MAX3158 Datasheet, PDF (1/14 Pages) Maxim Integrated Products – High CMRR RS-485 Transceiver with ±60V Isolation

19-2778; Rev 0; 2/03
High CMRR RS-485 Transceiver
with ±60V Isolation
General Description
The MAX3158 is a high CMRR RS-485/RS-422 data-com-
munications interface providing ±60V isolation in a
hybrid microcircuit. A single +5V supply on the logic side
powers both sides of the interface, with external 100V
capacitors transferring power from the logic side to the
isolated side. Each MAX3158 contains one transmitter
and one receiver and is guaranteed to operate at data
rates up to 250kbps. Drivers are short-circuit current lim-
ited and protected against excessive power dissipation
by thermal shutdown circuitry that places the driver out-
puts into a high-impedance state. The receiver input has
a fail-safe feature that guarantees a logic-high receiver
output if the inputs are open, shorted, or connected to a
terminated transmission line with all drivers disabled.
The MAX3158 typically draws 25mA of supply current
when unloaded or when fully loaded with the driver dis-
abled. Supply current drops to 25µA when the device is
placed in shutdown mode. The device is pin selectable
between half- and full-duplex mode and also features
an independently programmable receiver and transmit-
ter output phase through separate pins. The MAX3158
is a low-cost replacement for opto-isolated trans-
ceivers. For fully isolated RS-485/RS-422 transceivers,
refer to the MAX1480 family data sheet.
________________________Applications
Industrial Controls
Telecommunications
Level Translators
Local Area Networks
Features
o ±60V Isolated Data Interface
o +5V Single Supply
o Low-Cost Replacement for Opto-Isolated
Transceivers
o True Fail-Safe Receiver While Maintaining
EIA/TIA-485 Compliance
o Pin-Selectable Full/Half-Duplex Operation
o Phase Controls to Correct for Twisted-Pair
Reversal
o 25µA Low-Power Shutdown Mode
o Thermal Shutdown for Driver Overload Protection
o 28-Pin SSOP Package
o Slew-Rate-Limited Reduced EMI
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX3158CAI
0°C to +70°C
28 SSOP
MAX3158CPI
0°C to +70°C
28 PDIP
MAX3158EAI
-40°C to +85°C
28 SSOP
MAX3158EPI
-40°C to +85°C
28 PDIP
Pin Configurations appear at end of data sheet.
V_CC
0.1µF
MICRO
Typical Operating Circuit
V_CC
H/F
TXP
RXP
DE
DI
RE
RO
GND
MAX3158
ISOVCC
A
B
Y
Z
YR
ZR
AR
BR
C1LO C1HI C2LO C2HI ISOCOM
C3
1µF
RT = 100Ω
RG
±60V
C1
C2
C4
0.047µF 0.047µF
10nF
GND OFFSET
RS-485
NODE
REMOTE GND
________________________________________________________________ Maxim Integrated Products 1
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