Method of improving noise immunity in a signal processing apparatus, and a signal processing apparatus having improved noise immunity

A method for improving noise immunity in an electronic apparatus including first and second capacitors, comprising:

• during a first period:
• coupling the first capacitor to the electronic apparatus to provide charge to the electronic apparatus, and
• coupling the second capacitor to a power supply for recharging;
• and
• during a second period:
• coupling the first capacitor to the power supply for recharging, and
• coupling the second period to the electronic apparatus to provide charge to the electronic apparatus.

A charge transfer circuit adapted to convey charge from a power supply to a signal processing apparatus, the charge transfer circuit comprising:

• a capacitor for providing charge to the electronic apparatus;
• a first switch coupled to the capacitor and the power supply, wherein the first switch connects the capacitor to the power supply;
• and
• a second switch coupled to the capacitor and the electronic apparatus, wherein the second switch connects the capacitor to the electronic apparatus.