Low voltage ripple charge pump with shared capacitor oscillator

Abstract

A low voltage ripple charge pump with slew rate control includes a frequency divider, a clock generator, a current mirror, a switching circuit, a diode network, two capacitors, and a comparator. The frequency divider generates a clock signal from an oscillating signal. The clock generator generates first and second clock signals from the clock signal. The current mirror generates first and second current signals using a reference current. The switching circuit generates first and second voltage signals using the first and second clock signals and the first and second current signals. The comparator generates the oscillating signal based on the first and second voltage signals. The capacitors receive the voltage signals and are connected to the diode network for generating an output signal. The charge pump has low output voltage ripple with small filtering capacitance, which is achieved via slew rate control.