1.5 Mbps RS-232 receiver in a SOT-23-5
The MAX3181EUK+T is a single RS-232 receiver from Analog Devices, handling data rates up to 1.5 Mbps with 300 mV of hysteresis on the input. That hysteresis is the key figure for a single-ended bus like RS-232 — it rejects noise on long cable runs where a clean zero-crossing is not guaranteed, so the receiver does not chatter on a slow or noisy edge. With zero drivers and one receiver, this part is a dedicated receive-only line buffer. It takes an RS-232-level signal from a DB-9 or terminal-block connector and presents a logic-level output to the UART on the other side, running from a single 3V to 5.5V supply rail.
Packaged in a SOT-23-5 (SC-74A), the footprint is 2.9 mm × 1.6 mm — about the size of a single bypass capacitor. The small body suits space-constrained designs like a dongle, a protocol converter, or a multi-port serial card where every square mm counts.