DATASHEET
ISL3330, ISL3331 FN6361
Rev 0.00
May 20, 2008 3.3V, В±15kV ESD Protected, Dual Protocol (RS-232/RS-485) Transceivers
These devices are BiCMOS interface ICs that are user
configured as either a single RS-422/RS-485 differential
transceiver, or as a dual (2 Tx, 2 Rx) RS-232 transceiver.
In RS-232 mode, the on-board charge pump generates
RS-232 compliant В±5V Tx output levels, from a supply as low
as 3.15V. Four small 0.1ВµF capacitors are required for the
charge pump. The transceivers are RS-232 compliant, with
the Rx inputs handling up to В±25V.
In RS-485 mode, the transceivers support both the RS-485
and RS-422 differential communication standards. The
RS-485 receiver features "full failsafe" operation, so the Rx
output remains in a high state if the inputs are open or
shorted together. The RS-485 transmitter supports up to
three data rates, two of which are slew rate limited for
problem free communications. The charge pump disables in
RS-485 mode, thereby saving power, minimizing noise, and
eliminating the charge pump capacitors.
Both RS-232/RS-485 modes feature loopback and shutdown
functions. The loopback mode internally connects the Tx …
