SP333 Datasheet, PDF (9/13 Pages) Sipex Corporation – +5V Only RS-232/AppleTalk Programmable Transceiver

Shutdown Mode
The SP333 can be put into a low power shut-
down mode by connecting the Shutdown pin
(SD, Pin 26) to a logic HIGH. During Shut-
down, the driver outputs are put into a high
impedance tri-state, and the charge pump is put
into stand-by mode. The supply current drops to
less than 10µA during shutdown and can be
activated in either RS-232 or AppleTalk mode.
For normal operation, the SD pin should be
connected to a logic LOW.
Receiver Enable
The SP333 has a control line to enable or disable
the receiver outputs. Pin 3 (RXEN) is active
LOW; a logic LOW on Pin 3 will enable the
receiver outputs. A logic HIGH on Pin 3 will
disable the receiver outputs. The receiver en-
able function can be initiated in either RS-232 or
AppleTalk mode.
Wake-Up
The SP333 also features a "wake-up" function.
The wake up function allows the RS-232 receiv-
ers to remain active during Shutdown mode
unless they are disabled by the Receiver Enable
control pin (Pin 3). The wake-up feature allows
users to take advantage of the low power Shut-
down mode and keep the receivers active to
accept an incoming "ring indicator" signal.
TGoddard/SP333/9617R0
SP333 RS-232/AppleTalk Programmable Transceiver
9
© Copyright 2000 Sipex Corporation