±60V Fault Protected, 3.3V to 5V, ±20V Common Mode
Range, RS-485/RS-422 Transceivers with Cable Invert
and ±15kV ESD
ISL32450E, ISL32452E, ISL32453E, ISL32455E, ISL32457E
The ISL32450E through ISL32457E are 3.3V to 5V powered, fault
Features
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
±60V, and against ±15kV ESD strikes. These transceivers operate
in environments with common mode voltages up to ±20V
(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 ISL32457E).
The ISL32457E 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.
• Fault Protected RS-485 Bus Pins . . . . . . . . . . . . . . Up to ±60V
• Extended Common Mode Range . . . . . . . . . . . . . . . . . . . ±20V
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 (ISL32457E 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 . . . . . . . . . . . . . . . ±80V
• 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
FN7784,
“ISL32470E, ISL32472E, ISL32475E,
ISL32478E: Fault Protected, Extended Common Mode Range,
RS-485/RS-422 Transceivers with ±16.5kV ESD”
20
B
VOLTAGE (V)
15
10
5
RO
0
VID = ±1V
2Mbps
COMMON MODE RANGE (V)
A
V
CC
= 3V
20
12
0
-7
-20
TIME (200ns/DIV)
STANDARD RS-485
TRANSCEIVER
ISL3245XE
FIGURE 1. EXCEPTIONAL ISL32453E RX OPERATES AT >1Mbps
EVEN WITH ±20V COMMON MODE VOLTAGE
FIGURE 2. TRANSCEIVERS DELIVER SUPERIOR COMMON MODE
RANGE vs STANDARD RS-485 DEVICES
February 20, 2012
FN7921.0
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774
|
Copyright Intersil Americas Inc. 2012. All Rights Reserved
Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries.
All other trademarks mentioned are the property of their respective owners.
ISL32450E, ISL32452E, ISL32453E, ISL32455E, ISL32457E
TABLE 1. SUMMARY OF FEATURES
PART
NUMBER
ISL32450E
ISL32452E
ISL32453E
ISL32455E
ISL32457E
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)
ISL32450EIBZ
ISL32450EIUZ
ISL32452EIBZ
ISL32452EIUZ
ISL32453EIBZ
ISL32453EIUZ
ISL32455EIBZ
ISL32455EIUZ
ISL32457EIBZ
ISL32457EIUZ
NOTES:
1. Add “-T*” suffix for tape and reel. Please refer to Tech Brief
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 pages for
ISL32450E
,
ISL32452E, ISL32453E, ISL32455E, ISL32457E.
For more
information on MSL please see Tech Brief
TB363.
PART
MARKING
ISL32450 EIBZ
2450E
32452 EIBZ
2452E
ISL32453 EIBZ
2453E
32455 EIBZ
2455E
32457 EIBZ
2457E
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
2
FN7921.0
February 20, 2012
ISL32450E, ISL32452E, ISL32453E, ISL32455E, ISL32457E
Pin Configurations
ISL32450E, ISL32453E
(14 LD SOIC)
TOP VIEW
NC 1
RO 2
RE 3
DE 4
DI
5
D
R
14 V
CC
13 NC
12 A
11 B
10 Z
9 Y
8 NC
ISL32450E, ISL32453E
(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
GND 6
GND 7
ISL32452E, ISL32455E
(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
ISL32457E
(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
NOTE: Evaluate creepage and clearance requirements at your maximum fault voltage before using small pitch packages (e.g., MSOP).
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”.
5. Low Power Shutdown Mode (see Notes 14 and 19).
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
(Note 5)
OUTPUTS
Z
0
1
1
0
High-Z
High-Z
(Note 5)
RE
(Note 19)
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
1
1
0
1
0
1
X
X
High-Z
(Note 5)
High-Z
3
FN7921.0
February 20, 2012
ISL32450E, ISL32452E, ISL32453E, ISL32455E, ISL32457E
Pin Descriptions
PIN
NAME
RO
ISL32450E,
ISL32450E,
ISL32453E,
ISL32453E,
(14 LD SOIC) (10 LD MSOP)
PIN #
PIN #
2
1
ISL32452E,
ISL32455E
(8 LD SOIC,
8 LD MSOP)
PIN #
1
ISL32457E
(8 LD SOIC,
8 LD MSOP)
PIN #
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.
±60V 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.
±60V 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.
±60V Fault Protected and ±15kV ESD protected RS-485/RS-422 non-inverting
receiver input.
±60V Fault Protected and ±15kV ESD protected RS-485/RS-422 inverting
receiver input.
±60V Fault Protected and ±15kV ESD protected RS-485/RS-422 non-inverting
driver output.
±60V 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.
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
B/Z
N/A
N/A
7
7
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
4
FN7921.0
February 20, 2012
ISL32450E, ISL32452E, ISL32453E, ISL32455E, ISL32457E
Typical Operating Circuits
+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
ISL32450E, ISL32453E FULL 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
ISL32452E, ISL32455E HALF DUPLEX NETWORK
+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
ISL32457E HALF DUPLEX NETWORK USING CABLE INVERT FUNCTION
5
FN7921.0
February 20, 2012
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