5.7 kV Isolated, Half-Duplex RS-485 Transceiver with Fault Protection

The ADM2495E/ADM2495E-1 are 5.7kVRMS, signal isolated RS-485 transceivers with ±60V fault protection on the RS-485 A and B pins. These devices are designed for balanced transmission lines and comply with ANSI/TIA/EIA-485-A-98 and ISO 8482:1987(E). The devices can pass radiated emissions testing to the EN 55032 Class B standard with margin on a 2-layer printed circuit board (PCB) with high-frequency decoupling capacitors. The isolation barrier provides robust system level immunity to IEC 61000-4-x system level electromagnetic compatibility (EMC) standards. The devices are suitable for applications that require reinforced insulation against working voltages of 1060VRMS and 1500VDC for the lifetime of the device. The devices are protected against ±4kV contact IEC 61000-4-2 and ±15kV human body model (HBM) electrostatic discharge (ESD) events on the RS-485 A and B pins and ±8kV contact IEC 61000-4-2 ESD across the barrier without latch-up or damage.

The ADM2495E/ADM2495E-1 feature over voltage protection on the RS-485 A and B pins to withstand up to ±60V dc or ac peak to the transceiver side GND2. This allows for robust protection against transients and accidental connection to ±12V and ±24V power supplies. The common mode range of the device is extended to ±25V for applications with large ground offsets and long cable runs.

The ADM2495E/ADM2495E-1 are half-duplex transceivers. The ADM2495E has a reduced slew rate with 250kbps speed for operation over long cable runs with lower emissions. The ADM2495E-1 has a high 20Mbps data rate for maximum data transfer. The high differential output voltage makes these devices suitable for PROFIBUS® nodes when powered with 5V on the VDD2 supply. The VDD1 primary supply and VDD2 isolated supply both support a wide range of voltages (1.7V to 5.5V and 3.0V to 5.5V, respectively). The ADM2495E/ADM2495E-1 is available in the industry standard 16‑lead, wide body, standard SOICW package with 8.1mm creepage and clearance.

APPLICATIONS

* Solar inverters

* Electrical test and measurement

* Heating, ventilation, and air conditioning (HVAC) networks

* Industrial field buses

* Building automation

* 5.7kVRMS isolated half-duplex RS-485/RS-422 transceiver

* ±60V fault protection on RS-485 A and B pins

* Meets EN 55032 Class B radiated emissions on a 2-layer PCB

* Robust protection on the RS-485 A and B bus pins

* ≥ ±4kV IEC 61000-4-2 ESD

* ±10kV HBM ESD

* ≥ ±4kV IEC 61000-4-4 EFT

* Extended ±25V common-mode range

* Two speed options

* ADM2495E - low speed 250kbps for EMI control

* ADM2495E-1 - high speed 20Mbps data rate

* Flexible power supply inputs

* Primary VDD1 supply of 1.7V to 5.5V

* Isolated VDD2 supply of 3.0V to 5.5V

* PROFIBUS compliant for 5V VDD2

* Wide operating temperature range: −40°C to +125°C