ANALOG DEVICES ADM2490E Service Manual
High Speed, ESD-Protected, Full-Duplex,
V
V
www.BDTIC.com/ADI
FEATURES
Isolated, full-duplex RS-485/RS-422 transceiver
±8 kV ESD protection on RS-485 input/output pins
16 Mbps data rate
Complies with ANSI TIA/EIA-485-A-1998 and
ISO 8482: 1987(E)
Suitable for 5 V or 3 V operation (V
High common-mode transient immunity: >25 kV/μs
Receiver has open-circuit, fail-safe design
32 nodes on the bus
Thermal shutdown protection
Safety and regulatory approvals
UL recognition: 5000 V rms isolation voltage
for 1 minute per UL 1577
VDE certificate of conformity
DIN EN 60747-5-2 (VDE 0884-10 Part 2): 2003-01
DIN EN 60950 (VDE 0805): 2001-12; EN 60950: 2000
V
= 848 V peak
IORM
Operating temperature range: −40°C to +105°C
Wide body, 16-lead SOIC package
DD1
)
iCoupler Isolated RS-485 Transceiver
ADM2490E
FUNCTIONAL BLOCK DIAGRAM
DD2
ADM2490E
GND
2
Y
Z
A
B
05889-001
TxD
RxD
DD1
GND
GALVANIC ISOLATION
1
Figure 1.
APPLICATIONS
Isolated RS-485/RS-422 interfaces
Industrial field networks
INTERBUS
Multipoint data transmission systems
GENERAL DESCRIPTION
The ADM2490E is an isolated data transceiver with ±8 kV ESD
protection that is suitable for high speed, full-duplex communication on multipoint transmission lines. It is designed for balanced
transmission lines and complies with ANSI TIA/EIA-485-A-1998
and ISO 8482: 1987(E). The device employs Analog Devices, Inc.,
iCoupler® technology to combine a 2-channel isolator, a threestate differential line driver, and a differential input receiver into
a single package.
The differential transmitter outputs and receiver inputs feature
electrostatic discharge circuitry that provides protection to ±8 kV
using the human body model (HBM). The logic side of the device
can be powered with either a 5 V or a 3 V supply, whereas the
bus side requires an isolated 5 V supply.
The device has current-limiting and thermal shutdown features
to protect against output short circuits and situations where bus
contention could cause excessive power dissipation.
The ADM2490E is available in a wide body, 16-lead SOIC package
and operates over the −40°C to +105°C temperature range.
Rev. A
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 ©2006–2008 Analog Devices, Inc. All rights reserved.
ADM2490E
www.BDTIC.com/ADI
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications ....................................................................................... 1
Functional Block Diagram .............................................................. 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications ..................................................................................... 3
Timing Specifications .................................................................. 4
Package Characteristics ............................................................... 4
Regulatory Information ............................................................... 5
Insulation and Safety-Related Specifications ............................ 5
VDE 0884-10 Insulation Characteristics ................................... 5
Absolute Maximum Ratings ............................................................ 6
ESD Caution .................................................................................. 6
Pin Configuration and Function Descriptions ............................. 7
Test Circuits ....................................................................................... 8
Switching Characteristics .................................................................9
Typical Performance Characteristics ........................................... 10
Circuit Description......................................................................... 12
Electrical Isolation ...................................................................... 12
Truth Tables................................................................................. 12
Thermal Shutdown .................................................................... 13
Fail-Safe Receiver Inputs ........................................................... 13
Magnetic Field Immunity .......................................................... 13
Applications Information .............................................................. 14
Isolated Power Supply Circuit .................................................. 14
PCB Layout ................................................................................. 14
Typical Applications ................................................................... 15
Outline Dimensions ....................................................................... 16
Ordering Guide .......................................................................... 16
REVISION HISTORY
8/08—Rev. 0 to Rev. A
Changes to Regulatory Approval Status Throughout .................. 1
Changed VDE 0884 to VDE 0884-10 Throughout ...................... 1
Changes to Table 5 ............................................................................ 5
Changes to Table 8 ............................................................................ 6
Changes to Figure 9 .......................................................................... 9
Changes to iCoupler Technology Section ................................... 12
Changes to Magnetic Field Immunity Section ........................... 13
Changes to Isolated Power Supply Circuit Section .................... 14
Changes to Figure 25 ...................................................................... 14
Added Typical Applications Section ............................................ 15
Updated Outline Dimensions ....................................................... 16
Changes to Ordering Guide .......................................................... 16
10/06—Revision 0: Initial Version
Rev. A | Page 2 of 16
ADM2490E
www.BDTIC.com/ADI
SPECIFICATIONS
All voltages are relative to their respective ground; 2.7 ≤ V
over the entire recommended operation range, unless otherwise noted. All typical specifications are at T
unless otherwise noted.
Table 1.
