Linear 1986A Demo Manual

DESCRIPTION
Demonstration circuit 1986A is an I
featuring the LTM2892-I. The demo circuit operates from
external supply voltages on V
communicates all necessary signaling across the isolation
barrier through LTC's Isolator™ μModule Technology.
PERFORMANCE SUMMARY
SYMBOL PARAMETER
V , V Input Supply Range
CC1 CC2
V , V Logic Supply Range
L1 L2
f Maximum Data Rate
MAX
V Maximum Working Insulation Voltage
IORM
Common Mode Transient Immunity
OPERATING PRINCIPLES
The LTM2892-I requires two to four external power sup-
plies for operation, one for power and one for the signal
interface, on each side of the isolation barrier. The logic
supplies may be tied to the input supplies. Isolation is
maintained by the separation of GND1 and GND2 where
significant operating voltages and transients can exist
without affecting the operation of the LTM2892-I. The ON1
and/or ON2 pins enable or shut down the LTM2892-I, both
must be driven to their respective logic supply voltage for
2
proper operation. All I C or digital signals are referenced
to the logic supply pins V
2
I C signaling does not require any additional components.
The demo board includes pull-up resistors on SDA1 and
SCLIN. SCLOUT and SDA2 do not require external pull-ups,
SCLOUT is a push-pull output and SDA2 is pulled high
through an integral current source within the LTM2892-I.
2
C μModule ® Isolator
, V , V , and V
CC1 L1 CC2
Specifications are at T
CONDITIONS
INx → OUTx, C
2
I
GND1 to GND2
or V .
L1 L2
DEMO MANUAL DC1986A
2
I
Design files for this circuit board are available at
http://www.linear.com/demo
. It
L, LT, LTC, LTM, Linear Technology, the Linear logo and μModule are registered trademarks
L2
and Isolator is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
= 25°C
A
= 15pF
L
C Communication
Do not use external pull-up resistors or current sources
on SCLOUT or SDA2.
2
I C signaling is configured by defining the LTM2892-I
pins as follows:
Logic Side: SCLIN = SCL(IN), and SDA1 = SDA(IN).
Isolated Side: SCLOUT = SCL(OUT), SDA2 = SDA(OUT).
Reference Figure 1 for schematic representation.
No special precautions are required for low RF emissions.
EMI performance is shown in Figure 2, measured using
a gigahertz transverse electromagnetic (GTEM) cell and
method detailed in IEC 61000-4-20, Testing and Measure-
ment Techniques – Emission and Immunity Testing in
Transverse Electromagnetic Waveguides.
LTM2892-I
C µModule Isolator
MIN TYP
3.0
3.0
20
400
850
600
50
MAX UNITS
5.5 V
5.5 V
MHz
kHz
V
DC
V
RMS
kV/μs
dc1986af
1