INTERSIL ISL3285E

ISL3280E, ISL3281E, ISL3282E,
ISL3283E, ISL3284E, ISL3285E
®
Data Sheet
October 18, 2007
±16.5kV ESD Protected, +125°C, 3.0V to
5.5V, SOT-23/TDFN Packaged, 20Mbps,
Full Fail-safe, Low Power, RS-485/RS-422
Receivers
FN6543.2
Features
• IEC61000 ESD Protection on RS-485 Inputs . . . ±16.5kV
- Class 3 ESD Level on all Other Pins . . . . . . >5kV HBM
• Pb-Free (RoHS Compliant)
The Intersil ISL3280E, ISL3281E, ISL3282E, ISL3283E,
ISL3284E, ISL3285E are ±16.5kV IEC61000 ESD
Protected, 3.0V to 5.5V powered, single receivers that meet
both the RS-485 and RS-422 standards for balanced
communication. These receivers have very low bus currents
(+125µA/-100µA), so they present a true “1/8 unit load” to the
RS-485 bus. This allows up to 256 receivers on the network
without violating the RS-485 specification’s 32 unit load
maximum and without using repeaters.
• Wide Supply Range . . . . . . . . . . . . . . . . . . . 3.0V to 5.5V
• Specified for +125°C Operation
• Logic Supply Pin (VL) Eases Operation in Mixed Supply
Systems (ISL3282E, ISL3284E, ISL3285E Only)
• Full Fail-safe (Open, Short, Terminated/Undriven)
• True 1/8 Unit Load Allows up to 256 Devices on the Bus
• High Data Rates . . . . . . . . . . . . . . . . . . . . . up to 20Mbps
Receiver inputs feature a “Full Fail-Safe” design, which
ensures a logic high Rx output if Rx inputs are floating,
shorted, or terminated but undriven.
• Low Quiescent Supply Current . . . . . . . . . . 500µA (Max)
- Very Low Shutdown Supply Current . . . . . . 20µA (Max)
• -7V to +12V Common Mode Input Voltage Range
The ISL3280E and ISL3284E feature an always enabled Rx;
the ISL3281E and ISL3285E feature an active high Rx
enable pin, and the ISL3282E and ISL3283E include an
active low enable pin. All versions are offered in Industrial
and Extended Industrial (-40°C to +125°C) temperature
ranges.
• Tri-statable Rx Available (Active Low or High EN Input)
• 5V Tolerant Logic Inputs When VCC ≤ 5V
Applications
• Clock Distribution
A 26% smaller footprint is available with the ISL3282E and
ISL3285E TDFN package. These devices, plus the
ISL3284E, also feature a logic supply pin (VL) that sets the
VOH level of the RO output (and the switching points of the
RE / RE input) to be compatible with another supply voltage
in mixed voltage systems.
• High Node Count Systems
• Space Constrained Systems
• Security Camera Networks
• Building Environmental Control/Lighting Systems
For companion single RS-485 transmitters in micro
packages, please see the ISL3293E, ISL3294E, ISL3295E,
ISL3296E, ISL3297E, ISL3298E data sheet.
• Industrial/Process Control Networks
TABLE 1. SUMMARY OF FEATURES
PART
NUMBER
FUNCTION
DATA RATE
(Mbps)
# DEVICES
ON BUS
RX
ENABLE?
VL PIN?
QUIESCENT
ICC (µA)
LOW POWER
SHUTDOWN?
LEAD
COUNT
ISL3280E
1 Rx
20
256
NO
NO
350
NO
5-SOT
ISL3281E
1 Rx
20
256
ACTIVE HIGH
NO
350
YES
6-SOT
ISL3282E
1 Rx
20
256
ACTIVE LOW
YES
350
YES
8-TDFN
ISL3283E
1 Rx
20
256
ACTIVE LOW
NO
350
YES
6-SOT
ISL3284E
1 Rx
20
256
NO
YES
350
NO
6-SOT
ISL3285E
1 Rx
20
256
ACTIVE HIGH
YES
350
YES
8-TDFN
1
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. 2007. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
ISL3280E, ISL3281E, ISL3282E, ISL3283E, ISL3284E, ISL3285E
Pinouts
ISL3281E
(6 LD SOT-23)
TOP VIEW
ISL3280E
(5 LD SOT-23)
TOP VIEW
VCC
1
5
GND 2
A
VCC
R
RO 3
4
B
1
6
A
GND 2
5
RE
4
B
6
A
5
RE
4
B
ISL3283E
(6 LD SOT-23)
TOP VIEW
ISL3282E
(8 LD TDFN)
TOP VIEW
RO
1
GND
2
R
8
B
7
RE
NC
3
6
VL
VCC
4
5
A
VCC
1
GND 2
1
GND 2
R
RO 3
2
R
RO 3
ISL3285E
(8 LD TDFN)
TOP VIEW
ISL3284E
(6 LD SOT-23)
TOP VIEW
VCC
R
RO 3
6
A
5
VL
4
B
RO
1
8
B
GND
2
7
RE
NC
3
6
VL
VCC
4
5
A
R
FN6543.2
October 18, 2007
ISL3280E, ISL3281E, ISL3282E, ISL3283E, ISL3284E, ISL3285E
Ordering Information
PART NUMBER
(Notes 1, 2)
PART
MARKING (Note 3)
TEMP. RANGE (°C)
PACKAGE
(Tape and Reel)
(Pb-Free)
PKG. DWG. #
ISL3280EFHZ-T
280F
-40 to +125
5 Ld SOT-23
P5.064
ISL3280EIHZ-T
280I
-40 to +85
5 Ld SOT-23
P5.064
ISL3281EFHZ-T
281F
-40 to +125
6 Ld SOT-23
P6.064
ISL3281EIHZ-T
281I
-40 to +85
6 Ld SOT-23
P6.064
ISL3282EFRTZ-T
82F
-40 to +125
8 Ld TDFN
L8.2x3A
ISL3282EIRTZ-T
82I
-40 to +85
8 Ld TDFN
L8.2x3A
ISL3283EFHZ-T
283F
-40 to +125
6 Ld SOT-23
P6.064
ISL3283EIHZ-T
283I
-40 to +85
6 Ld SOT-23
P6.064
ISL3284EFHZ-T
284F
-40 to +125
6 Ld SOT-23
P6.064
ISL3284EIHZ-T
284I
-40 to +85
6 Ld SOT-23
P6.064
ISL3285EFRTZ-T
85F
-40 to +125
8 Ld TDFN
L8.2x3A
ISL3285EIRTZ-T
85I
-40 to +85
8 Ld TDFN
L8.2x3A
NOTES:
1. 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.
