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ADM1486AR-REEL7 ,+5 V Low Power RS-485 PROFIBUS TransceiverSPECIFICATIONSCC MIN MAXParameter Min Typ Max Unit Test Conditions/CommentsDRIVERPropagation Delay ..
ADM1486ARZ ,+5 V Low Power RS-485 PROFIBUS TransceiverSPECIFICATIONSCC MIN MAXParameter Min Typ Max Unit Test Conditions/CommentsDRIVERDifferential Outpu ..
ADM1486ARZ-REEL7 ,+5 V Low Power RS-485 PROFIBUS TransceiverSpecifications subject to change without notice.–2– REV. 0ADM1486ABSOLUTE MAXIMUM RATINGS* Operatin ..
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ADM1485AN-ADM1485AR-ADM1485JN-ADM1485JR
+-5 V Low Power EIA RS-485 Transceiver
REV.A
+5 V Low Power
EIA RS-485 Transceiver
FUNCTIONAL BLOCK DIAGRAM
8-Lead
FEATURES
Meets EIA RS-485 Standard
30 Mb/s Data Rate
Single +5 V Supply
–7 V to +12 V Bus Common-Mode Range
High Speed, Low Power BiCMOS
Thermal Shutdown Protection
Short Circuit Protection
Zero Skew Driver
Driver Propagation Delay: 10 ns
Receiver Propagation Delay: 25 ns
High Z Outputs with Power Off
Superior Upgrade for LTC1485
APPLICATIONS
Low Power RS-485 Systems
DTE-DCE Interface
Packet Switching
Local Area Networks
Data Concentration
Data Multiplexers
Integrated Services Digital Network (ISDN)
GENERAL DESCRIPTIONThe ADM1485 is a differential line transceiver suitable for high
speed bidirectional data communication on multipoint bus
transmission lines. It is designed for balanced data transmission
and complies with both EIA Standards RS-485 and RS-422.
The part contains a differential line driver and a differential line
receiver. Both the driver and the receiver may be enabled inde-
pendently. When disabled, the outputs are tristated.
The ADM1485 operates from a single +5 V power supply.
Excessive power dissipation caused by bus contention or by
output shorting is prevented by a thermal shutdown circuit.
This feature forces the driver output into a high impedance state
if during fault conditions a significant temperature increase is
detected in the internal driver circuitry.
Up to 32 transceivers may be connected simultaneously on a
bus, but only one driver should be enabled at any time. It is
important therefore that the remaining disabled drivers do not
load the bus. To ensure this, the ADM1485 driver features high
output impedance when disabled and also when powered down.
This minimizes the loading effect when the transceiver is not
being utilized. The high impedance driver output is maintained
over the entire common-mode voltage range from –7 V to +12 V.
The receiver contains a fail safe feature which results in a logic
high output state if the inputs are unconnected (floating).
The ADM1485 is fabricated on BiCMOS, an advanced mixed
technology process combining low power CMOS with fast
switching bipolar technology. All inputs and outputs contain
protection against ESD; all driver outputs feature high source
and sink current capability. An epitaxial layer is used to guard
against latch-up.
The ADM1485 features extremely fast switching speeds. Mini-
mal driver propagation delays permit transmission at data rates
up to 30 Mbits/s while low skew minimizes EMI interference.
The part is fully specified over the commercial and industrial
temperature range and is available in an 8-lead DIL/SOIC
package.
ADM1485–SPECIFICATIONS(VCC = +5 V � 5%. All specifications TMIN to TMAX unless otherwise noted.)Specifications subject to change without notice.
TIMING SPECIFICATIONSSpecifications subject to change without notice.
(VCC = +5 V � 5%. All specifications TMIN to TMAX unless otherwise noted.)
ABSOLUTE MAXIMUM RATINGS*(TA = +25°C unless otherwise noted)
VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .+7 V
Inputs
Driver Input (DI) . . . . . . . . . . . . . . . .–0.3 V to VCC + 0.3 V
Control Inputs (DE, RE) . . . . . . . . . .–0.3 V to VCC + 0.3 V
Receiver Inputs (A, B) . . . . . . . . . . . . . . . . .–14 V to +14 V
Outputs
Driver Outputs . . . . . . . . . . . . . . . . . . . . . . .–14 V to +14 V
Receiver Output . . . . . . . . . . . . . . . . .–0.5 V to VCC + 0.5 V
Power Dissipation 8-Lead DIP . . . . . . . . . . . . . . . . .500 mW
θJA, Thermal Impedance . . . . . . . . . . . . . . . . . .+130°C/W
Power Dissipation 8-Lead SOIC . . . . . . . . . . . . . . . .450 mW
θJA, Thermal Impedance . . . . . . . . . . . . . . . . . .+170°C/W
Power Dissipation 8-Lead Cerdip . . . . . . . . . . . . . . .500 mW
θJA, Thermal Impedance . . . . . . . . . . . . . . . . . .+125°C/W
Operating Temperature Range
Commercial (J Version) . . . . . . . . . . . . . . . . .0°C to +70°C
Industrial (A Version) . . . . . . . . . . . . . . . .–40°C to +85°C
Storage Temperature Range . . . . . . . . . . .–65°C to +150°C
Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . .+300°C
Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . . .+215°C
Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . . .+220°C
*Stresses above those listed under Absolute Maximum Ratings may cause perma-
nent damage to the device. This is a stress rating only; functional operation of the
device at these or any other conditions above those listed in the operational
sections of this specification is not implied. Exposure to absolute maximum ratings
for extended periods of time may affect device reliability.
Table I.Transmitting
Table II.Receiving
PIN FUNCTION DESCRIPTION
PIN CONFIGURATION
ORDERING GUIDE
CAUTIONESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000V readily
accumulate on the human body and test equipment and can discharge without detection. Although
the ADM1485 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.
ADM1485
Test CircuitsFigure 1.Driver Voltage Measurement Test Circuit
Figure 2.Driver Voltage Measurement Test Circuit 2
Figure 3.Driver Propagation Delay Test Circuit
Figure 4.Driver Enable/Disable Test Circuit
Figure 5.Receiver Propagation Delay Test Circuit
Figure 6.Receiver Enable/Disable Test Circuit
Switching CharacteristicsFigure 7.Driver Propagation Delay, Rise/Fall Timing
Figure 9.Receiver Propagation Delay
Figure 11.Receiver Output Low
Voltage vs. Output Current
Figure 14.Receiver Output Low
Voltage vs. Temperature
Figure 17.Driver Output Low
Voltage vs. Output Current
Figure 12.Receiver Output High
Voltage vs. Output Current
Figure 15.Driver Differential Out-
put Voltage vs. Output Current
Figure 18.Driver Output High
Voltage vs. Output Current
Figure 13.Receiver Output High
Voltage vs. Temperature
TEMPERATURE – �C
DIFFERENTIAL VOLTAGE
Volts
2.1Figure 16.Driver Differential Output
Voltage vs. Temperature, RL = 54 Ω
TEMPERATURE – �C
SUPPLY CURRENT
mA
0.60Figure 19.Supply Current vs.
Temperature
ADM1485–Typical Performance Characteristics
TEMPERATURE – �C
TIME
ns–50
–250255075100125Figure 20.Receiver tPLH–tPHL vs.
Temperature
Figure 23.Loaded Driver
Differential Outputs
Figure 26.Typical RS-485 Network
Figure 21.Driver Skew vs.
Temperature
Figure 24.Driver/Receiver Propaga-
tion Delays Low to High
Figure 22.Unloaded Driver
Differential Outputs
Figure 25.Driver/Receiver Propaga-
tion Delays High to Low
