Quad RS422/RS485 line driver for 5 V industrial buses
The Maxim Integrated MAX3042BCSE+T is a quad RS422/RS485 line driver in a 16-SOIC package, designed for 5 V nominal supplies (4.75 V to 5.25 V) and data rates up to 20 Mbps. With four drivers and no receivers, it handles the transmit side of multi-drop differential buses used in factory automation, building management, and instrumentation backplanes.
20 Mbps — what it means for bus timing
At 20 Mbps, the driver supports short-run, high-throughput links such as Profibus-DP at 12 Mbps or general-purpose RS422 point-to-point. The rise/fall times are fast enough that stub length and termination placement matter — keep the stub under 300 mm and use a 120 Ω termination at the receiver end. This is not a slow 250 kbps part; the layout needs controlled impedance and minimal capacitive loading per node.
Active lifecycle, no replacement needed
There is no last-time-buy window, no NRND flag, and no official successor — it remains a standard catalog item. For dual-sourcing, Maxim's own MAX3042 family includes the MAX3042B (same speed grade) and the MAX3042C (lower speed); the B variant is the 20 Mbps choice. Pin-compatible alternatives from other vendors exist in the quad RS485 driver space, but no direct second-source cross is cited in the record.
Supply and package — fitting the 5 V rail
The 4.75 V to 5.25 V supply range ties it to a regulated 5 V rail — not a 3.3 V system without level translation. The 16-SOIC (3.90 mm width) is a common footprint shared with many quad RS485 transceivers, so a layout designed for a MAX3485 or SN65HVD3082 will accept this part with minor adjustments.