Date: 14/09/2008

New transceiver from Intersil can switch between RS232 and RS485/422

Intersil Corporation launched the new ISL333X family of dual protocol transceivers. The functional flexibility of this family reduces as many as five different component functions into one single transceiver. The interesting feature of this device is that it can operate as one or two-channel transceivers, as well as switch between RS-232 and RS-485/RS-422 protocols. This adaptability enables the device to replace two RS-232s, two RS-485/RS-422s and a multiplexing network.

The devices available in this family include the two dual port ICs, the ISL3332 and ISL3333, and two single port ICs ISL3330 and ISL3331.


The other key features and specifications are,

1. Comes with 15kV (Human Body Model) ESD protection.
2. Fast Data Rates Up To 20 Mbp
3. All four versions operate on 3.3V supplies,
4. Flow-through pin-outs to simplify board layouts.
5. ISL3331 & ISL3333 provide additional functionality, such as lower speed and edge rate options for electromagnetic interference sensitive designs, or to allow longer bus lengths.

Some of the interesting features of RS 232/485/422 protocols used in this device are listed below.

1. Suppose any port on each of the devices is in RS-232 mode. Then an on-board charge pump generates compliant ±5V output levels.
2. Each transceiver is RS-232 compliant with the receiver outputs handling up to ±25V and the transmitter output handling ±8V.
3. In RS-485 mode, each transceiver supports RS-485 and RS-422 differential communication standards.
4. The RS-485 receiver features full failsafe operation. So output remains high even if inputs are open or shorted.
5. The RS-485 transmitter supports three data rates, in which two are slew-rate limited.
6. Charge pumps are disabled when both ports on the dual port ICs are in RS-485 mode, to save power, minimize noise and eliminate pump capacitors.

Some of the applications include single board computers, factory automation systems, security networks, industrial and process control networks, point-of-sale equipment, gaming, and level transistors.

Package: 40-pin QFN packages (ISL3331 & ISL3333)
20-lead SSOP (ISL3330)
28-lead SSOP package (ISL3332)

Price: single port ISL3330 and ISL3331 start at $3.30 each in 1K-unit quantities.
dual port ISL3332 and ISL3333 are priced at $3.90 each in 1K unit quantities.

For further details visit: http://www.intersil.com