Providing reference voltage with desired accuracy in a short duration to a dynamically varying load

An apparatus for providing a reference voltage to an output node during a clock phase of a switched-capacitor system, the apparatus comprising:

• means for generating an intermediate voltage contribution to the reference voltage;
• means for generating an additional voltage contribution to the reference voltage;
• means for coupling the intermediate voltage contribution to the output node in a first duration of the clock phase;
• and
• means for coupling the additional voltage contribution to the output node in a subsequent duration of the clock phase.

A method of providing a reference voltage to an output node for a switched-capacitor system, during a first duration and a subsequent duration related to a clock phase;

• the method comprising the steps of:
• generating an intermediate voltage contribution to the reference voltage;
• generating an additional voltage contribution to the reference voltage;
• coupling the intermediate voltage contribution to the output node in the first duration;
• and
• coupling the additional voltage contribution to the output node in the subsequent duration;
• wherein the first and the subsequent durations are less than the clock phase duration.

A voltage generation circuit, in a switched-capacitor system, for coupling a reference voltage to an output node in a clock phase, the voltage generation circuit comprising:

• a first circuit for generating an intermediate voltage contribution to the reference voltage;
• a second circuit for generating an additional voltage contribution to the reference voltage;
• and
• a switch circuit for coupling the first circuit to the output node during a first duration of the clock phase, and then for coupling the second circuit to the output node during a subsequent duration of the clock phase duration;
• and the first duration and subsequent duration are adapted to be non-overlapping durations.