General Description
The MAX3430 fault-protected RS-485 transceiver features
±80V protection from overvoltage signal faults on commu-
nication bus lines. Each device contains one driver and
one receiver, and the output pins can withstand faults,
with respect to ground, of up to ±80V. Even if the faults
occur when the transceiver is active, shut down, or pow-
ered off, the device will not be damaged. The MAX3430
operates from a 3.3V supply and features a slew-rate-lim-
ited driver that minimizes EMI and reduces reflections
caused by improperly terminated cables, allowing error-
free data transmission at data rates up to 250kbps. The
MAX3430 has a 1/4-unit-load receiver input impedance
allowing up to 128 transceivers on a single bus and fea-
tures fail-safe circuitry, which guarantees a logic-high
receiver output when the receiver inputs are open.
Hot-swap circuitry eliminates false transitions on the
data cable during circuit initialization or connection to a
live backplane. Short-circuit current limiting and ther-
mal-shutdown circuitry protect the driver against exces-
sive power dissipation.
The MAX3430 is available in 8-pin SO and 8-pin PDIP
packages, and is specified over commercial and indus-
trial temperature ranges.
Applications
RS-422/RS-485 Communications
Lighting Systems
Industrial-Control Local Area Networks
Profibus Applications
Multimaster RS-485 Networks
Features
♦±80V Fault Protection
♦±12kV ESD Protection
♦+3.3V Operation
♦Internal Slew-Rate Limiting
♦250kbps Data Rate
♦Allows Up to 128 Transceivers on the Bus
♦-7V to +12V Common-Mode Input Voltage Range
♦True Fail-Safe Inputs
♦Hot-Swap Input Structure on DE
♦Available in 8-Pin SO and PDIP Packages
MAX3430
±80V Fault-Protected, Fail-Safe,
1/4-Unit Load, +3.3V RS-485 Transceiver
________________________________________________________________ Maxim Integrated Products 1
Pin Configuration and Typical Operating Circuit
Ordering Information
1
2
3
4
8
5
VCC 0.1µF
GND
DI
DE
RE
RO R
D
Rt
Rt
7
6
D
R
DE
RE
DI
RO
A
B
B
A
MAX3430
19-2756; Rev 1; 4/03
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.
PART TEMP RANGE PIN-PACKAGE
MAX3430CPA 0°C to +70°C 8 Plastic DIP
MAX3430CSA 0°C to +70°C 8 SO
MAX3430EPA -40°C to +85°C 8 Plastic DIP
MAX3430ESA -40°C to +85°C 8 SO
TOP VIEW
1
2
3
4
8
7
6
5
VCC
B
A
GND
DI
DE
RE
RO
DIP/SO
R
D
MAX3430
±80V Fault-Protected, Fail-Safe,
1/4-Unit Load, +3.3V RS-485 Transceiver
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
DC ELECTRICAL CHARACTERISTICS
(VCC = +3.3V ±10%, TA= TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +3.3V and TA= +25°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.
(All voltages are referenced to GND.)
VCC ........................................................................................+5V
RE, DE, DI...................................................-0.3V to (VCC + 0.3V)
Driver Output Voltage (A, B) (Note 1) ..................................±80V
Receiver Input Voltage (A, B) (Note 1) ................................±80V
RO ..............................................................-0.3V to (VCC + 0.3V)
Continuous Power Dissipation (TA= +70°C)
8-Pin SO (derate 5.88mW/°C above +70°C)................471mW
8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) ...727mW
Operating Temperature Ranges
MAX3430C_ _ .....................................................0°C to +70°C
MAX3430E_ _ ..................................................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1: A, B must be terminated with 54Ωor 100Ωto guarantee ±80V fault protection.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
DRIVER
Figure 1, RL = 100Ω2.0 VCC
Differential Driver Output VOD Figure 1, RL = 54Ω1.5 VCC
V
Change in Magnitude of
Differential Output Voltage ∆VOD Figure 1, RL = 100Ω or 54Ω (Note 2) 0.2 V
Driver Common-Mode Output
Voltage VOC Figure 1, RL = 100Ω or 54ΩVCC / 2 3 V
Change in Magnitude of
Common-Mode Voltage ∆VOC Figure 1, RL = 100Ω or 54Ω (Note 2) 0.2 V
