ADM483EAR-REEL Analog Devices Inc, ADM483EAR-REEL Datasheet - Page 13

• Manufacturer Part Number: ADM483EAR-REEL
• Description: IC,LINE TRANSCEIVER,BICMOS,1 DRIVER,1 RCVR,SOP,8PIN,PLASTIC
• Manufacturer: Analog Devices Inc
• Type: Transceiverr

Specifications of ADM483EAR-REEL

• Rohs Status: RoHS non-compliant
• Number Of Drivers/receivers: 1/1
• Protocol: RS422, RS485
• Voltage - Supply: 4.5 V ~ 5.5 V
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Other names: ADM483EAR-REELTR

APPLICATIONS INFORMATION
DIFFERENTIAL DATA TRANSMISSION
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 common-mode voltages on the
line. There are two main standards approved by the Electronics
Industries Association (EIA) that specify the electrical character-
istics of transceivers used in differential data transmission.
The RS-422 standard specifies data rates up to 10 MBaud and
line lengths up to 4000 feet. A single driver can drive a transmission
line with up to 10 receivers.
To accommodate true multipoint communications, the RS-485
standard was defined. This standard meets or exceeds all the
requirements of RS-422 and also allows for up to 32 drivers and
32 receivers to be connected to a single bus. An extended
common-mode range of −7 V to +12 V is defined. The most
significant difference between RS-422 and RS-485 is the fact
that the drivers can be disabled, thereby allowing more than one
(32, in fact) 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.
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CABLE AND DATA RATE
The transmission line of choice for RS-485 communications is a
twisted pair. Twisted pair cable tends to cancel common-mode
noise and also cancels the magnetic fields generated by the
current flowing through each wire, thereby reducing the
effective inductance of the pair.
A typical application showing a multipoint transmission
network is shown in Figure 26. 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.
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Figure 26. Typical RS-485 Network
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ADM483E
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