MAX22027FAWA+

Overview

The MAX22027FAWA+ is a compact, isolated half-duplex RS-485/RS-422 transceiver featuring AutoDirection control. It provides 3.5kVRMS galvanic isolation between the UART and cable sides. The device supports data rates up to 0.5Mbps with slew-rate limited drivers to minimize EMI. Logic-side supply voltage (VDDA) ranges from 1.71V to 5.5V, while cable-side supply (VDDB) operates between 4.75V and 5.25V. It includes ±10kV HBM ESD protection on driver outputs and receiver inputs. The component is housed in an 8-pin wide SOIC package and functions within a temperature range of -40°C to +85°C.

Feature Summary

• 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.
• Slew-rate limited drivers reduce electromagnetic interference and signal reflections, ensuring error-free transmission at speeds up to 0.5Mbps.
• Receiver output always follows the differential bus voltage (VA-VB), providing consistent monitoring of the line state during both transmit and receive operations.

Applications

• Utility meters requiring isolated communication ports
• Industrial automation equipment with ground potential differences
• Programmable logic controllers needing robust noise immunity

Procurement Notes

Verify the specific suffix 'FAWA+' against the manufacturer's current ordering guide to confirm RoHS compliance and package variant accuracy. Ensure the design accommodates the required VDDB supply voltage range of 4.75V to 5.25V distinct from the VDDA logic supply. Confirm thermal management requirements for the 8-pin SOIC package under maximum load conditions.

Selection Notes

Select this part when high-speed 16Mbps operation is not required but reduced EMI is critical. Unlike the MAX22026/MAX22028 series, the MAX22027 features slew-rate limiting. Choose this model over the 'F' variants if failsafe receiver functionality is not necessary. Verify that the application can support the dual-supply architecture required for the isolation barrier.

Part Context

This component belongs to the MAX22025-MAX22028 family of isolated transceivers. It shares the same physical package and isolation characteristics as other members of the series but differs in electrical performance specifications regarding data rate limits and receiver behavior during driver enable states.

Replacement Considerations

MAX22025FAWA+

FAQ

How does the receiver output behave when the driver is enabled?

Unlike standard receivers that may ignore the bus during transmission, the MAX22027 receiver output always follows the differential bus voltage (VA-VB), allowing for continuous line monitoring.

What is the maximum data rate supported by this device?

The MAX22027 supports a maximum data rate of 0.5Mbps due to its slew-rate limited drivers.

Does this device include failsafe receiver functionality?

No, the MAX22027 does not feature failsafe receivers. This function is available only in the MAX22025F through MAX22028F variants.