What is the MAX253EPA+ and what does it do?
The MAX253EPA+ from Analog Devices (formerly Maxim Integrated) is a transformer driver specifically designed for isolated RS485 interfaces. It takes a 3.3V or 5V supply and drives a center-tapped transformer to create the isolated power rail for the RS485 transceiver side. The part is housed in an 8-pin DIP package (8-DIP, 0.300" body width) with through-hole mounting, making it a natural fit for boards that avoid SMT or where isolation creepage demands a larger package.
Key ratings and what they mean for your BOM
Supply current is 450 µA typical — that's the current the driver itself consumes, not the load it can deliver to the transformer. For a low-power isolated RS485 node, this quiescent draw is small enough that the entire interface (driver plus transceiver) can run off a 3.3V rail without a separate regulator. The 3.3V and 5V supply rating means you can use either rail without a jumper or LDO; the part self-adjusts. The -40°C to 85°C temperature range covers industrial control cabinets, outdoor telecom pedestals, and factory-floor sensors — no need for a wider-temp variant unless you're going downhole or into an engine bay.
Package and mounting
The 8-DIP package is a rework tech's best friend. Through-hole leads are robust enough to survive multiple soldering cycles; a hot-air station set to 300°C will lift the part cleanly without pad damage if you need to swap it. The 0.300" body width fits standard DIP sockets, so you can socket it during prototyping and solder it in production.
Lifecycle and sourcing posture
The MAX253EPA+ is listed as Active with ROHS3 compliance. For a BOM line that needs a transformer driver for isolated RS485, this part is a safe choice for new designs — no imminent obsolescence risk.