Converter with an additional DC offset and method thereof
AssigneeRealtek Semiconductor Corp.
InventorsMing-Cheng Chiang, Wei-Cheng Tang
Life of this patent
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Abstract
A converter with an additional DC offset includes a switch circuit, a first capacitor, a plurality of additional capacitor cells and an operational amplifier. The converter uses a first additional capacitor cell and a second additional capacitor cell having a capacitor difference with the first additional capacitor to store two charges having different polarity and magnitude with each other, and further generate an inverted DC offset according to a difference between the two charges to compensate a DC offset.
Claims12
A converter, comprising:
- a switch circuit, comprising a plurality of switches;
- a first capacitor, storing a first charge according to switching control of the switch circuit and comprising a first additional capacitor cell and a second additional capacitor cell wherein there is a capacitor difference between the first additional capacitor cell and the second additional capacitor cell;
- and the first additional capacitor cell and the second additional capacitor cell store a second charge and a third charge having different polarity and magnitude with the second charge, respectively, according to switching control of the switch circuit;
- and
- an operational amplifier, generating a DC bias including a DC offset according to the first charge and further generating an inverted DC offset according to a difference between the second charge and the third charge to compensate the DC offset.
A converter, comprising:
- an operational amplifier, generating a DC bias;
- a first capacitor, comprising a plurality of first capacitor cells to generate a first charge with a charge error value wherein at least one of the first capacitor cells has a capacitance error value related to the charge error value;
- a first additional capacitor cell, storing a positive charge;
- and
- a second additional capacitor cell, storing a negative charge wherein there is a charge difference value between the positive charge and the negative charge;
- wherein the operational amplifier generates the DC bias according to the first charge, the positive charge and the negative charge and the charge difference value is used to compensate the charge error value.
A method for compensating an offset of a converter, comprising:
- providing a switch circuit, comprising a plurality of switches;
- using a first capacitor to store a first charge according to switching control of the switch circuit to generate a DC bias wherein the first capacitor comprises a plurality of first capacitor cells and the DC bias includes a DC offset generated due to mismatch among the plurality of first capacitor cells;
- and
- compensating the DC offset according to switching control of the switch circuit and a capacitance difference value between a first additional capacitor cell and a second additional capacitor cell.
Dependencies are inferred from the claim text.