SP6661 Datasheet, PDF (4/8 Pages) Sipex Corporation – High Frequency 200mA Charge Pump Inverter or Doubler

Optimizing Capacitor Selection
Refer to Figure 1 for the total output resistance for various capacitance values and oscillator
frequencies. The reservoir and charge pump capacitor values are equal. The capacitance values
required to maintain comparable ripple and output resistance typically diminish proportionately as the
pump frequency of the SP6661 increases.
20
18
16
14
12
10
8
6
4
2
0
1
10KHz
20KHz
50KHz
100KHz
200KHz
500KHz
1000KHz
10
100
C1, C2 Capacitance (uF)
1000
Figure 1. Total Output Resistance for various capacitance values and oscillator frequen-
cies.
Date: 09/16/04
SP6661 High Frequency 200mA Charge Pump Inverter or Doubler
4
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