
11
SP3238EDS/04
SP3238E +3.0V to +5.5V RS-232 Transceivers
Copyright 1999 Sipex Corporation
Figure 10. Auto-Online Timing Waveforms
RECEIVER
RS-232 INPUT
VOLTAGES
STATUS
+5V
0V
-5V
t
STSL
t
STSH
t
ONLINE
V
CC
0V
DRIVER
RS-232 OUTPUT
VOLTAGES
0V
+2.7V
-2.7V
S
H
U
T
D
O
W
N
Figure 12. Charge Pump — Phase 2
V
CC
= +5V
–10V
V
SS
Storage Capacitor
V
DD
Storage Capacitor
C
1
C
2
C
3
C
4
+
+
+
+
–
–
–
–
V
CC
= +5V
–5V
–5V
+5V
V
SS
Storage Capacitor
V
DD
Storage Capacitor
C
1
C
2
C
3
C
4
+
+
+
+
–
–
–
–
Figure 11. Charge Pump — Phase 1