2. Please refer to TB347 for details on reel specifications.
3. SOT-23 “PART MARKING” is branded on the bottom side.
3
FN6543.2
October 18, 2007
ISL3280E, ISL3281E, ISL3282E, ISL3283E, ISL3284E, ISL3285E
Truth Table
RECEIVING
INPUTS
OUTPUT
RE, RE
A-B
RO
1, 0
≥ -0.05V
1
1, 0
≤ -0.2V
0
1, 0
Inputs Open/Shorted
1
0, 1
X
High-Z*
NOTE: *Shutdown Mode, except for ISL3280E, ISL3284E
Pin Descriptions
PIN NAME
FUNCTION
RO
Receiver output: If A - B ≥ -50mV, RO is high; If A - B ≤ -200mV, RO is low; RO = High if A and B are unconnected (floating) or shorted.
RE, RE
Receiver output enable. RO is enabled when RE/RE is high / low; RO is high impedance when RE/RE is low/high. If the Rx enable
function isn’t used, connect RE directly to GND, or connect RE through a 1kΩ, or greater, resistor to VCC. RE/RE are internally pulled
low/high.
GND
Ground connection. This is also the potential of the TDFN thermal pad.
A
±16.5kV IEC61000 ESD Protected RS-485, RS-422 level, noninverting receiver input.
B
±16.5kV IEC61000 ESD Protected RS-485, RS-422 level, inverting receiver input.
VCC
System power supply input (3.0V to 5.5V). On devices with a VL pin, power-up VCC first.
VL
Logic-Level Supply which sets the VIL / VIH levels for the RE (ISL3282E only) and RE (ISL3285E only) pins, and sets the VOH level
of the RO output (ISL3282E, ISL3284E, ISL3285E only). Power-up this supply after VCC, and keep VL ≤ VCC.
NC
No Connection.
Typical Operating Circuits
NETWORK WITH ENABLES
+3.3V TO 5V
+3.3V
+
1
0.1µF
0.1µF
+
2
VCC
VCC
ISL3281E
3 RO
R
ISL329xE
A
6
B
4
RT
6
Y
4
Z
D
5 RE
DI 1
DE 3
GND
GND
2
5
4
FN6543.2
October 18, 2007
ISL3280E, ISL3281E, ISL3282E, ISL3283E, ISL3284E, ISL3285E
Typical Operating Circuits (Continued)
NETWORK WITHOUT ENABLES
+3.3V TO 5V
+3.3V
+
0.1µF
1
VCC
0.1µF
+
2
R
3
VCC
ISL3280E
3 RO
1kΩ TO 3kΩ
ISL329xE
A
5
B
4
RT
6
Y
4
Z
DE
D
GND
GND
2
5
DI 1
NETWORK WITH VL PIN FOR INTERFACE TO LOWER VOLTAGE LOGIC DEVICES
1.8V
+3.3V TO 5V
+3.3V
+
4
6
VCC
0.1µF
0.1µF
8
VCC
VL
1 RO
R
1
VCC
ISL3282E
LOGIC
DEVICE
(µP, ASIC,
UART)
2.5V
+
VL
ISL3298E
A
5
B
8
RT
6
Y
7
Z
D
7 RE
DI 3
DE 2
GND
2
5
VCC
LOGIC
DEVICE
(μP, ASIC,
UART)
GND
4, 5
FN6543.2
October 18, 2007
ISL3280E, ISL3281E, ISL3282E, ISL3283E, ISL3284E, ISL3285E
Absolute Maximum Ratings
Thermal Information
VCC to GND. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 7V
VL to GND (ISL3282E, ISL3284E, ISL3285E Only). . -0.3V to (VCC
+0.3V)
Input Voltages
RE, RE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 7V
Input/Output Voltages
A, B. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -8V to +13V
RO (Not ISL3282E, ISL3284E, ISL3285E). . -0.3V to (VCC +0.3V)
RO (ISL3282E, ISL3284E, ISL3285E) . . . . . . -0.3V to (VL +0.3V)
Short Circuit Duration
RO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Indefinite
ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . See Specification Table
Thermal Resistance (Typical)
θJA (°C/W) θJC (°C/W)
