Full-duplex RS-485/RS-422 transceiver at 1 Mbps
The SN65HVD55DR is a full-duplex RS-485/RS-422 transceiver from Texas Instruments, rated for 1 Mbps data rate on a 4.5-5.5 V supply rail — the full-duplex architecture means it drives and receives simultaneously over a four-wire bus, which halves the cable count for point-to-point RS-422 links and eliminates the turnaround delay on multi-drop RS-485 networks.
Supply voltage and noise margin
The receiver hysteresis of 50 mV means the input differential threshold has a built-in dead band that rejects low-amplitude noise on the bus — on a 1 Mbps line with 120-ohm termination, this prevents the receiver from oscillating on the signal edges when the cable is unterminated or the stub length exceeds the rise-time budget.
Housed in a 14-SOIC (3.90 mm width) package with a surface-mount footprint, the SN65HVD55DR is a standard SOIC-14 body — the 0.154-inch width matches the common narrow SOIC land pattern, and the 1.27 mm pin pitch is compatible with most automated soldering profiles. The supplier device package is 14-SOIC, so the reflow profile follows the standard JEDEC MSL level for this package family.
The 1/1 driver/receiver count is a single-node transceiver; for multi-drop RS-485 networks, the driver output is designed to drive up to 256 unit loads on the bus.