µModule Isolators
Transformer
Isolated Power
Decoupling
Caps
Diodes
Isolators
Coupled Signal
Inductors
LDO
Application Die
Complete Isolation and Power for Standard Serial Interfaces and Devices
Linear Technology’s µModule
®
isolators are complete system-in-package (SiP) solutions that provide up to 7.5kV
RMS
isolation for
the most popular serial interfaces and devices, including USB, RS485, RS232, SPI/Digital, I
2
C, ADCs, DACs and switches. Most
devices provide up to 1W of isolated power to neighboring components. Boasting high integration and performance in small
footprints, absolutely no external components are required.
L,
LT, LTC, LTM, Linear Technology, the Linear logo and µModule are registered trademarks and the
Isolator logo and Anyside are trademarks of Analog Devices, Inc. All other trademarks are the property
of their respective owners.
Galvanic Isolation
Linear Technology μModule isolators use embedded, inductively
coupled coils to pass data differentially across the isolation boundary,
resulting in an extremely robust communications scheme. Simple
isolated solutions are made available with the integration of isolated
data, isolated power and all passive components, including bypass
capacitors, in a single package. High distance through-insulation
ultimately translates to higher ESD protection and reliability.
Common Mode Transient Immunity
A differential signaling scheme enables communication through
common mode transient events greater than 70kV/μs, and is
unaffected by the transient without any priority data jitter or data
corruption. The system includes data refresh, error checking and safe
shutdown for robust digital communications.
3.9
–3 VERSIONS
3.6
–5 VERSIONS
5.5
6.0
5V/DIV
5V/DIV
INA
OUTD
REPETITIVE
COMMON MODE
TRANSIENTS
FROM GND1
TO GND2
200V/
DIV
20ns/DIV
LTM2892
Isolated Power
V
IN
(V)
3.3
5.0
3.0
LTM2881
0.6
V
CC2
≥ 4.75V
0.8
1.2 1.4
1
OUTPUT POWER (W)
1.6
4.5
With the exception of the LTM
®
2892/LTM2893/LTM2894/LTM2895, all
µModule isolators provide at least one isolated power supply for powering
neighboring components, such as data converters. These supplies are
regulated, up to 65% efficient, fault tolerant and, in some cases, adjustable
using a single resistor.
V
IN
(V)
2.7
0.4
4.0
1.8
Safety, EMC and EMI
µModule isolators are certified to stringent component level safety, electromagnetic compatibility (EMC) and electromagnetic
interference (EMI) standards. All µModule isolators pass accepted safety standards, including UL1577 and CSA component
acceptance notice #5A, which test isolation barrier performance under various environmental conditions and require 100%
production screening. In addition, all devices are 100% tested to the more sensitive partial discharge IEC 60747 requirements.
EMC refers to a device’s ability to operate
properly in the presence of EMI. All µModule
isolators pass EMC tests per IEC 61000-4-3/-
8/-9, which subject the devices to particular
magnetic field frequencies and strengths.
EMI refers to a device’s actual radiated
emissions. All µModule isolators are well below
CISPR 22 Class A and B limits, as well as the
Federal Communications Commission (FCC)
Class A limit.
60
50
40
AMPLITUDE (dBµV/m)
30
20
10
0
−10
−20
−30
10
100
FREQUENCY (MHz)
1k
PREDICTED
DATA COIL
EMISSIONS
CISPR 22 CLASS B LIMIT
LTM2881 LOW EMI DEMO BOARD EMISSIONS
RBW = 120kHz
VBW = 300kHz
DETECTOR = PEAK
SWEEP TIME = 17s
FCC CLASS B LIMIT
CISPR 22 CLASS A LIMIT
FCC CLASS A LIMIT
2
RS485 Transceivers
• Single TIA/EIA-485-A (and PROFIBUS)
Compatible Transceiver
• Half- or Full-Duplex Operation
• Integrated Isolated DC/DC and Bypass Caps
• 1.62V to 5.5V Logic Supply
• Selectable 20Mbps or 250kbps Data Rate
• 30kV/µs Common Mode Transient Immunity
• ±15kV HBM ESD
• 14.6mm Creepage & Distance (LTM2885)
Galvanic Isolation
A pin-selectable 120Ω termination is available for minimizing reflections that
may be present on an unterminated transmission line. RS485 networks require
120Ω termination resistors to be installed by the end-user based on the physical
layout of the twisted-pair wires and the placement of the nodes. Pin-selectable
termination allows the proper nodes to be terminated by switching the integrated
termination on or off, under software control, without the need of physical
intervention by the user.
