SP6660 Datasheet, PDF (13/22 Pages) Sipex Corporation – 200mA Charge Pump Inverter or Doubler

For a nominal f_PUMP of 5kHz (where f_OSC =10kHz)
and C2=150µF with an ESR of 0.2Ω, the ripple
is approximately 90mV with a 100mA load
current. If C2 is raised to 390µF, the ripple drops
to 45mV. The output ripple voltage is calculated
by noting that capacitor C2 supplies the output
current during one-half of the charge pump cycle.
OSC is internally connected to a 15pF capacitor.
An external capacitor can be added to slow the
oscillator. Designers should take care to
minimize stray capacitance. An external
oscillator may also be connected to overdrive
OSC. Refer to the Oscillator Control section
for further details.
Positive Voltage Doubler
The SP6660 can double the output voltage of an
input power supply or battery. From a +4.25V
input, the circuit in Figure 22 can provide 100mA
with +8.0V at V+. The no-load voltage output at
V+ is 2(V_INL).
LV may be tied to OUT pin for all input voltages
in the positive voltage doubler mode. Connect
the power-supply positive voltage input to GND
pin. Connect the power-supply ground input to
OUT pin. V+ is the positive voltage output in
this mode.
Designers may overdrive OSC in the positive
voltage doubler mode. Refer to the Oscillator
Control section for further details.
+V_IN
+1.5V to +4.25V
TYPICAL CIRCUIT: VOLTAGE DOUBLER
FC
C1
1µF to 150µF
1
CAP+
2
GND
3
CAP- ₄
SP6660
+V
8
7
OSC
LV
6
5 ^OUT
DOUBLE
VOLTAGE
OUTPUT
C2
1µF to 150µF
Figure 22. Typical Operating Circuit for the Positive Voltage Doubler
SP6660DS/11
SP6660 200mA Charge Pump Inverter or Doubler
13
© Copyright 2000 Sipex Corporation