MAX22028AWA+

Overview

The MAX22028AWA+ is a compact, isolated half-duplex RS-485/RS-422 transceiver featuring Maxim’s proprietary AutoDirection control. It provides 3.5kVRMS of digital galvanic isolation between the UART-side and cable-side domains. The device supports data rates up to 16Mbps with non-slew-rate-limited drivers. It operates on a VDDA supply range of 1.71V to 5.5V and a VDDB supply range of 4.75V to 5.25V. Driver outputs and receiver inputs are protected against ±10kV electrostatic discharge (HBM). The component is housed in an 8-pin wide body SOIC package and functions within a temperature range of -40°C to +85°C.

Feature Summary

• AutoDirection control eliminates the need for separate driver-enable and receiver-enable signals by using an internal state machine.
• High-level integration reduces overall solution size through a fully isolated half-duplex design in a compact 8-pin package.
• Integrated protection ensures robust communication with ±10kV ESD protection on driver outputs and receiver inputs.
• Receiver output always follows the differential voltage (VA-VB) during driver-enabled states.

Applications

• Utility Meters
• Industrial Automation Equipment
• Programmable Logic Controllers
• HVAC Systems

Procurement Notes

Verify the specific ordering suffix 'WA+' corresponds to the required RoHS compliance status and tape-and-reel packaging configuration before finalizing procurement. Confirm that the 8-pin wide body SOIC footprint matches the target PCB land pattern dimensions. Ensure the selected distributor sources directly from Analog Devices or authorized channels to guarantee authenticity and traceability.

Selection Notes

Select this model when high-speed transmission up to 16Mbps is required alongside galvanic isolation. The MAX22028 differs from the MAX22025/MAX22027 series by lacking slew-rate limiting, which allows for faster signal transitions. Verify that the system design accommodates the specific VDDB supply requirement of 4.75V to 5.25V for the cable side.

Part Context

This component belongs to the MAX22025-MAX22028 family of compact isolated RS-485/RS-422 transceivers. The family shares common features such as AutoDirection control and 3.5kVRMS isolation but varies in data rate capabilities and receiver output behavior. The MAX22028 specifically represents the high-speed variant within this lineup.

Replacement Considerations

The MAX22028F is a functional substitute within the same family offering failsafe receiver characteristics. Other variants like the MAX22025 or MAX22027 provide lower data rates due to slew-rate limiting and may require re-evaluation of timing constraints if used as replacements.