DATASHEET
ISL32430E, ISL32432E, ISL32433E, ISL32435E, ISL32437E
±40V Fault Protected, 3.3V to 5V, ±15V Common Mode Range, RS-485/RS-422
Transceivers With Cable Invert and ±15kV ESD
The ISL32430E through ISL32437E are 3.3V to 5V powered,
fault protected, extended common mode range differential
transceivers for balanced communication. The RS-485 bus pins
(driver outputs and receiver inputs) are protected against
overvoltages up to ±40V, and against ±15kV ESD strikes.
Additionally, these transceivers operate in environments with
common mode voltages up to ±15V (exceeds the RS-485
requirement), making this RS-485 family one of the more
robust on the market.
Transmitters are RS-485 compliant with V
CC
≥
4.5V and
deliver a 1.1V differential output voltage into the RS-485
specified 54Ω load even with V
CC
= 3V.
Receiver (Rx) inputs feature a “Full Fail-Safe” design, which
ensures a logic high Rx output if Rx inputs are floating, shorted,
or on a terminated but undriven (idle) bus. Rx full fail-safe
operation is maintained even when the Rx input polarity is
switched (cable invert function on ISL32437E).
The ISL32437E includes a cable invert function that reverses
the polarity of the Rx and Tx bus pins in case the cable is
misconnected during installation.
See Table 1 on page 2 for key features and configurations by
device number.
FN7920
Rev 0.00
Mar 1, 2012
Features
• Fault Protected RS-485 Bus Pins . . . . . . . . . . . . . . up to ±40V
• Extended Common Mode Range . . . . . . . . . . . . . . . . . . . ±15V
Larger Than Required for RS-485
• ±15kV HBM ESD Protection on RS-485 Bus Pins
• Wide Supply Range . . . . . . . . . . . . . . . . . . . . . . . . . 3V to 5.5V
• Cable Invert Pin (ISL32437E Only)
Corrects for Reversed Cable Connections While Maintaining
Rx Full Fail-safe Functionality
• 1/4 Unit Load for up to 128 Devices on the Bus
• High Transient Overvoltage Tolerance . . . . . . . . . . . . . . . ±60V
• Full Fail-safe (Open, Short, Terminated) RS-485 Receivers
• Choice of RS-485 Data Rates . . . . . . . . . . . . 250kbps or 1Mbps
• Low Quiescent Supply Current . . . . . . . . . . . . . . . . . . . 2.1mA
Ultra Low Shutdown Supply Current . . . . . . . . . . . . . . . . 10µA
• Pb-Free (RoHS Compliant)
Applications
• Utility Meters/Automated Meter Reading Systems
• Air Conditioning Systems
• Security Camera Networks
• Building Lighting and Environmental Control Systems
• Industrial/Process Control Networks
Related Literature
• See
FN7921,
“ISL32450E, ISL32452E, ISL32453E,
ISL32455E, ISL32457E: ±60V Fault Protected, 3.3V to 5V,
±20V Common Mode Range, RS-485/RS-422 Transceivers
with Cable Invert and ±15kV ESD”
20
V
CC
= 3V
15
COMMON MODE RANGE (V)
12
A
15
VOLTAGE (V)
B
10
VID = ±1V
2Mbps
0
5
RO
0
-7
-15
TIME (200ns/DIV)
STANDARD RS-485
TRANSCEIVER
ISL3243XE
FIGURE 1. EXCEPTIONAL ISL32433E RX OPERATES AT >1Mbps
EVEN WITH ±15V COMMON MODE VOLTAGE
FIGURE 2. TRANSCEIVERS DELIVER SUPERIOR COMMON MODE
RANGE vs STANDARD RS-485 DEVICES
FN7920 Rev 0.00
Mar 1, 2012
Page 1 of 21
ISL32430E, ISL32432E, ISL32433E, ISL32435E, ISL32437E
TABLE 1. SUMMARY OF FEATURES
PART
NUMBER
ISL32430E
ISL32432E
ISL32433E
ISL32435E
ISL32437E
HALF/FULL
DUPLEX
Full
Half
Full
Half
Half
DATA RATE
(Mbps)
0.25
0.25
1
1
0.25
SLEW-RATE
LIMITED?
Yes
Yes
Yes
Yes
Yes
EN
PINS?
Yes
Yes
Yes
Yes
Tx Only
HOT
PLUG
No
No
No
No
No
CABLE INVERT
(INV) PIN?
No
No
No
No
Yes
QUIESCENT I
CC
(mA)
2.1
2.1
2.1
2.1
2.1
LOW POWER
SHDN?