Parameter Symbol Min Typ Max Unit Test Conditions
SUPPLY CURRENT
Power Supply Current, Logic Side
TxD/RxD Data Rate < 2 Mbps I
TxD/RxD Data Rate = 16 Mbps I
3.0 mA 2.7 V ≤ V
DD1
6 mA 100 Ω load between Y and Z
DD1
Power Supply Current, Bus Side
TxD/RxD Data Rate < 2 Mbps I
TxD/RxD Data Rate = 16 Mbps I
4.0 mA 2.7 V ≤ V
DD2
60 mA 100 Ω load between Y and Z
DD2
DRIVER
Differential Outputs
Differential Output Voltage, Loaded |V
| 2.0 5.0 V RL = 50 Ω (RS-422), see Figure 3
OD2
1.5 5.0 V RL = 27 Ω (RS-485), see Figure 3
|V
| 1.5 5.0 V −7 V ≤ V
OD4
∆|VOD| for Complementary Output States ∆|VOD| 0.2 V RL = 54 Ω or 100 Ω, see Figure 3
Common-Mode Output Voltage VOC 3.0 V RL = 54 Ω or 100 Ω, see Figure 3
∆|VOC| for Complementary Output States ∆|VOC| 0.2 V RL = 54 Ω or 100 Ω, see Figure 3
Short-Circuit Output Current IOS 200 mA
Logic Inputs
Input Threshold Low VIL 0.25 × V
Input Threshold High VIH 0.7 × V
TxD Input Current I
−10 +0.01 +10 μA
TxD
RECEIVER
Differential Inputs
Differential Input Threshold Voltage VTH −0.2 +0.2 V
Input Voltage Hysteresis V
70 mV VOC = 0 V
HYS
Input Current (A, B) II 1.0 mA VOC = 12 V
−0.8 mA VOC = −7 V
Line Input Resistance RIN 12 kΩ
Logic Outputs
Output Voltage Low V
Output Voltage High V
OLRxD
OHRxD
Short-Circuit Current 100 mA
COMMON-MODE TRANSIENT IMMUNITY
1
CM is the maximum common-mode voltage slew rate that can be sustained while maintaining specification-compliant operation. VCM 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 common-mode voltage slew rates
apply to both rising and falling common-mode voltage edges.
1
25 kV/μs
≤ 5.5 V, 4.5 V ≤ V
DD1
V
DD1
≤ 5.5 V. All minimum/maximum specifications apply
DD2
V
DD1
0.2 0.4 V I
V
− 0.3 V
DD1
− 0.2 V I
DD1
= 25°C, V
A
DD1
= V
≤ 5.5 V, unloaded
DD1
≤ 5.5 V, unloaded
DD1
≤ +12 V, see Figure 4
TEST1
= 1.5 mA, VA − VB = −0.2 V
ORxD
= −1.5 mA, VA − VB = 0.2 V
ORxD
= 1 kV, transient
V
CM
magnitude = 800 V
= 5.0 V,
DD2
Rev. A | Page 3 of 16
ADM2490E
www.BDTIC.com/ADI
TIMING SPECIFICATIONS
TA = −40°C to +85°C.
Table 2.
Parameter Symbol Min Typ Max Unit Test Conditions
DRIVER
Maximum Data Rate 16 Mbps
Propagation Delay t
Pulse Width Distortion,
PWD = |t
PYLH
|, PWD = |t
PYHL
PZLH
− t
PZHL
|
− t
Single-Ended Output Rise/Fall Times tR, tF 20 ns
RECEIVER
Propagation Delay t
Pulse Width Distortion, PWD = |t
PLH
− t
| t
PHL
T
= −40°C to +105°C.
A
Table 3.
Parameter Symbol Min Typ Max Unit Test Conditions
DRIVER
Maximum Data Rate 10 Mbps
Propagation Delay
Pulse Width Distortion,
PWD = |t
PYLH
|, PWD = |t
PYHL
PZLH
− t
PZHL
|
− t
Single-Ended Output Rise/Fall Time tR, tF 27 ns
RECEIVER
Propagation Delay t
Pulse Width Distortion, PWD = |t
PLH
− t
PHL
| t
, t
45 60 ns
PLH
PHL
, t
t
PWD
PLH
PWD
7 ns
PWD
, t
60 ns CL = 15 pF, see Figure 7 and Figure 9
PHL
10 ns CL = 15 pF, see Figure 7 and Figure 9
t
t
t
PYLH
PZLH
PWD
, t
PYHL
, t
PZHL
, t
PWD
45 60 ns
,
9 ns
= 54 Ω, CL1 = C
R
L
= 100 pF,
L2
see Figure 6 and Figure 8
= 54 Ω, CL1 = CL2 = 100 pF,
R
L
see Figure 6 and Figure 8
= 54 Ω, CL1 = CL2 = 100 pF,
R
L
see Figure 6 and Figure 8
= 54 Ω, CL1 = CL2 = 100 pF,
R
L
see Figure 6 and Figure 8
= 54 Ω, CL1 = CL2 = 100 pF,
R
L
see Figure 6 and Figure 8
= 54 Ω, CL1 = CL2 = 100 pF,
R
L
see Figure 6 and Figure 8
, t
60 ns
PLH
PHL
10 ns
PWD
= 15 pF, see Figure 7 and
C
L
Figure 9
C
Figure 9
= 15 pF, see Figure 7 and
L
PACKAGE CHARACTERISTICS
Table 4.
