The ADM2483 differential bus transceiver is an integrated,
galvanically isolated component designed for bidirectional data
communication on balanced, multipoint bus transmission lines.
It complies with ANSI EIA/TIA-485-A and ISO 8482: 1987(E).
Using the iCoupler technology from Analog Devices, Inc., the
ADM2483 combines 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 3 V
supply, and the bus side uses a 5 V supply only.
The ADM2483 is slew-limited to reduce reflections with
improperly terminated transmission lines. The controlled slew
rate limits the data rate to 500 kbps. The device’s input impedance
is 96 kΩ, allowing up to 256 transceivers on the bus. Its driver
has an active-high enable feature. The driver differential outputs
and receiver differential inputs are connected internally to form
a differential input/output (I/O) port.
When the driver is disabled or when VDD1 or VDD2 = 0 V, this
imposes minimal loading on the bus. An active-high receiver
disable feature, which causes the receive output to enter a high
impedance state, is provided as well.
The receiver inputs have a true fail-safe feature that ensures a
logic-high receiver output level when the inputs are open or
shorted. This guarantees that the receiver outputs are in a
known state before communication begins and at the point
when communication ends.
Current limiting and thermal shutdown features protect against
output short circuits and bus contention situations that 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.
Applications
- Low power RS-485/RS-422 networks
- Isolated interfaces
- Building control networks
- Multipoint data transmission systems