Yes
Yes
Yes
Yes
No
PIN COUNT
10, 14
8
10, 14
8
8
Ordering Information
PART NUMBER
(Notes 1, 2, 3)
ISL32430EIBZ
ISL32430EIUZ
ISL32432EIBZ
ISL32432EIUZ
ISL32433EIBZ
ISL32433EIUZ
ISL32435EIBZ
ISL32435EIUZ
ISL32437EIBZ
ISL32437EIUZ
NOTES:
1. Add “-T*” suffix for tape and reel. Please refer to
TB347
for details on reel specifications.
2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte
tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil
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), please see device information page for
ISL32430E, ISL32432E, ISL32433E, ISL32435E, ISL32437E.
For more
information on MSL please see tech brief
TB363.
PART
MARKING
ISL32430 EIBZ
2430E
32432 EIBZ
2432E
ISL32433 EIBZ
2433E
32435 EIBZ
2435E
32437 EIBZ
2437E
TEMP. RANGE
(°C)
-40 to +85
-40 to +85
-40 to +85
-40 to +85
-40 to +85
-40 to +85
-40 to +85
-40 to +85
-40 to +85
-40 to +85
PACKAGE
(Pb-Free)
14 Ld SOIC
10 Ld MSOP
8 Ld SOIC
8 Ld MSOP
14 Ld SOIC
10 Ld MSOP
8 Ld SOIC
8 Ld MSOP
8 Ld SOIC
8 Ld MSOP
PKG.
DWG. #
M14.15
M10.118
M8.15
M8.118
M14.15
M10.118
M8.15
M8.118
M8.15
M8.118
Pin Configurations
ISL32430E, ISL32433E
(14 LD SOIC)
TOP VIEW
NC 1
RO 2
RE 3
DE 4
DI 5
GND 6
GND 7
D
R
14 V
CC
13 NC
12 A
11 B
10 Z
9 Y
8 NC
ISL32430E, ISL32433E
(10 LD MSOP)
TOP VIEW
RO 1
RE 2
DE 3
DI 4
GND 5
D
R
10 V
CC
9 A
8 B
7 Z
6 Y
FN7920 Rev 0.00
Mar 1, 2012
Page 2 of 21
ISL32430E, ISL32432E, ISL32433E, ISL32435E, ISL32437E
Pin Configurations
(Continued)
ISL32432E, ISL32435E
(8 LD SOIC, 8 LD MSOP)
TOP VIEW
RO 1
RE 2
DE 3
DI 4
D
8
7
6
5
V
CC
B/Z
A/Y
GND
ISL32437E
(8 LD SOIC, 8 LD MSOP)
TOP VIEW
RO 1
INV 2
DE 3
DI 4
D
8
7
6
5
V
CC
B/Z
A/Y
GND
R
R
Truth Tables
TRANSMITTING
INPUTS
RE
X
X
X
X
0
1
NOTES:
4. Parts without the INV pin follow the rows with INV = “0” and “X”.
*Low Power Shutdown Mode (See Notes 13 and 18).
DE
1
1
1
1
0
0
DI
1
0
1
0
X
X
INV (Note 4)
0
0
1
1
X
X
Y
1
0
0
1
High-Z
High-Z*
OUTPUTS
Z
0
1
1
0
High-Z
High-Z*
1
1
0
1
0
1
RE
(Note 18)
0
0
0
0
0
DE (Half
Duplex)
0
0
0
0
0
RECEIVING
INPUTS
DE (Full
Duplex)
X
X
X
X
X
A-B
-0.01V
-0.2V
0.01V
0.2V
Inputs
Open or
Shorted
X
X
INV (Note 4)
0
0
1
1
X
OUTPUT
RO
1
0
1
0
1
X
X
High-Z*
High-Z
NOTE: *Low Power Shutdown Mode (See Notes 13 and 18).
Pin Descriptions
PIN NUMBER
PIN
NAME
RO
ISL32430E, ISL32430E,
ISL32433E, ISL32433E, ISL32432E,
14 LD SOIC 10 LD MSOP ISL32435E ISL32437E
2
1
1
1
FUNCTION
Receiver output. For parts without the cable invert function - or if INV is low - then: If
A - B
-10mV, RO is high; if A - B
-200mV, RO is low. If INV is high, then: If B - A
-10mV,
RO is high; if B - A
-200mV, RO is low. In all cases, RO = High if A and B are unconnected
(floating), or shorted together, or connected to an undriven, terminated bus (i.e., Rx is
always failsafe open, shorted, and idle, even if polarity is inverted).
