MAXIM MAX3281EAUT-T

19-2320; Rev 0; 1/02
±15kV ESD-Protected 52Mbps, 3V to 5.5V, SOT23
RS-485/RS-422 True Fail-Safe Receivers
Features
♦ ESD Protection:
±15kV–Human Body Model
±6kV–IEC 1000-4-2, Contact Discharge
±12kV–IEC 1000-4-2, Air-Gap Discharge
♦ Guaranteed 52Mbps Data Rate
♦ Guaranteed 15ns Receiver Propagation Delay
♦ Guaranteed 2ns Receiver Skew
♦ Guaranteed 8ns Package-to-Package Skew Time
♦ VL Pin for Connection to FPGAs/ASICs
♦ Allow Up to 128 Transceivers on the Bus
(1/4-unit-load)
♦ Tiny SOT23 Package
♦ True Fail-Safe Receiver
♦ -7V to +12V Common-Mode Range
♦ 3V to 5.5V Power-Supply Range
♦ Enable (High and Low) Pins for Redundant
Operation
♦ Three-State Output Stage (MAX3281E/MAX3283E)
♦ Thermal Protection Against Output Short Circuit
Applications
Ordering Information
Clock Distribution
PART
Telecom Racks
TEMP RANGE
PINPACKAGE
TOP
MARK
ADVM
Base Stations
MAX3280EAUK-T
-40°C to +125°C
5 SOT23-5
Industrial Control
MAX3281EAUT-T
-40°C to +125°C
6 SOT23-6
ABAT
MAX3283EAUT-T
-40°C to +125°C
6 SOT23-6
ABAU
MAX3284EAUT-T
-40°C to +125°C
6 SOT23-6
ABAV
Local Area Networks
Pin Configurations appear at end of data sheet.
Selector Guide
PART
VL
ENABLE
DATA RATE
PACKAGE
MAX3280E
—
—
52Mbps
5-Pin SOT23
MAX3281E
—
Active High
52Mbps
6-Pin SOT23
MAX3283E
—
Active Low
52Mbps
6-Pin SOT23
MAX3284E
✔
—
52Mbps (Note 1)
6-Pin SOT23
Note 1: MAX3284E data rate is dependent on VL.
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX3280E/MAX3281E/MAX3283E/MAX3284E
General Description
The MAX3280E/MAX3281E/MAX3283E/MAX3284E are
single receivers designed for RS-485 and RS-422 communication. These devices guarantee data rates up to
52Mbps, even with a 3V power supply. Excellent propagation delay (15ns max) and package-to-package
skew time (8ns max) make these devices ideal for multidrop clock distribution applications.
The MAX3280E/MAX3281E/MAX3283E/MAX3284E
have true fail-safe circuitry, which guarantees a logichigh receiver output when the receiver inputs are
opened or shorted. The receiver output will be a logic
high if all transmitters on a terminated bus are disabled
(high impedance). These devices feature 1/4-unit-load
receiver input impedance, allowing up to 128 receivers
on the same bus.
The MAX3280E is a single receiver available in a 5-pin
SOT23 package. The MAX3281E/MAX3283E single
receivers have a receiver enable (EN or EN) function
and are offered in a 6-pin SOT23 package. The
MAX3284E features a voltage logic pin that allows compatibility with low-voltage logic levels, as in digital
FPGAs/ASICs. On the MAX3284E, the voltage threshold
for a logic high is user-defined by setting VL in the
range from 1.65V to V CC . The MAX3284E is also
offered in a 6-pin SOT23 package.