Integrated Selectable 120Ω Termination
Part
Number
LTM2881
LTM2885
Interface
RS485
RS485
Isolation # Dri/ Supply Max Data
(V
RMS
)
Rec Voltage (V)
Rate
2500
6500
1/1
1/1
5/3.3
5
20Mbps
20Mbps
Isolated Power Output(s)
5V (1W)
5V (1W)
Max
Temp
Package
105°C 15mm × 11mm BGA-32 or LGA-32
105°C
22mm × 9mm BGA-42
RS232 Transceiver
•
•
•
•
•
•
•
Dual TIA/EIA-232-F Compatible Transceiver
Half- or Full-Duplex Operation
Integrated Isolated DC/DC and Bypass Caps
1.62V to 5.5V Logic Supply
Up to 1Mbps Data Rate
30kV/µs Common Mode Transient Immunity
±10kV HBM ESD
Flexible Extra Channel
Galvanic Isolation
An extra isolated digital channel supports any auxiliary signaling and functions,
including slave-side control of the low latency Driver Enable (DE) pin in half-
duplex operations. When toggled, each driver is enabled and disabled in less
than 2µs, while each receiver remains continuously active.
Part
Number
LTM2882
Interface
RS232
Isolation # Dri/ Supply Max Data
(V
RMS
)
Rec Voltage (V)
Rate
2500
2/2
5/3.3
1Mbps
Isolated Power Output(s)
5V (1W)
Max
Temp
85°C
Package
15mm × 11mm BGA-32 or LGA-32
3
SPI or I
2
C Transceivers
• 6-Channel SPI/Digital or I
2
C Transceiver
• Integrated Isolated DC/DC
(LTM2883, LTM2886 & LTM2887)
• 1.62V to 5.5V Logic Supply
• 10MHz SPI or 400kHz I
2
C Data Rate
• Up to 50kV/µs Common Mode Transient Immunity
• Up to ±15kV HBM ESD
Galvanic Isolation
Multiple Isolated Power Outputs
Except for the LTM2892, up to three regulated isolated power
outputs are available and source up to 100mA to neighboring
isolated components, eliminating the need for separate isolated
supplies. Some of these power outputs may be adjusted from their
nominal value using a single external resistor.
Part
Number
LTM2883
LTM2886
LTM2887
LTM2892
Interface
SPI/I C
SPI/I
2
C
SPI/I
2
C
SPI/I
2
C
2
Isolation # Dri/ Supply Max Data
(V
RMS
)
Rec Voltage (V)
Rate
2500
2500
2500
3500
3/3
3/3
3/3
3/3
5/3.3
5/3.3
5/3.3
1.62 to 5.5
10MHz
10MHz
10MHz
10MHz
Isolated Power Output(s)
Max
Temp
Package
15mm × 11mm BGA-32
15mm × 11mm BGA-32
15mm × 11mm BGA-32
9mm × 6mm BGA-24
Adj. 3V to 5V, Adj. ±12V (0.6W)
85°C
Adj. 3V to 5V, Fixed. ±5V (1W)
125°C
Adj. 1.8V to 5V, Adj. 0.6 to 5V (1W) 125°C
–
125°C
SPI Data Converter Controllers
• Up to 100MHz SPI Interface with Data
Converter Controls
• Configurable SPI Word Length: 8 to 32 Bits
• Low 30ps
RMS
Jitter Conversion Start
and /LOAD Signals
• Three Isolated Control or Multiplexer
Select Signals
• 1.71V to 5.5V Logic Supply
100
SNR
Galvanic Isolation
96
MAGNITUDE (dB)
SINAD
92
Optimized for High Performance Conversions
88
84
Up to 10 isolated logic channels support the most demanding data
converters, as well as dual data converter configurations, analog
multiplexers and programmable gain amplifiers. Crucial data converter
specifications, such as high signal-to-noise ratio (SNR) or low jitter, are
maintained with SPI read/write speeds of up to 100MHz.
