R-REF03-CAN1

The R-REF03-CAN1 Reference Board demonstrates the ISO1042 isolated CAN transceiver supplied by the R1SX-3.305/H isolated DC/DC converter. To supply the reference board only one 3.3V external supply is required. The greed LED indicates the presence of the VCC2 supply on the secondary (CAN bus) side. The reference board allows designers to quickly develop and analyze isolated systems.

The reference board is pre-configured with a "split" termination network (R2 and R4) with a common-mode capacitance and additional caps (C7, C8 and C9) on the CAN bus for protection. It also includes an option to populate a 120-? resistor R3 which can be used with the EVM as a terminated line end (CAN is defined for 120? impedance twisted pair cable). Protection components like TVS diodes (D1) and common mode (CM) choke (L1) are also provided with bypass paths if necessary. Using these options, the customer is allowed installation of the desired components.

The output of the R1SX-3.305/H (U2) is used to supply the secondary (CAN bus) side of the digital isolator U1 and the green LED (LED1) which indicates the presence of the voltage on VCC2. VCC2 is loaded with a 120? resistor R7, too, to keep the VCC2 safely below 5.3V. Since the reference board internally consumes about 80mA from the output of the U2, a user can use about 120mA to supply circuits outside of this reference board through connector pin J2-1 or test point TP10.