MAX3280E/MAX3281E/MAX3283E/MAX3284E
±15kV ESD-Protected 52Mbps, 3V to 5.5V, SOT23
RS-485/RS-422 True Fail-Safe Receivers
ABSOLUTE MAXIMUM RATINGS
(All Voltages Referenced to GND)
Supply Voltage (VCC) ...............................................-0.3V to +6V
Control Input Voltage (EN, EN).................................-0.3V to +6V
VL Input Voltage .......................................................-0.3V to +6V
Receiver Input Voltage (A, B)..............................-7.5V to +12.5V
Receiver Output Voltage (RO)....................-0.3V to (VCC + 0.3V)
Receiver Output Voltage
(RO) (MAX3284E) .....................................-0.3V to (VL + 0.3V)
Receiver Output Short-Circuit Current .......................Continuous
Continuous Power Dissipation (TA = +70°C)
5-Pin SOT23 (derate 7.1mW/°C above +70°C)............571mW
6-Pin SOT23 (derate 8.7mW/°C above +70°C)............696mW
Operating Temperature Range
MAX328_EA__ ..............................................-40°C to +125°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature ......................................................+150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VCC = 3V to 5.5V, VL = VCC, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = 5V and TA = +25°C.) (Notes 2, 3)
PARAMETER
SYMBOL
CONDITIONS
Supply Voltage
VCC
Supply Current
ICC
No load
VL Input Range
VL
MAX3284E
VL Supply Current
IL
No load (MAX3284E)
MIN
TYP
3.0
9
1.65
MAX
UNITS
5.5
V
15
mA
VCC
V
10
µA
RECEIVER
VIN = +12V
250
VIN = -7V
-200
Input Current (A and B)
IA, B
VCC = GND or 5.5V
Receiver Differential Threshold
Voltage
VTH
-7V ≤ VCM ≤ +12V
(Note 4)
Receiver Input Hysteresis
∆VTH
V A + VB = 0
Receiver Enable Input Low
VENIL
MAX3281E, MAX3283E only
Receiver Enable Input High
VENIH
MAX3281E, MAX3283E only
Receiver Enable Input Leakage
ILEAK
MAX3281E, MAX3283E only
Receiver Output High Voltage
Receiver Output Low Voltage
VOH
VOL
-200
-125
-50
25
2
MAX3284E, IOH = -1mA, 1.65V ≤ VL ≤ VCC,
RO high
VL - 0.4
0.4
MAX3284E, IOL = 1mA, 1.65V ≤ VL ≤ VCC,
RO low
0.4
±5
IOZR
0 ≤ VO ≤ VCC, RO = high impedance
Receiver Input Resistance
RIN
-7V ≤ VCM ≤ +12V (Note 5)
Receiver Output Short-Circuit
Current
IOSR
0 ≤ VRO ≤ VCC
µA
V
MAX3280E/MAX3281E/MAX3283E,
IOL = 4mA, RO low
Three-State Output Current at
Receiver
V
V
±10
VCC - 0.4
mV
mV
0.4
MAX3280E/MAX3281E/MAX3283E,
IOH = -4mA, RO high
µA
V
48
µA
kΩ
±130
mA
ESD PROTECTION
ESD Protection (A, B)
2
Human Body Model
±15
IEC1000-4-2 (Air-Gap Discharge)
±12
IEC1000-4-2 (Contact Discharge)
±6
_______________________________________________________________________________________
kV
±15kV ESD-Protected 52Mbps, 3V to 5.5V, SOT23
RS-485/RS-422 True Fail-Safe Receivers
(VCC = 3V to 5.5V, VL = VCC, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = 5V and TA = +25°C.) (Notes 2, 3)
PARAMETER
SYMBOL
Maximum Data Rate
Receiver Propagation Delay
Receiver Output |tPLH - tPHL|
CONDITIONS
TYP
MAX
Figure 1, CL = 15pF, VID = 2V, VCM = 0
7
15
Figure 1, CL = 15pF, VID = 2V, VCM = 0
8
15
fMAX
CL = 15pF (Notes 5, 6)
tPLH
tPHL
tPSKEW
Device-to-Device Propagation
Delay Matching
MIN
52
UNITS
Mbps
ns
Figure 1, CL = 15pF, TA = +25°C
2
ns
Same power supply, maximum temperature
difference between devices = +30°C.
(Note 5)
8
ns
ENABLE/DISABLE TIME FOR MAX3281E/MAX3283E
Receiver Enable to Output Low
tPRZL
Figure 2, CL = 15pF
500
ns
Receiver Enable to Output High
tPRZH
Figure 2, CL = 15pF
500
ns
Receiver Disable Time from Low
tPRLZ
Figure 2, CL = 15pF
500
ns
Receiver Disable Time from High
tPRHZ
Figure 2, CL = 15pF
500
ns
Note 2: Parameters are 100% production tested at +25°C, limits over temperature are guaranteed by design.
Note 3: All currents into the device are positive; all currents out of the device are negative. All voltages are referenced to device
ground, unless otherwise noted.
Note 4: VCM is the common-mode input voltage. VID is the differential input voltage.
Note 5: Not production tested. Guaranteed by design.
Note 6: See Table 2 for MAX3284E data rates with VL < VCC.
Typical Operating Characteristics
(VCC = 3.3V, TA = +25°C, unless otherwise noted.)
