SP3221E Datasheet, PDF (11/20 Pages) Sipex Corporation – Intelligent +3.0V to +5.5V RS-232 Transceiver

V_CC = +5V
+
C_{1 –}
–5V
+5V
+
C_{2 –}
–5V
C₄
+ – _{VDD Storage Capacitor}
– + _{VSS Storage Capacitor}
C₃
Figure 8. Charge Pump - Phase 1
V_CC = +5V
+
C_{1 –}
Figure 9. Charge Pump - Phase 2
a) C2+
1
2
2
+
C_{2 –}
–10V
C₄
+ – _{VDD Storage Capacitor}
– + _{VSS Storage Capacitor}
C₃
[
T
]
+6V
T
0V
0V
b) C2-
T
-6V
Ch1 2.00V Ch2 2.00V M 1.00ms Ch1 1.96V
Figure 10. Charge Pump Waveforms
V_CC = +5V
+
C_{1 –}
–5V
+5V
+
C_{2 –}
–5V
C₄
+ – _{VDD Storage Capacitor}
– + _{VSS Storage Capacitor}
C₃
Figure 11. Charge Pump - Phase 3
V_CC = +5V
+10V
+
C_{1 –}
+
C_{2 –}
C₄
+ – _{VDD Storage Capacitor}
– + _{VSS Storage Capacitor}
C₃
Figure 12. Charge Pump - Phase 4
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • [phone] • www.exar.com
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SP3221E_102_091014