5 Ld SOT-23 Package (Note 4) . . . . . .
190
N/A
6 Ld SOT-23 Package (Note 4) . . . . . .
177
N/A
8 Ld TDFN Package (Notes 5, 6). . . . .
65
8
Maximum Junction Temperature (Plastic Package) . . . . . . +150°C
Maximum Storage Temperature Range . . . . . . . . . .-65°C to +150°C
Pb-free reflow profile . . . . . . . . . . . . . . . . . . . . . . . . . .see link below
http://www.intersil.com/pbfree/Pb-FreeReflow.asp
Operating Conditions
Temperature Range
F Suffix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-40°C to +125°C
I Suffix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-40°C to +85°C
CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and
result in failures not covered by warranty.
NOTE:
4. θJA is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
5. θJA is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See
Tech Brief TB379.
6. For θJC, the “case temp” location is the center of the exposed metal pad on the package underside.
Electrical Specifications
PARAMETER
Test Conditions: VCC = 3.0V to 5.5V; VL = VCC (ISL3282E, ISL3284E, ISL3285E only); Typicals are at
TA = +25°C (Note 11); Unless Otherwise Specified (Note 7).
SYMBOL
TEST CONDITIONS
TEMP
MIN
TYP
MAX
(°C) (Note 10) (Note 11) (Note 10) UNITS
DC CHARACTERISTICS
VIH1
Input High Voltage (RE, RE)
(Notes 8, 9)
VIH2
Input Low Voltage (RE, RE)
(Notes 8, 9)
VL = VCC if ISL3282E, or
ISL3285E
VCC ≤ 3.6V
Full
2
-
-
V
VCC ≤ 5.5V
Full
2.4
-
-
V
ISL3282E and
ISL3285E Only
Full
1.7
-
-
V
Full
1.6
-
-
V
VIH3
2.7V ≤ VL < 3.0V
VIH4
2.3V ≤ VL < 2.7V
VIH5
1.6V ≤ VL < 2.3V
Full
0.72*VL
-
-
V
VIH6
1.35V ≤ VL < 1.6V
25
-
0.5*VL
-
V
VIL1
VL = VCC if ISL3282E or ISL3285E
Full
-
-
0.7
V
VIL2
VL ≥ 2.7V
Full
-
-
0.7
V
VIL3
2.3V ≤ VL < 2.7V
Full
-
-
0.6
V
VIL4
1.6V ≤ VL < 2.3V
Full
-
-
0.25*VL
V
ISL3282E and
ISL3285E Only
VIL5
1.35V ≤ VL < 1.6V
25
-
0.33*VL
-
V
Logic Input Current (Note 8)
IIN1
RE = RE = 0V or VCC
Full
-15
±9
15
µA
Input Current (A, B)
IIN2
VCC = 0V, 3.6V, or 5.5V
Receiver Differential
Threshold Voltage
VTH
VIN = 12V
Full
-
80
125
µA
VIN = -7V
Full
-100
-50
-
µA
Full
-200
-125
-50
mV
-7V ≤ VCM ≤ 12V
Receiver Input Hysteresis
ΔVTH
VCM = 0V
25
-
15
-
mV
Receiver Input Resistance
RIN
-7V ≤ VCM ≤ 12V
Full
-
150
-
kΩ
Receiver Short-Circuit Current
IOSR
0V ≤ VO ≤ VCC
Full
±7
±30
±85
mA
Receiver Output High Voltage
VOH1
IO = -3.5mA, VID = -50mV (VL = VCC if ISL3282E,
ISL3284E, ISL3285E)
Full
VCC - 0.4
-
-
V
VOH2
IO = -1mA, VL ≥ 1.6V
Full
VL - 0.4
-
-
V
VOH3
IO = -500µA, VL = 1.5V
Full
1.2
-
-
V
VOH4
IO = -150µA, VL = 1.35V
Full
1.15
-
-
V
VOH5
IO = -100µA, VL ≥ 1.35V
Full
VL - 0.1
-
-
V
6
ISL3282E,
ISL3284E, and
ISL3285E Only
FN6543.2
October 18, 2007
ISL3280E, ISL3281E, ISL3282E, ISL3283E, ISL3284E, ISL3285E
Electrical Specifications
Test Conditions: VCC = 3.0V to 5.5V; VL = VCC (ISL3282E, ISL3284E, ISL3285E only); Typicals are at
TA = +25°C (Note 11); Unless Otherwise Specified (Note 7). (Continued)
TEMP
MIN
TYP
MAX
(°C) (Note 10) (Note 11) (Note 10) UNITS
PARAMETER
SYMBOL
TEST CONDITIONS
Receiver Output Low Voltage
VOL1
IO = 4mA, VID = -200mV, VL ≥ 2.2V if ISL3282E,
ISL3284E, ISL3285E
Full
-
0.2
0.4
V
VOL2
IO = 2mA, VL ≥ 1.5V
Full
-
0.2
0.4
V
VOL3
