Intersil’s ultra-flexible dual protocol transceivers

8th September 2008

ES Admin

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Intersil has introduced the ISL333X family of dual protocol transceivers. The functional flexibility of this family is designed to reduce component count and eliminate multiplexing networks, reducing as many as five different component functions into one single transceiver.

These devices 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 ISL333X family to potentially replace two RS-232s, two RS-485/RS-422s and a multiplexing network.

For the first time ever in tiny 6mm x 6mm QFN size, this best-in-class flexibility comes with the added benefit of 15kV (HBM) ESD protection. This high level of ESD protection is available across the full ISL333XE product family, including the two dual port ICs, the ISL3332 and ISL3333, and the ISL3330 and ISL3331 single port ICs.

The ISL3331 and ISL3333 are available in ultra-small 40-pin QFN packages and all four versions operate on 3.3V supplies, provide data rates of 20Mbps and feature flow-through pinouts to simplify board layouts.

The ISL3331 and ISL3333 provide additional functionality, including lower speed and edge rate options for EMI (electromagnetic interference) sensitive designs, or to allow longer bus lengths. These devices also feature a logic supply voltage pin (VL) that sets the VOH level of logic outputs and the switching points of logic inputs, to be compatible with another supply voltage in mixed voltage systems.

When any port on each of the devices is in RS-232 mode, an on-board charge pump generates compliant ±5V output levels. Each transceiver is RS-232 compliant with the Rx outputs handling up to ±25V and the Tx output handling ±8V. In RS-485 mode, each transceiver supports RS-485 and RS-422 differential communication standards. The RS-485 receiver features full failsafe operation so output remains high even if inputs are open or shorted. The RS-485 transmitter supports as many as three data rates; two are slew-rate limited. 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.

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

The ISL3331 and ISL3333 are available in small 40-pin QFN packages. The ISL3330 is available in a 20-lead SSOP and the ISL3332 is available in a 28-lead SSOP package.