Datasheet

5
LTC1337
1337fa
UU
U
PI FU CTIO S
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 Shutdown
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 Levels.
Outputs are in a high impedance state when in Shutdown
mode to allow data line sharing.
TEST CIRCUITS
DRIVER
DRIVER
INPUT
3k
51pF
DRIVER
OUTPUT
1337 F03
Figure 3. Driver Timing Test Load
ESD Test Circuit
1337 TC01
V
CC
C1
0.1µF
LTC1337
1
2
3
4
5
6
7
8
9
10
11
12
13
14
DRIVER 1 OUT
RX1 IN
DRIVER 2 OUT
RX2 IN
RX3 IN
RX4 IN
DRIVER 3 OUT
RX5 IN
ON/OFF
28
27
26
25
24
23
22
21
20
19
18
17
16
15
C3
0.1µF
DRIVER 1 IN
RX1 OUT
DRIVER 2 IN
RX2 OUT
RX3 OUT
RX4 OUT
DRIVER 3 IN
RX5 OUT
V
–
V
+
C2
0.1µF
C4
0.1µF
GND
RS232
LINE PINS
PROTECTED
TO ±10kV
RX
RX IN
51pF
RX
OUTPUT
1337 F04
Figure 4. Receiver Timing Test Load
Figure 1. Driver Propagation Delay Timing
0.8V
V
CC
0V
0V
RX IN
RX
OUTPUT
1.3V
t
HLR
1.7V
t
LHR
1337 F02
V
CC
0V
Figure 2. Receiver Propagation Delay Timing
SWITCHI G TI E WAVEFOR S
UWW
1.4V
0V
V
CC
0V
V
+
V
–
0V
DRIVER
INPUT
DRIVER
OUTPUT
1.4V
t
HLD
t
LHD
1337 F01