LM2681

LM2681 Switched Capacitor Voltage Converter March 1999 LM2681 Switched Capacitor Voltage Converter General Description The LM2681 CMOS charge-pump voltage converter operates as a voltage doubler for an input voltage in the range of +2.5V to +5.5V. Two low cost capacitors and a diode (needed during start-up) is used in this circuit to provide up to 20 mA of output current. The LM2681 can also work as a voltage divider to split a voltage in the range of +1.8V to +11V in half. The LM2681 operates at 160 kHz oscillator frequency to reduce output resistance and voltage ripple. With an operating current of only 550 µA (operating efficiency greater than 90% with most loads) the LM2681 provides ideal performance for battery powered systems. The device is in SOT-23-6 package. Features n n n n Doubles or Splits Input Supply Voltage SOT23-6 Package 15Ω Typical Output Impedance 90% Typical Conversion Efficiency at 20 mA Applications n n n n n n Cellular Phones Pagers PDAs Operational Amplifier Power Suppliers Interface Power Suppliers Handheld Instruments Basic Application Circuits Voltage Doubler DS100965-1 Splitting Vin in Half DS100965-2 © 1999 National Semiconductor Corporation DS100965 www.national.com Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage (V+ to GND, or GND to OUT) V+ and OUT Continuous Output Current ...