DRIVER LOGIC
Driver Input High Voltage VIH DI 2.0 V
Driver Input Low Voltage VIL DI 0.8 V
Driver Input Current IIN DI ±1µA
0 ≤ VOUT ≤ 12V (Note 3) +250
Driver Short-Circuit Output
Current IOSD -7V ≤ VOUT ≤ VCC (Note 3) -250 mA
(VCC - 1V) ≤ VOUT ≤ 12V (Note 3) +10
Driver Short-Circuit Foldback
Output Current IOSDF -7V ≤ VOUT ≤ 1V (Note 3) -10 mA
RECEIVER
DE = GND, RE = GND, VIN = +12V 250
DE = GND, RE = GND, VIN = -7V -200 µA
Input Current (A, B) IA, B
VIN = -80V to +80V -6 +6 mA
Receiver Differential Threshold
Voltage VTH -7V ≤ VCM ≤ 12V -200 -50 mV
Receiver Input Hysteresis ∆VTH VA + VB = 0 25 mV
MAX3430
±80V Fault-Protected, Fail-Safe,
1/4-Unit Load, +3.3V RS-485 Transceiver
_______________________________________________________________________________________ 3
DC ELECTRICAL CHARACTERISTICS (continued)
(VCC = +3.3V ±10%, TA= TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +3.3V and TA= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
RECEIVER LOGIC
RO Output High Voltage VOH IO = -1.6mA VCC -
0.6 V
RO Output Low Voltage VOL IO = 1mA 0.4 V
Three-State Output Current at
Receiver IOZR 0 ≤ VO ≤ VCC ± 1µA
Receiver Input Resistance RIN -7V ≤ VCM ≤ 12V 48 kΩ
Receiver Output Short-Circuit
Current IOSR 0 ≤ VRO ≤ VCC ±95 mA
CONTROL
Control Input High Voltage VCIH DE, RE 2.0 V
Control Input Low Voltage VCIL DE, RE 0.8 V
Input Current DE Current Latch
During First DE Rising Edge 80 µA
Input Current RE Current Latch
During First RE Rising Edge 80 µA
PROTECTION SPECIFICATIONS
(VCC = +3.3V ±10%, TA= TMIN to TMAX,unless otherwise noted. Typical values are at VCC = +3.3V and TA= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
ESD Protection A, B Human Body Model ±12 kV
SUPPLY CURRENT
No load, RE = 0, DE = VCC, DI = 0 or VCC 3.5 10
Supply Current ICC No load, RE = VCC, DE = VCC,
DI = 0 or VCC 3.0 8 mA
Supply Current in Shutdown
Mode ISHDN RE = VCC, DE = 0 200 µA
MAX3430
±80V Fault-Protected, Fail-Safe,
1/4-Unit Load, +3.3V RS-485 Transceiver
4 _______________________________________________________________________________________
DRIVER SWITCHING CHARACTERISTICS
(VCC = +3.3V ±10%, TA= TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +3.3V and TA= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
tDPLH 700 1500
Driver Propagation Delay tDPHL
Figures 2 and 3, RL = 54Ω, CL = 50pF 700 1500 ns
Driver Differential Output Rise or
Fall Time tDR
,
tDF Figures 2 and 3, RL = 54Ω, CL = 50pF 250 1200 ns
Differential Driver Output Skew,
|tDPLH - tDPHL|tDSKEW Figures 2 and 3, RL = 54Ω, CL = 50pF 150 200 ns
Maximum Data Rate 250 kbps
Driver Enable to Output Low tDZL Figure 4, CL = 50pF 5200 ns
Driver Disable Time from Output
Low tDLZ Figure 4, CL = 50pF 1000 ns
Driver Output Enable Time from
Shutdown tDZL
(
SHDN
)
Figure 4, CL = 50pF 8000 ns
Driver Enable to Output High tDZH Figure 5, CL = 50pF 5200 ns
Driver Disable Time from Output
High tDHZ Figure 5, CL = 50pF 1000 ns
Driver Output Enable Time from
Shutdown tDZH
(
SHDN
)
Figure 5, CL = 50pF 8000 ns
Driver Time to Shutdown tSHDN 1000 ns
RECEIVER SWITCHING CHARACTERISTICS
(VCC = +3.3V ±10%, TA= TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +3.3V and TA= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
tRPLH 120
Receiver Propagation Delay tRPHL
Figure 6, CL = 20pF, VID = 2V, VCM = 0 120 ns
Receiver Output Skew,
|tRPLH - tRPHL|tSKEW Figure 6, CL = 20pF 40 ns
Receiver Enable to Output Low tRZL Figure 7, R = 1kΩ, CL = 20pF 80 ns
Receiver Enable to Output High tRZH Figure 7, R = 1kΩ, CL = 20pF 80 ns
Receiver Disable Time from Low tRLZ Figure 7, R = 1kΩ, CL = 20pF 80 ns
Receiver Disable Time form High tRHZ Figure 7, R = 1kΩ , CL = 20pF 80 ns
Receiver Output Enable Time
from Shutdown
tRZH
(
SHND
)
,
tRZL
(
SHND
)
Figure 7, R = 1kΩ, CL = 20pF 5000 ns
Receiver Time to Shutdown tSHDN 1000 ns
Note 2: ∆VOD and ∆VOC are the changes in VOD and VOC, respectively, when the DI input changes state.
