Isolated RS-485 transceiver for industrial bus networks
The 28-pin PDIP package (0.600-inch body) suits through-hole assembly for prototyping or production runs where mechanical retention matters. Operating from a 4.75 V to 5.25 V supply, the device includes one driver and one receiver with 25 mV of receiver hysteresis for noise immunity on long bus runs.
Data rate and bus topology constraints
At 250 kbps, the MAX3158EPI is suited for fieldbus links, sensor networks, and PLC-to-I/O communication where cable lengths exceed 100 m. The integrated isolation eliminates the need for external optocouplers or isolated DC-DC modules on the bus side, reducing BOM count and board area. Full-duplex mode allows simultaneous transmit and receive on a four-wire bus; half-duplex mode uses a two-wire bus with driver enable control. The 25 mV hysteresis ensures reliable edge detection in noisy industrial environments.
The part is RoHS non-compliant (lead-bearing termination), which may restrict use in EU RoHS-exempt applications or require a waiver for new designs.