Method and apparatus for reducing the effects of feedback switch charge injection into a plurality of serially connected sample data comparators

In an apparatus having first and second serially coupled sample data comparators, the first sample data comparator including a first feedback switch coupled thereto that is activated by a switching signal, and the second sample data comparator including a second feedback switch coupled thereto that is activated by the switching signal, an apparatus for reducing effects of charge injection from the first and second feedback switches comprising:

• delay selection means for selecting an amount of signal delay;
• delay means, coupled to the delay selection means and to the second feedback switch, for delaying the receipt of the switching signal by the second feedback switch from the receipt of the switching signal by the first feedback switch by the selected amount of signal delay, the delay means comprising:
• first voltage ramp means for ramping a first voltage in a first direction in response to the switching signal;
• first comparing means, coupled to the first voltage ramp means, for comparing the ramped first voltage to a first threshold value;
• first delayed signal generating means, coupled to the first comparing means, for providing a first delayed switching signal when the ramped first voltage passes the first threshold value;
• second voltage ramp means for ramping a second voltage in a second direction opposite the first direction in response to the first delayed switching signal;
• second comparing means, coupled to the second voltage ramp means, for comparing the ramped second voltage to a second threshold value;
• and
• second delayed signal generating means, coupled to the second comparing means, for communicating the switching signal to the second feedback when the ramped second voltage passes the second threshold value.

In an apparatus having first and second serially coupled sample data comparators, the first sample data comparator including a first feedback switch coupled thereto that is activated by a switching signal, and the second sample data comparator including a second feedback switch coupled thereto that is activated by the switching signal, an method for reducing the effects of charge injection from the first and second feedback switches comprising the steps of:

• ramping a voltage in response to the switching signal;
• comparing the ramped voltage to a threshold value;
• and
• communicating the switching signal to the second feedback switch when the ramped voltage passes the threshold value.

In an apparatus having first and second serially coupled sample data comparators, the first sample data comparator including a first feedback switch coupled thereto that is activated by a switching signal, and the second sample data comparator including a second feedback switch coupled thereto that is activated by the switching signal, a method for reducing the effects of charge injection from the first and second feedback switches comprising the steps of:

• ramping a first voltage in a first direction in response to the switching signal;
• comparing the ramped first voltage to a first threshold value;
• providing a first delayed switching signal when the ramped first voltage passes the first threshold value;
• ramping a second voltage in a second direction opposite the first direction in response to the first delayed switching signal;
• comparing the ramped second voltage to a second threshold value;
• and
• communicating the switching signal to the second feedback switch when the ramped second voltage passes the second threshold value.