Note 3: The short-circuit output current applies to peak current just prior to foldback current limiting; the short-circuit foldback output
current applies during current limiting to allow a recovery from bus contention.
MAX3430
±80V Fault-Protected, Fail-Safe,
1/4-Unit Load, +3.3V RS-485 Transceiver
_______________________________________________________________________________________ 5
0
1
3
2
4
5
-40 0-20 20 40 60 80
SUPPLY CURRENT
vs. TEMPERATURE
MAX3430 toc01
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
RE = 0
DE = VCC
0
75
50
25
150
125
100
175
200
-40 0-20 20 40 60 80
SHUTDOWN CURRENT
vs. TEMPERATURE
MAX3430 toc02
TEMPERATURE (°C)
SHUTDOWN CURRENT (µA)
0
4
12
8
16
20
0 1.00.5 1.5 2.0 2.5 3.0 3.5
OUTPUT CURRENT
vs. RECEIVER OUTPUT LOW VOLTAGE
MAX3430 toc03
OUTPUT LOW VOLTAGE (V)
OUTPUT CURRENT (mA)
0
3
12
9
6
15
18
0 1.00.5 1.5 2.0 2.5 3.0 3.5
OUTPUT CURRENT
vs. RECEIVER OUTPUT HIGH VOLTAGE
MAX3430 toc04
OUTPUT HIGH VOLTAGE (V)
OUTPUT CURRENT (mA)
3.00
3.10
3.05
3.20
3.15
3.25
3.30
-40 0-20 20 40 60 80
RECEIVER OUTPUT HIGH VOLTAGE
vs. TEMPERATURE
MAX3430 toc05
TEMPERATURE (°C)
OUTPUT HIGH VOLTAGE (V)
IO = -1.6mA
0
0.1
0.3
0.2
0.4
0.5
-40 0-20 20 40 60 80
RECEIVER OUTPUT LOW VOLTAGE
vs. TEMPERATURE
MAX3430 toc06
TEMPERATURE (°C)
OUTPUT LOW VOLTAGE (V)
IO = +1mA
0
20
80
60
40
100
120
0 1.00.5 1.5 2.0 2.5 3.0 3.5
DRIVER OUTPUT CURRENT
vs. DIFFERENTIAL OUTPUT VOLTAGE
MAX3430 toc07
DIFFERENTIAL OUTPUT VOLTAGE (V)
OUTPUT CURRENT (mA)
0
1.5
1.0
0.5
2.5
2.0
3.0
3.5
-40 0-20 20 40 60 80
DRIVER DIFFERENTIAL OUTPUT VOLTAGE
vs. TEMPERATURE
MAX3430 toc08
TEMPERATURE (°C)
DIFFERENTIAL OUTPUT VOLTAGE (V)
RL = 54Ω
RL = 100Ω
-3
-2
-1
0
1
2
3
-80 -40-60 -20 0 20 40 60 80
A, B CURRENT
vs. A, B VOLTAGE (TO GROUND)
MAX3430 toc09
A, B VOLTAGE (V)
A, B CURRENT (mA)
RE = DE = GND
Typical Operating Characteristics
(VCC = +3.3V, TA= +25°C, unless otherwise noted.)
