LM2664 Switched Capacitor Voltage Converter
November 1999
LM2664
Switched Capacitor Voltage Converter
General Description
The LM2664 CMOS charge-pump voltage converter inverts
a positive voltage in the range of +1.8V to +5.5V to the cor-
responding negative voltage of −1.8V to −5.5V. The LM2664
uses two low cost capacitors to provide up to 40 mA of out-
put current.
The LM2664 operates at 160 kHz oscillator frequency to re-
duce output resistance and voltage ripple. With an operating
current of only 220 µA (operating efficiency greater than 91%
with most loads) and 1 µA typical shutdown current, the
LM2664 provides ideal performance for battery powered
systems. The device is in SOT-23-6 package.
Features
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Inverts Input Supply Voltage
SOT23-6 Package
12Ω Typical Output Impedance
91% Typical Conversion Efficiency at 40 mA
1µA Typical Shutdown Current
Applications
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Cellular Phones
Pagers
PDAs
Operational Amplifier Power Suppliers
Interface Power Suppliers
Handheld Instruments
Basic Application Circuits
Voltage Inverter
DS100031-1
+5V to −10V Converter
DS100031-25
© 1999 National Semiconductor Corporation
DS100031
www.national.com
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