Datasheet

5
LTC1338
PI FU CTIO S
U
UU
DRIVER IN: RS232 Driver Input Pins. Inputs are TTL/
CMOS compatible. Inputs should not be allowed to float.
Tie unused inputs to V
CC
.
DRIVER OUT: Driver Outputs at RS232 Voltage Levels.
Outputs are in a high impedance state when in SHUT-
DOWN, RECEIVER ALIVE mode or V
CC
= 0V. The driver
outputs are protected against ESD to ±10kV for human
body model discharges.
RX IN: Receiver Inputs. These pins can be forced to ±25V
without damage. The receiver inputs are protected against
ESD to ±10kV for human body model discharges. Each
receiver provides 0.4V of hysteresis for noise immunity.
RX OUT: Receiver Outputs with TTL/CMOS Voltage Lev-
els. Outputs are in a high impedance state when in SHUT-
DOWN or RECEIVER DISABLE mode to allow data line
sharing.
Table 1. Functional Description
MODE RX ENABLE DR ENABLE DRIVERS RECEIVERS I
CC
(µA)(TYP)
SHUTDOWN 0 0 All driver outputs are All receiver outputs are 0.2
high impedance. high impedance.
Receiver Disable 0 1 All drivers alive. All receiver outputs are 500
high impedance.
RECEIVER ALIVE 1 0 All driver outputs are All receivers alive. 50
high impedance.
Normal 1 1 All drivers alive. All receivers alive. 500
TI
W
E
WAVEFORS
U
G
WITCHI
W
S
Figure 1. Driver Propagation Delay Timing
Figure 2. Receiver Propagation Delay Timing
1.4V
0V
V
CC
0V
V
+
V
–
0V
DRIVER
INPUT

DRIVER
OUTPUT

1.4V
t
HLD
t
LHD
LTC1338 • F01
0.8V
V
CC
0V
2.4V
RX
INPUT
RX
OUTPUT

1.3V
t
HLR
1.7V
t
LHR
LTC1338 • F02
V
CC
0V