MAX3430
±80V Fault-Protected, Fail-Safe,
1/4-Unit Load, +3.3V RS-485 Transceiver
6 _______________________________________________________________________________________
VOD
VOC
2
RL
2
RL
A
B
Figure 1. Driver DC Test Load
VO
3V
RL
CL
CL
DI
DE
A
B
Figure 2. Driver Timing Test Circuit
tDPLH tDPHL
DI
0
VCC
A
B
1/2 VO
1/2 VO
VOD = V (A) - V (B)
tSKEW = |tDPLH - tDPHL|
VCC/2
tDR tDF
VO
20%
80%
80%
20%
VO
Figure 3. Driver Propagation Delays
VCC
50Ω
RL = 500Ω
CL
50pF
GENERATOR
D
0 OR +3V OUT
S1
VCC
0
0.25V
VOL
tDZL, tDZL(SHDN)
VOM = (VOL + VCC)/2
VCC/2
VCC
OUT
DE
tDLZ
Figure 4. Driver Enable and Disable Times (tDZL, tDLZ,
tDLZ(SHDN))
VCC
0
0
VOH
0.25V
50Ω
RL = 500Ω
CL
50pF
GENERATOR
D
0 OR +3V
tDZH, tDZH(SHDN)
VOM = (0 + VOH)/2
VCC/2
OUT
OUT
S1
DE
tDHZ
Figure 5. Driver Enable and Disable Times (tDHZ, tDZH, tDZH(SHDN))
Test Circuits/Timing Diagrams
MAX3430
±80V Fault-Protected, Fail-Safe,
1/4-Unit Load, +3.3V RS-485 Transceiver
_______________________________________________________________________________________ 7
CL
20pF
R
0
A
B
VOH
VOL
1.5V
tRPLH tRPHL
RO
VID
Figure 6. Receiver Propagation Delays
50Ω
GENERATOR
CL
20pF
VCC
3V
0
VCC
VOL
R
+1.5V
-1.5V VID
(VOL + VCC)/2
RO
S1
S2
R
1kΩ
RE 1.5V
S1 CLOSED
S2 OPEN
S3 = -1.5V
tRZL, tRZL (SHDN)
3V
0
VOH
0
VOH/2
RE
S1 OPEN
S2 CLOSED
S3 = +1.5V
tRZH, tRZH(SHDN)
3V
0
VCC
VOL
0.25V
RO
RE 1.5V
S1 CLOSED
S2 OPEN
S3 = -1.5V
tRLZ
3V
0
VOH
0
0.25V
1.5V
RO
RE
S1 OPEN
S2 CLOSED
S3 = +1.5V
tRHZ
S3
RO
RO
Figure 7. Receiver Enable and Disable Times
Test Circuits/Timing Diagrams (continued)
MAX3430
±80V Fault-Protected, Fail-Safe,
1/4-Unit Load, +3.3V RS-485 Transceiver
8 _______________________________________________________________________________________
Pin Description
PIN NAME FUNCTION
1 RO Receiver Output
2RE Receiver Output Enable. RO is enabled when RE is low; RO is high impedance when RE is high. The
device enters a low-power shutdown mode if RE is high and DE is low.
3DE
Driver Output Enable. Driving DE high enables the driver outputs. Pulling DE low puts the driver
outputs in a high-impedance state. If RE is high and DE is low, the device enters a low-power
shutdown mode. If the driver outputs are enabled, the device functions as a line driver, and when
they are high impedance it functions as a line receiver if RE is low.
4DI
Driver Input. A logic low on DI forces output A low and output B high, while a logic high on DI forces
output A high and output B low.
5 GND Ground
6 A Noninverting Receiver Input/Driver Output
7 B Inverting Receiver Input/Driver Output
8V
CC Positive Supply, VCC = +3.3V ±10%. Bypass VCC to GND with a 0.1µF ceramic capacitor.
Function Tables
Table 1. Transmitting
INPUTS OUTPUTS
RE DE DI B A MODE
X 1 1 0 1 Normal
X 1 0 1 0 Normal
0 0 X High-Z High-Z Normal
1 0 X High-Z High-Z Shutdown
Table 2. Receiving
INPUTS OUTPUTS
RE DE (A - B) RO MODE
00≥ -50mV 1 Normal
00≤ -200mV 0 Normal
00
Inputs
open 1 Normal
1 0 X High-Z Shutdown
X= Don’t care.
