Analog Devices ADM2486 c Datasheet
High Speed, Half-Duplex iCoupler
®
FEATURES
Half-duplex, isolated RS-485 transceiver
PROFIBUS®-compliant
ANSI EIA/TIA 485-A and ISO 8482: 1987(E) compliant
20 Mbps data rate
5 V or 3 V operation (V
High common-mode transient immunity: >25 kV/μs
Isolated DE status output
Receiver open-circuit, fail-safe design
Thermal shutdown protection
50 nodes on bus
Safety and regulatory approvals
UL recognition—2500 V
CSA Component Acceptance Notice #5A
VDE Certificate of Conformity
DIN EN 60747-5-2 (VDE 0884 Part 2): 2003-01
DIN EN 60950 (VDE 0805): 2001-12; EN 60950: 2000
V
= 560 V peak
IORM
Operating temperature range: −40°C to +85°C
Wide body, 16-lead SOIC package
APPLICATIONS
Isolated RS-485/RS-422 interfaces
PROFIBUS networks
Industrial field networks
Multipoint data transmission systems
GENERAL DESCRIPTION
The ADM2486 differential bus transceiver is an integrated,
galvanically isolated component designed for bidirectional
data communication on multipoint bus transmission lines. It
is designed for balanced transmission lines and complies with
ANSI EIA/TIA-485-A and ISO 8482: 1987(E).
)
DD1
for 1 minute per UL 1577
rms
Isolated RS-485 Transceiver
ADM2486
FUNCTIONAL BLOCK DIAGRAM
V
DD1
RTS
TxD
LOGIC SIDE
PV
RxD
RE
GND
GALVANIC ISOLATION
1
Figure 1.
The device employs Analog Devices’ iCoupler technology to
combine a 3-channel isolator, a three-state differential line
driver, and a differential input receiver into a single package.
The logic side of the device is powered with either a 5 V or a
3 V supply, and the bus side uses an isolated 5 V supply.
The ADM2486 driver has an active-high enable feature. The
driver differential outputs and the receiver differential inputs
are connected internally to form a differential input/output port
that imposes minimal loading on the bus when the driver is
or V
disabled or when V
DD1
= 0 V. Also provided is an active-
DD2
high receiver disable feature that causes the receive output to
enter a high impedance state.
The device has current-limiting and thermal shutdown features
to protect against output short circuits and situations where bus
contention might cause excessive power dissipation. The part is
fully specified over the industrial temperature range and is
available in a 16-lead, wide body SOIC package.
V
DD2
ADM2486
GND
2
DE
A
B
BUS SIDE
04604-001
Rev. C
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: 781.461.3113 © 2005 Analog Devices, Inc. All rights reserved.
ADM2486
TABLE OF CONTENTS
Specifications..................................................................................... 3
Timing Specifications....................................................................... 5
Absolute Maximum Ratings............................................................ 6
ESD Caution.................................................................................. 6
ADM2486 Characteristics ............................................................... 7
Package Characteristics ............................................................... 7
Regulatory Information............................................................... 7
Insulation and Safety-Related Specifications............................ 7
VDE 0884 Insulation Characteristics ........................................8
Pin Configuration and Function Descriptions............................. 9
Test Circuits..................................................................................... 10
Switching Characteristics ..............................................................11
Typical Performance Characteristics ........................................... 12
REVISION HISTORY
Circuit Description......................................................................... 14
Electrical Isolation...................................................................... 14
Truth Tables................................................................................. 14
Power-Up/Power-Down Thresholds ....................................... 14
Thermal Shutdown .................................................................... 15
Receiver Fail-Safe Inputs ........................................................... 15
Magnetic Field Immunity.......................................................... 15
Applications Information.............................................................. 16
Power_Valid Input ..................................................................... 16
Isolated Power Supply Circuit .................................................. 17
Outline Dimensions....................................................................... 18
Ordering Guide .......................................................................... 18
3/05—Rev. B to Rev. C
Change to Package Characteristics................................................. 7
Changes to Figure 12, Figure 14, and Figure 15 ......................... 11
Change to Power_Valid Input Section......................................... 16
1/05—Rev. A to Rev. B
Added PROFIBUS logo ................................................................... 1
11/04—Rev. 0 to Rev. A
Changes to Figure 1.......................................................................... 1
Changes to Figure 6........................................................................ 10
Added Figure 22 through Figure 25............................................. 13
Updated Outline Dimensions....................................................... 18
Changes to Ordering Guide.......................................................... 18
Rev. C | Page 2 of 20
ADM2486
SPECIFICATIONS
2.7 V ≤ V
Table 1.