IO = 1mA, VL ≥ 1.35V
VOL4
IO = 500µA, VL ≥ 1.35V
IOZR
ISL3282E,
ISL3284E, and
ISL3285E Only
Full
-
0.1
0.4
V
25
-
0.1
-
V
0V ≤ VO ≤ VCC
Full
-1
0.015
1
µA
ICC
RE/RE = VCC/0V
Full
-
400
500
µA
ISHDN
RE/RE = 0V/VCC
Full
-
-
20
µA
Three-State (high impedance)
Receiver Output Current
(Notes 8, 9)
SUPPLY CURRENT
No-Load Supply Current
Shutdown Supply Current
(Note 8)
ESD PERFORMANCE
RS-485 Pins (A, B)
All Pins
IEC61000-4-2, Air-Gap Discharge Method
25
-
±16.5
-
kV
IEC61000-4-2, Contact Discharge Method
25
-
±9
-
kV
Human Body Model, From Bus Pins to GND
25
-
±16.5
-
kV
HBM, per MIL-STD-883 Method 3015
25
-
±5
-
kV
MM
25
-
±250
-
V
VID = ±2V, VCM = 0V (Figure 1 and Table 2)
(Note 11)
Full
20
30, 24
-
Mbps
VID = ±2V, VCM = 0V (Figure 1)
Full
20
36
60
ns
VL ≥ 1.5V (Figure 1)
25
-
44
-
ns
RECEIVER SWITCHING CHARACTERISTICS
Maximum Data Rate
Receiver Input to Output Delay
fMAX
tPLH, tPHL
Receiver Skew | tPLH - tPHL |
ISL3282E,
ISL3284E, and
ISL3285E Only
VCC = 3.3V ±10% (Figure 1) VL = VCC if
ISL3282E,
VCC = 5V ±10% (Figure 1)
ISL3284E, or
ISL3285E
Full
-
1
5.5
ns
tSK2
Full
-
2
7.5
ns
tSK3
VL ≥ 1.8V (Figure 1)
-
2
-
ns
VL = 1.5V (Figure 1)
ISL3282E,
ISL3284E, and
ISL3285E Only
25
tSK4
25
-
4
-
ns
Receiver Enable to Output
High (Note 8)
tZH
RL = 1kΩ, CL = 15pF,
SW = GND (Figure 2)
Note 11
Full
-
240, 90
500
ns
VL ≥ 1.5V, Note 11
25
-
250, 120
-
ns
Receiver Enable to Output
Low (Note 8)
tZL
RL = 1kΩ, CL = 15pF,
SW = VCC (Figure 2)
Note 11
Full
-
240, 90
500
ns
25
-
250, 120
-
ns
Receiver Disable from Output
High (Note 8)
tHZ
RL = 1kΩ, CL = 15pF,
SW = GND (Figure 2)
Full
-
10
20
ns
Receiver Disable from Output
Low (Note 8)
tLZ
RL = 1kΩ, CL = 15pF,
SW = VCC (Figure 2)
tSK1
VL ≥ 1.5V, Note 11
VL ≥ 1.5V, Note 11
VL ≥ 1.5V, Note 11
25
-
24, 20
-
ns
Full
-
10
20
ns
25
-
24, 20
-
ns
NOTES:
7. 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.
8. Does not apply to the ISL3280E or ISL3284E.
9. If the Rx enable function isn’t needed, connect the enable pin to the appropriate supply, as described in the “Pin Descriptions” table.
10. Parts are 100% tested at +25°C. Over-temperature limits established by characterization and are not production tested.
11. Typical values are at 3.3V, 5V. Parameters with a single entry in the “TYP” column apply to 3.3V and 5V.
7
FN6543.2
October 18, 2007
ISL3280E, ISL3281E, ISL3282E, ISL3283E, ISL3284E, ISL3285E
Test Circuits and Waveforms
RE
VCC
0V
B
R
A
+1V
B
RE
GND
15pF
RO
0V
-1V
A
tPLH
tPHL
VCC OR VL
SIGNAL
GENERATORS
50%
RO
50%
0V
FIGURE 1A. TEST CIRCUIT
FIGURE 1B. MEASUREMENT POINTS
FIGURE 1. RECEIVER PROPAGATION DELAY AND DATA RATE
3V
RE OR RE
GND
B
A
1kΩ
RO
R
VCC OR VL
SW
SIGNAL
GENERATOR
RE
(INVERT FOR RE)
1.5V
0V
GND
tZH
15pF
OUTPUT HIGH
A
SW
tHZ
+1.5V
GND
tLZ
-1.5V
VCC OR VL
tZH
+1.5V
GND
tZL
-1.5V
V
VOH - 0.25V OH
0V
tZL
RO
tLZ
VCC OR VL
50%
OUTPUT LOW
VCC OR VL
FIGURE 2A. TEST CIRCUIT
tHZ
50%
RO
PARAMETER
1.5V
VOL + 0.25V V
OL
FIGURE 2B. MEASUREMENT POINTS
FIGURE 2. RECEIVER ENABLE AND DISABLE TIMES (EXCEPT ISL3280E AND ISL3284E)
Application Information
Receiver Features
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
point-to-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.
