LTC1347
PI FU CTIO S
C1+, C1–, C2+, C2–: Commutating Capacitor Inputs. These
pins require two external capacitors C = 0.1µF: one from
C1+ to C1–, and another from C2+ to C2–. To maintain
charge pump efficiency, the capacitor’s effective series
resistance should be less than 2Ω.
DRIVER IN: RS232 Driver Input Pins. Inputs are TTL/
CMOS compatible. Inputs should not be allowed to float.
Tie unused inputs to VCC.
DRIVER OUT: Driver Outputs at RS232 Voltage Levels.
Outputs are in a high impedance state when in shutdown
mode or VCC = 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. All receivers are kept alive in shutdown.
UW
W
SWITCHI G TI E WAVEFOR S
DRIVER
INPUT
1.4V
DRIVER
OUTPUT
0V
t LHD
1.4V
t HLD
VCC
0V
V+
0V
V–
1347 F01
Figure 1. Driver Propagation Delay Timing
RX
1.7V
INPUT
RX
OUTPUT
0.8V
t LHR
VCC
1.3V
0V
t HLR
2.4V VCC
0V
1347 F02
Figure 2. Receiver Propagation Delay Timing
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