1M
80
1k
10k
100k
FREQUENCY (Hz)
Part
Number
LTM2893
LTM2895
4
Interface
SPI ADC
SPI DAC
Isolation # Dri/ Supply Max Data
(V
RMS
)
Rec Voltage (V)
Rate
6000
6000
1/1
1/1
3 to 5.5
3 to 5.5
100MHz
100MHz
Isolated Power Output(s)
–
–
Max
Temp
125°C
125°C
Package
15mm × 6mm BGA-36
15mm × 6mm BGA-36
USB Transceivers
• USB 2.0 Full Speed (12Mbps) and Low
Speed (1.5Mbps) Compatible
• Integrated Isolated DC/DC, External or Bus
Powered (LTM2884)
• 17.4mm Creepage Distance (LTM2894)
• Up to 50kV/µs Common Mode Transient
Immunity
• Up to ±20kV HBM ESD
7500V
RMS
Galvanic Isolation
Auto-Configuration of Bus Speed
Automatic speed selection configures integrated pull-up
resistors on the upstream port – for 12Mbps (full speed) or
1.5Mbps (low speed) operation – to match those sensed
on the downstream device, eliminating external bus pull-up
resistors and any associated switches, jumpers or software.
Part
Number
LTM2884
LTM2894
Interface
USB
USB
Isolation # Dri/ Supply Max Data
(V
RMS
)
Rec Voltage (V)
Rate
2500
7500
1/1
1/1
4.4 to 16.5
4.4 to 36
12Mbps
12Mbps
Isolated Power Output(s)
2.5W from External Supply,
1W from USB
–
Max
Temp
105°C
125°C
Package
15mm × 15mm BGA-44
22mm × 6mm BGA-24
CAN Transceiver
•
•
•
•
•
•
•
CAN FD Compliant
Up to 4Mbps Data Rate
Integrated Isolated DC/DC and Bypass Caps
1.62V to 5.5V Logic Supply
±60V Fault Protection
30kV/µs Common Mode Transient Immunity
±25kV HBM ESD
Parameter
Number of Nodes
Min Differential
Input Resistance
Differential Input
Capacitance
Bus Pin Voltage
Range (Survivable)
Bus Pin Voltage
Range (Operation)
Connector
Mis-Wiring
Tests, All Pin-Pin
Combinations
DeviceNet
64
20k
25pF (Max)
–25V to 18V
–5V to 10V
±18V
ISO 11898-2
N/A
10k
10pF (Nom)
–3V to 16V
(for Battery)
–2V to 7V
N/A
LTM2889
166
50k
8.4pF (Typ)
–60V to 60V
–36V to 36V
(V
CC
= 5V)
±60V
Galvanic Isolation
ISO 11898-2 & DeviceNet Compatible
Designed for road vehicles, ISO 11898-2:2003 is the section of
the CAN standard that defines the physical and data link layers
of CAN, requiring CAN transceivers to support 1Mbps data and
other parameters (see table). The LTM2889 meets all of these
requirements, in addition to the more stringent requirements of
DeviceNet which is commonly used in automation networks to
interconnect control devices for data exchange.
Part
Number
LTM2889
Isolation # Dri/ Supply Max Data
Interface (V
RMS
)
Rec Voltage (V)
Rate
CAN
2500
1/1
5/3.3
4Mbps
Isolated Power Output(s)
Adj. 3V to 5V (0.75W)
Max
Temp
125°C
Package
15mm × 11mm BGA-32
5
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