Analog Devices / Maxim Integrated MAX2202x/F Isolated RS-485/RS-422 Transceivers

Analog Devices MAX2202x/F 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 MAX2202x/F Isolated RS-485/RS-422 Transceivers feature Analog Devices' proprietary AutoDirection control making these devices ideal for applications such as isolated RS-485 ports, where the driver input is used in conjunction with the driver-enable signal to drive the differential bus.

The MAX22025, MAX22027, MAX22025F, and MAX22027F 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, MAX22026F, and MAX22028F driver outputs are not slew-rate limited, allowing transmit speeds up to 16Mbps.

The receiver output of the MAX22025, MAX22026, MAX22025F, and MAX22026F does not follow (VA-VB) when the device is in the driver-enabled state. The receiver output on the MAX22027, MAX22028, MAX22027F, and MAX22028F 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). These devices are available in a compact 8-pin wide-body SOIC package and operate over the -40°C to +85°C temperature range.


  • High-level integration reduces overall solution size
    • Fully isolated half-duplex RS-485/RS-422 transceivers
    • Compact 8-pin wide-body SOIC package (5.5mm creepage)
  • Integrated protection ensures robust communication
    • ±10kV ESD (HBM) on driver outputs/receiver inputs
    • Failsafe receiver prevents fault transition on receiver input short or open events
    • Withstands 3.5kVRMS isolation voltage for 60 seconds (VISO)
    • Withstands 630VPEAK maximum repetitive peak- isolation voltage (VIORM)
    • Continuously withstands 445VRMS maximum working-isolation voltage (VIOWM)
  • Enables flexible system design
    • 0.5Mbps maximum data rate with slew-rate limited driver (MAX22025, MAX22027, MAX22025F, MAX22027F)
    • 16Mbps maximum data rate ((MAX22026, MAX22028, MAX22026F, MAX22028F)
    • AutoDirection eliminates the need for DE and active-low RE control signals


  • Utility meters
  • Heating, Ventilation, and Air Conditioning (HVAC)
  • Industrial automation equipment
  • Programmable logic controllers

Block Diagram

Block Diagram - Analog Devices / Maxim Integrated MAX2202x/F Isolated RS-485/RS-422 Transceivers

Typical Application Circuits

Application Circuit Diagram - Analog Devices / Maxim Integrated MAX2202x/F Isolated RS-485/RS-422 Transceivers

Pin Designations

Mechanical Drawing - Analog Devices / Maxim Integrated MAX2202x/F Isolated RS-485/RS-422 Transceivers
Published: 2020-06-24 | Updated: 2023-04-18