Fault Protected, Extended CMR, RS-485/RS-422
Transceivers with Cable Invert
ISL31480E, ISL31483E, ISL31485E, ISL31486E
The ISL3148xE are fault protected, 5V powered differential
Features
transceivers that exceed the RS-485 and RS-422 standards for
balanced communication. The RS-485 transceiver pins (driver
outputs and receiver inputs) are fault protected up to ±60V.
Additionally, the extended common mode range allows these
transceivers to operate in environments with common mode
voltages up to ±25V (>2X the RS-485 requirement), making this
fault protected RS-485 family one of the most robust on the
market.
Transmitters deliver an exceptional 2.5V (typical) differential
output voltage into the RS-485 specified 54Ω load. This yields
better noise immunity than standard RS-485 ICs, or allows up to
six 120Ω terminations in star network topologies.
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.
The ISL31483E, ISL31485E and ISL31486E include cable invert
functions that reverse the polarity of the Rx and/or Tx bus pins in
case the cable is misconnected. Unlike competing devices, Rx full
fail-safe operation is maintained even when the Rx input polarity is
switched.
The ISL31480E and ISL31486E feature a logic supply (V
L
) pin
that sets the V
OH
of the Rx outputs, and the switching points of
the logic input pins, to be compatible with a lower supply voltage
(down to 1.8V) in mixed voltage systems. 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 . . . . . . . . . . . . . . . . . . . ±25V
More Than Twice the Range Required for RS-485
• Cable Invert Pins (Except ISL31480)
Corrects for Reversed Cable Connections While Maintaining Rx
Full Fail-safe Functionality
• Logic Supply (V
L
) Pin (ISL31480E, ISL31486E)
Simplifies Interface to Lower Voltage Logic Devices
• Full Fail-safe (Open, Short, Terminated) RS-485 Receivers
• 1/4 Unit Load (UL) for up to 128 Devices on the Bus
• High Rx I
OL
for Opto-Couplers in Isolated Designs
• Hot Plug Circuitry - Tx and Rx Outputs Remain Three-State
During Power-up/Power-down
• Slew Rate Limited RS-485 Data Rate . . . . . . . . . . . . . 1Mbps
• Low Quiescent Supply Current . . . . . . . . . . . . . . . . . . . 2.3mA
Ultra Low Shutdown Supply Current . . . . . . . . . . . . . . . 10µA
Applications
• Utility Meters/Automated Meter Reading Systems
• High Node Count RS-485 Systems
• PROFIBUS® and RS-485 Based Field Bus Networks, and
Factory Automation
• Security Camera Networks
• Building Lighting and Environmental Control Systems
• Industrial/Process Control Networks
30
B
25
20
VOLTAGE (V)
15
10
5
RO
0
-5
TIME (400ns/DIV)
A
VID = ±1V
25
COMMON MODE RANGE
12
0
-7
-12
-20
-25
STANDARD RS-485
TRANSCEIVER
CLOSEST
COMPETITOR
ISL3148XE
FIGURE 1. EXCEPTIONAL Rx OPERATES AT 1Mbps EVEN WITH
±25V COMMON MODE VOLTAGE
FIGURE 2. TRANSCEIVERS DELIVER SUPERIOR COMMON
MODE RANGE vs. STANDARD RS-485 DEVICES
January 20, 2011
FN7638.2
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. 2010, 2011. 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.
ISL31480E, ISL31483E, ISL31485E, ISL31486E
TABLE 1. SUMMARY OF FEATURES
PART
NUMBER
Coming Soon
ISL31480E
ISL31483E
ISL31485E
Coming Soon
ISL31486E
HALF/FULL
DUPLEX
Half
Full
Half
Half
DATA RATE
(Mbps)
1
1
1
1
SLEW-RATE
LIMITED?
Yes
Yes
Yes
Yes
EN
PINS?
Yes
Yes
Tx Only
Yes
HOT
PLUG
Yes
Yes
Yes
Yes
POLARITY
REVERSAL
PINS?
No
Yes
Yes
Yes
QUIESCENT I
CC
(mA)
2.3
2.3
2.3
2.3
LOW
POWER
SHDN?
Yes
Yes
No
Yes
V
L
PIN?
Yes
No
No
Yes
PIN COUNT
10
14
8
10, 12, 14
Ordering Information
PART NUMBER
(Notes 1, 2, 3)
Coming Soon
ISL31480EIRTZ
Coming Soon
ISL31480EIUZ
ISL31483EIBZ
ISL31485EIBZ
Coming Soon
ISL31486EIBZ
Coming Soon
ISL31486EIRTZ
Coming Soon
ISL31486EIUZ
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 ISL31480E,
ISL31483E, ISL31485E,
and ISL31486E. For more
information on MSL please see techbrief
TB363.
480E
1480E
ISL31483 EIBZ
31485 EIBZ
ISL31486 EIBZ
486E
1486E
PART
MARKING
TEMP. RANGE
(°C)
-40 to +85
-40 to +85
-40 to +85
-40 to +85
-40 to +85
-40 to +85
-40 to +85
PACKAGE
(Pb-Free)
10 Ld TDFN
10 Ld MSOP
14 Ld SOIC
8 Ld SOIC
14 Ld SOIC
12 Ld TDFN
10 Ld MSOP
PKG.
