INTERSIL ISL8485E

ISL8483E, ISL8485E
®
Data Sheet
December 2003
ESD Protected to ±15kV, 5V, Low Power,
High Speed or Slew Rate Limited,
RS-485/RS-422 Transceivers
FN6048.3
Features
• RS-485 I/O Pin ESD Protection . . . . . . . . . . . . . ±15kV HBM
- Class 3 ESD Level on all Other Pins . . . . . . >7kV HBM
• Specified for 10% Tolerance Supplies
These Intersil RS-485/RS-422 devices are ESD protected,
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).
• High Data Rate Version (ISL8485E) . . . . . . up to 5Mbps
• Slew Rate Limited Version for Error Free Data
Transmission (ISL8483E) . . . . . . . . . . . . . .up to 250kbps
• Single Unit Load Allows up to 32 Devices on the Bus
• 1nA Low Current Shutdown Mode (ISL8483E)
The ISL8483E utilizes slew rate limited drivers which reduce
EMI, and minimize reflections from improperly terminated
transmission lines, or unterminated stubs in multidrop and
multipoint applications.
• Low Quiescent Current:
- 160µA (ISL8483E)
- 340µA (ISL8485E)
Data rates up to 5Mbps are achievable by using the
ISL8485E which features higher slew rates.
• -7V to +12V Common Mode Input Voltage Range
Both devices present a “single unit load” to the RS-485 bus,
which allows up to 32 transceivers on the network.
• 30ns Propagation Delays, 5ns Skew (ISL8485E)
Receiver (Rx) inputs feature a “fail-safe if open” design,
which ensures a logic high Rx output, if Rx inputs are
floating.
• Current Limiting and Thermal Shutdown for driver
Overload Protection
• Three State Rx and Tx Outputs
• Operate from a Single +5V Supply (10% Tolerance)
Applications
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.
• Factory Automation
• Security Networks
• Building Environmental Control Systems
These half duplex configurations multiplex the Rx inputs and
Tx outputs to allow transceivers with Rx and Tx disable
functions in 8 lead packages.
• Industrial/Process Control Networks
• Level Translators (e.g., RS-232 to RS-422)
• RS-232 “Extension Cords”
TABLE 1. SUMMARY OF FEATURES
PART
NUMBER
HALF/FULL NO. OF DEVICES DATA RATE
DUPLEX
ALLOWED ON BUS
(Mbps)
SLEW-RATE RECEIVER/DRIVER QUIESCENT LOW POWER
PIN
LIMITED?
ENABLE?
ICC (µA)
SHUTDOWN? COUNT
ISL8483E
Half
32
0.25
Yes
Yes
160
Yes
8
ISL8485E
Half
32
5
No
Yes
340
No
8
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2003. All R ights Reserved.
All other trademarks mentioned are the property of their respective owners.
ISL8483E, ISL8485E
Pinout
ISL8483E, ISL8485E (PDIP, SOIC)
TOP VIEW
RO 1
R
RE 2
DE 3
DI 4
Ordering Information
PART NO.
(BRAND)
D
8
VCC
7
B/Z
6
A/Y
5
GND
Truth Tables
TRANSMITTING
TEMP.
RANGE (oC)
PACKAGE
PKG. DWG. #
ISL8483EIB
(8483EIB)
-40 to 85
8 Ld SOIC
M8.15
ISL8483EIB-T
(8483EIB)
-40 to 85
8 Ld SOIC
Tape and Reel
M8.15
ISL8483EIP
-40 to 85
8 Ld PDIP
ISL8485ECB
(8485ECB)
0 to 70
ISL8485ECB-T
(8485ECB)
INPUTS
OUTPUTS
RE
DE
DI
Z
Y
X
1
1
0
1
X
1
0
1
0
E8.3
0
0
X
High-Z
High-Z
8 Ld SOIC
M8.15
1
0
X
High-Z *
High-Z *
0 to 70
8 Ld SOIC
Tape and Reel
M8.15
ISL8485ECP
0 to 70
8 Ld PDIP
E8.3
ISL8485EIB
(8485EIB)
-40 to 85
8 Ld SOIC
M8.15
ISL8485EIB-T
(8485EIB)
-40 to 85
8 Ld SOIC
Tape and Reel
M8.15
ISL8485EIP
-40 to 85
8 Ld PDIP
E8.3
*Shutdown Mode for ISL8483E (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 ISL8483E (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 noninverting 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.
VCC
System power supply input (4.5V to 5.5V).
