19-2756; Rev 1; 4/03
±80V Fault-Protected, Fail-Safe,
1/4-Unit Load, +3.3V RS-485 Transceiver
Features
o ±80V Fault Protection
o ±12kV ESD Protection
o +3.3V Operation
o Internal Slew-Rate Limiting
o 250kbps Data Rate
o Allows Up to 128 Transceivers on the Bus
o -7V to +12V Common-Mode Input Voltage Range
o True Fail-Safe Inputs
o Hot-Swap Input Structure on DE
o Available in 8-Pin SO and PDIP Packages
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.
Ordering Information
The MAX3430 is available in 8-pin SO and 8-pin PDIP
packages, and is specified over commercial and industrial temperature ranges.
PART
TEMP RANGE
PIN-PACKAGE
MAX3430CPA
0°C to +70°C
8 SO
MAX3430EPA
-40°C to +85°C
8 Plastic DIP
MAX3430ESA
RS-422/RS-485 Communications
8 Plastic DIP
MAX3430CSA
Applications
0°C to +70°C
-40°C to +85°C
8 SO
Lighting Systems
Industrial-Control Local Area Networks
Profibus Applications
Multimaster RS-485 Networks
Pin Configuration and Typical Operating Circuit
TOP VIEW
VCC
RO
1
RE
2
R
DI
4
B
6
D
VCC
7
DE 3
8
A
5
GND
RO
1
RE 2
3
DE
4
DI
R
DE
0.1µF
MAX3430
8
D
7 B
6
D
5
DI
B
Rt
A
Rt
A
RO
R
GND
RE
DIP/SO
________________________________________________________________ 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
MAX3430
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.
