Introduction
The CA-IS309x series are isolated RS-485/RS-422 transceivers with an integrated DC-DC converter, eliminating the need for an external isolated power supply. The series delivers high electrical isolation and excellent performance to meet the demands of industrial applications. Internally, logic input and output buffers are isolated via silicon dioxide (SiO2) insulating barriers, capable of withstanding isolation voltages up to 5000V<sub>RMS</sub> (60s) and a typical CMTI of ±150kV/μs. The insulating barrier blocks ground loops between the logic side and bus side, helping to reduce noise caused by high ground potential differences between ports and ensuring correct data transmission.
The CA-IS309x series is designed to support multi-node data communication. Bus-side pins feature ±8kV HBM ESD protection and ±12kV IEC 61000-4-2 contact discharge ESD protection. The receiver input impedance is 1/8 unit load, allowing up to 256 transceivers on the same bus. While maintaining multi-node communication, the series supports higher data rates, effectively improving the reliability of industrial communication. Within the series, CA-IS3090 and CA-IS3096 are full-duplex transceivers; CA-IS3092 and CS-IS3098 are half-duplex transceivers, with transmit/receive state controlled via receiver enable and transmitter enable pins. CA-IS3096 and CA-IS3098 support high-speed communication up to 10Mbps, while CA-IS3090 and CA-IS3092 support data rates up to 0.5Mbps.
CA-IS3090W, CA-IS3092W, CA-IS3096W, and CA-IS3098W come in 16-pin wide-body SO packages, compatible with industry-standard isolated RS-485/RS-422 package footprints. CA-IS3090T and CA-IS3096T come in 20-pin wide-body SOIC packages. All devices operate over a temperature range of -40°C to +125°C.
The CA-IS309x isolated RS-485/RS-422 transceivers provide electrical isolation up to 5kV<sub>RMS</sub> between the bus side and the controller side (logic side). These devices feature 150kV/μs common-mode transient immunity, allowing data transmission across the isolation barrier at rates up to 10Mbps (CA-IS3096/98) or 0.5Mbps (CA-IS3090/92). The integrated DC-DC converter provides power isolation, generating a 3.3V or 5V supply voltage for the bus side. This eliminates the need for an external isolated power supply — only a few bypass capacitors are required to form a complete isolated RS-485/RS-422 interface. With robust isolation characteristics combined with enhanced ESD protection and high-speed communication capability, the CA-IS309x ensures reliable data transmission in noisy environments, making it suitable for a wide range of industrial applications including motor drives, PLC communication modules, and HVAC systems. The series employs two mechanisms to prevent high power dissipation during bus faults or bus contention: first, output current limiting protection on the transmitter output stage — within the allowable common-mode voltage range, the device immediately enters a protection state upon output short-circuit; second, thermal shutdown protection, which forces the transmitter output to a high-impedance state when overheating is detected. Within the series, CA-IS3090 and CA-IS3096 offer full-duplex RS-485/RS-422 transceivers, while CA-IS3092 and CA-IS3098 offer half-duplex RS-485/RS-422 transceivers.
