MAX22025FAWA+

Drivers, Receivers, Transceivers Overview

The MAX22025FAWA+ is a compact, isolated half-duplex RS-485/RS-422 transceiver featuring 3.5kVRMS digital galvanic isolation between the UART and cable sides. It operates with a logic-side supply voltage (VDDA) ranging from 1.71V to 5.5V and a cable-side supply voltage (VDDB) of 4.75V to 5.25V. The device supports a maximum data rate of 0.5Mbps due to slew-rate limited drivers. Key electrical parameters include ±10kV ESD protection on driver outputs and receiver inputs, a typical supply current of 0.7mA for VDDA and 5.5mA for VDDB, and an operating temperature range of -40°C to +85°C.

Drivers, Receivers, Transceivers Feature Summary

• Integrated AutoDirection control eliminates the need for separate DE and RE signals by using an internal state machine to manage driver and receiver states based on TXD input and bus voltage.
• Provides robust communication through high-level integration in a compact 8-pin wide body SOIC package with 5.5mm creepage distance.
• Includes failsafe receiver functionality that ensures a logic-high output during receiver input short or open events.

Drivers, Receivers, Transceivers Applications

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

Drivers, Receivers, Transceivers Procurement Notes

Verify component authenticity by checking markings against official datasheet specifications. Confirm RoHS compliance status via manufacturer documentation. Ensure proper handling procedures are followed due to moisture sensitivity level requirements. Validate packaging integrity prior to installation to prevent damage to the isolation barrier.

Drivers, Receivers, Transceivers Selection Notes

Select this component when designing isolated RS-485 ports requiring simplified control logic without external direction pins. The integrated AutoDirection feature reduces system complexity compared to standard transceivers. Ensure the application requires a maximum data rate of 0.5Mbps or lower to match the slew-rate limited driver characteristics.

Drivers, Receivers, Transceivers Part Context

This part belongs to the MAX22025-MAX22028/MAX22025F-MAX22028F family of isolated transceivers. The 'F' suffix indicates the inclusion of failsafe receiver capabilities. The 'W' denotes the 8-pin wide body SOIC package format. These devices share common isolation architecture but differ in data rate limits and receiver behavior configurations.

Drivers, Receivers, Transceivers Replacement Considerations

Direct substitutes within the same family include MAX22026FAWA+, MAX22027FAWA+, and MAX22028FAWA+. Note that non-F variants lack failsafe features, while higher-numbered models support up to 16Mbps data rates instead of 0.5Mbps.

Drivers, Receivers, Transceivers FAQ

How does the AutoDirection circuitry function?

The AutoDirection circuitry uses an internal state machine that monitors the TXD input and the differential bus voltage (VA-VB). It automatically enables or disables the driver and receiver to maintain the correct bus state without external control signals.

What is the purpose of the pullup and pulldown resistors?

External pullup and pulldown resistors on the A and B lines are required to hold the bus in the high state following a low-to-high transition of the TXD input, ensuring proper operation of the AutoDirection mechanism.

Does the receiver output follow the bus during transmission?

For the MAX22025F, the receiver output does not follow the bus voltage when the driver is enabled, allowing for line interference detection. This behavior differs from other variants in the family where the output may follow the bus.