New Industry Products

Intersil Unveils New RS-485/422 Data Transceivers

October 22, 2003 by Jeff Shepard

Intersil Corp. (Milpitas, CA) announced two new LINEARLINK RS-485/422 serial data transceivers, the ISL83488 and ISL83490. Both ICs are full-duplex transceivers that operate from a nominal 3.3V supply over a wide ±10% voltage range of +3V to +3.6V, which relaxes supply requirements and reduces costs. The new ICs satisfy both low-speed and high-speed (250kbps and 10Mbps) serial communications needs as used in, but not limited to, factory automation, security networks and building environmental control.

The ISL83488 and ISL83490 are both configured for full-duplex operation with separate Rx-input and Tx-output pins. The devices are well suited for RS-422 applications because they don’t typically require Tx and Rx enable functions, and both driver and receiver are independently accessible. By eliminating the enable functions, full duplex functionality is realized in a small, eight-lead package. The 3.3V devices can be driven with 5V logic levels in mixed voltage systems. Rx inputs feature a fail-safe-if-open design, which ensures a logic high Rx output if Rx inputs are floating. This prevents the Rx output from chattering, and accidentally generating interrupts, if the receiver becomes disconnected from the bus.

The ISL83488 is slew-rate-limited for error-free data transmission in applications where the data rate is less than 250kbps, typically used for long runs. The ISL83490 can operate up to 10Mbps for high-speed applications. The transceivers are built using the Intersil BiCMOS process and meet both the RS-485 and RS-422 standards for balanced communication.

The ISL83488 and ISL83490 are available now. Pricing for 100-unit to 999-unit quantities is $1.20 each for the ISL83488IB (SOIC package), ISL83488IP (PDIP package), ISL83490IB (SOIC package) and ISL83490IP (PDIP package). SOIC packages are available on tape and reel.