Multi-level D/A converter incorporated with multi-level quantizer in multi-bit sigma-delta A/D converter
OwnerWensheng Vincent Kuanginventor
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Abstract
A Multi-level digital-to-analog (D/A) converter is incorporated with a multi-level quantizer in a multi-bit sigma-delta analog-to-digital (A/D) converter. The multi-level D/A converter is realized by feeding back reference voltages of the multi-level quantizer through a switch. The summation of electrical energy from multiple D/A converter elements found in conventional D/A converters is avoided so that element mismatch and circuit complexity are reduced significantly in the multi-bit sigma-delta A/D converter.
Claims16
A multi-bit sigma-delta analog-to-digital (A/D) converter, comprising:
- a summer having a first input for analog input signals and a second input for analog feedback signals;
- a loop filter of filtering the summed signals supplied by the output of said summer;
- N comparators configured in parallel, each of said N comparators having a first input and a second input, said N comparators outputting digital thermometer code, where N is an integer greater than one;
- a switch having single pole and N throws, in which said single pole can be connected to each of said N throws by digital control, said single pole being externally connected to said second input of said summer in negative sense;
- a voltage divider network of dividing a voltage reference signal into various voltage levels, which are applied to said N second inputs of said N comparators and to said N throws of said switch;
- a switching control logic unit that transforms said digital thermometer code supplied by said N comparators into digital control signals used to control said switch;
- an encoder that transforms said digital thermometer code supplied by said N comparators into binary code;
- and
- a digital decimation filter in connection with said encoder.
A multi-level digital-to-analog (D/A) converter that is incorporated with a multi-level quantizer to reduce element mismatch in a multi-bit sigma-delta analog-to-digital (A/D) converter, comprising:
- N comparators configured in parallel, each of said N comparators having a first input and a second input, said N comparators outputting digital thermometer code, where N is an integer greater than one;
- a switch having single pole and N throws, in which said single pole can be connected to each of said N throws by digital control, said single pole being the output of said multi-level D/A converter;
- a voltage divider network of dividing a voltage reference signal into various voltage levels, which are applied to said N second inputs of said N comparators and to said N throws of said switch;
- and
- a switching control logic unit that transforms said digital thermometer code supplied by said N comparators into digital control signals used to control said switch.
Dependencies are inferred from the claim text.