2
ISL8483E, ISL8485E
Typical Operating Circuits
ISL8483E, ISL8485E
+5V
+5V
+
0.1µF
8
+
0.1µF
8
VCC
1
2
RO
R
D
RE
3
DE
4
DI
VCC
7
B/Z
A/Y
6
RT
RT
B/Z
DE
3
6
A/Y
RE
2
RO
1
R
GND
5
5
3
4
7
D
GND
DI
ISL8483E, ISL8485E
Absolute Maximum Ratings
Thermal Information
VCC to Ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7V
Input Voltages
DI, DE, RE . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to (VCC +0.5V)
Input / Output Voltages
A/Y, B/Z . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -8V to +12.5V
RO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to (VCC +0.5V)
Short Circuit Duration
Y, Z. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Continuous
ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . See Specification Table
Thermal Resistance (Typical, Note 1)
θJA (oC/W)
8 Ld SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . .
170
8 Ld PDIP Package . . . . . . . . . . . . . . . . . . . . . . . . .
140
Moisture Sensitivity (see Technical Brief TB363)
All Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Level 1
Maximum Junction Temperature (Plastic Package) . . . . . . . 150oC
Maximum Storage Temperature Range . . . . . . . . . -65oC to 150oC
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . 300oC
(SOIC - Lead Tips Only)
Operating Conditions
Temperature Range
ISL8485ECX. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0oC to 70oC
ISL848XEIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40oC to 85oC
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. θJA 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: VCC = 4.5V to 5.5V; Unless Otherwise Specified.
Typicals are at VCC = 5V, TA = 25oC, (Note 2)
PARAMETER
SYMBOL
TEST CONDITIONS
TEMP
(oC)
MIN
TYP
MAX
UNITS
Full
-
-
VCC
V
Full
2
3
-
V
DC CHARACTERISTICS
Driver Differential VOUT (no load)
VOD1
Driver Differential VOUT (with load)
VOD2
R = 27Ω (RS-485), (Figure 1)
Full
1.5
2.3
5
V
Change in Magnitude of Driver
Differential VOUT for
Complementary Output States
∆VOD
R = 27Ω or 50Ω, (Figure 1)
Full
-
0.01
0.2
V
VOC
R = 27Ω or 50Ω, (Figure 1)
Full
-
-
3
V
∆VOC
R = 27Ω or 50Ω, (Figure 1)
Full
-
0.01
0.2
V
Driver Common-Mode VOUT
Change in Magnitude of Driver
Common-Mode VOUT for
Complementary Output States
R = 50Ω (RS-422), (Figure 1)
Logic Input High Voltage
VIH
DE, DI, RE
Full
2
-
-
V
Logic Input Low Voltage
VIL
DE, DI, RE
Full
-
-
0.8
V
Logic Input Current
IIN1
DE, DI, RE (ISL8483E)
Full
-2
-
2
µA
IIN1
DI (ISL8485E)
Full
-2
-
2
µA
IIN1
DE, RE (ISL8485E)
IIN2
DE = 0V, VCC = 0V or
4.5 to 5.5V
Input Current (A, B), (Note 10)
Receiver Differential Threshold
Voltage
VTH
Full
-25
-
25
µA
VIN = 12V
Full
-
-
1
mA
VIN = -7V
Full
-
-
-0.8
mA
-7V ≤ VCM ≤ 12V
Full
-0.2
-
0.2
V
Receiver Input Hysteresis
∆VTH
VCM = 0V
25
-
70
-
mV
Receiver Output High Voltage
VOH
IO = -4mA, VID = 200mV
Full
3.5
-
-
V
Receiver Output Low Voltage
VOL
IO = -4mA, VID = 200mV
Full
-
-
0.4
V
Three-State (high impedance)
Receiver Output Current
IOZR
0.4V ≤ VO ≤ 2.4V
Full
-
-
±1
µA
Receiver Input Resistance
RIN
-7V ≤ VCM ≤ 12V
Full
12
-
-
kΩ
4
ISL8483E, ISL8485E
Electrical Specifications
Test Conditions: VCC = 4.5V to 5.5V; Unless Otherwise Specified.