RECEIVER OUTPUT HIGH VOLTAGE
vs. OUTPUT CURRENT
3
VCC = 3.3V
VCC = 5V
2
4
VCC = 5V
3
VCC = 3.3V
2
1
1
0
0
0
10
20
30
40
OUTPUT CURRENT (mA)
50
60
-50
-40
-30
-20
OUTPUT CURRENT (mA)
-10
0
5.0
MAX3280/1/3/4E toc03
MAX3280/1/3/4E toc02
OUTPUT VOLTAGE (V)
4
5
OUTPUT VOLTAGE (V)
MAX3280/1/3/4E toc01
5
RECEIVER OUTPUT HIGH VOLTAGE
vs. TEMPERATURE
RECEIVER OUTPUT HIGH VOLTAGE (V)
RECEIVER OUTPUT LOW VOLTAGE
vs. OUTPUT CURRENT
VCC = 5V
4.5
4.0
3.5
VCC = 3.3V
3.0
A = 1V, B = GND, IOH = -4mA
2.5
-50
-25
0
25
50
75
100
125
TEMPERATURE (°C)
_______________________________________________________________________________________
3
MAX3280E/MAX3281E/MAX3283E/MAX3284E
SWITCHING CHARACTERISTICS
Typical Operating Characteristics (continued)
(VCC = 3.3V, TA = +25°C, unless otherwise noted.)
150
10
MAX3280/1/3/4E toc05
9
MAX3280/1/3/4E toc04
200
RECEIVER PROPAGATION DELAY (tPHL)
vs. TEMPERATURE
RECEIVER PROPAGATION DELAY (tPLH)
vs. TEMPERATURE
8
VCC = 3.3V
MAX3280/1/3/4E toc06
RECEIVER OUTPUT LOW VOLTAGE
vs. TEMPERATURE
9
VCC = 5V
VCC = 5V
100
7
tPHL (ns)
tPLH (ns)
RECEIVER OUTPUT LOW VOLTAGE (mV)
VCC = 3.3V
VCC = 5V
8
VCC = 3.3V
6
50
7
5
A = GND, B = 1V, IOL = 4mA
0
6
4
-50
-25
0
25
50
75
100
125
-50
-25
TEMPERATURE (°C)
0
25
50
75
100
-25
0
7
MAX3280/1/3/4E toc08
60
50
DATA RATE (Mbps)
8
50
MAX3284E MAXIMUM DATA RATE
vs. VOLTAGE LOGIC LEVEL
MAX3280/1/3/4E toc07
VCC = 5V
25
6
40
30
VCC = 3.3V
5
20
0
25
50
75
100
125
2.5
3.5
SUPPLY CURRENT vs. DATA RATE
VL SUPPLY CURRENT
vs. TEMPERATURE
MAX3280/1/3/4E toc09
ICC, VCC = VL = 5V
8
ICC, VCC = VL = 3.3V
IL, VCC = VL = 5V
4
2
5.5
10
1
VCC = VL = 5V
DATA RATE = 52Mbps VCC = VL = 3.3V
DATA RATE = 52Mbps
0.1
VCC = VL = 5V
DATA RATE = 100kbps
0.01
VCC = VL = 3.3V
DATA RATE = 100kbps
IL, VCC = VL = 3.3V
0
0.001
10
100
1000
DATA RATE (kbps)
4
4.5
VOLTAGE LOGIC LEVEL (V)
10
6
1.5
TEMPERATURE (°C)
MAX3280/1/3/4 toc10
-25
VL SUPPLY CURRENT (mA)
-50
10,000
100,000
75
TEMPERATURE (°C)
TEMPERATURE (°C)
9
SUPPLY CURRENT (mA)
-50
125
SUPPLY CURRENT vs. TEMPERATURE
SUPPLY CURRENT (mA)
MAX3280E/MAX3281E/MAX3283E/MAX3284E
±15kV ESD-Protected 52Mbps, 3V to 5.5V, SOT23
RS-485/RS-422 True Fail-Safe Receivers
-50
-25
0
25
50
75
100
TEMPERATURE (°C)
_______________________________________________________________________________________
125
100
125
±15kV ESD-Protected 52Mbps, 3V to 5.5V, SOT23
RS-485/RS-422 True Fail-Safe Receivers
PIN
NAME
FUNCTION
MAX3280E
MAX3281E
MAX3283E
MAX3284E
1
1
1
1
VCC
Positive Supply: 3V ≤ VCC ≤ 5.5V. Bypass with a 0.1µF
capacitor to GND.
