DATASHEET
ISL32705E
Low-EMI Isolated Full-Duplex RS-485 Transceiver
FN8949
Rev.2.00
Jan 11, 2018
The
ISL32705E
is a galvanically isolated, full-duplex
differential bus transceiver, designed for bidirectional
data transmission meeting the RS-485 and RS-422
standards for balanced communication. All bus terminals
are protected against ±7kV ESD strikes without latch-up.
The device uses Giant Magnetoresistance (GMR) as
isolation technology. A unique ceramic/polymer
composite barrier provides excellent isolation and nearly
unlimited barrier life.
The part is available in a 16 Ld wide-body SOIC package
providing true 8mm creepage distance.
The ISL32705E delivers a minimum of 1.5V into a 54Ω
differential load for excellent data integrity over long
cable lengths.
The device is compatible with 3V and 5V input supplies,
allowing an interface to standard microcontrollers
without additional level shifting.
Current limiting and thermal shutdown features protect
against output short-circuits and bus contention that may
cause excessive power dissipation. Receiver inputs
feature a “fail-safe if open” design, ensuring a logic high
R-output if A/B are floating.
Features
• 4Mbps data rate
• 2.5kV
RMS
isolation/600V
RMS
working voltage
• 3V to 5V power supplies
• Drives up to 44 devices on an isolated bus
• 50kV/µs (typical), 30kV/µs (minimum)
common-mode transient immunity
• 44,000 year barrier life
• 7kV ESD protection
• Low EMC footprint
• Thermal shutdown protection
• -40°C to +85°C temperature range
• Meets or exceeds ANSI RS-485
• 0.3” true 8mm 16 Ld SOIC package
• UL 1577 recognized
• VDE V 0884-10 certified
Applications
• Factory automation
• Security networks
• Building environmental control systems
• Industrial/process control networks
• Level translators (for example, RS-232 to RS-485)
• Equipment covered under IEC 61010-1 Edition 3
Related Literature
• For a full list of related documents, visit our website
•
ISL32705E
product page
100n
ISOLATION
BARRIER
3.3V
5V
1
VDD1
3
4
5
6
R
RE
DE
D
GND1
2,8
ISL32705EIBZ
16
VDD2
A
B
Y
Z
ISODE
GND2
9,15
100n
R
B
14
13
11
12
10
R
B
R
B
R
T
R
T
R
B
100n
16
ISOLATION
BARRIER
5V
3.3V
1
VDD1
D
DE
RE
R
GND1
2,8
ISL32705EIBZ
6
5
4
3
100n
VDD2
11
12
14
13
10
Y
Z
A
B
ISODE
GND2
9,15
Figure 1. Typical Isolated Full-Duplex RS-485 Application
FN8949 Rev.2.00
Jan 11, 2018
Page 1 of 20
ISL32705E
1. Overview
1.
1.1
Overview
Typical Operating Circuit
ISO
DC-DC
Vs
1
100n
VDD
RxD
100n
10k
2
VDD1
VDD2
16
100n
R
B
A
B
Z
Y
R
B
GND1
3 R
4 RE
5 DE
6 D
15
GND2
A 14
B 13
Z 12
Y 11
ISODE 10
GND2
9
MCU
REN
DEN
3x
10k
R
T
TxD
DGND
GND
7
8
NC
GND1
ISL32705E
Figure 2. Typical Operating Circuit
1.2
Ordering Information
Part Number
(Notes
1, 2, 3)
Part Marking
32705EIBZ
Temp. Range
(°C)
-40 to +85
Package
(RoHS Compliant)
16 Ld SOICW
Pkg. Dwg. #
M16.3A
ISL32705EIBZ
ISL32705EVAL1Z
Evaluation board for ISL32705EIBZ
Notes:
1. Add “-T” suffix for 1k unit or -T7A” suffix for 250 unit tape and reel options. Refer to
TB347
for details on reel specifications.
2. Pb-free plus anneal products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin
plate termination finish, which are RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Pb-free
products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J
STD-020.
3. For Moisture Sensitivity Level (MSL), see the product information page for the
ISL32705E.
For more information on MSL, see
TB363.