DWG. #
L10.3x3A
M10.118
M14.15
M8.15
M14.15
L12.4x3A
M10.118
2
FN7638.2
ISL31480E, ISL31483E, ISL31485E, ISL31486E
Pin Configurations
ISL31483E
(14 LD SOIC)
TOP VIEW
RINV 1
RO 2
RE 3
DE 4
DI 5
GND 6
GND 7
D
R
14 V
CC
13 V
CC
12 A
11 B
10 Z
9 Y
8 DINV
RO 1
INV 2
DE 3
DI 4
D
ISL31485E
(8 LD SOIC)
TOP VIEW
R
8
7
6
5
V
CC
B/Z
A/Y
GND
Pin Descriptions
PIN
NAME
RO
ISL31480E
PIN #
2
ISL31483E
PIN #
2
ISL31485E
PIN #
1
ISL31486E
(12 LD)
PIN #
1
ISL31486E
(10 LD)
PIN #
1
ISL31486E
(14 LD)
PIN #
1
FUNCTION
Receiver output. On the ISL31480E, or if
INV or RINV is low, then: If
A - B
≥
-10mV, RO is high; if A - B
≤
-200mV,
RO is low. If INV or RINV 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 (to V
L
on
ISL31480E and ISL31486E; to V
CC
on
other versions).
Driver input. On the ISL31480E, or if INV or
DINV 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 or
DINV is high.
Ground connection.This is also the
potential of the TDFN EPAD.
±60V Fault Protected RS-485/RS-422
level I/O pin. On the ISL31480E, 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
4
3
N/A
2
2
2
DE
3
4
3
4
4
4
DI
5
5
4
5
5
6
GND
A/Y
6
8
6, 7
N/A
5
6
7, 8
9
6
7
8, 9
11
3
FN7638.2
ISL31480E, ISL31483E, ISL31485E, ISL31486E
Pin Descriptions
(Continued)
PIN
NAME
B/Z
ISL31480E
PIN #
9
ISL31483E
PIN #
N/A
ISL31485E
PIN #
7
ISL31486E
(12 LD)
PIN #
10
ISL31486E
(10 LD)
PIN #
8
ISL31486E
(14 LD)
PIN #
12
FUNCTION
±60V Fault Protected RS-485/RS-422
level I/O pin. On the ISL31480E, 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 RS-485/RS-422
level input. If RINV is low, then A is the non-
inverting receiver input. If RINV is high,
then A is the inverting receiver input.
±60V Fault Protected RS-485/RS-422
level input. If RINV is low, then B is the
inverting receiver input. If RINV is high,
then B is the non-inverting receiver input.
±60V Fault Protected RS-485/RS-422
level output. If DINV is low, then Y is the
non-inverting driver output. If DINV is
high, then Y is the inverting driver output
±60V Fault Protected RS-485/RS-422
level. If DINV is low, then Z is the inverting
driver output. If DINV is high, then Z is the
non-inverting driver output
System power supply input (4.5V to 5.5V).
Logic-Level Supply input (1.62V to V
CC
)
which powers all the TTL/CMOS inputs and
the RO output (logic pins). V
L
sets the V
IH
and V
IL
levels for logic input pins, and sets
the V
OH
level for the RO pin. Power up this
supply after V
CC
, and keep V
L
≤
V
CC
. To
minimize input current, logic input pins that
are strapped high externally should connect
to V
L
, but they may be connected to V
CC
if
necessary.
Receiver and driver 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.
Receiver polarity selection input. When
driven high this pin swaps the polarity of the
receiver input pins. If unconnected (floating)
or connected low, normal RS-485 polarity
conventions apply. Internally pulled low.
Driver polarity selection input. When driven
high this pin swaps the polarity of the driver
output pins. If unconnected (floating) or
connected low, normal RS-485 polarity
conventions apply. Internally pulled low.
TDFN exposed thermal pad (EPAD).
Connect to GND.
No Internal Connection.
A
N/A
12
N/A
N/A
N/A
N/A
B
N/A
11
N/A
N/A
N/A
N/A
Y
N/A
9
N/A
N/A
N/A
N/A
Z
N/A
10
N/A
N/A
N/A
N/A
V
CC
V
L
10
1
13, 14
N/A
8
N/A
11
12
9
10
13
14
INV
N/A
N/A
2
3
3
3
RINV
N/A
1
N/A
N/A
N/A
N/A
DINV
N/A
8
N/A
N/A
N/A
N/A
PD
NC
TDFN
ONLY
7
N/A
N/A
N/A
N/A
EPAD
6
N/A
N/A
N/A
5, 7, 10
4
FN7638.2
ISL31480E, ISL31483E, ISL31485E, ISL31486E
Truth Tables
TRANSMITTING
INPUTS
RE
X
X
X
X
0
1
DE
1
1
1
1
0
0
DI
1
0
1
0
X
X
INV or DINV
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
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 or
RINV
0
0
1
1
X
OUTPUT
RO
1
0
1
0
1
NOTE: *Low Power Shutdown Mode (See Note 13), except for
ISL31485E.
X
X
High-Z*
High-Z
NOTE: *Low Power Shutdown Mode (See Note 13), except for
ISL31485E.
Typical Operating Circuits
ISL31486E HALF DUPLEX EXAMPLE (MSOP PIN NUMBERS SHOWN)
+1.8V
0.1µF
+
10
V
L
INV
1 RO
3
2 RE
4 DE
5 DI
D
GND
6
GND
6
D
9
V
CC
R
R
T
+5V
+
0.1µF
0.1µF
+
9
V
CC
R
10
V
L
RO 1
RE 2
DE 4
DI
5
3
+5V
+1.8V
+
0.1µF
A/Y
B/Z
7
8
R
T
8
B/Z
7 A/Y
INV
THE IC ON THE LEFT HAS THE CABLE CONNECTIONS
SWAPPED, SO THE INV PIN IS STRAPPED HIGH TO
INVERT ITS RX AND TX POLARITY
5
FN7638.2
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