2
2
2
2
GND
Ground
3
3
3
3
RO
4
4
4
4
B
—
—
5
—
EN
Receiver Output Enable. Drive EN low to enable RO. When EN
is high, RO is high impedance.
—
5
—
—
EN
Receiver Output Enable. Drive EN high to enable RO. When
EN is low, RO is high impedance.
—
—
—
5
VL
Low-Voltage Logic-Level Supply Voltage. VL is a user-defined
voltage, ranging from 1.65V to VCC. RO output high is pulled up
to VL. Bypass with a 0.1µF capacitor to GND.
5
6
6
6
A
Noninverting Receiver Input
Detailed Description
The MAX3280E/MAX3281E/MAX3283E/MAX3284E are
single, true fail-safe receivers designed to operate at
data rates up to 52Mbps. The fail-safe architecture guarantees a high output signal if both input terminals are
open or shorted together. See the True Fail-Safe section.
This feature assures a stable and predictable output
logic state with any transmitter driving the line. These
receivers function with a 3.3V or 5V supply voltage and
feature excellent propagation delay times (15ns).
The MAX3280E is a single receiver available in a 5-pin
SOT23 package. The MAX3281E (EN, active high) and
MAX3283E (EN, active low) are single receivers that
also contain an enable pin. Both the MAX3281E and
MAX3283E are available in a 6-pin SOT23 package.
The MAX3284E is a single receiver that contains a VL
pin, which allows communication with low-level logic
included in digital FPGAs. The MAX3284E is available
in a 6-pin SOT23 package.
The MAX3284E’s low-level logic application allows
users to set the logic levels. A logic high level of 1.65V
will limit the maximum data rate to 20Mbps.
±15kV ESD Protection
ESD-protection structures are incorporated on the
receiver input pins to protect against ESD encountered
during handling and assembly. The MAX3280E/
MAX3281E/MAX3283E/MAX3284E receiver inputs (A,
B) have extra protection against static electricity found
in normal operation. Maxim’s engineers developed
state-of-the-art structures to protect these pins against
Receiver Output. RO will be high if (A–B) ≥ -50mV. RO will be
low if (A–B) ≤ -200mV.
Inverting Receiver Input
±15kV ESD without damage. After an ESD event, this
family of parts continues working without latchup.
ESD protection can be tested in several ways. The
receiver inputs are characterized for protection to the
following:
• ±15kV using the Human Body Model
• ±6kV using the Contact Discharge method specified
in IEC 1000-4-2 (formerly IEC 801-2)
• ±12kV using the Air-Gap Discharge method specified in IEC 1000-4-2 (formerly IEC 801-2)
ESD Test Conditions
ESD performance depends on a number of conditions.
Contact Maxim for a reliability report that documents
test setup, methodology, and results.
Human Body Model
Figure 3a shows the Human Body Model, and Figure
3b shows the current waveform it generates when discharged into a low impedance. This model consists of
a 100pF capacitor charged to the ESD voltage of interest, which is then discharged into the device through a
1.5kΩ resistor.
IEC 1000-4-2
Since January 1996, all equipment manufactured
and/or sold in the European community has been
required to meet the stringent IEC 1000-4-2 specification. The IEC 1000-4-2 standard covers ESD testing
and performance of finished equipment; it does not
specifically refer to integrated circuits. The
MAX3280E/MAX3281E/MAX3283E/MAX3284E help
_______________________________________________________________________________________
5
MAX3280E/MAX3281E/MAX3283E/MAX3284E
Pin Description
MAX3280E/MAX3281E/MAX3283E/MAX3284E
±15kV ESD-Protected 52Mbps, 3V to 5.5V, SOT23
RS-485/RS-422 True Fail-Safe Receivers
users design equipment that meets Level 3 of IEC 10004-2, without additional ESD-protection components.
The main difference between tests done using the
Human Body Model and IEC 1000-4-2 is higher peak
current in IEC 1000-4-2. Because series resistance is
lower in the IEC 1000-4-2 ESD test model (Figure 4a),
the ESD-withstand voltage measured to this standard is
generally lower than that measured using the Human
Body Model. Figure 4b shows the current waveform for
the ±8kV IEC 1000-4-2 Level 4 ESD Contact Discharge
test. The Air-Gap test involves approaching the device
with a charger probe. The Contact Discharge method
connects the probe to the device before the probe is
energized.
