Differential charge pump circuit

A differential charge pump circuit for eliminating influence of mismatches between current sources, the differential charge pump circuit comprising:

• a capacitor for providing an output voltage and having a first terminal and a second terminal;
• a slicer for outputting a comparison signal to control charge/discharge actions of said capacitor;
• a first current source having a positive terminal and a negative terminal, the positive terminal being connected to a positive reference voltage;
• a first switch connected between the negative terminal of said first current source and the first terminal of said capacitor, said first switch being turned ON when said comparison signal is a first level;
• a second current source having a positive terminal and a negative terminal, the negative terminal being connected to a negative reference voltage;
• a second switch connected between the second terminal of said capacitor and the positive terminal of said second current source, said second switch being turned ON when said comparison signal is the first level;
• a third switch connected between the negative terminal of said first current source and the second terminal of said capacitor, said third switch being turned ON when said comparison signal is a second level;
• a fourth switch connected between the first terminal of said capacitor and the positive terminal of said second current source, said fourth switch being turned ON when said comparison signal is the second level;
• a first-common-mode current source having a positive terminal and a negative terminal, the negative terminal being connected to the negative reference voltage, and the positive terminal being connected to the negative terminal of said first current source;
• a second-common-mode current source having a positive terminal and a negative terminal, the negative terminal being connected to the negative reference voltage, and the positive terminal being connected to the positive terminal of said second current source;
• and
• a third-common-mode current source connected in parallel with said first current source.

A differential charge pump circuit for eliminating influence of mismatches between current sources, the differential charge pump circuit comprising:

• a capacitor for providing an output voltage and having a first terminal and a second terminal;
• a slicer for outputting a comparison signal to control charge/discharge actions of said capacitor;
• a first current source having a positive terminal and a negative terminal, the positive terminal being connected to a positive reference voltage;
• a first switch connected between the negative terminal of said first current source and the first terminal of said capacitor, said first switch being turned ON when said comparison signal is a first level;
• a second current source having a positive terminal and a negative terminal, the negative terminal being connected to a negative reference voltage;
• a second switch connected between the second terminal of said capacitor and the positive terminal of said second current source, said second switch being turned ON when said comparison signal is the first level;
• a third switch connected between the negative terminal of said first current source and the second terminal of said capacitor, said third switch being turned ON when said comparison signal is a second level;
• a fourth switch connected between the first terminal of said capacitor and the positive terminal of said second current source, said fourth switch being turned ON when said comparison signal is the second level;
• and
• a common mode current source having a positive terminal and a negative terminal, the negative terminal being connected to the negative reference voltage, and the positive terminal being connected to the negative terminal of said first current source.