1
FN6051.6
ISL8487E, ISL81487L, ISL81487E
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
HALF/FULL
DUPLEX
NO. OF DEVICES
ALLOWED ON BUS
DATA RATE
(Mbps)
SLEW-RATE
LIMITED?
RECEIVER/
DRIVER ENABLE?
QUIESCENT
I
CC
(
A)
LOW POWER
SHUTDOWN?
PIN
COUNT
ISL8487E
Half
256
0.25
Yes
Yes
120
Yes
8
ISL81487L
Half
256
0.25
Yes
Yes
120
Yes
8
ISL81487E
Half
256
5
No
Yes
350
No
8
Data Sheet
September 15, 2005
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774
|
Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2003-2005. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
2
FN6051.6
Pinout
ISL8487E, ISL81487L, ISL81487E (PDIP, SOIC)
TOP VIEW
Ordering Information
PART NO.
(BRAND)
TEMP.
RANGE (C)
PACKAGE
PKG.
DWG. #
ISL8487EIB*
(8487EIB)
-40 to 85
8 Ld SOIC
M8.15
ISL8487EIBZ*
(8487EIB)(Note)
-40 to 85
8 Ld SOIC
(Pb-free)
M8.15
ISL8487EIP
-40 to 85
8 Ld PDIP
E8.3
ISL81487LIB*
(81487LIB)
-40 to 85
8 Ld SOIC
M8.15
ISL81487LIBZ*
(81487LIB)(Note)
-40 to 85
8 Ld SOIC
(Pb-free)
M8.15
ISL81487LIP
-40 to 85
8 Ld PDIP
E8.3
ISL81487EIB*
(81487EIB)
-40 to 85
8 Ld SOIC
M8.15
ISL81487EIBZ*
(81487EIB)(Note)
-40 to 85
8 Ld SOIC
(Pb-free)
M8.15
ISL81487EIP
-40 to 85
8 Ld PDIP
E8.3
ISL81487EIPZ
(ISL81487EIPZ)(Note)
-40 to 85
8 Ld PDIP
(Pb-free)
E8.3
*Add "-T" suffix to part number for tape and reel packaging.
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.
RO
RE
DE
DI
1
2
3
4
8
7
6
5
V
CC
B/Z
A/Y
GND
D
R
Truth Tables
TRANSMITTING
INPUTS
OUTPUTS
RE
DE
DI
Z
Y
X
1
1
0
1
X
1
0
1
0
0
0
X
High-Z
High-Z
1
0
X
High-Z *
High-Z *
*Shutdown Mode for ISL8487E, ISL81487L (See Note 7)
RECEIVING
INPUTS
OUTPUT
RE
DE
A-B
RO
0
0
+0.2V
1
0
0
-0.2V
0
0
0
Inputs Open
1
1
0
X
High-Z *
1
1
X
High-Z
*Shutdown Mode for ISL8487E, ISL81487L (See Note 7)
Pin Descriptions
PIN
FUNCTION
RO
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).
RE
Receiver output enable. RO is enabled when RE is low; RO is high impedance when RE is high.
DE
Driver output enable. The driver outputs, Y and Z, are enabled by bringing DE high. They are high impedance when DE is low.
DI
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.
GND
Ground connection.
A/Y
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.
B/Z
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.
V
CC
System power supply input (4.5V to 5.5V).
ISL8487E, ISL81487L, ISL81487E
3
FN6051.6
Typical Operating Circuits
ISL8487E, ISL81487L, ISL81487E
0.1
F
+
D
R
7
6
8
1
2
3
4
5
V
CC
GND
RO
RE
DE
DI
A/Y
B/Z
+5V
0.1
F
+
D
R
6
7
8
1
2
3
4
5
V
CC
GND
RO
RE
DE
DI
A/Y
B/Z
+5V
R
T
R
T
ISL8487E, ISL81487L, ISL81487E
4
FN6051.6
(
Absolute Maximum Ratings
Thermal Information
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
Operating Conditions
Temperature Range
ISL8XXXIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-40C to 85C
Thermal Resistance (Typical, Note 1)
JA
(C/W)