Table 1. Key Differences Between Family of Parts
Part Number
ISL32704E
ISL32705E
ISL32740E
ISL32741E
Full/Half Duplex
Half
Full
Half
Half
V
DD1
(V)
3.0 – 5.5
3.0 – 5.5
3.0 – 5.5
3.0 – 5.5
V
DD2
(V)
4.5 – 5.5
4.5 – 5.5
4.5 – 5.5
4.5 – 5.5
Data Rate
(Mbps)
4
4
40
40
Isolation Voltage
(kV
RMS
)
2.5
2.5
2.5
6
FN8949 Rev.2.00
Jan 11, 2018
Page 2 of 20
ISL32705E
1. Overview
1.3
Pin Configuration
ISL32705E
(16 Ld SOIC)
Top View
VDD1 1
GND1 2
R 3
RE 4
DE 5
D 6
NC 7
GND1 8
16 VDD2
15 GND2
14 A
13 B
12 Z
11 Y
10 ISODE
9 GND2
1.4
Truth Tables
Transmitting
Inputs
RE
X
X
0
1
DE
1
1
0
0
D
1
0
X
X
ISODE
1
1
0
0
Outputs
Z
0
1
High-Z
High-Z
Y
1
0
High-Z
High-Z
Receiving
Inputs
RE
0
0
0
0
1
DE
X
X
X
X
X
A-B
V
AB
≥0.2V
0.2V > V
AB
> -0.2V
V
AB
≤ -0.2V
Inputs Open
X
Output
RO
1
Undetermined
0
1
High-Z
FN8949 Rev.2.00
Jan 11, 2018
Page 3 of 20
ISL32705E
1. Overview
1.5
Pin
Number
1
2, 8
3
4
5
6
7
9, 15
10
11
12
13
14
16
Pin Descriptions
Pin
Name
VDD1
GND1
R
RE
DE
D
NC
GND2
Input power supply.
Input power supply ground return. Pin 2 is internally connected to Pin 8.
Receiver output. R is high when A-B ≥200mV or A and B are floating. R is low when A-B ≤-200mV.
Receiver output enable. R is enabled when RE is low; R is high impedance when RE is high.
Driver output enable. The driver outputs, Y and Z, are enabled when DE is high. They are high-impedance when
DE is low.
Driver input. A high on D forces output Y high and output Z low. Similarly, a low on D forces output Y low and
output Z high.
No internal connection.
Output power supply ground return. Pin 9 is internally connected to Pin 15.
Function
ISODE Isolated DE output for use in applications in which the state of the isolated drive enable node needs to be
monitored.
Y
Z
B
A
VDD2
±7kV ESD protected noninverting driver output.
±7kV ESD protected inverting driver output.
±7kV ESD protected inverting receiver input.
±7kV ESD protected noninverting receiver input.
Output power supply.
FN8949 Rev.2.00
Jan 11, 2018
Page 4 of 20
ISL32705E
2. Specifications
2.
2.1
Specifications
Absolute Maximum Ratings
Parameter
(Note 4)
Minimum
Maximum
Unit
Supply Voltages
(Note 7)
VDD1 to GND1
VDD2 to GND2
Input Voltages D, DE, RE
Input/Output Voltages
A, B
R
Short-Circuit Duration A, B
ESD Rating
-9
-0.5
Continuous
See “Electrical Specifications” table on
page 6
+13
VDD1 + 1
V
V
V
-0.5
-0.5
+7
7
VDD1 + 0.5
V
V
V
Note:
4. Absolute Maximum specifications mean the device will not be damaged if operated under these conditions. It does not
guarantee performance.
CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may
adversely impact product reliability and result in failures not covered by warranty.
2.2
Thermal Information
Thermal Resistance (Typical)
JA
(°C/W)
60
JC
(°C/W)
12
16 Ld SOICW Package (Notes
5, 6)
Notes:
5.
JA
is measured in free air with the component soldered to a double-sided board.
6. For
JC
, the “case temp” location is the center of the package top side.
Parameter
Maximum Junction Temperature (Plastic Package)
Maximum Storage Temperature Range
Maximum Power Dissipation
Pb-Free Reflow Profile
Minimum
-55
-55
Maximum
+150
+150
800
Refer to
TB493
Unit
°C
°C
mW
2.3
Recommended Operation Conditions
Parameter
Minimum
Maximum
Unit
Supply Voltages
V
DD1
V
DD2
High-Level Digital Input Voltage, V
IH
V
DD1
= 3.3V
V
DD1
= 5.0V
Low-Level Digital Input Voltage, V
IL
Differential Input Voltage, V
ID
(Note 8)
2.4
3.0
0
-7
V
DD1
V
DD1
0.8
12
V
V
V
V
3.0
4.5
5.5
5.5
V
V
FN8949 Rev.2.00
Jan 11, 2018
Page 5 of 20
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