Receiver output enable. RO is enabled when RE is low; RO is high impedance when RE
is high. Internally pulled low.
Driver output enable. The driver outputs, Y and Z, are enabled by bringing DE high, and
they are high impedance when DE is low. Internally pulled high.
Driver input. For parts without the cable invert function - or if INV is low - a low on DI
forces output Y low and output Z high, while a high on DI forces output Y high and
output Z low. The output states, relative to DI, invert if INV is high.
Ground connection.
±40V Fault Protected and ±15kV ESD protected RS-485/RS-422 I/O pin. For parts
without the cable invert function - or if INV is low - A/Y is the non-inverting receiver input
and non-inverting driver output. If INV is high, A/Y is the inverting receiver input and
the inverting driver output. Pin is an input if DE = 0; pin is an output if DE = 1.
RE
DE
DI
3
4
5
2
3
4
2
3
4
N/A
3
4
GND
A/Y
6, 7
N/A
5
N/A
5
6
5
6
FN7920 Rev 0.00
Mar 1, 2012
Page 3 of 21
ISL32430E, ISL32432E, ISL32433E, ISL32435E, ISL32437E
Pin Descriptions
(Continued)
PIN NUMBER
PIN
NAME
B/Z
ISL32430E, ISL32430E,
ISL32433E, ISL32433E, ISL32432E,
14 LD SOIC 10 LD MSOP ISL32435E ISL32437E
N/A
N/A
7
7
FUNCTION
±40V Fault Protected and ±15kV ESD protected RS-485/RS-422 I/O pin. For parts
without the cable invert function - or if INV is low - B/Z is the inverting receiver input and
inverting driver output. If INV is high, B/Z is the non-inverting receiver input and the
non-inverting driver output. Pin is an input if DE = 0; pin is an output if DE = 1.
±40V Fault Protected and ±15kV ESD protected RS-485/RS-422 non-inverting
receiver input.
±40V Fault Protected and ±15kV ESD protected RS-485/RS-422 inverting receiver
input.
±40V Fault Protected and ±15kV ESD protected RS-485/RS-422 non-inverting driver
output.
±40V Fault Protected and ±15kV ESD protected RS-485/RS-422 inverting driver
output.
System power supply input (3V to 5.5V).
Receiver and driver Cable Invert (polarity selection) input. When driven high this pin
swaps the polarity of the driver output and receiver input pins. If unconnected
(floating) or connected low, normal RS-485 polarity conventions apply. Internally
pulled low.
No Internal Connection.
A
B
Y
Z
V
CC
INV
12
11
9
10
14
N/A
9
8
6
7
10
N/A
N/A
N/A
N/A
N/A
8
N/A
N/A
N/A
N/A
N/A
8
2
NC
1, 8, 13
N/A
N/A
N/A
FN7920 Rev 0.00
Mar 1, 2012
Page 4 of 21
ISL32430E, ISL32432E, ISL32433E, ISL32435E, ISL32437E
Typical Operating Circuits
ISL32430E, ISL32433E FULL DUPLEX NETWORK
+3.3V
+
14
V
CC
2 RO
3 RE
4 DE
5 DI
Z 10
D
Y 9
GND
6, 7
SOIC PINOUT SHOWN
R
T
11 B
12 A
R
GND
6, 7
R
A 12
B 11
0.1µF
R
T
0.1µF
+
14
9 Y V
CC
10 Z
D
DI 5
DE 4
RE 3
RO 2
+3.3V
ISL32432E, ISL32435E HALF DUPLEX NETWORK
+3.3V
8
V
CC
1 RO
2 RE
3 DE
4 DI
D
GND
5
GND
5
R
B/Z
A/Y
7
6
R
T
R
T
7
6
B/Z
A/Y
R
+
0.1µF
0.1µF
+
+3.3V
8
V
CC
D
DI 4
DE 3
RE 2
RO 1
ISL32437E HALF DUPLEX NETWORK USING CABLE INVERT FUNCTION
+3.3V
+
8
2
INV
1 RO
V
CC
R
R
T
0.1µF
0.1µF
+
8
V
CC
R
RO 1
+3.3V
A/Y
B/Z
6
7
R
T
7
6
B/Z
A/Y
3 DE
4 DI
D
GND
5
THE IC ON THE LEFT HAS THE CABLE CONNECTIONS
SWAPPED, SO THE INV PIN IS STRAPPED HIGH TO
INVERT THE RX AND TX POLARITY
GND
5
D
DE 3
DI 4
INV
2
FN7920 Rev 0.00
Mar 1, 2012
Page 5 of 21