These devices utilize a differential input receiver for maximum
noise immunity and common mode rejection. Input sensitivity
is better than ±200mV, as required by the RS-422 and RS-485
specifications.
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
ground potential differences, as well as voltages induced in
the cable by external fields.
8
Receiver input resistance of 96kΩ surpasses the RS-422
specification of 4kΩ and is eight times the RS-485 “Unit
Load (UL)” requirement of 12kΩ minimum. Thus, these
products are known as “one-eighth UL” transceivers and
there can be up to 256 of these devices on a network while
still complying with the RS-485 loading specification.
Receiver inputs function with common mode voltages as great
as +9V/-7V outside the power supplies (i.e., +12V and -7V),
making them ideal for long networks where induced voltages,
and ground potential differences are realistic concerns.
FN6543.2
October 18, 2007
ISL3280E, ISL3281E, ISL3282E, ISL3283E, ISL3284E, ISL3285E
All the receivers include a “full fail-safe” function that
guarantees a high level receiver output if the receiver inputs
are unconnected (floating), shorted together, or connected to
a terminated but undriven bus. Fail-safe with shorted inputs is
achieved by setting the Rx upper switching point to -50mV,
thereby ensuring that the Rx sees 0V differential as a high
input level.
All receivers easily support a 20Mbps data rate, and all
receiver outputs (except on the ISL3280E and ISL3284E)
are tri-statable via the active low RE input or by the active
high RE input.
TABLE 2. VIH, VIL AND DATA RATE vs VL FOR VCC = 3.3V OR
5V
VL
(V)
VIH
(V)
VIL
(V)
DATA RATE
(Mbps)
1.35
0.55
0.5
11
1.6
0.7
0.6
16
1.8
0.8
0.7
23
2.3
1
0.9
27
2.7
1.1
1
30
3.3
1.3
1.2
30
5.5 (i.e., VCC)
2
1.8
24
VCC = +3.3V
RO
RE
VCC = +2V
VOH = 3.3V
RXD
VOH ≤ 2V
ISL3283E
RXEN
GND
UART/PROCESSOR
VCC = +3.3V TO 5V
VCC = +2V
VL
RO
RE
GND
The ISL3280E, ISL3281E, ISL3282E, ISL3283E,
ISL3284E, ISL3285E are designed to operate with a wide
range of supply voltages from 3.0V to 5.5V. These devices
meet the RS-422 and RS-485 specifications over this full
range.
Logic Supply (VL Pin, ISL3282E, ISL3284E,
ISL3285E Only)
Note: Power-up VCC before powering up the VL supply.
The ISL3282E, ISL3284E, and ISL3285E include a VL pin
that powers the logic input (RE or RE) and / or the Rx output.
These pins interface with “logic” devices such as UARTs,
ASICs, and microcontrollers and today most of these
devices use power supplies significantly lower than 3.3V.
Thus, a 3.3V output level from a 3.3V powered RS-485 IC
might seriously overdrive and damage the logic device input.
Similarly, the logic device’s low VOH might not exceed the
VIH of a 3.3V or 5V powered RE input. Connecting the VL
pin to the power supply of the logic device (as shown in
Figure 3) limits the ISL3282E, ISL3284E, ISL3285E’s Rx
output VOH to VL (see Figures 6 through 10), and reduces
the RE / RE input switching point to a value compatible with
the logic device’s output levels. Tailoring the logic pin input
switching point and output levels to the supply voltage of the
UART, ASIC, or microcontroller eliminates the need for a
level shifter/translator between the two ICs.
VL can be anywhere from VCC down to 1.35V, but the input
switching points may not provide enough noise margin when
VL < 1.6V. Table 2 indicates typical VIH, VIL, and data rate
values for various VL settings so the user can ascertain
whether or not a particular VL voltage meets his/her needs.
The quiescent, RO unloaded, VL supply current (IL) is
typically less than 60µA for VL ≤ 3.3V, as shown in Figure 5.
VIH ≥ 2V
GND
ESD
DIODE
Wide Supply Range
VOH = 2V
RXD
VIH = 1V
VOH ≤ 2V
ISL3282E
ESD
DIODE
RXEN
GND
UART/PROCESSOR
ESD Protection
All pins on these devices include class 3 (>4kV) Human
Body Model (HBM) ESD protection structures, but the
RS-485 pins (receiver inputs) incorporate advanced
structures allowing them to survive ESD events in excess
of ±16.5kV HBM and ±16.5kV IEC61000. 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, 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.
