Linear Technology DC1903A Demo Manual

Description
Demonstration circuit 1903A is an isolated CAN μModule
transceiver plus power featuring the
circuit features an EMI optimized circuit configuration and
printed circuit board layout. All components are integrated
into the μModule isolator. The demo circuit operates from
a single supply on V
performance summary
SYMBOL PARAMETER
V Input Supply Range
CC
V Regulated Output Voltage
CC2
f Maximum Data Rate
MAX
V Maximum Working Insulation Voltage
IORM
Common Mode Transient Immunity
operating principles
The LTM2889 contains an isolated DC/DC converter that
delivers power to V
Isolation is maintained by the separation of GND and GND2
where significant operating voltages and transients can
exist without affecting the operation of the LTM2889. The
logic side ON pin enables or shuts down the LTM2889.
All logic side signals are referenced to the logic supply
pin V , connected to the input supply voltage V
L
LTM2889 is available with two input voltage ranges, 3V
to 3.6V (LTM2889-3) or 4.5V to 5.5V (LTM2889-5). The
isolated side and CAN interface is capable of operating at
3.3V. The V voltage is jumper selectable for either 5V
CC2
or 3.3V operation.
Arrow.com.
Downloaded from
LTM 2889. The demo
®
. The part generates an isolated
CC
at 5V from the input supply V
CC2
DEMO MANUAL DC1903A
Isolated CAN µModule
Transceiver Plus Power
output voltage on V
®
signaling across the isolation barrier through LTC's isolator
µModule technology.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1903A
L, LT, LTC, LTM, Linear Technology, µModule, 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
LTM2889-3
LTM2889-5
I = 100mA, LTM2889-3
LOAD
I = 150mA, LTM2889-5
LOAD
GND to GND2
CAN signaling is controlled by the logic input TXD and
. the silent pin S. RE controls the RXD output. Connection
CC
to the transceiver pins (CANL and CANH) allows for half-
duplex communication on the isolated side of the demo
circuit. Termination resistors are included on the demo
circuit, with support for split termination to reduce com-
mon mode perturbations.
. The
CC
Data on the TXD input is transmitted differentially on
CANH-CANL when the silent pin (S) is low. Differential
data received on CANH-CANL is delivered at the RXD
output when RE is low. The CAN driver features adjust-
able slew rate via RV1 connected to the RS pin. A jumper
easily allows selection between a fixed fast slew rate and
adjustable rate.
LTM2889
and communicates all necessary
CC2
MIN TYP MAX
3.0 3.3 3.6
4.5 5.0 5.5
4.75 5 5.25
4
560
400
30
UNITS
V
V
V
Mbps
V
DC
V
RMS
kV/µs
dc1903af
1