SP232A Datasheet, PDF (7/16 Pages) Sipex Corporation – Enhanced RS-232 Line Drivers/Receivers

VDD
a) C₂₊
GND
GND
b) C_2–
Vss
Figure 6. Charge Pump Waveforms
that generate V^– from V⁺ will show a decrease in
the magnitude of V^– compared to V⁺ due to the
inherent inefficiencies in the design.
The clock rate for the charge pump typically
operates at greater than 15kHz. The external
capacitors can be as low as 0.1µF with a 10V
breakdown voltage rating.
Shutdown (SD) and Enable (EN) for the
SP310A and SP312A
Both the SP310A and SP312A have a shutdown/
standby mode to conserve power in battery-pow-
ered systems. To activate the shutdown mode,
which stops the operation of the charge pump, a
logic “0” is applied to the appropriate control line.
For the SP310A, this control line is ON/OFF (pin
18). Activating the shutdown mode also puts the
V_CC= +5V
+
C_{1 –}
–5V
+5V
+
C_{2 –}
–5V
C₄
+ – _{VDDStorage Capacitor}
– + _{VSSStorage Capacitor}
C₃
Figure 7. Charge Pump — Phase 3
Vcc = +5V
+
C_{1 –}
VDD
+
C_{2 –}
C₄
+ – _{VDDStorage Capacitor}
– + _{VSSStorage Capacitor}
C₃
Figure 8. Charge Pump — Phase 4
Jan 31-07 Rev B
SP232A/233A/310A/312A

© 2007 Sipex Corporation