Parameter Symbol Min Typ Max Unit Test Conditions
Resistance (Input to Output)
Capacitance (Input to Output)
Input Capacitance
2
C
Input IC Junction-to-Case Thermal Resistance θ
Output IC Junction-to-Case Thermal Resistance θ
1
Device considered a 2-terminal device: Pin 1, Pin 2, Pin 3, Pin 4, Pin 5, Pin 6, Pin 7, and Pin 8 are shorted together and Pin 9, Pin 10, Pin 11, Pin 12, Pin 13, Pin 14, Pin 15,
and Pin 16 are shorted together.
2
Input capacitance is from any input data pin to ground.
1
1
R
1012 Ω
I-O
C
3 pF f = 1 MHz
I-O
4 pF
I
33 °C/W
JCI
28 °C/W
JCO
Rev. A | Page 4 of 16
Thermocouple located at center
of package underside
ADM2490E
www.BDTIC.com/ADI
REGULATORY INFORMATION
Table 5. ADM2490E Approvals
Organization Approval Type Notes
UL
VDE
INSULATION AND SAFETY-RELATED SPECIFICATIONS
Table 6.
Parameter Symbol Value Unit Conditions
Rated Dielectric Insulation Voltage 5000 V rms 1 minute duration
Minimum External Air Gap (Clearance) L(I01) 7.45 mm min
Minimum External Tracking (Creepage) L(I02) 8.1 mm min
Minimum Internal Gap (Internal Clearance) 0.017 mm min Insulation distance through insulation
Tracking Resistance (Comparative Tracking Index) CTI >175 V DIN IEC 112/VDE 0303 Part 1
Isolation Group IIIa Material Group (DIN VDE 0110, 1/89)
Recognized under the Component Recognition
Program of Underwriters Laboratories, Inc.
Certified according to DIN EN 60747-5-2
(VDE 0884-10 Part 2): 2003-01,
DIN EN 60950 (VDE 0805): 2001-12; EN 60950: 2000
In accordance with UL 1577, each ADM2490E is proof tested by
applying an insulation test voltage ≥ 6000 V rms for 1 second
(current leakage detection limit = 10 μA).
In accordance with DIN EN 60747-5-2, each ADM2490E is proof
tested by applying an insulation test voltage ≥ 1590 V peak for
1 second (partial discharge detection limit = 5 pC).
Measured from input terminals to output
terminals, shortest distance through air
Measured from input terminals to output
terminals, shortest distance along body
VDE 0884-10 INSULATION CHARACTERISTICS
This isolator is suitable for basic electrical isolation only within the safety limit data. Maintenance of the safety data must be ensured by
means of protective circuits.
An asterisk (*) on a package denotes VDE 0884-10 approval for 848 V peak working voltage.
Table 7.
Description Symbol Characteristic Unit
Installation Classification per DIN VDE 0110 for Rated Mains Voltage
≤300 V rms I to IV
≤450 V rms I to II
≤600 V rms I to II
Climatic Classification 40/105/21
Pollution Degree (DIN VDE 0110, see Table 1 ) 2
Maximum Working Insulation Voltage V
Input-to-Output Test Voltage, Method b1 VPR 1590 V peak
V
× 1.875 = VPR, 100% Production Tested, tm = 1 sec, Partial Discharge < 5 pC
IORM
Input-to-Output Test Voltage, Method a
After Environmental Tests, Subgroup 1
V
× 1.6 = VPR, tm = 60 sec, Partial Discharge < 5 pC 1357 V peak
IORM
After Input and/or Safety Test, Subgroup 2/3
V
× 1.2 = VPR, tm = 60 sec, Partial Discharge < 5 pC VPR 1018 V peak
IORM
Highest Allowable Overvoltage (Transient Overvoltage, tTR = 10 sec) VTR 6000 V peak
Safety-Limiting Values (Maximum Value Allowed in the Event of a Failure; see Figure 16)
Case Temperature TS 150 °C
Input Current I
Output Current I
Insulation Resistance at TS, VIO = 500 V RS >109 Ω
848 V peak
IORM
265 mA
S, INPUT
335 mA
S, OUTPUT
Rev. A | Page 5 of 16
Loading...