FIGURE 3. USING VL PIN TO ADJUST LOGIC LEVELS
9
FN6543.2
October 18, 2007
ISL3280E, ISL3281E, ISL3282E, ISL3283E, ISL3284E, ISL3285E
IEC61000-4-2 Testing
The IEC61000 test method applies to finished equipment,
rather than to an individual IC. Therefore, the pins most likely
to suffer an ESD event are those that are exposed to the
outside world (the RS-485 pins in this case), and the IC is
tested in its typical application configuration (power applied)
rather than testing each pin-to-pin combination. The lower
current limiting resistor coupled with the larger charge
storage capacitor yields a test that is much more severe than
the HBM test. The extra ESD protection built into this
device’s RS-485 pins allows the design of equipment
meeting level 4 criteria without the need for additional board
level protection on the RS-485 port.
AIR-GAP DISCHARGE TEST METHOD
For this test method, a charged probe tip moves toward the
IC pin until the voltage arcs to it. The current waveform
delivered to the IC pin depends on approach speed,
humidity, temperature, etc., so it is difficult to obtain
repeatable results. The A and B RS-485 pins withstand
±16.5kV air-gap discharges.
CONTACT DISCHARGE TEST METHOD
During the contact discharge test, the probe contacts the
tested pin before the probe tip is energized, thereby
eliminating the variables associated with the air-gap
discharge. The result is a more repeatable and predictable
test, but equipment limits prevent testing devices at voltages
higher than ±9kV. The ISL3280E, ISL3281E, ISL3282E,
ISL3283E, ISL3284E, ISL3285E survive ±9kV contact
discharges on the RS-485 pins.
Data Rate, Cables, and Terminations
RS-485, RS-422 are intended for network lengths up to
4000’, but the maximum system data rate decreases as the
Typical Performance Curves
transmission length increases. Networks operating at
20Mbps are limited to lengths less than 100’, while a
250kbps network that uses slew rate limited transmitters can
operate at that data rate over lengths of several thousand
feet.
Twisted pair is the cable of choice for RS-485, RS-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 receiver in these ICs.
To minimize reflections, proper termination is imperative for
high data rate networks. Short networks using slew rate
limited transmitters 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 transmitter or
receiver to the main cable should be kept as short as
possible.
Low Power Shutdown Mode
These BiCMOS receivers all use a fraction of the power
required by their bipolar counterparts, and the versions with
output enable functions include a shutdown feature that
reduces the already low quiescent ICC to a 20µA trickle.
These versions enter shutdown whenever the receiver
disables (RE = VCC or RE = GND).
CL = 15pF, TA = +25°C; Unless Otherwise Specified.
0.50
250
VCC = 5V OR 3.3V
VCC = VL = 5V
0.45
0.40
200
VCC = VL = 3.3V
0.30
IL (μA)
ICC (mA)
0.35
0.25
0.20
150
VL = 5V, VCC = 5V ONLY
100
0.15
VL ≤ 1.8V
0.10
50
VL = 3.3V
0.05
0
-40
RE = VCC, RE = 0V
-15
10
60
35
TEMPERATURE (°C)
85
110 125
FIGURE 4. SUPPLY CURRENT vs TEMPERATURE
10
0
VL = 2.5V
0
1
2
3
4
5
6
7 7.5
RE VOLTAGE (V)
FIGURE 5. VL SUPPLY CURRENT vs ENABLE PIN VOLTAGE
FN6543.2
October 18, 2007
ISL3280E, ISL3281E, ISL3282E, ISL3283E, ISL3284E, ISL3285E
Typical Performance Curves
30
VCC = VL = 5V
50
VOL, +25°C
VOH, +25°C
VOL, +85°C
VOL, +125°C
40
VOH, +125°C
30
VOH, +85°C
20
10
RECEIVER OUTPUT CURRENT (mA)
RECEIVER OUTPUT CURRENT (mA)
60
CL = 15pF, TA = +25°C; Unless Otherwise Specified. (Continued)
VOL, +25°C
25