Typicals are at VCC = 5V, TA = 25oC, (Note 2) (Continued)
PARAMETER
SYMBOL
No-Load Supply Current, (Note 3)
ICC
TEMP
(oC)
MIN
TYP
MAX
UNITS
DE = VCC
Full
-
550
900
µA
DE = 0V
Full
-
340
500
µA
DE = VCC
Full
-
390
650
µA
DE = 0V
Full
-
160
250
µA
TEST CONDITIONS
ISL8485E, DI, RE = 0V
or VCC
ISL8483E, DI, RE = 0V
or VCC
Shutdown Supply Current
ISHDN
ISL8483E, DE = 0V, RE = VCC, DI = 0V or VCC
Full
-
1
50
nA
Driver Short-Circuit Current,
VO = High or Low
IOSD1
DE = VCC, -7V ≤ VY or VZ ≤ 12V, (Note 4)
Full
35
-
250
mA
Receiver Short-Circuit Current
IOSR
0V ≤ VO ≤ VCC
Full
7
-
85
mA
Full
18
30
50
ns
SWITCHING CHARACTERISTICS (ISL8485E)
tPLH, tPHL RDIFF = 54Ω, CL = 100pF, (Figure 2)
Driver Input to Output Delay
Driver Output Skew
Driver Differential Rise or Fall Time
tSKEW
RDIFF = 54Ω, CL = 100pF, (Figure 2)
Full
-
2
10
ns
tR, tF
RDIFF = 54Ω, CL = 100pF, (Figure 2)
Full
3
11
25
ns
Driver Enable to Output High
tZH
CL = 100pF, SW = GND, (Figure 3)
Full
-
17
70
ns
Driver Enable to Output Low
tZL
CL = 100pF, SW = VCC, (Figure 3)
Full
-
14
70
ns
Driver Disable from Output High
tHZ
CL = 15pF, SW = GND, (Figure 3)
Full
-
19
70
ns
Driver Disable from Output Low
tLZ
CL = 15pF, SW = VCC, (Figure 3)
Full
-
13
70
ns
tPLH, tPHL (Figure 4)
Receiver Input to Output Delay
Receiver Skew | tPLH - tPHL |
tSKD
Full
30
40
150
ns
(Figure 4)
25
-
5
-
ns
Receiver Enable to Output High
tZH
CL = 15pF, SW = GND, (Figure 5)
Full
-
9
50
ns
Receiver Enable to Output Low
tZL
CL = 15pF, SW = VCC, (Figure 5)
Full
-
9
50
ns
Receiver Disable from Output High
tHZ
CL = 15pF, SW = GND, (Figure 5)
Full
-
9
50
ns
Receiver Disable from Output Low
tLZ
CL = 15pF, SW = VCC, (Figure 5)
Full
-
9
50
ns
Full
5
-
-
Mbps
tPLH, tPHL RDIFF = 54Ω, CL = 100pF, (Figure 2)
Full
250
800
2000
ns
tSKEW
RDIFF = 54Ω, CL = 100pF, (Figure 2)
Full
-
160
800
ns
tR, tF
RDIFF = 54Ω, CL = 100pF, (Figure 2)
Full
250
800
2000
ns
tZH
CL = 100pF, SW = GND, (Figure 3), (Note 5)
Full
250
-
2000
ns
Driver Enable to Output Low
tZL
CL = 100pF, SW = VCC, (Figure 3), (Note 5)
Full
250
-
2000
ns
Driver Disable from Output High
tHZ
CL = 15pF, SW = GND, (Figure 3)
Full
300
-
3000
ns
Driver Disable from Output Low
tLZ
CL = 15pF, SW = VCC, (Figure 3)
Full
300
-
3000
ns
Full
250
350
2000
ns
Maximum Data Rate
fMAX
SWITCHING CHARACTERISTICS (ISL8483E)
Driver Input to Output Delay
Driver Output Skew
Driver Differential Rise or Fall Time
Driver Enable to Output High
tPLH, tPHL (Figure 4)
Receiver Input to Output Delay
Receiver Skew | tPLH - tPHL |
(Figure 4)
25
-
25
-
ns
Receiver Enable to Output High
tSKD
tZH
CL = 15pF, SW = GND, (Figure 5), (Note 6)
Full
-
10
50
ns
Receiver Enable to Output Low
tZL
CL = 15pF, SW = VCC, (Figure 5), (Note 6)
Full
-
10
50
ns
Receiver Disable from Output High
tHZ
CL = 15pF, SW = GND, (Figure 5)
Full
-
10
50
ns
tLZ
CL = 15pF, SW = VCC, (Figure 5)
Receiver Disable from Output Low
Maximum Data Rate
fMAX
Time to Shutdown
tSHDN
(Note 7)
tZH(SHDN) CL = 100pF, SW = GND, (Figure 3), (Notes 7, 8)
Driver Enable from Shutdown to
Output High
5
Full
-
10
50
ns
Full
250
-
-
kbps
Full
50
200
600
ns
Full
-
-
2000
ns
ISL8483E, ISL8485E
Electrical Specifications
Test Conditions: VCC = 4.5V to 5.5V; Unless Otherwise Specified.
