down unless both the driver and the
receiver are disabled (high impedance). In shutdown mode, the
devices typically draw less than 1 μA of supply current. For
these devices, the tPSH and the tPSL enable times assume the part
was in the low power shutdown mode; the tPZH and the tPZL
enable times assume the receiver or the driver was disabled, but
the part was not shut down.
Table 9. Transmitting Truth Table
Transmitting Inputs
DE
DI
RE
Transmitting Outputs
A1, Y2
B1, Z2
X3
X3
0
1
1
0
High-Z4
High-Z4
1
1
0
0
1
0
X3
X3
0
1
High-Z4
High-Z4
Mode
Normal
Normal
Normal
Shutdown
1
ADM3483E and ADM3486E only.
ADM3491E only.
3
X = don’t care.
4
High-Z = high impedance.
2
Table 10. Receiving Truth Table
RE
Receiving Inputs
DE1 DE2 A – B
0
0
0
1
0
0
0
0
X3
X3
X3
X3
Receiving Output
RO
≥ +0.2 V
≤ −0.2 V
Inputs open
X3
1
0
1
High-Z4
Mode
Normal
Normal
Normal
Shutdown
1
ADM3483E and ADM3486E only.
ADM3491E only.
3
X = don’t care.
4
High-Z = high impedance.
2
DEVICES WITHOUT RECEIVER/DRIVER ENABLE―
ADM3488E/ADM3490E
Table 11. Transmitting Truth Table
Transmitting Input
DI
1
0
Z
0
1
Transmitting Outputs
Y
1
0
Receiving Input
A–B
≥ +0.2 V
≤ −0.2 V
Inputs open
Receiving Output
RO
1
0
1
LOW POWER SHUTDOWN MODE—ADM3483E/
ADM3486E/ADM3491E
DRIVER OUTPUT PROTECTION
The ADM34xxE family implements two ways to prevent
excessive output current and power dissipation caused by faults
or by bus contention. A current limit on the output stage
provides immediate protection against short circuits over the
whole common-mode voltage range (see the Typical
Performance Characteristics section). In addition, a thermal
shutdown circuit forces the driver outputs into a high
impedance state if the die temperature rises excessively.
PROPAGATION DELAY
Figure 11, Figure 14, Figure 26, and Figure 27 show the typical
propagation delays. Skew time is simply the difference between
the low-to-high and the high-to-low propagation delays. Small
driver/receiver skew times help maintain a symmetrical markspace ratio (50% duty cycle).
The receiver skew time, |tPRHL – tPRHL|, is under 10 ns (20 ns for
the ADM3483E/ADM3488E). The driver skew time is 8 ns for
the ADM3490E/ADM3491E, 12 ns for the ADM3486E, and
typically under 50 ns for the ADM3483E/ADM3488E.
LINE LENGTH VS. DATA RATE
The RS-485/RS-422 standard covers line lengths up to 4000 feet.
For line lengths greater than 4000 feet, Figure 34 illustrates an
example of a line repeater.
Rev. A | Page 14 of 20
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
±15 kV ESD PROTECTION
HIGH
VOLTAGE
GENERATOR
Two coupling methods are used for ESD testing: contact discharge and air-gap discharge. Contact discharge
calls for a direct connection to the unit being tested. Airgap discharge uses a higher test voltage but does not make
direct contact with the test unit. With air-gap discharge,
the discharge gun is moved toward the unit under test,
developing an arc across the air gap, therefore the term airgap discharge. This method is influenced by humidity,
temperature, barometric pressure, distance, and rate of
closure of the discharge gun. The contact discharge
method, while less realistic, is more repeatable and is
gaining acceptance and preference over the airgap method.
Input/output lines are particularly vulnerable to ESD damage.
Simply touching or connecting an input/output cable can result
in a static discharge that can damage or completely destroy the
interface product connected to the input/output port. It is
extremely important, therefore, to have high levels of ESD
protection on the input/output lines.
The ESD discharge can induce latch-up in the device under test,
so it is important that ESD testing on the input/output pins be
carried out while device power is applied. This type of testing is
more representative of a real-world input/output discharge,
which occurs when the equipment is operating normally.
The transmitter outputs and receiver inputs of the ADM34xxE
family are characterized for protection to a ±15 kV limit using
the human body model.
DEVICE
UNDER
TEST
C1
ESD TEST METHOD
R2
C1
HUMAN BODY MODEL
ESD ASSOC. STD 55.1
1.5kΩ
100pF
100%
IPEAK
90%
36.8%
10%
tRL
tDL
TIME t
06284-016
Although very little energy is contained within an ESD pulse,
the extremely fast rise time, coupled with high voltages, can
cause failures in unprotected semiconductors. Catastrophic
destruction can occur immediately as a result of arcing or
heating. Even if catastrophic failure does not occur immediately,
the device can suffer from parametric degradation that can
result in degraded performance. The cumulative effects of
continuous exposure can eventually lead to complete failure.
R2
R1
Figure 30. Human Body Model and Current Waveform
TYPICAL APPLICATIONS
The ADM3483E/ADM3486E/ADM3491E transceivers are
designed for bidirectional data communications on multipoint
bus transmission lines. The ADM3488E/ADM3490E full-duplex
transceiver is designed to be used in a daisy-chain network
topology or in a point-to-point application (see Figure 32). The
ADM3483E/ADM3486E are half-duplex RS-485 transceivers
that can be used in a multidrop bus configuration, as shown in
Figure 31. The ADM3488E/ADM3490E/ADM3491E can also
be used as a line repeater, for use with cable lengths longer than
4000 feet, as shown in Figure 34. To minimize reflections, the
line must be terminated at both ends in its characteristic
impedance, and stub lengths off the main line should be kept as
short as possible.
