ISL3155E
5V, RS-485/RS-422 Transceiver with 16kV ESD Protection

Key Features

• High Driver V_OD 2.4V (Min) @ RD = 54Ω Better Noise Immunity, or Drive Up to 8 Terminations
• IEC61000 ESD Protection on RS-485 I/O Pins ±16.5kV
• Class 3 ESD Level on all Other Pins >7kV HBM
• Tiny MSOP Packages Save 50% Board Space
• Full Fail-safe (Open, Short, Terminated and Undriven) Receivers
• High Rx IOL to Drive Opto-Couplers for Isolated Applications
• Hot Plug Circuitry - Tx and Rx Outputs Remain Three-State During Power-up/Power-Down
• True 1/8 Unit Load Allows up to 256 Devices on the Bus
• Specified for Single 5V, 10% Tolerance, Supplies
• High Data Rates up to 20Mbps
• Low Quiescent Supply Current 600µA Ultra Low Shutdown Supply Current 70nA
• -7V to +12V Common Mode Input Voltage Range
• Half and Full Duplex Pinouts
• Pb-Free Packaging (RoHS Compliant)
• Three-State Rx and Tx Outputs
• Current Limiting and Thermal Shutdown for Driver Overload Protection

Description

The ISL315XE are BiCMOS, IEC61000 ESD protected, 5V powered, single transceivers that meet both the RS-485 and RS-422 standards for balanced communication. Each driver output and receiver input is protected against ±16.5kV ESD strikes without latch-up.

The ISL315XE transmitters all deliver exceptional differential output voltages (2.4V min), into the RS-485 required 54Ω load, for better noise immunity or to allow up to eight 120Ω terminations in "star" or other non-standard bus topologies.

These devices have very low bus currents (+125µA/-75µA), so they present a true "1/8 unit load" to the RS-485 bus. This allows up to 256 transceivers on the network without violating the RS-485 specification's 32 unit load maximum, and without using repeaters.

Receiver (Rx) inputs feature a "Full Fail-Safe" design, which ensures a logic high Rx output if Rx inputs are floating, shorted, or on a terminated but undriven bus. Rx outputs feature high drive levels - typically 28mA @ V_OL = 1V (to ease the design of optocoupled isolated interfaces).

The ISL3150E, ISL3152E, ISL3153E, ISL3155E utilize slew rate limited drivers which reduce EMI, and minimize reflections from improperly terminated transmission lines, or unterminated stubs in multidrop and multipoint applications.

Hot Plug circuitry ensures that the Tx and Rx outputs remain in a high impedance state until the power supply has stabilized, and the Tx outputs are fully short circuit protected.

The ISL3150E, ISL3153E, ISL3156E are configured for full duplex applications. The half duplex versions multiplex the Rx inputs and Tx outputs to allow transceivers with output disable functions in 8 Ld packages.

Applications

• Utility Meters and Automated Meter Reading Systems
• High Node Count Systems
• PROFIBUS® and Field Bus Networks, and Factory Automation
• Security Camera Networks
• Building Lighting and Environmental Control Systems
• Industrial/Process Control Networks