Typicals are at VCC = 5V, TA = 25oC, (Note 2) (Continued)
PARAMETER
SYMBOL
TEST CONDITIONS
TEMP
(oC)
MIN
TYP
MAX
UNITS
Driver Enable from Shutdown to
Output Low
tZL(SHDN)
CL = 100pF, SW = VCC, (Figure 3), (Notes 7, 8)
Full
-
-
2000
ns
Receiver Enable from Shutdown to
Output High
tZH(SHDN) CL = 15pF, SW = GND, (Figure 5), (Notes 7, 9)
Full
-
-
2500
ns
Receiver Enable from Shutdown to
Output Low
tZL(SHDN)
CL = 15pF, SW = VCC, (Figure 5), (Notes 7, 9)
Full
-
-
2500
ns
Human Body Model
25
-
±15
-
kV
25
-
>±7
-
kV
ESD PERFORMANCE
RS-485 Pins (A/Y, B/Z)
All Other Pins
NOTE:
2. All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to device ground unless
otherwise specified.
3. Supply current specification is valid for loaded drivers when DE = 0V.
4. Applies to peak current. See “Typical Performance Curves” for more information.
5. When testing the ISL8483E, keep RE = 0 to prevent the device from entering SHDN.
6. When testing the ISL8483E, the RE signal high time must be short enough (typically <200ns) to prevent the device from entering SHDN.
7. The ISL8483E is put into shutdown by bringing RE high and DE low. If the inputs are in this state for less than 50ns, the parts are guaranteed
not to enter shutdown. If the inputs are in this state for at least 600ns, the parts are guaranteed to have entered shutdown. See “Low-Power
Shutdown Mode” section.
8. Keep RE = VCC, and set the DE signal low time >600ns to ensure that the device enters SHDN.
9. Set the RE signal high time >600ns to ensure that the device enters SHDN.
10. Devices meeting these limits are denoted as “single unit load (1 UL)” transceivers. The RS-485 standard allows up to 32 Unit Loads on the bus.
Test Circuits and Waveforms
R
VCC
DE
Z
DI
VOD
D
Y
R
FIGURE 1. DRIVER VOD AND VOC
6
VOC
ISL8483E, ISL8485E
Test Circuits and Waveforms (Continued)
3V
DI
1.5V
1.5V
0V
tPHL
tPLH
VOH
VCC
CL = 100pF
DE
50%
OUT (Y)
50%
VOL
Z
DI
tPHL
RDIFF
D
Y
tPLH
VOH
CL = 100pF
OUT (Z)
50%
SIGNAL
GENERATOR
50%
VOL
90%
DIFF OUT (Y - Z)
+VOD
90%
10%
10%
tR
-VOD
tF
SKEW = |tPLH (Y or Z) - tPHL (Z or Y)|
FIGURE 2B. MEASUREMENT POINTS
FIGURE 2A. TEST CIRCUIT
FIGURE 2. DRIVER PROPAGATION DELAY AND DIFFERENTIAL TRANSITION TIMES
DE
Z
DI
500Ω
VCC
D
SIGNAL
GENERATOR
SW
Y
GND
3V
DE
NOTE 7
CL
1.5V
1.5V
0V
tZH, tZH(SHDN)
(SHDN) FOR ISL8483E ONLY
PARAMETER OUTPUT
tHZ
Y/Z
OUTPUT HIGH
NOTE 7
tHZ
VOH - 0.5V
RE
DI
SW
CL (pF)
X
1/0
GND
15
OUT (Y, Z)
0V
tZL, tZL(SHDN)
tLZ
Y/Z
X
0/1
VCC
15
tZH
Y/Z
0 (Note 5)
1/0
GND
100
NOTE 7
tZL
Y/Z
0 (Note 5)
0/1
VCC
100
OUT (Y, Z)
tZH(SHDN)
Y/Z
1 (Note 8)
1/0
GND
100
tZL(SHDN)
Y/Z
1 (Note 8)
0/1
VCC
100
FIGURE 3A. TEST CIRCUIT
tLZ
VCC
2.3V
OUTPUT LOW
VOL + 0.5V V
OL
FIGURE 3B. MEASUREMENT POINTS
FIGURE 3. DRIVER ENABLE AND DISABLE TIMES
7
VOH
2.3V
ISL8483E, ISL8485E
Test Circuits and Waveforms (Continued)
3V
RE
B
+1.5V
A
15pF
R
A
1.5V
1.5V
RO
0V
tPLH
tPHL
VCC
SIGNAL
GENERATOR
50%
RO
50%
0V
FIGURE 4B. MEASUREMENT POINTS
FIGURE 4A. TEST CIRCUIT
FIGURE 4. RECEIVER PROPAGATION DELAY
RE
B
SIGNAL
GENERATOR
1kΩ
RO
R
VCC
SW
A
GND
NOTE 7
3V
RE
1.5V
15pF
1.5V
0V
tZH, tZH(SHDN)
(SHDN) FOR ISL8483E ONLY
tHZ
OUTPUT HIGH
NOTE 7
VOH - 0.5V
PARAMETER
DE
A
SW
tHZ
0
+1.5V
GND
tLZ
0
-1.5V
VCC
tZH (Note 6)
0
+1.5V
