LTM2881 uModule Transceiver Breaks Ground Loops
The LTM2881 isolated RS485 uModule transceiver is suitable for applications such as breaking ground loops, working with large common-mode voltages and when using multiple unterminated line taps. The transceiver guards against large ground-to-ground differentials and common-mode transients. It breaks ground loops by isolating the logic level interface and line transceiver using internal inductive signal isolation that allows for a larger common-mode voltage range, plus superior common-mode rejection of more than 30kV/uS.
A low EMI DC-DC converter powers the transceiver and provides an isolated 5V supply output for powering any supporting external components. With 2,500VRMS of galvanic isolation, onboard secondary power and a fully compliant RS485 transmitter and receiver, the LTM2881 requires no external components, ensuring a complete, small uModule solution for isolated serial data communications. The +/-15kV ESD-protected transceiver operates at 20Mbps or low EMI 250kbps, in half-duplex or full-duplex configurations.
The driver maintains high impedance over the entire common mode range and has a short circuit current limit, as well as slew-rate control for minimising EMI. Its counterpart, the failsafe receiver, allows up to 256 devices to be connected on the same lines and defaults to a logic '1' if the receiver inputs are open, shorted or terminated but not driven, all without the need to pre-bias the network. Integrated selectable termination allows cables to be properly terminated to avoid signal reflections and distorted waveforms, with the flexibility to add or remove termination anywhere onto the bus via a software switch.
The device also features thermal shutdown protection, disabling the transceiver outputs in case of excessive power dissipation. The self-powered LTM2881 guarantees safe and reliable communications in RS485 or RS422 systems. Two versions are available to support 3.3 and 5V input supply voltages. The LTM2881 is available in 11.25 x 15 x 2.8mm surface-mount LGA and BGA packages.
A low EMI DC-DC converter powers the transceiver and provides an isolated 5V supply output for powering any supporting external components. With 2,500VRMS of galvanic isolation, onboard secondary power and a fully compliant RS485 transmitter and receiver, the LTM2881 requires no external components, ensuring a complete, small uModule solution for isolated serial data communications. The +/-15kV ESD-protected transceiver operates at 20Mbps or low EMI 250kbps, in half-duplex or full-duplex configurations.
The driver maintains high impedance over the entire common mode range and has a short circuit current limit, as well as slew-rate control for minimising EMI. Its counterpart, the failsafe receiver, allows up to 256 devices to be connected on the same lines and defaults to a logic '1' if the receiver inputs are open, shorted or terminated but not driven, all without the need to pre-bias the network. Integrated selectable termination allows cables to be properly terminated to avoid signal reflections and distorted waveforms, with the flexibility to add or remove termination anywhere onto the bus via a software switch.
The device also features thermal shutdown protection, disabling the transceiver outputs in case of excessive power dissipation. The self-powered LTM2881 guarantees safe and reliable communications in RS485 or RS422 systems. Two versions are available to support 3.3 and 5V input supply voltages. The LTM2881 is available in 11.25 x 15 x 2.8mm surface-mount LGA and BGA packages.
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