Datasheet

2 EVM Setup and Operation www.ti.com
2.3 Using Customer Installable I/O options for Current Limiting, Pullup/Pulldown, Noise
Filtering
The CAN EVM has footprints on the PCB for the installation of various filtering and protection options to
adapt the EVM to match CAN network topology requirements if the EVM is being used as a CAN node.
Each digital input or output pin has footprints to allow for series current limiting resistors (default populated
with 0Ω), pull up or down resistors depending on pin use and a capacitor to GND which configured with
the serial resistor allows for RC filters (noisy environments). The table below lists these features for each
of the digital input and output pins of the EVM. Replace or populate the RC components as necessary for
the application.
Table 5. RC Filter / Protection Lists
Device Pin Jumperable
Pull
Series R C to GND Description
Up/Down
No. Description Type Pull Up Pull Down
1 TXD Input N/A N/A R10 R6 PU C3
2 RXD Output N/A N/A R13 R5 PU C5
No
NC N/A N/A N/A N/A N/A
Connect
Split termination: JMP6 to
route output to split
termination center point
V
REF
/SPLIT Output N/A N/A R17 N/A C4 / C6
capacitor C4. EMC for
systems not using split
5
termination: C6 to GND.
Use TM6, JMP6 & JMP2 as
Supply
V
RXD
/V
IO
N/A N/A R17 N/A C9 / C6 necessary to provide supply
Input
input.
AB / EN / R18 R19
Input R17 N/A C6
LBK (JMP6) (JMP6)
R2 pull down to GND (JMP1)
R2 / R3 user installable for use with
S, R
S
, STB Input R1 (JMP1) R4 N/A C1
(JMP1) slope mode on devices with
8
R
S
pin.
No
NC N/A N/A N/A N/A N/A
Connect
8
CAN EVM User Guide SLLU158– December 2011
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