Quad RS-485 receiver in a through-hole DIP
The SN75LBC175N is a quad differential line receiver from Texas Instruments, designed for RS-422, RS-423, and RS-485 networks. It packs four independent receivers into a single 16-pin DIP package, making it a compact choice for multi-drop bus interfaces where you need to listen to multiple nodes without dedicating separate ICs per channel. Each receiver converts a differential bus signal into a single-ended logic output, with a typical input hysteresis of 45 mV to reject noise on long cable runs. The supply range is 4.75 V to 5.25 V, so it runs directly off a standard 5 V rail without an extra regulator.
Supply rail and noise margin for bus interfaces
The 4.75 V to 5.25 V supply range means the part stays within spec even if your 5 V rail droops by 250 mV under load — common on long backplanes or daisy-chained bus boards. The 45 mV hysteresis is the key number for signal integrity: it sets the dead band where the receiver ignores small fluctuations on the differential pair, so a 100-metre RS-485 run at 115 kbps stays clean without external filtering. Compared to a part like the SN75LBC176 (a single transceiver), the SN75LBC175N is purely a receiver — no driver on chip. That matters if your bus topology is receive-only (e.g., a monitoring node that never transmits) or if you already have a separate driver elsewhere on the board.