1

dc2063af

DEMO MANUAL DC2063A

Description

LTC2875

±60V Fault Protected 3.3V or 5V

High Speed CAN Transceiver

Demonstration circuit 2063A is a robust high speed, low

power, ISO 11898-2 compliant CAN transceiver featuring

the LTC®2875. The demo circuit operates on 3.3V or 5V

suppliesandfeatures±60Vovervoltagefaultprotectionon

the data transmission lines during all modes of operation.

The demo circuit contains all the components necessary

to demonstrate the features of the LTC2875 in a CAN

network, including a terminated SMB jack for TXD data

L

, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear

Technology Corporation. All other trademarks are the property of their respective owners.

performance summary

operating principles

input, jumper selectable CAN bus termination (supporting

either single or split termination configurations), and a

jumper selectable variable slew rate control.

Design files for this circuit board are available at

http://www.linear.com/demo/DC2063A

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Input Supply Range

3.0

3.3

3.6

V

4.5

5.0

5.5

V

Maximum Data Rate

JP3 in ‘MAX’ position

4

Mbps

Interface I/O: CANH, CANL

–60

60

V

Bus Differential Voltage (CANH-CANL)

JP2 in ‘SINGLE’ or ‘SPLIT’ position

10

V

The LTC2875 is enabled by pulling the RS pin low. The

slew rate of the transmitter can be controlled by pulling RS

low with a resistor ≤ 200kΩ, with the slew rate decreasing

with increasing resistor value. The DC2063A provides two

jumper positions to enable the LTC2875. With a jumper

in the JP3:MAX position, the RS pin is grounded and the

LTC2875operatesatitsmaximumslewrate.Withajumper

in the JP3:ADJ position, the transmitter slew rate can be

varied from its minimum to maximum using 200kΩ vari-

able resistor RV1. When no jumper is placed on JP3, the

RS pin in the LTC2875 is pulled up by an internal 250kΩ

resistor, putting the chip in the shut-down state.

ThedatainputsignalcanbeappliedtotheLTC2875TXDpin

through either the TXD turret or the SMB jack J1. To apply

the TXD signal through the SMB jack J1, place a jumper

on the JP1:SMB position. The SMB input is terminated to

GNDbya50Ωresistor.ToapplytheTXDsignalthroughthe

TXD turret, place a jumper on the JP1:TURRET position.

The TXD turret input contains a 100Ω series resistor but is

not terminated. Jumpers may be applied to both JP1:SMB

and JP1:TURRET to enable applying a signal from a pulse

generator through the SMB jack J1 and monitoring the

signal with a scope probe on the TXD turret.