Parameter Min Typ Max Unit Test Conditions/Comments
DRIVER
Differential Outputs
Bus Enable Output
Logic Inputs
RECEIVER
Differential Inputs
RxD Logic Output
≤ 5.5 V, 4.75 V ≤ V
DD1
≤ 5.25 V, TA = T
DD2
MIN
to T
, unless otherwise noted.
MAX
Differential Output Voltage, VOD 5 V R = ∞, see Figure 3
2.1 5 V R = 50 Ω (RS-422), see Figure 3
2.1 5 V R = 27 Ω (RS-485), see Figure 3
2.1 5 V
= −7 V to 12 V, V
V
TST
DD1
≥ 4.7,
see Figure 4
∆ |VOD| for Complementary Output States 0.2 V R = 27 Ω or 50 Ω, see Figure 3
Common-Mode Output Voltage, VOC 3 V R = 27 Ω or 50 Ω, see Figure 3
∆ |VOC| for Complementary Output States 0.2 V R = 27 Ω or 50 Ω, see Figure 3
Output Short-Circuit Current, V
Output Short-Circuit Current, V
Output High Voltage V
V
V
Output Low Voltage 0.1 V I
0.1 0.3 V I
0.2 0.4 V I
Input High Voltage 0.7 V
Input Low Voltage 0.25 V
CMOS Logic Input Current (TxD, RTS, RE, PV)
= High 60 200 mA −7 V ≤ V
OUT
= Low 60 200 mA −7 V ≤ V
OUT
− 0.1 V I
DD2
− 0.3 V
DD2
− 0.4 V
DD2
V
DD1
− 0.1 V I
DD2
− 0.2 V I
DD2
V
DD1
−10 0.01 10 µA
ODE
ODE
ODE
ODE
ODE
ODE
TxD, RTS, RE
TxD, RTS, RE
TxD, RTS, RE, PV = V
≤ +12 V
OUT
≤ +12 V
OUT
= 20 µA
= 1.6 mA
= 4 mA
= −20 µA
= −1.6 mA
= −4 mA
, PV
, PV
DD1
or 0 V
Differential Input Threshold Voltage, VTH −200 200 mV −7 V ≤ VCM ≤ +12V
Input Hysteresis 70 mV −7 V ≤ VCM ≤ +12V
Input Resistance (A, B) 20 30 kΩ −7 V ≤ VCM ≤ +12V
Input Current (A, B)
Output High Voltage V
V
Output Low Voltage 0.1 V I
0.2 0.4 V I
Output Short-Circuit Current 7 85 mA V
Three-State Output Leakage Current ±1 µA 0.4 V ≤ V
0.6 mA VIN = +12 V
−0.35 mA VIN = −7 V
− 0.1 V I
DD1
− 0.4 V
DD1
− 0.2 V I
DD1
= 20 µA, VA − VB = 0.2 V
OUT
= 4 mA, VA − VB = 0.2 V
OUT
= −20 µA, VA − VB = −0.2 V
OUT
= −4 mA, VA − VB = −0.2 V
OUT
= GND or VCC
OUT
≤ 2.4 V
OUT
Rev. C | Page 3 of 20
ADM2486
Parameter Min Typ Max Unit Test Conditions/Comments
POWER SUPPLY CURRENT
Logic Side 1.3 mA RTS = 0 V, V
2.9 mA 2 Mbps, V
10.2 mA 20 Mbps, V
0.8 mA RTS = 0 V, V
1.1 mA 2 Mbps, V
4.3 mA 20 Mbps, V
Bus Side 3.0 mA RTS = 0 V
53.4 mA 2 Mbps, RTS = V
86.7 mA 20 Mbps, RTS = V
COMMON-MODE TRANSIENT IMMUNITY1 25 kV/µs
HIGH FREQUENCY, COMMON-MODE NOISE
IMMUNITY
1
Common-mode transient immunity is the maximum common-mode voltage slew rate that can be sustained while maintaining specification-compliant operation.
