Analog Devices Inc. ADM2895E/ADM2895E-1 RS-485 Transccievers
Analog Devices ADM2895E/ADM2895E-1 Half-Duplex RS-485 Transceivers are 5.7kVRMS signal and power 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 a margin on a 2-layer printed circuit board (PCB) with high-frequency decoupling capacitors and two small external 0402 ferrites on isolated power and ground pins. The device features an integrated, low electromagnetic interference (EMI), isolated DC-to-DC converter, eliminating the need for an external isolated power supply. The isolation barrier protects system-level electromagnetic compatibility (EMC) standards. The ADM2895E/ADM2895E-1 devices are suitable for applications that require reinforced insulation against working voltages of 400VRMS and 566VDC for the device's lifetime. 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 Analog Devices ADM2895E/ADM2895E-1 feature overvoltage protection on the RS-485 A and B pins to withstand up to ±60V DC or AC peak to the transceiver side GND2. This feature allows for robust protection against transients and accidental connection to ±12V or ±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 ADM2895E/ADM2895E-1 are half-duplex transceivers. The ADM2895E has a reduced slew rate with a 250kbps speed for operation over long cable runs with lower emissions. The ADM2895E-1 has a high 20Mbps data rate for maximum data transfer. The high-differential output voltage makes these devices suitable for PROFIBUS® nodes when the VISO supply is configured for 5V. Two primary supplies allow different supply voltages for the logic pins (VIO: 1.7V to 5.5V) and the isolated supply input (VCC: 3.0V to 5.5V). The ADM2895E/ADM2895E-1 are available in the industry standard 28-lead, wide body, standard SOIC_W package with 8.3mm creepage and clearance.
Features
- 5.7kVRMS isolated half-duplex RS-485/RS-422 transceiver
- ±60V fault protection on RS-485 A and B pins
- Low radiated emissions, integrated, isolated DC-to-DC converter
- 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
- ADM2895E - low-speed 250kbps for EMI control
- ADM2895E-1 - high-speed 20Mbps data rate
- Flexible power supplies
- Primary input VCC supply of 3.0V to 5.5V
- Primary logic VIO supply of 1.7V to 5.5V
- VSEL pin to select isolated VISO supply of 5V (VCC > 4.5V) or 3.3V
- PROFIBUS compliant for 5V VISO
- Wide operating temperature range of -40°C to +105°C
- High common-mode transient immunity of 250kV/μs
- Short-circuit, open-circuit, and floating input receiver fail-safe
- Supports >224x bus nodes (112kΩ receiver input impedance)
- Full hot-swap support (glitch-free power-up/power-down)
- Safety and regulatory approvals
- IEC 60747-17 (pending) with reinforced VIORM = 566VPEAK
- UL 1577 (pending) with VISO = 5700VRMS for 1 minute
- IEC/EN/CSA 62368-1 (pending)
- IEC/EN/CSA 61010-1 (pending)
- IEC/CSA 60601-1 (pending)
- GB 4943.1 (pending)
- Complies with ANSI/TIA/EIA-485-A-98 and ISO 8482:1987(E)
- 8.3mm creepage and clearance in standard pinout
Applications
- Heating, ventilation, and air conditioning (HVAC) networks
- Industrial field buses
- Building automation
- Utility networks
- Energy meters
Functional Block Diagram
Development Tool
Analog Devices Inc. EVAL-ADM2895EEBZ Evaluation Board for ADM2895E
Allows for simplified, efficient evaluation of the ADM2895E 250kbps half-duplex RS-485 transceiver.