Date
11/15/2016
PDF
LTM2885 isolated RS485 µModule transceiver
Linear Technology introduced the LTM2885, an isolated RS485 µModule transceiver for guarding against large ground-to-ground differentials. Many industrial, utility, medical, military, and intrinsic safety applications require isolation components with increased voltage and spatial separation for human safety. The LTM2885 provides 6500VRMS reinforced isolation between the logic level interface and the transceiver bus pins, far surpassing the IEC 60747 basic and reinforced isolation standards. With creepage and clearance distances greater than 14mm and a distance through insulation (DTI) greater than 0.2mm, the LTM2885 exceeds many overvoltage category II and material group IIIA equipment requirements, including the provision of two means of patient protection (MOPP) for medical equipment per IEC 60601-1.
The LTM2885 provides an extensive feature set to support its robust isolation. A ±15kV ESD-protected RS485 transceiver operates at 20Mbps or low EMI 250kbps, with uninterrupted communication guaranteed for common mode transients up to 50kV/µs. An internal low EMI DC/DC converter powers the transceiver and provides an isolated 1W supply output for powering external support components. Integrated selectable termination allows cables to be properly terminated, with the flexibility to add or remove termination anywhere on the bus via software control. Operating from a 5V supply, the LTM2885 requires no additional external components, providing a self-contained μModule solution for isolated RS485 serial data communications.
Summary of Features: LTM2885
Isolated RS485/RS422 Transceiver: 6500VRMS
Isolated DC Power: 5V at Up to 200mA
Reinforced Insulation & Creepage > 14mm
No External Components Required
20Mbps or Low EMI 250kbps Data Rate
High ESD: ±15kV HBM on Transceiver Interface
High Common Mode Transient Immunity: 50kV/µs
Integrated Selectable 120Ω Termination
1.62V to 5.5V Logic Supply Pin for Flexible Digital Interface
General Purpose CMOS Isolated Channel
22mm x 9mm x 5.16mm Surface Mount BGA Package
The LTM2885 is offered in commercial, industrial and automotive versions, supporting operating temperature ranges from 0°C to 70°C, –40°C to 85°C, and –40°C to 105°C, respectively. The LTM2885 is offered in a 22mm x 9mm x 5.16mm surface mount BGA package; all integrated circuits and passive components are housed in this Linear Technology, RoHS-compliant μModule package. Pricing starts at $11.98 each in 1,000-piece quantities. Please visit www.linear.com/product/LTM2885 for more product selection and information.
