1. SN65LBC179DR Substitution Conclusion The SN65LBC179DR serves as a drop-in replacement for the SN65LBC179D, sharing fundamental compatibility in core functionality and package. Both are full-duplex RS-422/RS-485 transceivers manufactured by TI, offered in the same 8-SOIC package with identical pinout and supply voltage range (4.75V–5.25V). Key differences include a reduction in receiver hysteresis from 50 mV to 45 mV, and the omission of a clearly specified data rate on the DR variant (the original part is rated for 30 Mbps). The 5 mV decrease in hysteresis slightly reduces the receiver’s immunity to input noise, which may increase the risk of signal misinterpretation in high-noise environments. The unspecified data rate requires verification through the detailed datasheet to confirm whether the DR version still supports 30 Mbps or if performance has been downgraded. For applications with low noise levels and non‑critical speed requirements, the DR variant can be substituted. However, in high‑reliability or high‑speed scenarios, thorough validation of actual performance is recommended.