**The ADN4691EBRZ: A High-Performance, 20 Mbps, Tolerant RS-485/RS-422 Transceiver**

In the realm of industrial automation, building control systems, and long-distance data communication, robust and reliable data transmission is paramount. The **ADN4691EBRZ** from Analog Devices stands out as a premier solution, engineered to meet the rigorous demands of these applications. This integrated circuit is a high-performance, **20 Mbps, fully differential transceiver** that strictly complies with the TIA/EIA-485-A (RS-485) and TIA/EIA-422-B (RS-422) standards, offering a superior blend of speed, robustness, and flexibility.

A defining characteristic of the ADN4691EBRZ is its **exceptional fault tolerance and ruggedness**. The device features **±65 V of DC fault protection** on its bus pins. This means the transceiver can withstand severe overvoltage conditions—such as short circuits to high-voltage rails—that are common in electrically harsh industrial environments, without sustaining damage. This robust protection ensures system longevity and reduces maintenance costs.

Furthermore, the ADN4691EBRZ is designed for **true fail-safe operation**. Its receiver input impedance is a high 96 kΩ (1/8 unit load), allowing up to 256 transceivers to be connected on a single bus. More importantly, the receiver's differential input threshold is a precise 200 mV, guaranteeing a logic-high output when the bus is open, shorted, or idle (0 V differential). This eliminates the uncertainty of undefined states and prevents data errors without relying on external bias resistors.

Performance is at the core of this transceiver's design. Capable of data rates up to **20 Mbps**, it is well-suited for high-speed networks requiring the rapid exchange of data. It also boasts low electromagnetic interference (EMI) and reduced reflections due to its slew-rate limited outputs, which contribute to a cleaner signal integrity and easier compliance with EMC regulations.

The device operates from a single **3.3 V power supply**, making it an ideal choice for modern low-voltage systems while maintaining compatibility with 5V logic levels on the interface side. It includes a wide common-mode voltage range of -9 V to +14 V, allowing the receiver to reject significant ground potential differences between nodes—a common challenge in long cable runs.

Housed in a compact SOIC-8 package, the ADN4691EBRZ offers a full suite of features including hot-swap capability, current-limited drivers, and thermal shutdown protection, making it a comprehensive and reliable choice for designers.

**ICGOO**DFIND

In summary, the **ADN4691EBRZ** is an exemplary transceiver that delivers **high-speed, robust communication** for demanding industrial networks. Its **unmatched fault tolerance**, **true fail-safe receiver**, and high node count capability make it an indispensable component for building resilient and high-performance data links.

**Keywords:** RS-485 Transceiver, Fault Tolerance, 20 Mbps, Fail-Safe Receiver, Industrial Communication.