特性 Features

? Exceeds Requirements of EIA-485 Standard

? Hot Plug Circuitry - Tx and Rx Outputs Remain

Three-State During Power-up/Power-down

? Data Rate: Up to 250 kbps

? Full Fail-safe (Open, Short, Terminated)

Receivers

? Up to 256 Nodes on a Bus (1/8 unit load)

? Wide Supply Voltage 3V to 5.5V

? SOIC-8 Package for Backward Compatibility

? Bus-Pin Protection:

– ±12 kV HBM protection

Applications

? E-Metering Networks

? Industrial Automation

? HVAC Systems

? Process Control

? DMX512-Networks

? Battery-Powered Applications

描述 Description

The TP8485E are 3V~5.5V powered transceivers that

meet the RS-485 and RS-422 standards for balanced

communication. Driver outputs and receiver inputs are

protected against ±12kV ESD strikes without latch-up.

Transmitters in this family deliver exceptional differential

output voltages (2.5V min/5Vcc), into the RS-485 required

54Ω load, for better noise immunity, or to allow up to eight

120Ω terminations in “star” topologies. These devices

have very low bus currents so they present a true “1/8 unit

load” to the RS-485 bus. This allows up to 256

transceivers on the network 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 25mA @ VOL

= 1V (to ease the design of optocoupled isolated

interfaces).

The TP8485E is available in an SOIC-8 and MSOP-8

package, and is characterized from –40°C to 125°C.