MAXIM MAX3430 Technical data
General Description
The MAX3430 fault-protected RS-485 transceiver features
±80V protection from overvoltage signal faults on communication 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 powered off, the device will not be damaged. The MAX3430
operates from a 3.3V supply and features a slew-rate-limited driver that minimizes EMI and reduces reflections
caused by improperly terminated cables, allowing errorfree 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 features 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 thermal-shutdown circuitry protect the driver against excessive power dissipation.
The MAX3430 is available in 8-pin SO and 8-pin PDIP
packages, and is specified over commercial and industrial 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
V
CC 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
RO
RE
DE
DI
R
1
2
3
4
D
DIP/SO
V
8
CC
B
7
A
6
GND
5
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= T
MIN
to T
MAX
, 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.)
V
CC
........................................................................................+5V
RE, DE, DI...................................................-0.3V to (V
CC
+ 0.3V)
Driver Output Voltage (A, B) (Note 1) ..................................±80V
Receiver Input Voltage (A, B) (Note 1) ................................±80V
RO ..............................................................-0.3V to (V
CC
+ 0.3V)
Continuous Power Dissipation (T
A
= +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 54Ω or 100Ω to guarantee ±80V fault protection.
DRIVER
Differential Driver Output V
Change in Magnitude of
Differential Output Voltage
Driver Common-Mode Output
Voltage
Change in Magnitude of
Common-Mode Voltage
DRIVER LOGIC
Driver Input High Voltage V
Driver Input Low Voltage V
Driver Input Current I
Driver Short-Circuit Output
Current
Driver Short-Circuit Foldback
Output Current
RECEIVER
Input Current (A, B) I
Receiver Differential Threshold
Voltage
Receiver Input Hysteresis ∆V
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
OD
∆V
V
OC
∆V
IN
I
OSD
I
OSDF
A, B
V
Figure 1, RL = 100Ω 2.0 V
Figure 1, RL = 54Ω 1.5 V
Figure 1, RL = 100Ω or 54Ω (Note 2) 0.2 V
OD
Figure 1, RL = 100Ω or 54Ω V
Figure 1, RL = 100Ω or 54Ω (Note 2) 0.2 V
OC
DI 2.0 V
IH
DI 0.8 V
IL
DI ±1µA
0 ≤ V
-7V ≤ V
(V
-7V ≤ V
DE = GND, RE = GND, VIN = +12V 250
DE = GND, RE = GND, VIN = -7V -200
VIN = -80V to +80V -6 +6 mA
-7V ≤ VCM ≤ 12V -200 -50 mV
TH
VA + VB = 0 25 mV
TH
≤ 12V (Note 3) +250
OUT
≤ VCC (Note 3) -250
OUT
- 1V) ≤ V
CC
≤ 1V (Note 3) -10
OUT
CC
CC
/ 2 3 V
CC
≤ 12V (Note 3) +10
OUT
V
mA
mA
µA
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= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at VCC= +3.3V and TA= +25°C.)
PROTECTION SPECIFICATIONS
(VCC= +3.3V ±10%, TA= T
MIN
to T
MAX
,
unless otherwise noted. Typical values are at V
CC
= +3.3V and TA= +25°C.)
RECEIVER LOGIC
RO Output High Voltage V
RO Output Low Voltage V
Three-State Output Current at
Receiver
Receiver Input Resistance R
Receiver Output Short-Circuit
Current
CONTROL
Control Input High Voltage V
Control Input Low Voltage V
Input Current DE Current Latch
During First DE Rising Edge
Input Current RE Current Latch
During First RE Rising Edge
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
V
CC
0.6
I
OZR
I
OSR
OH
OL
IN
CIH
CIL
IO = -1.6mA
IO = 1mA 0.4 V
0 ≤ VO ≤ V
-7V ≤ VCM ≤ 12V 48 kΩ
0 ≤ VRO ≤ V
DE, RE 2.0 V
DE, RE 0.8 V
CC
CC
-
± 1µA
±95 mA
80 µA
80 µA
ESD Protection A, B Human Body Model ±12 kV
SUPPLY CURRENT
Supply Current I
Supply Current in Shutdown
Mode
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
No load, RE = 0, DE = VCC, DI = 0 or V
CC
I
SHDN
No load, RE = VCC, DE = V
DI = 0 or V
RE = VCC, DE = 0 200 µA
CC
CC,
CC
3.5 10
3.0 8
V
mA
MAX3430
±80V Fault-Protected, Fail-Safe,
1/4-Unit Load, +3.3V RS-485 Transceiver
4 _______________________________________________________________________________________
DRIVER SWITCHING CHARACTERISTICS
(VCC= +3.3V ±10%, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at VCC= +3.3V and TA= +25°C.)
)
)
RECEIVER SWITCHING CHARACTERISTICS
(VCC= +3.3V ±10%, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at VCC= +3.3V and TA= +25°C.)
)
)
Note 2: ∆VODand ∆VOCare the changes in VODand 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.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Driver Propagation Delay
Driver Differential Output Rise or
Fall Time
Differential Driver Output Skew,
|t
- t
DPHL
|
DPLH
Maximum Data Rate 250 kbps
Driver Enable to Output Low t
Driver Disable Time from Output
Low
Driver Output Enable Time from
Shutdown
Driver Enable to Output High t
Driver Disable Time from Output
High
Driver Output Enable Time from
Shutdown
Driver Time to Shutdown t
t
DPLH
t
DPHL
t
DR, tDF
t
DSKEW
DZL
t
DLZ
t
DZL(SHDN
DZH
t
DHZ
t
DZH(SHDN
SHDN
Figures 2 and 3, RL = 54Ω, CL = 50pF
Figures 2 and 3, RL = 54Ω, CL = 50pF 250 1200 ns
Figures 2 and 3, RL = 54Ω, CL = 50pF 150 200 ns
Figure 4, CL = 50pF 5200 ns
Figure 4, CL = 50pF 1000 ns
Figure 4, CL = 50pF 8000 ns
Figure 5, CL = 50pF 5200 ns
Figure 5, CL = 50pF 1000 ns
Figure 5, CL = 50pF 8000 ns
700 1500
700 1500
1000 ns
ns
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Receiver Propagation Delay
Receiver Output Skew,
|t
- t
RPHL
|
RPLH
Receiver Enable to Output Low t
Receiver Enable to Output High t
Receiver Disable Time from Low t
Receiver Disable Time form High t
Receiver Output Enable Time
from Shutdown
Receiver Time to Shutdown t
t
RPLH
t
RPHL
t
SKEW
RZL
RZH
RLZ
RHZ
t
RZH(SHND
t
RZL(SHND
SHDN
Figure 6, C
Figure 6, C
Figure 7, R = 1kΩ, C
Figure 7, R = 1kΩ, C
Figure 7, R = 1kΩ, C
Figure 7, R = 1kΩ , CL = 20pF 80 ns
,
Figure 7, R = 1kΩ, CL = 20pF 5000 ns
= 20pF, V
L
= 20pF 40 ns
L
= 2V, VCM = 0
ID
= 20pF 80 ns
L
= 20pF 80 ns
L
= 20pF 80 ns
L
120
120
ns
1000 ns
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