X= Don’t care.
MAX3430
±80V Fault-Protected, Fail-Safe,
1/4-Unit Load, +3.3V RS-485 Transceiver
_______________________________________________________________________________________ 9
Detailed Description
Driver
The driver accepts a single-ended, logic-level input
(DI) and transfers it to a differential, RS-485 level output
(A and B). Driving DE high enables the driver, while
pulling DE low places the driver outputs (A and B) into
a high-impedance state.
Receiver
The receiver accepts a differential, RS-485 level input
(A and B), and transfers it to a single-ended, logic-level
output (RO). Pulling RE low enables the receiver, while
driving RE high and DE low places the receiver inputs
(A and B) into a high-impedance state.
Low-Power Shutdown
Force DE low and RE high to shut down the MAX3430. A
time delay of 1µs prevents the device from accidentally
entering shutdown due to logic skews when switching
between transmit and receive modes. Holding DE low
and RE high for at least 1ms guarantees that the
MAX3430 enters shutdown. In shutdown, the device
consumes 100µA supply current.
±80V Fault Protection
The driver outputs/receiver inputs of RS-485 devices in
industrial network applications often experience voltage
faults resulting from transients that exceed the -7V to
+12V range specified in the EIA/TIA-485 standard. In
these applications, ordinary RS-485 devices (typical
absolute maximum ratings -8V to +12.5V) require costly
external protection devices. To reduce system com-
plexity and the need for external protection, the driver
outputs/receiver inputs of the MAX3430 withstand volt-
age faults of up to ±80V with respect to ground without
damage (see the Absolute Maximum Ratings section,
Note 1). Protection is guaranteed regardless of whether
the device is active, shut down, or without power.
True Fail-Safe
The MAX3430 uses a -50mV to -200mV differential
input threshold to ensure true fail-safe receiver inputs.
This threshold guarantees the receiver outputs a logic
high for shorted, open, or idle data lines. The -50mV to
-200mV threshold complies with the ±200mV threshold
EIA/TIA-485 standard.
±12kV ESD Protection
As with all Maxim devices, ESD-protection structures
are incorporated on all pins to protect against ESD
encountered during handling and assembly. The
MAX3430 receiver inputs/driver outputs (A, B) have
extra protection against static electricity found in nor-
mal operation. Maxim’s engineers have developed
state-of-the-art structures to protect these pins against
±12kV ESD without damage. After an ESD event, the
MAX3430 continues working without latchup.
ESD protection can be tested in several ways. The
receiver inputs are characterized for protection up to
±12kV using the Human Body Model.
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 8a shows the Human Body Model, and Figure
8b shows the current waveform it generates when dis-
charged into a low impedance. This model consists of
a 100pF capacitor charged to the ESD voltage of inter-
est, which is then discharged into the device through a
1.5kΩresistor.
Driver Output Protection
Two mechanisms prevent excessive output current and
power dissipation caused by faults or bus contention.
The first, a foldback current limit on the driver output
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Cs
100pF
RC
1MΩ
RD
1.5kΩ
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
Figure 8a. Human Body ESD Test Model
IP 100%
90%
36.8%
tRL TIME
tDL
CURRENT WAVEFORM
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
Ir
10%
0
0
AMPERES
Figure 8b. Human Body Model Current Waveform
MAX3430
±80V Fault-Protected, Fail-Safe,
1/4-Unit Load, +3.3V RS-485 Transceiver
10 ______________________________________________________________________________________
stage, provides immediate protection against short cir-
cuits over the whole common-mode voltage range. The
second, a thermal shutdown circuit, forces the driver
outputs into a high-impedance state if the die tempera-
ture exceeds +160°C. Normal operation resumes when
the die temperature cools by +140°C, resulting in a
pulsed output during continuous short-circuit conditions.