VOL, +85°C
VOH, +25°C
VOL, +125°C
20
15
VOH, +85°C
VOH, +125°C
10
5
VCC = 5V OR 3.3V, VL = 3.3V
0
1
0
2
3
4
0
5
0
0.5
FIGURE 6. RECEIVER OUTPUT CURRENT vs RECEIVER
OUTPUT VOLTAGE
VOL, +25°C
VOL, +85°C
16
14
VOL, +125°C
12 VOH, +25°C
10
8
VOH, +85°C
VOH, +125°C
6
4
2
0
VCC = 5V OR 3.3V, VL = 1.8V
2.5
3.0 3.3
VOL, +25°C
8
VOL, +85°C
7
VOL, +125°C
6
5
4
VOH, +25°C
VOH, +85°C
3
VOH, +125°C
2
1
0
0
0.5
1.0
1.5
2.0
0
2.5
0.5
RECEIVER OUTPUT VOLTAGE (V)
1.0
1.5
1.8
RECEIVER OUTPUT VOLTAGE (V)
FIGURE 8. RECEIVER OUTPUT CURRENT vs RECEIVER
OUTPUT VOLTAGE
FIGURE 9. RECEIVER OUTPUT CURRENT vs RECEIVER
OUTPUT VOLTAGE
55
5.0
VCC = 5V
VCC = 5V or 3.3V, VL = 1.5V
4.5
VOL, +85°C
VOL, +25°C
4.0
VOL, +125°C
3.5
3.0
2.5
2.0
VOH, +25°C
VOH, +85°C
1.5
VOH, +125°C
1.0
PROPAGATION DELAY (ns)
RECEIVER OUTPUT CURRENT (mA)
2.0
9
VCC = 5V OR 3.3V, VL = 2.5V
18
1.5
FIGURE 7. RECEIVER OUTPUT CURRENT vs RECEIVER
OUTPUT VOLTAGE
RECEIVER OUTPUT CURRENT (mA)
RECEIVER OUTPUT CURRENT (mA)
20
1.0
RECEIVER OUTPUT VOLTAGE (V)
RECEIVER OUTPUT VOLTAGE (V)
50
VL = 1.5V
45
VL = 1.8V
40
VL = 2.5V
35
0.5
0
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4 1.5
RECEIVER OUTPUT VOLTAGE (V)
FIGURE 10. RECEIVER OUTPUT CURRENT vs RECEIVER
OUTPUT VOLTAGE
11
30
-40
-15
10
35
60
85
110 125
TEMPERATURE (°C)
FIGURE 11. RECEIVER PROPAGATION DELAY vs
TEMPERATURE
FN6543.2
October 18, 2007
ISL3280E, ISL3281E, ISL3282E, ISL3283E, ISL3284E, ISL3285E
Typical Performance Curves
5.0
CL = 15pF, TA = +25°C; Unless Otherwise Specified. (Continued)
|tPLH - tPHL|
55
VCC = 5V
VCC = 3.3V
4.5
4.0
PROPAGATION DELAY (ns)
VL = 1.5V
SKEW (ns)
3.5
3.0
2.5
VL = 2.5V
2.0
VL = 1.8V
1.5
1.0
50
VL = 1.5V
45
VL = 1.8V
40
VL = 2.5V
35
0.5
0
-40
-15
10
35
60
85
110
30
-40
125
-15
10
TEMPERATURE (°C)
|tPLH - tPHL|
VCC = 3.3V
3.5
VL = 1.5V
2.0
RECEIVER OUTPUT (V)
SKEW (ns)
3.0
2.5
1.5 VL = 1.8V
1.0
VL = 2.5V
0.5
VL = 1.8V
0
-40
-15
10
35
60
85
110
VCC = 5V
0
A-B
-2.0
VL = 5V
5.0
4.0
VL = 2.5V
3.0
2.0
VL = 1.5V
1.0
0
125
TIME (20ns/DIV)
FIGURE 14. RECEIVER SKEW vs TEMPERATURE
RECEIVER INPUT (V)
110 125
85
2.0
TEMPERATURE (°C)
RECEIVER OUTPUT (V)
60
FIGURE 13. RECEIVER PROPAGATION DELAY vs
TEMPERATURE
RECEIVER INPUT (V)
FIGURE 12. RECEIVER SKEW vs TEMPERATURE
4.0
35
TEMPERATURE (°C)
VCC = 3.3V
2.0
0
FIGURE 15. RECEIVER WAVEFORMS
Die Characteristics
SUBSTRATE AND TDFN THERMAL PAD POTENTIAL
(POWERED UP):
A-B
-2.0
GND
4.0
VL = 3.3V
140
3.0
2.0
TRANSISTOR COUNT:
VL = 2.5V
VL = 1.5V
1.0
PROCESS:
Si Gate BiCMOS
0
TIME (20ns/DIV)
FIGURE 16. RECEIVER WAVEFORMS
12
FN6543.2
October 18, 2007
ISL3280E, ISL3281E, ISL3282E, ISL3283E, ISL3284E, ISL3285E
Small Outline Transistor Plastic Packages (SOT23-5)
P5.064
D
VIEW C
e1
5 LEAD SMALL OUTLINE TRANSISTOR PLASTIC PACKAGE
INCHES
5
SYMBOL
4
E
CL
1
2
CL
3
e
E1
b
CL
α
0.20 (0.008) M
C
C
CL
A
A2
SEATING
PLANE
A1
-C-
WITH
b
PLATING
b1
c
c1
MILLIMETERS
MAX
MIN
MAX
NOTES
A
0.036
0.057
0.90
1.45
-
A1
0.000
0.0059
0.00
0.15
-
A2
0.036
0.051
0.90
1.30
-
b
0.012
0.020
0.30
0.50
-
b1
0.012
0.018
0.30
0.45
c
0.003
0.009
0.08
0.22
6
c1
0.003
0.008
0.08
0.20
6
D
0.111
0.118
2.80
3.00
3
E
0.103
0.118
2.60
3.00
-
E1
0.060
0.067
1.50
1.70
3
e
0.0374 Ref
0.95 Ref
-
e1
0.0748 Ref
1.90 Ref
-
L
0.10 (0.004) C
MIN
0.014
0.022
0.35
0.55
L1
0.024 Ref.
0.60 Ref.
L2
0.010 Ref.
0.25 Ref.
N
5
5
4
5
R
0.004
-
0.10
-
R1
0.004
0.010
0.10
0.25
α
0o
8o
0o
8o
Rev. 2 9/03
NOTES:
BASE METAL
1. Dimensioning and tolerance per ASME Y14.5M-1994.
2. Package conforms to EIAJ SC-74 and JEDEC MO178AA.
4X θ1
3. Dimensions D and E1 are exclusive of mold flash, protrusions,
or gate burrs.
