Reference circuits for sampled-data circuits

A switched capacitor circuit, comprising:

• a level-crossing detector to generate a level-crossing detection signal when an input signal crosses a voltage reference level;
• a waveform generator to generate a predetermined waveform;
• a switched capacitance circuit operatively connected to said level-crossing detector;
• a switch operatively coupled to said level-crossing detector;
• and
• a voltage reference circuit operatively coupled to said switched capacitance circuit to provide a voltage reference level;
• said switch turning OFF when said level-crossing detection signal indicates said input signal crossed said voltage reference level.

A switched capacitor circuit, comprising:

• a first waveform generator to generate a first predetermined waveform;
• a first level-crossing detector to generate a first level-crossing detection signal when an input signal crosses a first voltage reference;
• a first switch operatively coupled to said first level-crossing detector;
• a first sampling capacitor operatively connected to said first level-crossing detector;
• a second waveform generator to generate a second predetermined waveform;
• a second level-crossing detector to generate a second level-crossing detection signal when a second input signal crosses a second voltage reference level;
• a second switch operatively coupled to said second level-crossing detector;
• a second sampling capacitor operatively connected to said first level-crossing detector;
• and p1 a third level-crossing detector differentially coupled to said first and second sampling capacitors;
• said first switch turning OFF when said first level-crossing detection signal indicates said input signal crossed said first voltage reference;
• said second switch turning OFF when said second level-crossing detection signal indicates said second predetermined waveform crossed said second voltage reference level.

A switched capacitor circuit, comprising:

• a level-crossing detector to generate a level-crossing detection signal when an input signal crosses a first predetermined level;
• a waveform generator to generate a first predetermined waveform;
• a switched capacitance circuit operatively connected to said level-crossing detector;
• a voltage reference circuit operatively coupled to said switched capacitance circuit to provide a voltage reference level;
• a switch operatively coupled to said level-crossing detector;
• and
• a sampling capacitor operatively connected to said level-crossing detector;
• said switch turning OFF when said level-crossing detection signal indicates said input signal crossed said first predetermined level.

A reference voltage source, comprising:

• a level-crossing detector to generate a level-crossing detection signal when an input signal crosses a predetermined level;
• a waveform generator to generate a first predetermined waveform;
• a switch operatively coupled to said level-crossing detector;
• a sampling capacitor operatively connected to said level-crossing detector;
• a first bias voltage source operatively connected to an input terminal of the level-crossing detector;
• and
• a second bias voltage source operatively connected to said input terminal of the level-crossing detector;
• said switch turning OFF when said level-crossing detection signal indicates said input signal crossed said predetermined level.

A reference voltage source, comprising:

• a waveform generator to generate a predetermined waveform;
• a first transistor operatively connected to said waveform generator;
• a second transistor operatively connected to said waveform generator;
• a level-crossing detector to generate a level-crossing detection signal when an input signal crosses a predetermined level;
• a switch operatively coupled to said level-crossing detector;
• and
• a sampling capacitor operatively connected to said level-crossing detector;
• said first switch turning OFF when said level-crossing detection signal indicates said input signal crossed said predetermined level.

A reference voltage source, comprising:

• a waveform generator to generate a predetermined waveform;
• an amplifier operatively connected to said waveform generator;
• a first bias voltage source operatively connected to said amplifier;
• a second bias voltage source operatively connected to said amplifier;
• and
• a level-crossing detector to generate a level-crossing detection signal when an input signal crosses a predetermined level;
• said waveform generator turning OFF when said level-crossing detection signal indicates said input voltage crossed said predetermined level.