DATASHEET
ISL8487E, ISL81487L, ISL81487E
±15kV ESD Protected, 1/8 Unit Load, 5V, Low Power, High Speed or Slew Rate
Limited, RS-485/RS-422 Transceivers
FN6051
Rev.7.00
February 27, 2006
15kV ESD Protected, 1/8 Unit Load, 5V,
Low Power, High Speed or Slew Rate
Limited, RS-485/RS-422 Transceivers
These Intersil RS-485/RS-422 devices are ESD protected,
fractional unit load (UL), BiCMOS, 5V powered, single
transceivers that meet both the RS-485 and RS-422
standards for balanced communication. Each driver output/
receiver input is protected against ±15kV ESD strikes,
without latch-up. Unlike competitive devices, this Intersil
family is specified for 10% tolerance supplies (4.5V to 5.5V).
All devices present a 1/8 “unit load” to the RS-485 bus,
which allows up to 256 transceivers on the network for large
node count systems (e.g., process automation, remote
meter reading systems). In a remote utility meter reading
system, individual (apartments for example) utility meter
readings are routed to a concentrator via an RS-485
network, so the high allowed node count minimizes the
number of repeaters required to network all the meters. Data
for all meters is then read out from the concentrator via a
single access port, or a wireless link.
Slew rate limited drivers on the ISL8487E and ISL81487L
reduce EMI, and minimize reflections from improperly
terminated transmission lines, or unterminated stubs in
multidrop and multipoint applications. Data rates up to
250kbps are achievable with these devices.
Data rates up to 5Mbps are achievable by using the
ISL81487E, which features higher slew rates.
Receiver (Rx) inputs feature a “fail-safe if open” design,
which ensures a logic high Rx output if Rx inputs are floating.
Driver (Tx) outputs are short circuit protected, even for
voltages exceeding the power supply voltage. Additionally,
on-chip thermal shutdown circuitry disables the Tx outputs to
prevent damage if power dissipation becomes excessive.
These half duplex devices multiplex the Rx inputs and Tx
outputs to allow transceivers with Rx and Tx disable
functions in 8 lead packages.
Features
• RS-485 I/O Pin ESD Protection . . . . . . . . . . ±15kV HBM
- Class 3 ESD Level on all Other Pins . . . . . . >7kV HBM
• Fractional Unit Load Allows up to 256 Devices on the Bus
• Specified for 10% Tolerance Supplies
• High Data Rate Version (ISL81487E) . . . . . up to 5Mbps
• Slew Rate Limited Versions for Error Free Data
Transmission (ISL8487E, ISL81487L) . . . . .up to 250kbps
• Low Current Shutdown Mode (Except ISL81487E). . . 0.5
A
• Low Quiescent Supply Current:
- ISL8487E, ISL81487L . . . . . . . . . . . . . . . 145
A (Max.)
- ISL81487E . . . . . . . . . . . . . . . . . . . . . . . . 420
A (Max.)
• -7V to +12V Common Mode Input Voltage Range
• Three State Rx and Tx Outputs
• 30ns Propagation Delays, 5ns Skew (ISL81487E)
• Half Duplex Pinouts
• Operate from a Single +5V Supply (10% Tolerance)
• Current Limiting and Thermal Shutdown for Driver
Overload Protection
• Pin Compatible Replacements for: MAX487E, (ISL8487E);
LTC1487, ADM1487 (ISL81487L); MAX1487E, ST485ER
(ISL81487E)
• Pb-Free Plus Anneal Available (RoHS Compliant)
Applications
• High Node Count Networks
• Automated Utility Meter Reading Systems
• Factory Automation
• Security Networks
• Building Environmental Control Systems
• Industrial/Process Control Networks
TABLE 1. SUMMARY OF FEATURES
PART
NUMBER
ISL8487E
ISL81487L
ISL81487E
HALF/FULL
DUPLEX
Half
Half
Half
NO. OF DEVICES
DATA RATE
ALLOWED ON BUS
(Mbps)
256
256
256
0.25
0.25
5
SLEW-RATE
LIMITED?
Yes
Yes
No
RECEIVER/
QUIESCENT LOW POWER
PIN
DRIVER ENABLE?
