Renesas Electronics America Inc. ISL41334 series Drivers Interface ICs

The ISL41334 is a two-port interface IC that can be independently configured as a single RS-485, RS-422 transceiver, or as a dual (2 Tx, 2 Rx) RS-232 transceiver. With both ports set to the same mode, two RS-485, RS-422 transceivers, or four RS-232 transceivers are available. If either port is in RS-232 mode, the onboard charge pump generates RS-232 compliant ±5V Tx output levels from a single V CC supply as low as 4.5V. The transceivers are RS-232 compliant, with the Rx inputs handling up to ±25V, and the Tx outputs handling ±12V. In RS-485 mode, the transceivers support both the RS-485 and RS-422 differential communication standards. The receivers feature “full fail-safe” operation, so the Rx outputs remain in a high state if the inputs are open or shorted together. The transmitters support up to three data rates, two of which are slew rate limited for problem-free communications. The charge pump disables when both ports are in RS-485 mode, thereby saving power, minimizing noise, and eliminating the charge pump capacitors. Both RS-232 and RS-485 modes feature loopback and shutdown functions. Loopback internally connects the Tx outputs to the corresponding Rx input, to facilitate board level self-test implementation. The outputs remain connected to the loads during loopback so connection problems (such as shorted connectors or cables) can be detected. Shutdown mode disables the Tx and Rx outputs, disables the charge pumps, and places the IC in a low current (µA) mode.