CAN FD module guards against common mode transients
A fully ISO 11898-2 compliant CAN (controller area network) uModule, the LTM2889, has been announced by Linear Technology.
It guards against large ground-to-ground differentials and common mode transients in 3.3 or 5.0V applications. Ground potentials can vary widely from node to node, and often exceed the tolerable range, which can result in an interruption of communications or destruction of a transceiver, explains the company. The devices separates grounds by isolating the CAN transceiver using internal inductive isolation. It implements multiple levels of protection to improve system reliability, including 2,500VRMS of galvanic isolation, ±60V bus voltage fault tolerance, greater than 30kV/µs common mode transient immunity, and ±25kV HBM ESD protection.
The design means that no external components are required. It integrates a low EMI, DC/DC converter that powers the isolated transceiver and provides up to 0.75W of isolated power for CAN node components. In addition to built-in protection mechanisms, there is an extended ±36V common mode range to enable operation in electrically noisy environments and in the presence of ground loops, says the company.
The module operates at data rates between 22kbit/s and 4Mbit/s, with an adjustable slew rate to reduce EMI at lower data rates. A shutdown mode brings all of the outputs to high impedance and reduces power consumption to less than 1microA.
Commercial, industrial and automotive temperature grades are available in a low profile 15 x 11.25 x 3.42mm surface mount BGA package.