I
CC
(A)
SHUTDOWN? COUNT
Yes
Yes
Yes
120
120
350
Yes
Yes
No
8
8
8
FN6051 Rev.7.00
February 27, 2006
Page 1 of 14
ISL8487E, ISL81487L, ISL81487E
Pinout
ISL8487E, ISL81487L, ISL81487E (PDIP, SOIC)
TOP VIEW
Truth Tables
TRANSMITTING
INPUTS
RO 1
RE 2
DE 3
DI 4
D
R
8
7
6
5
V
CC
B/Z
A/Y
GND
OUTPUTS
DI
1
0
X
X
Z
0
1
High-Z
High-Z *
Y
1
0
High-Z
High-Z *
RE
X
X
0
1
DE
1
1
0
0
Ordering Information
PART NO.
(BRAND)
ISL8487EIB*
ISL8487EIBZ*
(Note)
ISL8487EIP
ISL8487EIPZ
(Note)
ISL81487LIB*
PART
MARKING
8487EIB
8487EIBZ
ISL8487EIP
8487EIPZ
81487LIB
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
-40 to 85
-40 to 85
PKG.
PACKAGE DWG. #
8 Ld SOIC
8 Ld SOIC
(Pb-free)
8 Ld PDIP
M8.15
M8.15
E8.3
*Shutdown Mode for ISL8487E, ISL81487L (See Note 7)
RECEIVING
INPUTS
RE
0
0
0
1
1
DE
0
0
0
0
1
A-B
+0.2V
-0.2V
Inputs Open
X
X
OUTPUT
RO
1
0
1
High-Z *
High-Z
8 Ld PDIP** E8.3
(Pb-free)
8 Ld SOIC
8 Ld SOIC
(Pb-free)
8 Ld PDIP
M8.15
M8.15
E8.3
ISL81487LIBZ* 81487LIBZ
(Note)
ISL81487LIP
ISL81487LIPZ
(Note)
ISL81487EIB*
ISL81487LIP
81487LIPZ
81487EIB
*Shutdown Mode for ISL8487E, ISL81487L (See Note 7)
8 Ld PDIP** E8.3
(Pb-free)
8 Ld SOIC
8 Ld SOIC
(Pb-free)
8 Ld PDIP
M8.15
M8.15
E8.3
ISL81487EIBZ* 81487EIBZ
(Note)
ISL81487EIP
ISL81487EIP
ISL81487EIPZ ISL81487EIPZ
(Note)
8 Ld PDIP** E8.3
(Pb-free)
*Add “-T” suffix to part number for tape and reel packaging.
**Pb-free PDIPs can be used for through hole wave solder
processing only. They are not intended for use in Reflow solder
processing applications.
NOTE: Intersil 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. 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.
FN6051 Rev.7.00
February 27, 2006
Page 2 of 14
ISL8487E, ISL81487L, ISL81487E
Pin Descriptions
PIN
RO
RE
DE
DI
GND
A/Y
B/Z
V
CC
FUNCTION
Receiver output: If A > B by at least 0.2V, RO is high; If A < B by 0.2V or more, RO is low; RO = High if A and B are unconnected (floating).
Receiver output enable. RO is enabled when RE is low; RO is high impedance when RE is high.
Driver output enable. The driver outputs, Y and Z, are enabled by bringing DE high. They are high impedance when DE is low.
Driver input. A low on DI forces output Y low and output Z high. Similarly, a high on DI forces output Y high and output Z low.
Ground connection.
15kV
HBM ESD Protected, RS-485/422 level, noninverting receiver input and non-inverting driver output. Pin is an input (A) if
DE = 0; pin is an output (Y) if DE = 1.
15kV
HBM ESD Protected, RS-485/422 level, inverting receiver input and inverting driver output. Pin is an input (B) if DE = 0; pin is
an output (Z) if DE = 1.
System power supply input (4.5V to 5.5V).
Typical Operating Circuits
ISL8487E, ISL81487L, ISL81487E
+5V
+
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
0.1F
0.1F
+
8
V
CC
D
DI 4
DE 3
RE 2
RO 1
+5V
FN6051 Rev.7.00
February 27, 2006
Page 3 of 14
ISL8487E, ISL81487L, ISL81487E
Absolute Maximum Ratings
V
CC
to Ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7V
Input Voltages
DI, DE, RE . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to (V
CC
+0.5V)
Input/Output Voltages
A/Y, B/Z . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -8V to +12.5V
RO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to (V
CC
+0.5V)
Short Circuit Duration
Y, Z . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Continuous
ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . See Specification Table
Thermal Information
Thermal Resistance (Typical, Note 1)
JA
(°C/W)
8 Ld SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . .
170
8 Ld PDIP Package* . . . . . . . . . . . . . . . . . . . . . . . .
140
Maximum Junction Temperature (Plastic Package) . . . . . . . 150°C
Maximum Storage Temperature Range . . . . . . . . . . . -65°C to 150°C
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . 300°C
(SOIC - Lead Tips Only)
*Pb-free PDIPs can be used for through hole wave solder processing
only. They are not intended for use in Reflow solder processing
applications.