GND
tZL (Note 6)
0
-1.5V
VCC
tZH(SHDN) (Note 9)
0
+1.5V
GND
tZL(SHDN) (Note 9)
0
-1.5V
VCC
FIGURE 5A. TEST CIRCUIT
RO
VOH
1.5V
0V
tZL, tZL(SHDN)
tLZ
NOTE 7
VCC
RO
1.5V
OUTPUT LOW
VOL + 0.5V V
OL
FIGURE 5B. MEASUREMENT POINTS
FIGURE 5. RECEIVER ENABLE AND DISABLE TIMES
Application Information
RS-485 and RS-422 are differential (balanced) data
transmission standards for use in long haul or noisy
environments. RS-422 is a subset of RS-485, so RS-485
transceivers are also RS-422 compliant. RS-422 is a pointto-multipoint (multidrop) standard, which allows only one
driver and up to 10 (assuming one unit load devices)
receivers on each bus. RS-485 is a true multipoint standard,
which allows up to 32 one unit load devices (any
combination of drivers and receivers) on each bus. To allow
for multipoint operation, the RS-485 spec requires that
drivers must handle bus contention without sustaining any
damage.
Another important advantage of RS-485 is the extended
common mode range (CMR), which specifies that the driver
outputs and receiver inputs withstand signals that range
from +12V to -7V. RS-422 and RS-485 are intended for runs
as long as 4000’, so the wide CMR is necessary to handle
8
ground potential differences, as well as voltages induced in
the cable by external fields.
Receiver Features
These devices utilize a differential input receiver for maximum
noise immunity and common mode rejection. Input sensitivity
is ±200mV, as required by the RS422 and RS-485
specifications.
Receiver input impedance surpasses the RS-422 spec of
4kΩ, and meets the RS-485 “Unit Load” requirement of
12kΩ minimum.
Receiver inputs function with common mode voltages as
great as ±7V outside the power supplies (i.e., +12V and
-7V), making them ideal for long networks where induced
voltages are a realistic concern.
All the receivers include a “fail-safe if open” function that
guarantees a high level receiver output if the receiver inputs
are unconnected (floating).
ISL8483E, ISL8485E
Receivers easily meet the data rates supported by the
corresponding driver.
ISL8483E/85E receiver outputs are three-statable via the
active low RE input.
Driver Features
The RS-485/422 driver is a differential output device that
delivers at least 1.5V across a 54Ω load (RS-485), and at
least 2V across a 100Ω load (RS-422). The drivers feature
low propagation delay skew to maximize bit width, and to
minimize EMI.
Drivers of the ISL8483E/85E are three-statable via the active
high DE input.
The ISL8483E driver outputs are slew rate limited to
minimize EMI, and to minimize reflections in unterminated or
improperly terminated networks. Data rate on these slew
rate limited versions is a maximum of 250kbps. Outputs of
the ISL8485E driver are not limited, so faster output
transition times allow data rates of at least 5Mbps.
Data Rate, Cables, and Terminations
RS-485/422 are intended for network lengths up to 4000’,
but the maximum system data rate decreases as the
transmission length increases. Devices operating at 5Mbps
are limited to lengths less than 100’, while the 250kbps
versions can operate at full data rates with lengths in excess
of 1000’.
Twisted pair is the cable of choice for RS-485/422 networks.