8 Ld SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . .
170
8 Ld PDIP Package . . . . . . . . . . . . . . . . . . . . . . . . .
140
Maximum Junction Temperature (Plastic Package) . . . . . . . 150C
Maximum Storage Temperature Range . . . . . . . . . . . -65C to 150C
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . 300C
(SOIC - Lead Tips Only)
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
= 25C, (Note 2)
PARAMETER
SYMBOL
TEST CONDITIONS
TEMP
(C)
MIN
TYP
MAX
UNITS
DC CHARACTERISTICS
Driver Differential V
OUT
(no load)
V
OD1
Full
-
-
V
CC
V
Driver Differential V
OUT
(with load)
V
OD2
R = 50
(RS-422), (Figure 1)
Full
2
3
-
V
R = 27
(RS-485), (Figure 1)
Full
1.5
2.3
5
V
Change in Magnitude of Driver
Differential V
OUT
for
Complementary Output States
V
OD
R = 27
or 50, (Figure 1)
Full
-
0.01
0.2
V
Driver Common-Mode V
OUT
V
OC
R = 27
or 50, (Figure 1)
Full
-
-
3
V
Change in Magnitude of Driver
Common-Mode V
OUT
for
Complementary Output States
V
OC
R = 27
or 50, (Figure 1)
Full
-
0.01
0.2
V
Logic Input High Voltage
V
IH
DE, DI, RE
Full
2
-
-
V
Logic Input Low Voltage
V
IL
DE, DI, RE
Full
-
-
0.8
V
Logic Input Current
I
IN1
DE, DI, RE
Full
-2
-
2
A
Input Current (A/Y, B/Z), (Note 10)
I
IN2
DE = 0V, V
CC
= 4.5 to
5.5V
V
IN
= 12V
Full
-
-
140
A
V
IN
= -7V
Full
-
-
-120
A
I
IN2
DE = 0V, V
CC
= 0V
V
IN
= 12V
Full
-
-
180
A
V
IN
= -7V
Full
-
-
-100
A
Receiver Differential Threshold
Voltage
V
TH
-7V
V
CM
12V
Full
-0.2
-
0.2
V
Receiver Input Hysteresis
V
TH
V
CM
= 0V
25
-
70
-
mV
Receiver Output High Voltage
V
OH
I
O
= -4mA, V
ID
= 200mV
Full
3.5
-
-
V
Receiver Output Low Voltage
V
OL
I
O
= -4mA, V
ID
= 200mV
Full
-
-
0.4
V
Three-State (high impedance)
Receiver Output Current
I
OZR
0.4V
V
O
2.4V
Full
-
-
1
A
Receiver Input Resistance
R
IN
-7V
V
CM
12V
Full
96
-
-
k
ISL8487E, ISL81487L, ISL81487E
5
FN6051.6
No-Load Supply Current, (Note 3)
I
CC
ISL81487E, DI, RE = 0V
or V
CC
DE = V
CC
Full
-
400
500
A
DE = 0V
Full
-
350
420
A
ISL8487E, ISL81487L,
DI, RE = 0V or V
CC
DE = V
CC
Full
-
160
200
A
DE = 0V
Full
-
120
145
A
Shutdown Supply Current
I
SHDN
(Note 7), DE = 0V, RE = V
CC
, DI = 0V or V
CC
Full
-
0.5
8
A
Driver Short-Circuit Current,
V
O
= High or Low
I
OSD1
DE = V
CC
, -7V
V
Y
or V
Z
12V, (Note 4)
Full
35
-
250
mA
Receiver Short-Circuit Current
I
OSR
0V
V
O
V
CC
Full
7
-
85
mA
SWITCHING CHARACTERISTICS (ISL81487E)
Driver Input to Output Delay
t
PLH
, t
PHL
R
DIFF
= 54
, C
L
= 100pF, (Figure 2)
Full
15
24
50
ns
Driver Output Skew
t
SKEW
R
DIFF
= 54
, C
L
= 100pF, (Figure 2)
Full
-
3
10
ns
Driver Differential Rise or Fall Time
t
R
, t
F
R
DIFF
= 54
, C
L
= 100pF, (Figure 2)
Full
3
12
25
ns
Driver Enable to Output High