Hot-Swap Capability
Hot-Swap Inputs
Inserting circuit boards into a hot, or powered backplane
may cause voltage transients on DE, RE, and receiver
inputs A and B that can lead to data errors. For example,
upon initial circuit board insertion, the processor under-
goes a power-up sequence. During this period, the high-
impedance state of the output drivers makes them
unable to drive the MAX3430 enable inputs to a defined
logic level. Meanwhile, leakage currents of up to 10µA
from the high-impedance output, or capacitively coupled
noise from VCC or GND, could cause an input to drift to
an incorrect logic state. To prevent such a condition from
occurring, the MAX3430 features hot-swap input circuitry
on DE to safeguard against unwanted driver activation
during hot-swap situations. When VCC rises, an internal
pulldown circuit holds DE low for at least 10µs, and until
the current into DE exceeds 200µA. After the initial
power-up sequence, the pulldown circuit becomes
transparent, resetting the hot-swap tolerable input.
Hot-Swap Input Circuitry
At the driver enable input (DE), there are two NMOS
devices, M1 and M2 (Figure 9). When VCC ramps from
0, an internal 15µs timer turns on M2 and sets the SR
latch, which also turns on M1. Transistors M2, a 2mA
current sink, and M1, a 100µA current sink, pull DE to
GND through a 5.6kΩresistor. M2 pulls DE to the dis-
abled state against an external parasitic capacitance
up to 100pF that may drive DE high. After 15µs, the
timer deactivates M2 while M1 remains on, holding DE
low against three-state leakage currents that may drive
DE high. M1 remains on until an external current source
overcomes the required input current. At this time, the
SR latch resets M1 and turns off. When M1 turns off, DE
reverts to a standard, high-impedance CMOS input.
Whenever VCC drops below 1V, the input is reset.
VCC
TIMER
TIMER
DE DE
(HOT SWAP)
15µs
100µA
M1 M2
5.6kΩ
2mA
Figure 9. Simplified Structure of the Driver Enable Pin (DE)
DI RO DE
A
B
RE
RO
RO
RO
DI
DI
DI
DE
DE RE
DE
DD
D
R
R
R
BB
B
AA
A
120Ω120Ω
D
R
MAX3430
RE
RE
Figure 10. Typical RS-485 Network
MAX3430
±80V Fault-Protected, Fail-Safe,
1/4-Unit Load, +3.3V RS-485 Transceiver
______________________________________________________________________________________ 11
Applications Information
128 Transceivers on the Bus
The standard RS-485 receiver input impedance is 12kΩ
(one-unit load), and a standard driver can drive up to
32-unit loads. The MAX3430 transceiver 1/4-unit-load
receiver input impedance (48kΩ) allows up to 128
transceivers connected in parallel on one communica-
tion line. Connect any combination of these devices,
and/or other RS-485 devices, for a maximum of 32 unit
loads to the line.
RS-485 Applications
The MAX3430 transceiver provides bidirectional data
communications on multipoint bus transmission lines.
Figure 10 shows a typical network applications circuit.
The RS-485 standard covers line lengths up to 4000ft.
The signal line must be terminated at both ends in its
characteristic impedance, and stub lengths off the
main line kept as short as possible.
Chip Information
TRANSISTOR COUNT: 300
PROCESS: BiCMOS
MAX3430
±80V Fault-Protected, Fail-Safe,
1/4-Unit Load, +3.3V RS-485 Transceiver
12 ______________________________________________________________________________________
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
SOICN .EPS
PACKAGE OUTLINE, .150" SOIC
1
1
21-0041 B
REV.DOCUMENT CONTROL NO.APPROVAL
PROPRIETARY INFORMATION
TITLE:
TOP VIEW
FRONT VIEW
MAX
0.010
0.069
0.019
0.157
0.010
INCHES
0.150
0.007
E
C
DIM
0.014
0.004
B
A1
MIN
0.053A
0.19
3.80 4.00
0.25
MILLIMETERS
0.10
0.35
1.35
MIN
0.49
0.25
MAX
1.75
0.050
0.016L0.40 1.27
0.3940.386D
D
MINDIM
D
INCHES
MAX
9.80 10.00
MILLIMETERS
MIN MAX
16 AC
0.337 0.344 AB8.758.55 14
0.189 0.197 AA5.004.80 8
N MS012
N
SIDE VIEW
H 0.2440.228 5.80 6.20
e 0.050 BSC 1.27 BSC
C
HE
eBA1
A
D
0-8
L
1
VARIATIONS:
MAX3430
±80V Fault-Protected, Fail-Safe,
1/4-Unit Load, +3.3V RS-485 Transceiver
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 ____________________ 13
© 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
PDIPN.EPS