Machine Model
The Machine Model for ESD testing uses a 200pF storage capacitor and zero-discharge resistance. It mimics
the stress caused by handling during manufacturing
and assembly. All pins (not just the RS-485 inputs)
require this protection during manufacturing. Therefore,
the Machine Model is less relevant to the I/O ports than
are the Human Body Model and IEC 1000-4-2.
True Fail-Safe
The MAX3280E/MAX3281E/MAX3283E/MAX3284E
guarantee a logic-high receiver output when the receiver inputs are shorted or open, or when they are connected to a terminated transmission line with all drivers
disabled. This guaranteed logic high is achieved by setting the receiver threshold between -50mV and -200mV.
If the differential receiver input voltage (A-B) is greater
than or equal to -50mV, RO is logic high. If (A-B) is less
than or equal to -200mV, RO is logic low.
In the case of a terminated bus with all transmitters disabled, the receiver’s differential input voltage is pulled
to ground by the termination. This results in a logic high
with a 50mV minimum noise margin. Unlike previous
fail-safe devices, the -50mV to -200mV threshold complies with the ±200mV EIA/TIA-485 standard.
Receiver Enable
(MAX3281E and MAX3283E only)
The MAX3281E and MAX3283E feature a receiver output enable (EN, MAX3281E or EN, MAX3283E) input
that controls the receiver. The MAX3281E receiver
enable (EN) pin is active high, meaning the receiver
outputs are active when EN is high. The MAX3283E
receiver enable (EN) pin is active low. Receiver outputs
are high impedance when the MAX3281E’s EN pin is
low and when the MAX3283E’s EN pin is high.
6
Table 1. MAX3281E/MAX3283E Enable
Table
ENABLE = HIGH
ENABLE = LOW
MAX3281E
PART
Active
High Z
MAX3283E
High Z
Active
Low-Voltage Logic Levels
(MAX3284E only)
An increasing number of applications now operate at
low-voltage logic levels. To enable compatibility with
these low-voltage logic level applications, such as digital FPGAs, the MAX3284E VL pin is a user-defined supply voltage that designates the voltage threshold for a
logic high.
At lower VL voltages, the data rate will also be lower. A
logic-high level of 1.65V will receive data at 20Mbps.
Table 2 gives data rates at various voltages at VL.
Table 2. MAX3284E Data Rate Table
VCC = 3V TO 5.5V
VL
MAXIMUM DATA RATE
1.65V
20Mbps
2.2V
33Mbps
≥3.3V
52Mbps
Applications Information
Propagation Delay Matching
The MAX3280E/MAX3281E/MAX3283E/MAX3284E
(VCC = VL) exhibit propagation delays that are closely
matched from one device to another, even between
devices from different production lots. This feature
allows multiple data lines to receive data and clock signals with minimal skew with respect to each other.
Figure 5 shows the typical propagation delays. Small
receiver skew times, the difference between the low-tohigh and high-to-low propagation delay, help maintain a
symmetrical ratio (50% duty cycle). The receiver skew
time | tPLH - tPHL | is under 2ns for either a 3.3V supply
or a 5V supply.
Multidrop Clock Distribution
Low package-to-package skew (8ns max) makes the
MAX3280E/MAX3281E/MAX3283E/MAX3284E
(VCC = VL) ideal for multidrop clock distribution. When
distributing a clock signal to multiple circuits over long
transmission lines, receivers in separate locations, and
possibly at two different temperatures, would ideally
_______________________________________________________________________________________
±15kV ESD-Protected 52Mbps, 3V to 5.5V, SOT23
RS-485/RS-422 True Fail-Safe Receivers
128 Receivers on the Bus
The standard RS-485 input impedance is 12kΩ (oneunit load). The standard RS-485 transmitter can drive
32 unit loads. The MAX3280E/MAX3281E/MAX3283E/
MAX3284E present a 1/4-unit-load input impedance
(48kΩ), which allows up to 128 receivers on the bus.
Any combination of these RS-485 receivers with a total
of 32 unit loads can be connected to the same bus.
Thermal Protection
The MAX3280E/MAX3281E/MAX3283E/MAX3284E feature thermal protection. Thermal protection sets the output stage in high-impedance mode when a short circuit
occurs at the output, limiting both the power dissipation
and temperature. The thermal temperature threshold is
+165°C, with a hysteresis of 20°C.