Operating Conditions
Temperature Range
ISL8XXXIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-40°C to 85°C
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTE:
1.
JA
is measured with the component mounted on a low effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
Electrical Specifications
(
Test Conditions: V
CC
= 4.5V to 5.5V; Unless Otherwise Specified.
Typicals are at V
CC
= 5V, T
A
= 25°C, (Note 2)
SYMBOL
TEST CONDITIONS
TEMP
(°C)
MIN
TYP
MAX
UNITS
PARAMETER
DC CHARACTERISTICS
Driver Differential V
OUT
(no load)
Driver Differential V
OUT
(with load)
Change in Magnitude of Driver
Differential V
OUT
for
Complementary Output States
Driver Common-Mode V
OUT
Change in Magnitude of Driver
Common-Mode V
OUT
for
Complementary Output States
Logic Input High Voltage
Logic Input Low Voltage
Logic Input Current
Input Current (A/Y, B/Z), (Note 10)
V
OD1
V
OD2
V
OD
R = 50 (RS-422), (Figure 1)
R = 27 (RS-485), (Figure 1)
R = 27 or 50, (Figure 1)
Full
Full
Full
Full
-
2
1.5
-
-
3
2.3
0.01
V
CC
-
5
0.2
V
V
V
V
V
OC
V
OC
R = 27 or 50, (Figure 1)
R = 27 or 50, (Figure 1)
Full
Full
-
-
-
0.01
3
0.2
V
V
V
IH
V
IL
I
IN1
I
IN2
I
IN2
DE, DI, RE
DE, DI, RE
DE, DI, RE
DE = 0V, V
CC
= 4.5 to
5.5V
DE = 0V, V
CC
= 0V
-7V
V
CM
12V
V
CM
= 0V
I
O
= -4mA, V
ID
= 200mV
I
O
= -4mA, V
ID
= 200mV
0.4V
V
O
2.4V
-7V
V
CM
12V
V
IN
= 12V
V
IN
= -7V
V
IN
= 12V
V
IN
= -7V
Full
Full
Full
Full
Full
Full
Full
Full
25
Full
Full
Full
Full
2
-
-2
-
-
-
-
-0.2
-
3.5
-
-
96
-
-
-
-
-
-
-
-
70
-
-
-
-
-
0.8
2
140
-120
180
-100
0.2
-
-
0.4
1
-
V
V
A
A
A
A
A
V
mV
V
V
A
k
Receiver Differential Threshold
Voltage
Receiver Input Hysteresis
Receiver Output High Voltage
Receiver Output Low Voltage
Three-State (high impedance)
Receiver Output Current
Receiver Input Resistance
V
TH
V
TH
V
OH
V
OL
I
OZR
R
IN
FN6051 Rev.7.00
February 27, 2006
Page 4 of 14
ISL8487E, ISL81487L, ISL81487E
Electrical Specifications
Test Conditions: V
CC
= 4.5V to 5.5V; Unless Otherwise Specified.
