Linear Technology 1791A Manual

Description
Demonstration circuit 1791A is a serial peripheral interface
bus (SPI) or inter-IC bus (I
adjustable 5V regulators 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 external supply on V
perForMAnce sUMMArY
SYMBOL PARAMETER
V Input Supply Range
CC
V Regulated Output Voltage
CC2
Adjustable Output Voltage Range
Internal Current Limit
V Regulated Output Voltage
L2
Adjustable Output Voltage Range
Internal Current Limit
f Maximum Data Rate
MAX
V Maximum Working Insulation Voltage
IORM
Common Mode Transient Immunity
operAting principles
The LTM2887 contains an isolated DC/DC conversion
system with multiple LDOs to deliver power to the two
output voltage rails from V
the separation of GND and GND2 where significant operat-
ing voltages and transients can exist without affecting the
operation of the LTM2887. The logic side ON pin enables
SPI/Digital or I
with Dual Adjustable 5V Regulators
2
C) µModule isolator with dual
LTM 2887. The demo
®
. The part generates
CC
(T = 25°C)
A
CONDITIONS
LTM2887-3
LTM2887-5
∆V
CC2
∆V
L2
DI1 → O1, Ix → DOx, CL = 15pF
LTM2887-S, Bidirectional Communication
LTM2887-S, Unidirectional Communication
LTM2883-I
GND to GND2
. Isolation is maintained by
CC
DEMO MANUAL DC1791A
2
C µModule Isolator
output voltages on V
by external programming resistors. It communicates all
necessary 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
L, LT, LTC, LTM, µModule, Linear Technology and the Linear logo are registered trademarks of
Linear Technology Corporation. All other trademarks are the property of their respective owners.
= –5%
= –5%
or shuts down the LTM2887. All logic side signals are
referenced to the logic supply pin V
available in two data bus configurations, SPI (–S) or I
(–I), and with two input voltage ranges, 3.0 to 3.6 volts
(–3) or 4.5 to 5.5 volts (–5).
LTM2887
and V which may be adjusted
CC2 L2
MIN TYP MAX
3.0 3.3 3.6
4.5 5.0 5.5
4.75 5 5.25
0.6 5.5
110
4.75 5 5.25
1.62 5.5
110
20
4
8
400
560
400
30
. The LTM2887 is
L
UNITS
V
V
V
V
mA
V
V
mA
MHz
MHz
MHz
kHz
V
DC
V
RMS
kV/µs
2
C
dc1791afa
1