General Description
The MAX22025-MAX22028 compact isolated RS-485/
RS-422 transceivers provide 3.5kVRMS of digital galvanic
isolation between the cable-side (RS-485/RS-422 driver/
receiver-side) and the UART-side of the device. Isolation
improves communication by breaking ground loops and
reduces noise when there are large differences in ground
potential between ports. These devices allow for robust
communication up to 0.5Mbps or 16Mbps.
The MAX22025-MAX22028 feature Maxim’s proprietary
AutoDirection control making these devices ideal for
applications such as isolated RS-485 ports, where the
driver input is used in conjuction with the driver-enable
signal to drive the differential bus.
The MAX22025/MAX22027 feature reduced slew rate
drivers that minimize EMI and reduce reflections caused
by improper termination of cable allowing error-free
transmission up to 0.5Mbps. The MAX22026/MAX22028
driver outputs are not slew-rate limited, allowing
transmit speeds up to 16Mbps.
The receiver output of the MAX22025/MAX22026 does
not follow (VA-VB) when the device is in the driverenabled state. The receiver output on the MAX22027/
MAX22028 always follows (VA-VB).
The driver outputs and receiver inputs are protected
from ±10kV electrostatic discharge (ESD) to GNDB on
the cable side, as specified by the Human Body Model
(HBM). The MAX22025-MAX22028 are available in a
compact 8-pin wide body SOIC package and operate over
the -40°C to +85°C temperature range.

Applications
● Utility Meters
● Industrial Automation Equipment
● Programmable Logic Controllers
● HVAC