Linear Technology DC2063A Demo Manual

Description

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
®
supplies and features ±60V overvoltage fault protection on
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

performance summary

SYMBOL PARAMETER
V Input Supply Range
CC
f Maximum Data Rate
MAX
Interface I/O: CANH, CANL
Bus Differential Voltage (CANH-CANL)
Operating Principles
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
LTC2875 operates at its maximum slew rate. With a jumper
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.
DEMO MANUAL DC2063A
±60V Fault Protected 3.3V or 5V
High Speed CAN Transceiver
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
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.
Specifications are at T = 25°C
A
CONDITIONS
3.3V V Range
CC
5V V Range
CC
JP3 in 'MAX' position
JP2 in 'SINGLE' or 'SPLIT' position
The data input signal can be applied to the LTC2875 TXD pin
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
GND by a 50Ω resistor. To apply the TXD signal through the
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.
LTC2875
MIN TYP MAX UNITS
3.0 3.3 3.6
4.5 5.0 5.5
4
–60 60
10
dc2063af
V
V
Mbps
V
V
1