Twisted pair cables tend to pick up noise and other
electromagnetically induced voltages as common mode
signals, which are effectively rejected by the differential
receivers in these ICs.
Proper termination is imperative, when using the 5Mbps
devices, to minimize reflections. Short networks using the
250kbps versions need not be terminated, but, terminations
are recommended unless power dissipation is an overriding
concern.
In point-to-point, or point-to-multipoint (single driver on bus)
networks, the main cable should be terminated in its
characteristic impedance (typically 120Ω) at the end farthest
from the driver. In multi-receiver applications, stubs
connecting receivers to the main cable should be kept as
short as possible. Multipoint (multi-driver) systems require
that the main cable be terminated in its characteristic
impedance at both ends. Stubs connecting a transceiver to
the main cable should be kept as short as possible.
Built-In Driver Overload Protection
As stated previously, the RS-485 spec requires that drivers
survive worst case bus contentions undamaged. The
ISL848XE devices meet this requirement via driver output
short circuit current limits, and on-chip thermal shutdown
circuitry.
The driver output stages incorporate short circuit current
limiting circuitry which ensures that the output current never
9
exceeds the RS-485 spec, even at the common mode
voltage range extremes. Additionally, these devices utilize a
foldback circuit which reduces the short circuit current, and
thus the power dissipation, whenever the contending voltage
exceeds either supply.
In the event of a major short circuit condition, ISL848XE
devices also include a thermal shutdown feature that
disables the drivers whenever the die temperature becomes
excessive. This eliminates the power dissipation, allowing
the die to cool. The drivers automatically reenable after the
die temperature drops about 15 degrees. If the contention
persists, the thermal shutdown/reenable cycle repeats until
the fault is cleared. Receivers stay operational during
thermal shutdown.
Low Power Shutdown Mode (ISL8483E Only)
These CMOS transceivers all use a fraction of the power
required by their bipolar counterparts, but the ISL8483E
includes a shutdown feature that reduces the already low
quiescent ICC to a 1nA trickle. The ISL8483E enters
shutdown whenever the receiver and driver are
simultaneously disabled (RE = VCC and DE = GND) for a
period of at least 600ns. Disabling both the driver and the
receiver for less than 50ns guarantees that the ISL8483E
will not enter shutdown.
Note that receiver and driver enable times increase when
the ISL8483E enables from shutdown. Refer to Notes 5-8, at
the end of the Electrical Specification table, for more
information.
ESD Protection
All pins on these interface devices include class 3 Human
Body Model (HBM) ESD protection structures, but the
RS-485 pins (driver outputs and receiver inputs) incorporate
advanced structures allowing them to survive ESD events in
excess of ±15kV HBM. The RS-485 pins are particularly
vulnerable to ESD damage because they typically connect to
an exposed port on the exterior of the finished product.
Simply touching the port pins, or connecting a cable, can
cause an ESD event that might destroy unprotected ICs.
These new ESD structures protect the device whether or not
it is powered up, protect without allowing any latchup
mechanism to activate, and without degrading the RS-485
common mode range of -7V to +12V. This built-in ESD
protection eliminates the need for board level protection
structures (e.g., transient suppression diodes), and the
associated, undesirable capacitive load they present.
Human Body Model Testing
As the name implies, this test method emulates the ESD
event delivered to an IC during human handling. The tester
delivers the charge stored on a 100pF capacitor through a
1.5kΩ current limiting resistor into the pin under test. The
HBM method determines an ICs ability to withstand the ESD
events typically present during handling and manufacturing.
The RS-485 pin survivability on this high ESD family has
been characterized to be in excess of ±15kV, for discharges
to GND.