Test Circuits/Timing Diagrams
VOH
RO
VCC/2
VCC/2
VOL
OUTPUT
tPHL
1V
A
-1V
B
tPLH
INPUT
fIN = 1MHz
tr, tf ≤ 3ns
Figure 1. Receiver Propagation Delay
S3
S1
1.5V
VCC
1kΩ
-1.5V
VID
R
S2
CL
GENERATOR
50Ω
VCC
VCC
S1 OPEN
S2 CLOSED
S3 = 1.5V
VCC/2
0
EN
0
EN
tPRZH
tPRZL
VOH
OUT
VCC
VCC/2
VCC/2
OUT
0
VOL
VCC
VCC
S1 OPEN
S2 CLOSED
S3 = 1.5V
VCC/2
EN
S1 CLOSED
S2 OPEN
S3 = -1.5V
VCC/2
0
S1 CLOSED
S2 OPEN
S3 = -1.5V
VCC/2
0
EN
tPRHZ
tPRLZ
OUT
VOH
0.25V
VCC
OUT
0
FOR MAX3281E THE ENABLE SIGNAL IS INVERTED.
0.25V
VOL
Figure 2. MAX3281E/MAX3283E Receiver Enable/Disable Timing
_______________________________________________________________________________________
7
MAX3280E/MAX3281E/MAX3283E/MAX3284E
provide the same clock to their respective circuits.
Thus, minimal package-to-package skew is critical. The
skew must be kept well below the period of the clock
signal to ensure that all of the circuits on the network
are synchronized.
Test Circuits/Timing Diagrams (continued)
RC
1MΩ
RD
1.5kΩ
Cs
100pF
Ir
AMPERES
DEVICE
UNDER
TEST
STORAGE
CAPACITOR
36.8%
10%
0
0
Figure 3a. Human Body ESD Test Model
Cs
150pF
tDL
CURRENT WAVEFORM
I
100%
DISCHARGE
RESISTANCE
CHARGE-CURRENT
LIMIT RESISTOR
TIME
tRL
Figure 3b. Human Body Model Current Waveform
RD
330Ω
RC
50Ω to 100Ω
HIGHVOLTAGE
DC
SOURCE
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
DISCHARGE
RESISTANCE
CHARGE-CURRENT
LIMIT RESISTOR
HIGHVOLTAGE
DC
SOURCE
IP 100%
90%
90%
DEVICE
UNDER
TEST
STORAGE
CAPACITOR
I PEAK
MAX3280E/MAX3281E/MAX3283E/MAX3284E
±15kV ESD-Protected 52Mbps, 3V to 5.5V, SOT23
RS-485/RS-422 True Fail-Safe Receivers
10%
Figure 4a. IEC 1000-4-2 ESD Test Model
t r = 0.7ns to 1ns
t
30ns
60ns
Figure 4b. IEC 1000-4-2 ESD Generator Current Waveform
A, 1V/div
RO, 2.5V/div
B = GND
10ns
Figure 5. Receiver Propagation Delay Driven by External RS485 Device
8
_______________________________________________________________________________________
±15kV ESD-Protected 52Mbps, 3V to 5.5V, SOT23
RS-485/RS-422 True Fail-Safe Receivers
TRANSISTOR COUNT: 233
PROCESS: BiCMOS
TRANSMITTER
DATA IN
120Ω
MAX3283E
RO1
EN
MAX3281E
RO2
MAX3281E/MAX3283E IN REDUNDANT
RECEIVER APPLICATION
EN
Pin Configurations
TOP VIEW
VCC 1
GND 2
5
A
MAX3280E
RO 3
GND 2
4
SOT23-5
VCC 1
B
MAX3281E
MAX3283E
RO 3
SOT23-6
6
A
VCC 1
5
EN (EN)
GND 2
4
B
MAX3284E
RO 3
6
A
5
VL
4
B
SOT23-6
( ) ARE FOR MAX3283E
_______________________________________________________________________________________
9
MAX3280E/MAX3281E/MAX3283E/MAX3284E
Chip Information
Typical Operating Circuit
±15kV ESD-Protected 52Mbps, 3V to 5.5V, SOT23
RS-485/RS-422 True Fail-Safe Receivers
MAX3280E/MAX3281E/MAX3283E/MAX3284E
Package Information
10
______________________________________________________________________________________
±15kV ESD-Protected 52Mbps, 3V to 5.5V, SOT23
RS-485/RS-422 True Fail-Safe Receivers
6LSOT.EPS
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 11
© 2002 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
MAX3280E/MAX3281E/MAX3283E/MAX3284E
Package Information (continued)