Specifications

www.digikey.com/maxim-industrial 27
Programmable logic controllers (PLCs)
Fieldbus functions
Benefits
• Eliminates the need for external
isolation circuitry
– 2500V
RMS
RS-485 bus isolation using
on-chip high-voltage capacitors
• High-ESD protection up to ±15kV ESD
– 3.0V to 5.5V operation for interfacing
with multivoltage systems
MAX3535E
Galvanic isolation between the PLC’s backplane and the fieldbus
is required due to the harsh conditions and large common-mode
voltages that can occur between remotely located subsystems.
Maxim offers RS-485 transceivers with integrated isolation based on
capacitors, transformers, and optical techniques.
The MAX3535E RS-485 transceiver is designed for applications where
galvanic isolation is required up to ±2500V. By integrating the full
half-bridge driver and rectifier, the MAX3535E offers ease of use. It
provides extended ESD protection up to ±15kV.
Isolated RS-485 transceiver reduces BOM complexity
Block diagram of the MAX3535E. Dashed line signifies isolation barrier.
28
27
1
2 3 11 14
26
25
4
420kHz
GND1
V
CC
10µF
ST1
GND2
A
B
RO2
Y
Z
SLO
V
CC2
ST2
RO
TWISTED-PAIR
CABLE
RE
DE
DI
16
15
17
13
12
18
RS-485/RS-422 BUS
VOLTAGE
REGULATOR
R
D
MAX3535E