EVALUATION KIT AVAILABLE
MAX14938/MAX14939
2.75kV
Isolated 20Mbps Half-Duplex PROFIBUS/
RMS
RS-485 Transceivers with ±35kV ESD Protection
General Description
The MAX14938/MAX14939 isolated RS-485/PROFIBUS-DP
Benefits and Features
● High-Performance Transceiver Enables Flexible Designs
• Integrated LDO for Cable-Side Power
• Compliant with RS-485 EIA/TIa-485 Standard
• 20Mbps Maximum Data Rate
transceivers provide 2750V (60s) of galvanic isolation
RMS
between the cable side (RS-485 driver/receiver side) and
the UART side of the device. Isolation improves communication
by breaking ground loops and reduces noise when there
are large differences in ground potential between ports.
These devices allow for robust communication up to
20Mbps.
• Allows Up to 128 Devices on the Bus
● Integrated Protections Ensures Robust Communication
• ±35kV ESD (HBM) on Driver Outputs/Receiver Inputs
• 2.75kV
• 630V
Withstand Isolation Voltage for 60s (V
)
RMS
PEAK
ISO
Maximum Repetitive Peak-Isolation
)
An integrated LDO provides a simple and space-efficient
architecture for providing power to the cable side of the
IC.
Voltage (V
IORM
• 445V
Maximum Working-Isolation Voltage
RMS
(V
)
IOWM
Each device includes one half-duplex driver/receiver
channel. The receiver is 1/4-unit load, allowing up to 128
transceivers on a common bus.
• > 30 Years Lifetime at Rated Working Voltage
• Withstands ±10kV Surge per IEC 61000-4-5
• Thermal Shutdown
Integrated true fail-safe circuitry ensures a logic-high on
the receiver output when inputs are shorted or open.
Undervoltage lockout disables the driver when cable-side
or UART-side power supplies are below functional levels.
Safety Regulatory Approvals Pending
● UL According to UL1577
● cUL According to CSA Bulletin 5A
● VDE 0884-10
The driver outputs/receiver inputs are protected from
±35kV electrostatic discharge (ESD) to GNDB on the
cable side, as specified by the Human Body Model (HBM).
Applications
● Industrial Automation Equipment
● Programmable Logic Controllers
● HVAC
The MAX14938/MAX14939 are available in a wide-body
16-pin SOIC package and operate over the -40°C to
+105°C temperature range.
● Power Meters
Functional Diagram
Ordering Information appears at end of data sheet.
VDDA
VLDO
MAX14938
MAX14939
LDO
VDDB
(PV)
SBA+
RXD
RE
A
B
TXD
DE
(DEM)
() MAX14938 only
* MAX14939 only
GNDA
GNDB
19-8115; Rev 0; 4/16