ISL8483E, ISL8485E
VCC = 5V, TA = 25oC, ISL8483E and ISL8485E; Unless Otherwise Specified
90
3.6
80
3.4
DIFFERENTIAL OUTPUT VOLTAGE (V)
DRIVER OUTPUT CURRENT (mA)
Typical Performance Curves
70
60
50
40
30
20
10
0
0
1
2
3
4
3.2
RDIFF = 100Ω
3
2.8
2.6
2.4
RDIFF = 54Ω
2.2
2
-40
5
-25
DIFFERENTIAL OUTPUT VOLTAGE (V)
FIGURE 6. DRIVER OUTPUT CURRENT vs DIFFERENTIAL
OUTPUT VOLTAGE
50
75
85
600
140
550
120
Y OR Z = LOW
100
ISL8485E, DE = VCC, RE = X
500
80
450
60
ISL8483E, DE = VCC, RE = X
400
40
ICC (µA)
OUTPUT CURRENT (mA)
25
FIGURE 7. DRIVER DIFFERENTIAL OUTPUT VOLTAGE vs
TEMPERATURE
160
20
0
-20
Y OR Z = HIGH
-40
350
ISL8485E, DE = GND, RE = X
300
250
-60
200
-80
-100
150
-120
0
TEMPERATURE (oC)
-7 -6
-4
-2
0
2
4
6
OUTPUT VOLTAGE (V)
8
10
100
-40
12
ISL8483E, DE = GND, RE = GND
-25
0
25
50
75
85
TEMPERATURE (oC)
FIGURE 8. DRIVER OUTPUT CURRENT vs SHORT CIRCUIT
VOLTAGE
FIGURE 9. SUPPLY CURRENT vs TEMPERATURE
400
1200
tPLHY
1000
tPLHZ
300
|tPHLY - tPLHZ|
900
tPHLY
800
SKEW (ns)
PROPAGATION DELAY (ns)
1100
tPHLZ
700
200
|tPLHY - tPHLZ|
100
600
500
-40
|CROSS PT. OF Y↑ & Z↓ - CROSS PT. OF Y↓ & Z↑|
-25
0
25
50
TEMPERATURE (oC)
FIGURE 10. DRIVER PROPAGATION DELAY vs
TEMPERATURE (ISL8483E)
10
75
85
0
-40
-25
0
25
50
75
85
TEMPERATURE (oC)
FIGURE 11. DRIVER SKEW vs TEMPERATURE (ISL8483E)
ISL8483E, ISL8485E
VCC = 5V, TA = 25oC, ISL8483E and ISL8485E; Unless Otherwise Specified (Continued)
40
3
35
2.5
|tPHLY - tPLHZ|
tPHLY
tPHLZ
30
tPLHZ
tPLHY
25
|tPLHY - tPHLZ|
2
SKEW (ns)
PROPAGATION DELAY (ns)
Typical Performance Curves
1.5
|CROSSING PT. OF Y↑ & Z↓ - CROSSING PT. OF Y↓ & Z↑|
0
25
50
1
-40
85
75
-25
TEMPERATURE (oC)
0
5
RO
0
4
2
RECEIVER OUTPUT (V)
5
DRIVER INPUT (V)
RDIFF = 54Ω, CL = 100pF
3
B/Z
A/Y
1
0
5
DI
0
5
RO
0
4
3
A/Y
2
B/Z
1
0
0
RO
DRIVER OUTPUT (V)
4
3
2
RECEIVER OUTPUT (V)
5
DRIVER INPUT (V)
RECEIVER OUTPUT (V)
DRIVER OUTPUT (V)
FIGURE 15. DRIVER AND RECEIVER WAVEFORMS,
HIGH TO LOW (ISL8483E)
RDIFF = 54Ω, CL = 100pF
0
B/Z
A/Y
1
0
TIME (10ns / DIV)
FIGURE 16. DRIVER AND RECEIVER WAVEFORMS,
LOW TO HIGH (ISL8485E)
11
85
75
TIME (400ns / DIV)
FIGURE 14. DRIVER AND RECEIVER WAVEFORMS,
LOW TO HIGH (ISL8483E)
5
50
RDIFF = 54Ω, CL = 100pF
TIME (400ns / DIV)
DI
25
FIGURE 13. DRIVER SKEW vs TEMPERATURE (ISL8485E)
DRIVER OUTPUT (V)
DRIVER OUTPUT (V)
RECEIVER OUTPUT (V)
FIGURE 12. DRIVER PROPAGATION DELAY vs
TEMPERATURE (ISL8485E)
DI
0
TEMPERATURE (oC)
DRIVER INPUT (V)
-25
RDIFF = 54Ω, CL = 100pF
5
DI
0
5
RO
0
4
3
A/Y
2
B/Z
1
0
TIME (10ns / DIV)
FIGURE 17. DRIVER AND RECEIVER WAVEFORMS,
HIGH TO LOW (ISL8485E)
DRIVER INPUT (V)
20
-40
ISL8483E, ISL8485E
Die Characteristics
SUBSTRATE POTENTIAL (POWERED UP):
GND
TRANSISTOR COUNT:
518
PROCESS:
Si Gate CMOS
12
ISL8483E, ISL8485E
Dual-In-Line Plastic Packages (PDIP)
E8.3 (JEDEC MS-001-BA ISSUE D)
N
8 LEAD DUAL-IN-LINE PLASTIC PACKAGE
E1
INDEX
AREA
1 2 3
INCHES
N/2
-B-
-AD
E
BASE
PLANE
-C-
A2
SEATING
PLANE
A
L
D1
e
B1
D1
A1
eC
B
0.010 (0.25) M
C A B S
MILLIMETERS
SYMBOL
MIN
MAX
MIN
MAX
NOTES
A
-
0.210
-
5.33
4
A1
0.015
-
0.39
-
4
A2
0.115
0.195
2.93
4.95
-
B
0.014
0.022
0.356
0.558
-
C
L
B1
0.045
0.070
1.15
1.77
8, 10
eA
C
0.008
0.014
0.204
C
D
0.355
0.400
9.01
eB
NOTES:
1. Controlling Dimensions: INCH. In case of conflict between
English and Metric dimensions, the inch dimensions control.
