SN65HVD257 CAN EVM
2
SN65HVD257 CAN EVM
The EVM consists of 2 CAN bus “nodes” and the necessary logic to build functional safety networks. It is
pre-configured for redundant CAN network applications with the 2 CAN bus “nodes”, including the AND
gate to combine the RXD output from both buses and the XOR gate and filter (50kHz) to detect a bus
open fault. The EVM has simple connections to all necessary pins of the CAN transceiver devices and the
necessary logic to create a redundant network. Jumpers are provided where necessary to provide
flexibility for device pin and CAN bus configuration. There are test points (loops) for all main points where
probing is necessary for evaluation such as GND, V
CC
, TXD, RXD, CANH, CANL, S, FAULT. The EVM
supports many options for CAN bus configuration. It is pre-configured with two 120
Ω
resistors that may be
connected on the bus via jumpers; a single resistor is used with the EVM as a terminated line end (CAN is
defined for 120
Ω
impedance twisted pair cable) or both resistors in parallel for electrical measurements
representing the 60
Ω
load the transceiver “sees” in a properly terminated network (120
Ω
termination
resistors at both ends of the cable). If the application requires “split” termination, TVS diodes for protection
or Common Mode (CM) Choke the EVM has footprints available for these components via customer
installation of the desired component(s).
Figure 4. SN65HVD257 CAN EVM Top
4
SN65HVD257 CAN EVM: Functional Safety and Redundant CAN Network
SLLU172 – August 2012
Copyright © 2012, Texas Instruments Incorporated