R1
4. Footlength L measured at reference to gauge plane.
5. “N” is the number of terminal positions.
R
GAUGE PLANE
SEATING
PLANE
L
C
L1
α
L2
6. These Dimensions apply to the flat section of the lead between
0.08mm and 0.15mm from the lead tip.
7. Controlling dimension: MILLIMETER. Converted inch dimensions are for reference only.
4X θ1
VIEW C
13
FN6543.2
October 18, 2007
ISL3280E, ISL3281E, ISL3282E, ISL3283E, ISL3284E, ISL3285E
Small Outline Transistor Plastic Packages (SOT23-6)
0.20 (0.008) M
P6.064
VIEW C
C
6 LEAD SMALL OUTLINE TRANSISTOR PLASTIC PACKAGE
CL
INCHES
e
b
SYMBOL
6
5
4
CL
CL
E1
E
1
2
3
e1
C
D
CL
A
A2
SEATING
PLANE
A1
-C-
WITH
b
PLATING
b1
c
c1
MILLIMETERS
MAX
MIN
MAX
NOTES
A
0.036
0.057
0.90
1.45
-
A1
0.000
0.0059
0.00
0.15
-
A2
0.036
0.051
0.90
1.30
-
b
0.012
0.020
0.30
0.50
-
b1
0.012
0.018
0.30
0.45
c
0.003
0.009
0.08
0.22
6
c1
0.003
0.008
0.08
0.20
6
D
0.111
0.118
2.80
3.00
3
E
0.103
0.118
2.60
E1
0.060
0.068
1.50
3.00
-
1.75
3
e
0.0374 Ref
0.95 Ref
-
e1
0.0748 Ref
1.90 Ref
-
L
0.10 (0.004) C
MIN
0.014
0.022
0.35
0.55
L1
0.024 Ref.
0.60 Ref.
L2
0.010 Ref.
0.25 Ref.
N
6
6
4
5
R
0.004
-
0.10
-
R1
0.004
0.010
0.10
0.25
α
0o
8o
0o
8o
Rev. 3 9/03
BASE METAL
NOTES:
1. Dimensioning and tolerance per ASME Y14.5M-1994.
2. Package conforms to EIAJ SC-74 and JEDEC MO178AB.
4X θ1
3. Dimensions D and E1 are exclusive of mold flash, protrusions,
or gate burrs.
R1
4. Footlength L measured at reference to gauge plane.
R
5. “N” is the number of terminal positions.
GAUGE PLANE
SEATING
PLANE
L
C
L1
α
L2
6. These Dimensions apply to the flat section of the lead between
0.08mm and 0.15mm from the lead tip.
7. Controlling dimension: MILLIMETER. Converted inch dimensions are for reference only
4X θ1
VIEW C
14
FN6543.2
October 18, 2007
ISL3280E, ISL3281E, ISL3282E, ISL3283E, ISL3284E, ISL3285E
Thin Dual Flat No-Lead Plastic Package (TDFN)
L8.2x3A
2X
0.15 C A
A
D
8 LEAD THIN DUAL FLAT NO-LEAD PLASTIC PACKAGE
2X
MILLIMETERS
0.15 C B
SYMBOL
E
MIN
A
0.70
A1
-
6
A3
INDEX
AREA
b
TOP VIEW
D2
0.20
0.10
SIDE VIEW
C
SEATING
PLANE
D2
(DATUM B)
0.08 C
A3
7
0.75
0.80
-
-
0.05
-
0.25
0.32
1.50
1.65
1.75
1
7,8
3.00 BSC
-
8
1.65
e
1.80
1.90
7,8
0.50 BSC
-
k
0.20
-
-
-
L
0.30
0.40
0.50
8
N
8
Nd
4
D2/2
6
INDEX
AREA
5,8
C
E2
A
NOTES
2.00 BSC
E
//
MAX
0.20 REF
D
B
NOMINAL
2
3
Rev. 0 6/04
2
NX k
NOTES:
1. Dimensioning and tolerancing conform to ASME Y14.5-1994.
2. N is the number of terminals.
3. Nd refers to the number of terminals on D.
(DATUM A)
E2
4. All dimensions are in millimeters. Angles are in degrees.
E2/2
5. Dimension b applies to the metallized terminal and is measured
between 0.25mm and 0.30mm from the terminal tip.
NX L
6. The configuration of the pin #1 identifier is optional, but must be
located within the zone indicated. The pin #1 identifier may be
either a mold or mark feature.
N N-1
NX b
e
8
5
0.10
(Nd-1)Xe
REF.
M C A B
7. Dimensions D2 and E2 are for the exposed pads which provide
improved electrical and thermal performance.
8. Nominal dimensions are provided to assist with PCB Land
Pattern Design efforts, see Intersil Technical Brief TB389.
BOTTOM VIEW
CL
(A1)
NX (b)
L
5
SECTION "C-C"
C C
TERMINAL TIP
e
FOR EVEN TERMINAL/SIDE
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.
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
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com
15
FN6543.2
October 18, 2007