V
is the common-mode potential difference between the logic and bus sides. The transient magnitude is the range over which the common-mode is slewed. The
CM
common-mode voltage slew rates apply to both rising and falling common-mode voltage edges.
DD1
DD1
DD1
DD1
DD1
DD1
= 1 kV,
V
CM
= 5.5 V
= 5.5 V, see Figure 5
= 5.5 V, see Figure 5
= 3 V
= 3 V, see Figure 5
= 3 V, see Figure 5
, see Figure 5
DD1
, see Figure 5
DD1
transient magnitude = 800 V
100 mV
= +5 V, −2 V < V
V
HF
1 MHz < f
TEST
< 7 V,
TEST2
< 50 MHz, see Figure 6
Rev. C | Page 4 of 20
ADM2486
TIMING SPECIFICATIONS
2.7 V ≤ V
Table 2.
Parameter Min Typ Max Unit Test Conditions/Comments
DRIVER
Maximum Data Rate 20 Mbps
Propagation Delay, t
RTS-to-DE Propagation Delay 20 35 55 ns See Figure 8
Pulse Width Distortion, t
Switching Skew, t
Rise/Fall Time, tR, tF 5 15 ns
Enable Time 43 53 ns See Figure 9 and Figure 14
Disable Time 43 55 ns See Figure 9 and Figure 14
Enable Skew, |t
Disable Skew, |t
RECEIVER
Propagation Delay, t
Differential Skew, t
Enable Time 3 13 ns RL = 1 kΩ, CL = 15 pF, see Figure 11 and Figure 15
Disable Time 3 13 ns RL = 1 kΩ, CL = 15 pF, see Figure 11 and Figure 15
POWER_VALID INPUT
Enable Time 1 2 µs
Disable Time 3 5 µs
≤ 5.5 V, 4.75 V ≤ V
DD1
PLH
2 5 ns
SKEW
− t
AZH
BZL
− t
AHZ
BLZ
PLH
SKEW
≤ 5.25 V, TA = T
DD2
, t
25 45 55 ns R
PHL
5 ns
PWD
MIN
to T
, unless otherwise noted.
MAX
= 54 Ω, CL1 = CL2 = 100 pF, see Figure 7
LDIFF
= 54 Ω, CL1 = CL2 = 100 pF, see Figure 7 and
R
LDIFF
Figure 12
= 54 Ω, CL1 = CL2 = 100 pF, see Figure 7 and
R
LDIFF
Figure 12
= 54 Ω, CL1 = CL2 = 100 pF, see Figure 7 and
R
LDIFF
Figure 12
|, |t
− t
AZL
|, |t
, t
PHL
| 1 3 ns See Figure 9 and Figure 14
BZH
− t
ALZ
| 2 5 ns See Figure 9 and Figure 14
BHZ
25 45 55 ns CL = 15 pF, see Figure 10 and Figure 13
5 ns CL = 15 pF, see Figure 10 and Figure 13
Rev. C | Page 5 of 20
ADM2486
ABSOLUTE MAXIMUM RATINGS
TA = 25°C, unless otherwise noted. All voltages are relative to
their respective ground.
Table 3.
Parameter Rating
V
−0.5 V to +7 V
DD1
V
−0.5 V to +6 V
DD2
Digital Input Voltage (RTS, RE, TxD)
Digital Output Voltage
RxD −0.5 V to V
DE −0.5 V to V
Driver Output/Receiver Input Voltage −9 V to +14 V
Operating Temperature Range −40°C to +85°C
Storage Temperature Range −55°C to +150°C
Average Output Current per Pin −35 mA to +35 mA
θJA Thermal Impedance 73°C/W
Lead Temperature
Soldering (10 sec) 260°C
Vapor Phase (60 sec) 215°C
Infrared (15 sec) 220°C
−0.5 V to V
DD1
DD1
DD2
+ 0.5 V
+ 0.5 V
+ 0.5 V
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
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. C | Page 6 of 20
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