0.005
-
0.13
-
5
E
0.300
0.325
7.62
8.25
6
E1
0.240
0.280
6.10
7.11
5
e
0.100 BSC
eA
0.300 BSC
3. Symbols are defined in the “MO Series Symbol List” in Section
2.2 of Publication No. 95.
eB
-
L
0.115
5. D, D1, and E1 dimensions do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.010 inch
(0.25mm).
6. E and eA are measured with the leads constrained to be perpendicular to datum -C- .
7. eB and eC are measured at the lead tips with the leads unconstrained. eC must be zero or greater.
8. B1 maximum dimensions do not include dambar protrusions.
Dambar protrusions shall not exceed 0.010 inch (0.25mm).
9. N is the maximum number of terminal positions.
10. Corner leads (1, N, N/2 and N/2 + 1) for E8.3, E16.3, E18.3,
E28.3, E42.6 will have a B1 dimension of 0.030 - 0.045 inch
(0.76 - 1.14mm).
13
5
D1
2. Dimensioning and tolerancing per ANSI Y14.5M-1982.
4. Dimensions A, A1 and L are measured with the package seated
in JEDEC seating plane gauge GS-3.
0.355
10.16
N
8
2.54 BSC
7.62 BSC
0.430
-
0.150
2.93
8
6
10.92
7
3.81
4
9
Rev. 0 12/93
ISL8483E, ISL8485E
Small Outline Plastic Packages (SOIC)
M8.15 (JEDEC MS-012-AA ISSUE C)
N
INDEX
AREA
0.25(0.010) M
H
8 LEAD NARROW BODY SMALL OUTLINE PLASTIC
PACKAGE
B M
E
INCHES
-B-
1
2
SYMBOL
3
L
SEATING PLANE
-A-
h x 45o
A
D
-C-
µα
e
A1
B
0.25(0.010) M
C
C A M
B S
1. Symbols are defined in the “MO Series Symbol List” in Section 2.2 of
Publication Number 95.
MILLIMETERS
MIN
MAX
NOTES
A
0.0532
0.0688
1.35
1.75
-
0.0040
0.0098
0.10
0.25
-
B
0.013
0.020
0.33
0.51
9
C
0.0075
0.0098
0.19
0.25
-
D
0.1890
0.1968
4.80
5.00
3
E
0.1497
0.1574
3.80
4.00
4
0.050 BSC
1.27 BSC
-
H
0.2284
0.2440
5.80
6.20
-
h
0.0099
0.0196
0.25
0.50
5
L
0.016
0.050
0.40
1.27
6
8o
0o
N
NOTES:
MAX
A1
e
0.10(0.004)
MIN
α
8
0o
8
7
8o
Rev. 0 12/93
2. Dimensioning and tolerancing per ANSI Y14.5M-1982.
3. Dimension “D” does not include mold flash, protrusions or gate burrs.
Mold flash, protrusion and gate burrs shall not exceed 0.15mm (0.006
inch) per side.
4. Dimension “E” does not include interlead flash or protrusions. Interlead flash and protrusions shall not exceed 0.25mm (0.010 inch) per
side.
5. The chamfer on the body is optional. If it is not present, a visual index
feature must be located within the crosshatched area.
6. “L” is the length of terminal for soldering to a substrate.
7. “N” is the number of terminal positions.
8. Terminal numbers are shown for reference only.
9. The lead width “B”, as measured 0.36mm (0.014 inch) or greater
above the seating plane, shall not exceed a maximum value of
0.61mm (0.024 inch).
10. Controlling dimension: MILLIMETER. Converted inch dimensions
are not necessarily exact.
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Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
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14