ISL3332 Datasheet, PDF (5/26 Pages) Intersil Corporation – 3.3V, ±15kV ESD Protected, Two Port, Dua Protocol RS-232/RS-485 Transceivers

ISL3332, ISL3333
Pin Descriptions
PIN
MODE
FUNCTION
GND BOTH Ground connection.
LB BOTH Enables loopback mode when low. Internally pulled-high.
NC BOTH No Connection.
ON/OFF BOTH If either port is in RS-232 mode, a low on ON/OFF disables the charge pumps. In either mode, a low disables all the outputs,
and places the device in low power shutdown. Internally pulled-high. ON = 1 for normal operation.
RXEN BOTH Active low receiver output enable. The corresponding port’s Rx is enabled when RXEN is low; Rx is high impedance when
RXEN is high. Internally pulled low. (QFN only)
SEL BOTH Interface Mode Select input. High puts corresponding port in RS-485 Mode, while a low puts it in RS-232 Mode.
V_CC
V_L
DEN
BOTH System power supply input (3.3V).
BOTH Logic-Level Supply. All TTL/CMOS inputs and outputs are powered by this supply. QFN logic input pins that are externally
tied high in an application, should use the V_L supply for the high voltage level. (QFN only)
RS-232 Active high driver output enable. The corresponding port’s 232 mode drivers are enabled when DEN is high; drivers are
disabled when DEN is low. Internally pulled high. (QFN only).
A
RS-232 Receiver input with ±15kV ESD protection. A low on A forces R_A high; A high on A forces R_A low.
RS-485 Inverting receiver input with ±15kV ESD protection.
B
RS-232 Receiver input with ±15kV ESD protection. A low on B forces R_B high; A high on B forces R_B low.
RS-485 Noninverting receiver input with ±15kV ESD protection.
D_Y
D_Z / DE
RS-232 Driver input. A low on D_Y forces output Y high. Similarly, a high on D_Y forces output Y low.
RS-485 Driver input. A low on D_Y forces output Y high and output Z low. Similarly, a high on D_Y forces output Y low and output Z high.
RS-232 Driver input. A low on D_Z forces output Z high. Similarly, a high on D_Z forces output Z low.
RS-485 Driver output enable (DE). The driver outputs, Y and Z, are enabled by bringing DE high. They are high impedance when
DE is low. Internally pulled high when port selected for RS-485 mode.
R_A
RS-232 Receiver output.
RS-485 Receiver output: If B > A by at least -40mV, R_A is high; If B < A by -200mV or more, R_A is low; R_A = High if A and B are
unconnected (floating) or shorted together (i.e., full fail-safe).
R_B
RS-232 Receiver output.
RS-485 Not used. Internally pulled-high, and unaffected by RXEN.
Y
RS-232 Driver output with ±15kV ESD protection.
RS-485 Inverting driver output with ±15kV ESD protection.
Z
RS-232 Driver output with ±15kV ESD protection.
RS-485 Noninverting driver output with ±15kV ESD protection.
SP RS-485 Speed control. Internally pulled-high. (QFN only)
C1+ RS-232 External capacitor (voltage doubler) is connected to this lead. Not needed if both ports in RS-485 Mode.
C1- RS-232 External capacitor (voltage doubler) is connected to this lead. Not needed if both ports in RS-485 Mode.
C2+ RS-232 External capacitor (voltage inverter) is connected to this lead. Not needed if both ports in RS-485 Mode.
C2- RS-232 External capacitor (voltage inverter) is connected to this lead. Not needed if both ports in RS-485 Mode.
V+ RS-232 Internally generated positive RS-232 transmitter supply (+5.5V). C3 not needed if both ports in RS-485 Mode.
V-
RS-232 Internally generated negative RS-232 transmitter supply (-5.5V). C4 not needed if both ports in RS-485 Mode.
5
FN6362.0
May 27, 2008