HUMAN BODY MODEL
Figure 30 shows the human body model and the current waveform it generates when discharged into a low impedance. This
model consists of a 100 pF capacitor charged to the ESD voltage
of interest, which is then discharged into the test device
through a 1.5 kΩ resistor.
Rev. A | Page 15 of 20
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
ADM3483E/
ADM3486E
R
RO
ADM3483E/
ADM3486E
A
A
RE
RT
R
RO
RE
RT
DE
D
B
A
B
A
R
R
D
RO
D
DI
DE
06284-017
RE
Figure 31. ADM3483E/ADM3486E Typical Half-Duplex RS-485 Network
DI
DI
ADM3483E/
ADM3486E
RO RE DE DI
NOTES
1. MAXIMUM NUMBER OF TRANSCEIVERS ON BUS: 32.
2. RT IS EQUAL TO THE CHARACTERISTIC IMPEDANCE OF THE CABLE USED.
RO
D
B
ADM3483E/
ADM3486E
MASTER
SLAVE
ADM3488E/
ADM3490E
ADM3488E/
ADM3490E
A
Y
B
Z
Z
B
Y
A
R
D
D
R
DI
RO
Figure 32. ADM3488E/ADM3490E Full-Duplex Point-to-Point Applications
Rev. A | Page 16 of 20
06284-018
DI
DE
B
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
MASTER
ADM3491E
R
RO
SLAVE
A
B
Y
RT
Z
ADM3491E
D
DE
DI
RE
DE
DI
B
Z
D
RT
Y
A
R
RO
RE
SLAVE
A
B
R
A
Y
Z
B
R
D
Y
Z
SLAVE
D
ADM3491E
ADM3491E
RO RE DE
DI
RO
RE DE
DI
06284-019
NOTES
1. MAXIMUM NUMBER OF NODES: 32.
2. RT IS EQUAL TO THE CHARACTERISTIC IMPEDANCE OF THE CABLE USED.
Figure 33. ADM3491E Full-Duplex RS-485 Network
ADM3488E/
ADM3490E/
ADM3491E
A
R
B
RO
RT
DATA IN
RT
DATA OUT
RE
DE
Z
D
Y
NOTES
1. RT IS EQUAL TO THE CHARACTERISTIC
IMPEDANCE OF THE CABLE USED.
2. RE AND DE PINS ON ADM3491E ONLY.
06284-020
DI
Figure 34. Line Repeater for ADM3488E/ADM3490E/ADM3491E
Rev. A | Page 17 of 20
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
OUTLINE DIMENSIONS
5.00 (0.1968)
4.80 (0.1890)
8
5
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)
0.31 (0.0122)
COPLANARITY
0.10
SEATING
PLANE
0.50 (0.0196)
0.25 (0.0099)
45°
8°
0°
0.25 (0.0098)
0.17 (0.0067)
1.27 (0.0500)
0.40 (0.0157)
COMPLIANT TO JEDEC STANDARDS MS-012-A A
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.
060506-A
4.00 (0.1574)
3.80 (0.1497)
Figure 35. 8-Lead Standard Small Outline Package [SOIC_N]
Narrow Body
(R-8)
Dimensions shown in millimeters and (inches)
8.75 (0.3445)
8.55 (0.3366)
8
14
1
7
1.27 (0.0500)
BSC
0.25 (0.0098)
0.10 (0.0039)
COPLANARITY
0.10
0.51 (0.0201)
0.31 (0.0122)
6.20 (0.2441)
5.80 (0.2283)
0.50 (0.0197)
0.25 (0.0098)
1.75 (0.0689)
1.35 (0.0531)
SEATING
PLANE
45°
8°
0°
0.25 (0.0098)
0.17 (0.0067)
1.27 (0.0500)
0.40 (0.0157)
COMPLIANT TO JEDEC STANDARDS MS-012-AB
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.
060606-A
4.00 (0.1575)
3.80 (0.1496)
Figure 36. 14-Lead Standard Small Outline Package [SOIC_N]
Narrow Body
(R-14)
Dimensions shown in millimeters and (inches)
ORDERING GUIDE
Model
ADM3483EARZ 1
ADM3483EARZ-REEL71
ADM3486EARZ1
ADM3486EARZ-REEL71
ADM3488EARZ1
ADM3488EARZ-REEL71
ADM3490EARZ1
ADM3490EARZ-REEL71
ADM3491EARZ1
ADM3491EARZ-REEL71
1
Temperature
Range
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
Package Description
8-Lead Standard Small Outline Package (SOIC_N)
8-Lead Standard Small Outline Package (SOIC_N)
8-Lead Standard Small Outline Package (SOIC_N)
8-Lead Standard Small Outline Package (SOIC_N)
8-Lead Standard Small Outline Package (SOIC_N)
8-Lead Standard Small Outline Package (SOIC_N)
8-Lead Standard Small Outline Package (SOIC_N)
8-Lead Standard Small Outline Package (SOIC_N)
14-Lead Standard Small Outline Package (SOIC_N)
14-Lead Standard Small Outline Package (SOIC_N)
Z = Pb-free part.
Rev. A | Page 18 of 20
Package Option
R-8
R-8
R-8
R-8
R-8
R-8
R-8
R-8
R-14
R-14
Ordering Quantity
1,000
1,000
1,000
1,000
1,000
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
NOTES
Rev. A | Page 19 of 20
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E
NOTES
©2006 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D06284-0-10/06(A)
Rev. A | Page 20 of 20