Typicals are at V
CC
= 5V, T
A
= 25°C, (Note 2)
(Continued)
SYMBOL
I
CC
TEST CONDITIONS
ISL81487E, DI, RE = 0V DE = V
CC
or V
CC
DE = 0V
ISL8487E, ISL81487L,
DI, RE = 0V or V
CC
Shutdown Supply Current
Driver Short-Circuit Current,
V
O
= High or Low
Receiver Short-Circuit Current
I
SHDN
I
OSD1
I
OSR
t
PLH
, t
PHL
t
SKEW
t
R
, t
F
t
ZH
t
ZL
t
HZ
t
LZ
t
PLH
, t
PHL
t
SKD
t
ZH
t
ZL
t
HZ
t
LZ
f
MAX
t
PLH
, t
PHL
t
SKEW
t
R
, t
F
t
ZH
t
ZL
t
HZ
t
LZ
t
PLH
, t
PHL
t
SKD
t
ZH
t
ZL
t
HZ
t
LZ
f
MAX
t
SHDN
t
ZH(SHDN)
t
ZL(SHDN)
(Note 7)
C
L
= 100pF, SW = GND, (Figure 3, Notes 7, 8)
C
L
= 100pF, SW = V
CC
, (Figure 3, Notes 7, 8)
R
DIFF
= 54, C
L
= 100pF, (Figure 2)
R
DIFF
= 54, C
L
= 100pF, (Figure 2)
R
DIFF
= 54, C
L
= 100pF, (Figure 2)
C
L
= 100pF, SW = GND, (Figure 3, Note 5)
C
L
= 100pF, SW = V
CC
, (Figure 3, Note 5)
C
L
= 15pF, SW = GND, (Figure 3)
C
L
= 15pF, SW = V
CC
, (Figure 3)
(Figure 4)
(Figure 4)
C
L
= 15pF, SW = GND, (Figure 5, Note 6)
C
L
= 15pF, SW = V
CC
, (Figure 5, Note 6)
C
L
= 15pF, SW = GND, (Figure 5)
C
L
= 15pF, SW = V
CC
, (Figure 5)
DE = V
CC
DE = 0V
TEMP
(°C)
Full
Full
Full
Full
Full
Full
Full
MIN
-
-
-
-
-
35
7
TYP
400
350
160
120
0.5
-
-
MAX
500
420
200
145
8
250
85
UNITS
A
A
A
A
A
mA
mA
PARAMETER
No-Load Supply Current, (Note 3)
(Note 7), DE = 0V, RE = V
CC
, DI = 0V or V
CC
DE = V
CC
, -7V
V
Y
or V
Z
12V, (Note 4)
0V
V
O
V
CC
R
DIFF
= 54, C
L
= 100pF, (Figure 2)
R
DIFF
= 54, C
L
= 100pF, (Figure 2)
R
DIFF
= 54, C
L
= 100pF, (Figure 2)
C
L
= 100pF, SW = GND, (Figure 2)
C
L
= 100pF, SW = V
CC
, (Figure 2)
C
L
= 15pF, SW = GND, (Figure 2)
C
L
= 15pF, SW = V
CC
, (Figure 2)
(Figure 4)
(Figure 4)
C
L
= 15pF, SW = GND, (Figure 5)
C
L
= 15pF, SW = V
CC
, (Figure 5)
C
L
= 15pF, SW = GND, (Figure 5)
C
L
= 15pF, SW = V
CC
, (Figure 5)
SWITCHING CHARACTERISTICS (ISL81487E)
Driver Input to Output Delay
Driver Output Skew
Driver Differential Rise or Fall Time
Driver Enable to Output High
Driver Enable to Output Low
Driver Disable from Output High
Driver Disable from Output Low
Receiver Input to Output Delay
Receiver Skew | t
PLH
- t
PHL
|
Receiver Enable to Output High
Receiver Enable to Output Low
Receiver Disable from Output High
Receiver Disable from Output Low
Maximum Data Rate
Full
Full
Full
Full
Full
Full
Full
Full
25
Full
Full
Full
Full
Full
15
-
3
-
-
-
-
30
-
-
-
-
-
5
24
3
12
14
14
44
21
90
5
9
9
9
9
-
50
10
25
70
70
70
70
150
-
50
50
50
50
-
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Mbps
SWITCHING CHARACTERISTICS (ISL8487E)
Driver Input to Output Delay
Driver Output Skew
Driver Differential Rise or Fall Time
Driver Enable to Output High
Driver Enable to Output Low
Driver Disable from Output High
Driver Disable from Output Low
Receiver Input to Output Delay
Receiver Skew | t
PLH
- t
PHL
|
Receiver Enable to Output High
Receiver Enable to Output Low
Receiver Disable from Output High
Receiver Disable from Output Low
Maximum Data Rate
Time to Shutdown
Driver Enable from Shutdown to
Output High
Driver Enable from Shutdown to
Output Low
Full
Full
Full
Full
Full
Full
Full
Full
25
Full
Full
Full
Full
Full
Full
Full
Full
250
-
250
250
250
300
300
250
-
-
-
-
-
250
50
-
-
650
160
900
1000
860
660
640
500
60
10
10
10
10
-
120
1000
1000
2000
800
2000
2000
2000
3000
3000
2000
-
50
50
50
50
-
600
2000
2000
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
kbps
ns
ns
ns
FN6051 Rev.7.00
February 27, 2006
Page 5 of 14
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