t
ZH
C
L
= 100pF, SW = GND, (Figure 2)
Full
-
14
70
ns
Driver Enable to Output Low
t
ZL
C
L
= 100pF, SW = V
CC
, (Figure 2)
Full
-
14
70
ns
Driver Disable from Output High
t
HZ
C
L
= 15pF, SW = GND, (Figure 2)
Full
-
44
70
ns
Driver Disable from Output Low
t
LZ
C
L
= 15pF, SW = V
CC
, (Figure 2)
Full
-
21
70
ns
Receiver Input to Output Delay
t
PLH
, t
PHL
(Figure 4)
Full
30
90
150
ns
Receiver Skew | t
PLH
- t
PHL
|
t
SKD
(Figure 4)
25
-
5
-
ns
Receiver Enable to Output High
t
ZH
C
L
= 15pF, SW = GND, (Figure 5)
Full
-
9
50
ns
Receiver Enable to Output Low
t
ZL
C
L
= 15pF, SW = V
CC
, (Figure 5)
Full
-
9
50
ns
Receiver Disable from Output High
t
HZ
C
L
= 15pF, SW = GND, (Figure 5)
Full
-
9
50
ns
Receiver Disable from Output Low
t
LZ
C
L
= 15pF, SW = V
CC
, (Figure 5)
Full
-
9
50
ns
Maximum Data Rate
f
MAX
Full
5
-
-
Mbps
SWITCHING CHARACTERISTICS (ISL8487E)
Driver Input to Output Delay
t
PLH
, t
PHL
R
DIFF
= 54
, C
L
= 100pF, (Figure 2)
Full
250
650
2000
ns
Driver Output Skew
t
SKEW
R
DIFF
= 54
, C
L
= 100pF, (Figure 2)
Full
-
160
800
ns
Driver Differential Rise or Fall Time
t
R
, t
F
R
DIFF
= 54
, C
L
= 100pF, (Figure 2)
Full
250
900
2000
ns
Driver Enable to Output High
t
ZH
C
L
= 100pF, SW = GND, (Figure 3, Note 5)
Full
250
1000
2000
ns
Driver Enable to Output Low
t
ZL
C
L
= 100pF, SW = V
CC
, (Figure 3, Note 5)
Full
250
860
2000
ns
Driver Disable from Output High
t
HZ
C
L
= 15pF, SW = GND, (Figure 3)
Full
300
660
3000
ns
Driver Disable from Output Low
t
LZ
C
L
= 15pF, SW = V
CC
, (Figure 3)
Full
300
640
3000
ns
Receiver Input to Output Delay
t
PLH
, t
PHL
(Figure 4)
Full
250
500
2000
ns
Receiver Skew | t
PLH
- t
PHL
|
t
SKD
(Figure 4)
25
-
60
-
ns
Receiver Enable to Output High
t
ZH
C
L
= 15pF, SW = GND, (Figure 5, Note 6)
Full
-
10
50
ns
Receiver Enable to Output Low
t
ZL
C
L
= 15pF, SW = V
CC
, (Figure 5, Note 6)
Full
-
10
50
ns
Receiver Disable from Output High
t
HZ
C
L
= 15pF, SW = GND, (Figure 5)
Full
-
10
50
ns
Receiver Disable from Output Low
t
LZ
C
L
= 15pF, SW = V
CC
, (Figure 5)
Full
-
10
50
ns
Maximum Data Rate
f
MAX
Full
250
-
-
kbps
Time to Shutdown
t
SHDN
(Note 7)
Full
50
120
600
ns
Driver Enable from Shutdown to
Output High
t
ZH(SHDN)
C
L
= 100pF, SW = GND, (Figure 3, Notes 7, 8)
Full
-
1000
2000
ns
Driver Enable from Shutdown to
Output Low
t
ZL(SHDN)
C
L
= 100pF, SW = V
CC
, (Figure 3, Notes 7, 8)
Full
-
1000
2000
ns
Electrical Specifications
Test Conditions: V
CC
= 4.5V to 5.5V; Unless Otherwise Specified.
Typicals are at V
CC
= 5V, T
A
= 25C, (Note 2) (Continued)
PARAMETER
SYMBOL
TEST CONDITIONS
TEMP
(C)
MIN
TYP
MAX
UNITS
ISL8487E, ISL81487L, ISL81487E
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